From 0f3adc288df8ba2ac2fea0a8e4890f9fb4cd075d Mon Sep 17 00:00:00 2001
From: Lorenz Bauer <lmb@cloudflare.com>
Date: Fri, 22 Mar 2019 09:53:59 +0800
Subject: bpf: track references based on is_acquire_func

So far, the verifier only acquires reference tracking state for
RET_PTR_TO_SOCKET_OR_NULL. Instead of extending this for every
new return type which desires these semantics, acquire reference
tracking state iff the called helper is an acquire function.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 86f9cd5d1c4e..868a82ad5597 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3147,19 +3147,7 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 	} else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
-		if (is_acquire_function(func_id)) {
-			int id = acquire_reference_state(env, insn_idx);
-
-			if (id < 0)
-				return id;
-			/* For mark_ptr_or_null_reg() */
-			regs[BPF_REG_0].id = id;
-			/* For release_reference() */
-			regs[BPF_REG_0].ref_obj_id = id;
-		} else {
-			/* For mark_ptr_or_null_reg() */
-			regs[BPF_REG_0].id = ++env->id_gen;
-		}
+		regs[BPF_REG_0].id = ++env->id_gen;
 	} else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
@@ -3170,9 +3158,19 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 		return -EINVAL;
 	}
 
-	if (is_ptr_cast_function(func_id))
+	if (is_ptr_cast_function(func_id)) {
 		/* For release_reference() */
 		regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id;
+	} else if (is_acquire_function(func_id)) {
+		int id = acquire_reference_state(env, insn_idx);
+
+		if (id < 0)
+			return id;
+		/* For mark_ptr_or_null_reg() */
+		regs[BPF_REG_0].id = id;
+		/* For release_reference() */
+		regs[BPF_REG_0].ref_obj_id = id;
+	}
 
 	do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
 
-- 
cgit v1.2.3


From 85a51f8c28b9812642d76db6889f3f39dc3fbab3 Mon Sep 17 00:00:00 2001
From: Lorenz Bauer <lmb@cloudflare.com>
Date: Fri, 22 Mar 2019 09:54:00 +0800
Subject: bpf: allow helpers to return PTR_TO_SOCK_COMMON

It's currently not possible to access timewait or request sockets
from eBPF, since there is no way to return a PTR_TO_SOCK_COMMON
from a helper. Introduce RET_PTR_TO_SOCK_COMMON to enable this
behaviour.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 868a82ad5597..a476e13201d6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3148,6 +3148,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
 		regs[BPF_REG_0].id = ++env->id_gen;
+	} else if (fn->ret_type == RET_PTR_TO_SOCK_COMMON_OR_NULL) {
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON_OR_NULL;
+		regs[BPF_REG_0].id = ++env->id_gen;
 	} else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
-- 
cgit v1.2.3


From edbf8c01de5a104a71ed6df2bf6421ceb2836a8e Mon Sep 17 00:00:00 2001
From: Lorenz Bauer <lmb@cloudflare.com>
Date: Fri, 22 Mar 2019 09:54:01 +0800
Subject: bpf: add skc_lookup_tcp helper

Allow looking up a sock_common. This gives eBPF programs
access to timewait and request sockets.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a476e13201d6..dffeec3706ce 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -369,7 +369,8 @@ static bool is_release_function(enum bpf_func_id func_id)
 static bool is_acquire_function(enum bpf_func_id func_id)
 {
 	return func_id == BPF_FUNC_sk_lookup_tcp ||
-		func_id == BPF_FUNC_sk_lookup_udp;
+		func_id == BPF_FUNC_sk_lookup_udp ||
+		func_id == BPF_FUNC_skc_lookup_tcp;
 }
 
 static bool is_ptr_cast_function(enum bpf_func_id func_id)
-- 
cgit v1.2.3


From 3b0f31f2b8c9fb348e4530b88f6b64f9621f83d6 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Thu, 21 Mar 2019 22:51:02 +0100
Subject: genetlink: make policy common to family

Since maxattr is common, the policy can't really differ sanely,
so make it common as well.

The only user that did in fact manage to make a non-common policy
is taskstats, which has to be really careful about it (since it's
still using a common maxattr!). This is no longer supported, but
we can fake it using pre_doit.

This reduces the size of e.g. nl80211.o (which has lots of commands):

   text	   data	    bss	    dec	    hex	filename
 398745	  14323	   2240	 415308	  6564c	net/wireless/nl80211.o (before)
 397913	  14331	   2240	 414484	  65314	net/wireless/nl80211.o (after)
--------------------------------
   -832      +8       0    -824

Which is obviously just 8 bytes for each command, and an added 8
bytes for the new policy pointer. I'm not sure why the ops list is
counted as .text though.

Most of the code transformations were done using the following spatch:
    @ops@
    identifier OPS;
    expression POLICY;
    @@
    struct genl_ops OPS[] = {
    ...,
     {
    -	.policy = POLICY,
     },
    ...
    };

    @@
    identifier ops.OPS;
    expression ops.POLICY;
    identifier fam;
    expression M;
    @@
    struct genl_family fam = {
            .ops = OPS,
            .maxattr = M,
    +       .policy = POLICY,
            ...
    };

This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing
the cb->data as ops, which we want to change in a later genl patch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 kernel/taskstats.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 4e62a4a8fa91..1b942a7caf26 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -650,16 +650,37 @@ static const struct genl_ops taskstats_ops[] = {
 	{
 		.cmd		= TASKSTATS_CMD_GET,
 		.doit		= taskstats_user_cmd,
-		.policy		= taskstats_cmd_get_policy,
-		.flags		= GENL_ADMIN_PERM,
+		/* policy enforced later */
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_HASPOL,
 	},
 	{
 		.cmd		= CGROUPSTATS_CMD_GET,
 		.doit		= cgroupstats_user_cmd,
-		.policy		= cgroupstats_cmd_get_policy,
+		/* policy enforced later */
+		.flags		= GENL_CMD_CAP_HASPOL,
 	},
 };
 
+static int taskstats_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
+			      struct genl_info *info)
+{
+	const struct nla_policy *policy = NULL;
+
+	switch (ops->cmd) {
+	case TASKSTATS_CMD_GET:
+		policy = taskstats_cmd_get_policy;
+		break;
+	case CGROUPSTATS_CMD_GET:
+		policy = cgroupstats_cmd_get_policy;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return nlmsg_validate(info->nlhdr, GENL_HDRLEN, TASKSTATS_CMD_ATTR_MAX,
+			      policy, info->extack);
+}
+
 static struct genl_family family __ro_after_init = {
 	.name		= TASKSTATS_GENL_NAME,
 	.version	= TASKSTATS_GENL_VERSION,
@@ -667,6 +688,7 @@ static struct genl_family family __ro_after_init = {
 	.module		= THIS_MODULE,
 	.ops		= taskstats_ops,
 	.n_ops		= ARRAY_SIZE(taskstats_ops),
+	.pre_doit	= taskstats_pre_doit,
 };
 
 /* Needed early in initialization */
-- 
cgit v1.2.3


From 2011fccfb61bbd1d7c8864b2b3ed7012342e9ba3 Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Thu, 28 Mar 2019 18:01:57 -0700
Subject: bpf: Support variable offset stack access from helpers

Currently there is a difference in how verifier checks memory access for
helper arguments for PTR_TO_MAP_VALUE and PTR_TO_STACK with regard to
variable part of offset.

check_map_access, that is used for PTR_TO_MAP_VALUE, can handle variable
offsets just fine, so that BPF program can call a helper like this:

  some_helper(map_value_ptr + off, size);

, where offset is unknown at load time, but is checked by program to be
in a safe rage (off >= 0 && off + size < map_value_size).

But it's not the case for check_stack_boundary, that is used for
PTR_TO_STACK, and same code with pointer to stack is rejected by
verifier:

  some_helper(stack_value_ptr + off, size);

For example:
  0: (7a) *(u64 *)(r10 -16) = 0
  1: (7a) *(u64 *)(r10 -8) = 0
  2: (61) r2 = *(u32 *)(r1 +0)
  3: (57) r2 &= 4
  4: (17) r2 -= 16
  5: (0f) r2 += r10
  6: (18) r1 = 0xffff888111343a80
  8: (85) call bpf_map_lookup_elem#1
  invalid variable stack read R2 var_off=(0xfffffffffffffff0; 0x4)

Add support for variable offset access to check_stack_boundary so that
if offset is checked by program to be in a safe range it's accepted by
verifier.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 75 ++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 54 insertions(+), 21 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2fe89138309a..87221fda1321 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2157,6 +2157,29 @@ static int check_xadd(struct bpf_verifier_env *env, int insn_idx, struct bpf_ins
 				BPF_SIZE(insn->code), BPF_WRITE, -1, true);
 }
 
+static int __check_stack_boundary(struct bpf_verifier_env *env, u32 regno,
+				  int off, int access_size,
+				  bool zero_size_allowed)
+{
+	struct bpf_reg_state *reg = reg_state(env, regno);
+
+	if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
+	    access_size < 0 || (access_size == 0 && !zero_size_allowed)) {
+		if (tnum_is_const(reg->var_off)) {
+			verbose(env, "invalid stack type R%d off=%d access_size=%d\n",
+				regno, off, access_size);
+		} else {
+			char tn_buf[48];
+
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "invalid stack type R%d var_off=%s access_size=%d\n",
+				regno, tn_buf, access_size);
+		}
+		return -EACCES;
+	}
+	return 0;
+}
+
 /* when register 'regno' is passed into function that will read 'access_size'
  * bytes from that pointer, make sure that it's within stack boundary
  * and all elements of stack are initialized.
@@ -2169,7 +2192,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 {
 	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_func_state *state = func(env, reg);
-	int off, i, slot, spi;
+	int err, min_off, max_off, i, slot, spi;
 
 	if (reg->type != PTR_TO_STACK) {
 		/* Allow zero-byte read from NULL, regardless of pointer type */
@@ -2183,21 +2206,23 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		return -EACCES;
 	}
 
-	/* Only allow fixed-offset stack reads */
-	if (!tnum_is_const(reg->var_off)) {
-		char tn_buf[48];
-
-		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-		verbose(env, "invalid variable stack read R%d var_off=%s\n",
-			regno, tn_buf);
-		return -EACCES;
-	}
-	off = reg->off + reg->var_off.value;
-	if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
-	    access_size < 0 || (access_size == 0 && !zero_size_allowed)) {
-		verbose(env, "invalid stack type R%d off=%d access_size=%d\n",
-			regno, off, access_size);
-		return -EACCES;
+	if (tnum_is_const(reg->var_off)) {
+		min_off = max_off = reg->var_off.value + reg->off;
+		err = __check_stack_boundary(env, regno, min_off, access_size,
+					     zero_size_allowed);
+		if (err)
+			return err;
+	} else {
+		min_off = reg->smin_value + reg->off;
+		max_off = reg->umax_value + reg->off;
+		err = __check_stack_boundary(env, regno, min_off, access_size,
+					     zero_size_allowed);
+		if (err)
+			return err;
+		err = __check_stack_boundary(env, regno, max_off, access_size,
+					     zero_size_allowed);
+		if (err)
+			return err;
 	}
 
 	if (meta && meta->raw_mode) {
@@ -2206,10 +2231,10 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		return 0;
 	}
 
-	for (i = 0; i < access_size; i++) {
+	for (i = min_off; i < max_off + access_size; i++) {
 		u8 *stype;
 
-		slot = -(off + i) - 1;
+		slot = -i - 1;
 		spi = slot / BPF_REG_SIZE;
 		if (state->allocated_stack <= slot)
 			goto err;
@@ -2222,8 +2247,16 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 			goto mark;
 		}
 err:
-		verbose(env, "invalid indirect read from stack off %d+%d size %d\n",
-			off, i, access_size);
+		if (tnum_is_const(reg->var_off)) {
+			verbose(env, "invalid indirect read from stack off %d+%d size %d\n",
+				min_off, i - min_off, access_size);
+		} else {
+			char tn_buf[48];
+
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "invalid indirect read from stack var_off %s+%d size %d\n",
+				tn_buf, i - min_off, access_size);
+		}
 		return -EACCES;
 mark:
 		/* reading any byte out of 8-byte 'spill_slot' will cause
@@ -2232,7 +2265,7 @@ mark:
 		mark_reg_read(env, &state->stack[spi].spilled_ptr,
 			      state->stack[spi].spilled_ptr.parent);
 	}
-	return update_stack_depth(env, state, off);
+	return update_stack_depth(env, state, min_off);
 }
 
 static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
-- 
cgit v1.2.3


From 06ee7115b0d1742de745ad143fb5e06d77d27fba Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Apr 2019 21:27:40 -0700
Subject: bpf: add verifier stats and log_level bit 2

In order to understand the verifier bottlenecks add various stats
and extend log_level:
log_level 1 and 2 are kept as-is:
bit 0 - level=1 - print every insn and verifier state at branch points
bit 1 - level=2 - print every insn and verifier state at every insn
bit 2 - level=4 - print verifier error and stats at the end of verification

When verifier rejects the program the libbpf is trying to load the program twice.
Once with log_level=0 (no messages, only error code is reported to user space)
and second time with log_level=1 to tell the user why the verifier rejected it.

With introduction of bit 2 - level=4 the libbpf can choose to always use that
level and load programs once, since the verification speed is not affected and
in case of error the verbose message will be available.

Note that the verifier stats are not part of uapi just like all other
verbose messages. They're expected to change in the future.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 76 +++++++++++++++++++++++++++++++++++----------------
 1 file changed, 52 insertions(+), 24 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 87221fda1321..e2001c1e40b3 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1092,7 +1092,7 @@ static int check_subprogs(struct bpf_verifier_env *env)
 	 */
 	subprog[env->subprog_cnt].start = insn_cnt;
 
-	if (env->log.level > 1)
+	if (env->log.level & BPF_LOG_LEVEL2)
 		for (i = 0; i < env->subprog_cnt; i++)
 			verbose(env, "func#%d @%d\n", i, subprog[i].start);
 
@@ -1139,6 +1139,7 @@ static int mark_reg_read(struct bpf_verifier_env *env,
 			 struct bpf_reg_state *parent)
 {
 	bool writes = parent == state->parent; /* Observe write marks */
+	int cnt = 0;
 
 	while (parent) {
 		/* if read wasn't screened by an earlier write ... */
@@ -1155,7 +1156,11 @@ static int mark_reg_read(struct bpf_verifier_env *env,
 		state = parent;
 		parent = state->parent;
 		writes = true;
+		cnt++;
 	}
+
+	if (env->longest_mark_read_walk < cnt)
+		env->longest_mark_read_walk = cnt;
 	return 0;
 }
 
@@ -1455,7 +1460,7 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
 	 * need to try adding each of min_value and max_value to off
 	 * to make sure our theoretical access will be safe.
 	 */
-	if (env->log.level)
+	if (env->log.level & BPF_LOG_LEVEL)
 		print_verifier_state(env, state);
 
 	/* The minimum value is only important with signed
@@ -2938,7 +2943,7 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 	/* and go analyze first insn of the callee */
 	*insn_idx = target_insn;
 
-	if (env->log.level) {
+	if (env->log.level & BPF_LOG_LEVEL) {
 		verbose(env, "caller:\n");
 		print_verifier_state(env, caller);
 		verbose(env, "callee:\n");
@@ -2978,7 +2983,7 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
 		return err;
 
 	*insn_idx = callee->callsite + 1;
-	if (env->log.level) {
+	if (env->log.level & BPF_LOG_LEVEL) {
 		verbose(env, "returning from callee:\n");
 		print_verifier_state(env, callee);
 		verbose(env, "to caller at %d:\n", *insn_idx);
@@ -5001,7 +5006,7 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 			insn->dst_reg);
 		return -EACCES;
 	}
-	if (env->log.level)
+	if (env->log.level & BPF_LOG_LEVEL)
 		print_verifier_state(env, this_branch->frame[this_branch->curframe]);
 	return 0;
 }
@@ -6181,6 +6186,9 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 		states_cnt++;
 	}
 
+	if (env->max_states_per_insn < states_cnt)
+		env->max_states_per_insn = states_cnt;
+
 	if (!env->allow_ptr_leaks && states_cnt > BPF_COMPLEXITY_LIMIT_STATES)
 		return 0;
 
@@ -6194,6 +6202,8 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 	new_sl = kzalloc(sizeof(struct bpf_verifier_state_list), GFP_KERNEL);
 	if (!new_sl)
 		return -ENOMEM;
+	env->total_states++;
+	env->peak_states++;
 
 	/* add new state to the head of linked list */
 	new = &new_sl->state;
@@ -6278,8 +6288,7 @@ static int do_check(struct bpf_verifier_env *env)
 	struct bpf_verifier_state *state;
 	struct bpf_insn *insns = env->prog->insnsi;
 	struct bpf_reg_state *regs;
-	int insn_cnt = env->prog->len, i;
-	int insn_processed = 0;
+	int insn_cnt = env->prog->len;
 	bool do_print_state = false;
 
 	env->prev_linfo = NULL;
@@ -6314,10 +6323,10 @@ static int do_check(struct bpf_verifier_env *env)
 		insn = &insns[env->insn_idx];
 		class = BPF_CLASS(insn->code);
 
-		if (++insn_processed > BPF_COMPLEXITY_LIMIT_INSNS) {
+		if (++env->insn_processed > BPF_COMPLEXITY_LIMIT_INSNS) {
 			verbose(env,
 				"BPF program is too large. Processed %d insn\n",
-				insn_processed);
+				env->insn_processed);
 			return -E2BIG;
 		}
 
@@ -6326,7 +6335,7 @@ static int do_check(struct bpf_verifier_env *env)
 			return err;
 		if (err == 1) {
 			/* found equivalent state, can prune the search */
-			if (env->log.level) {
+			if (env->log.level & BPF_LOG_LEVEL) {
 				if (do_print_state)
 					verbose(env, "\nfrom %d to %d%s: safe\n",
 						env->prev_insn_idx, env->insn_idx,
@@ -6344,8 +6353,9 @@ static int do_check(struct bpf_verifier_env *env)
 		if (need_resched())
 			cond_resched();
 
-		if (env->log.level > 1 || (env->log.level && do_print_state)) {
-			if (env->log.level > 1)
+		if (env->log.level & BPF_LOG_LEVEL2 ||
+		    (env->log.level & BPF_LOG_LEVEL && do_print_state)) {
+			if (env->log.level & BPF_LOG_LEVEL2)
 				verbose(env, "%d:", env->insn_idx);
 			else
 				verbose(env, "\nfrom %d to %d%s:",
@@ -6356,7 +6366,7 @@ static int do_check(struct bpf_verifier_env *env)
 			do_print_state = false;
 		}
 
-		if (env->log.level) {
+		if (env->log.level & BPF_LOG_LEVEL) {
 			const struct bpf_insn_cbs cbs = {
 				.cb_print	= verbose,
 				.private_data	= env,
@@ -6621,16 +6631,6 @@ process_bpf_exit:
 		env->insn_idx++;
 	}
 
-	verbose(env, "processed %d insns (limit %d), stack depth ",
-		insn_processed, BPF_COMPLEXITY_LIMIT_INSNS);
-	for (i = 0; i < env->subprog_cnt; i++) {
-		u32 depth = env->subprog_info[i].stack_depth;
-
-		verbose(env, "%d", depth);
-		if (i + 1 < env->subprog_cnt)
-			verbose(env, "+");
-	}
-	verbose(env, "\n");
 	env->prog->aux->stack_depth = env->subprog_info[0].stack_depth;
 	return 0;
 }
@@ -7854,9 +7854,34 @@ static void free_states(struct bpf_verifier_env *env)
 	kfree(env->explored_states);
 }
 
+static void print_verification_stats(struct bpf_verifier_env *env)
+{
+	int i;
+
+	if (env->log.level & BPF_LOG_STATS) {
+		verbose(env, "verification time %lld usec\n",
+			div_u64(env->verification_time, 1000));
+		verbose(env, "stack depth ");
+		for (i = 0; i < env->subprog_cnt; i++) {
+			u32 depth = env->subprog_info[i].stack_depth;
+
+			verbose(env, "%d", depth);
+			if (i + 1 < env->subprog_cnt)
+				verbose(env, "+");
+		}
+		verbose(env, "\n");
+	}
+	verbose(env, "processed %d insns (limit %d) max_states_per_insn %d "
+		"total_states %d peak_states %d mark_read %d\n",
+		env->insn_processed, BPF_COMPLEXITY_LIMIT_INSNS,
+		env->max_states_per_insn, env->total_states,
+		env->peak_states, env->longest_mark_read_walk);
+}
+
 int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 	      union bpf_attr __user *uattr)
 {
+	u64 start_time = ktime_get_ns();
 	struct bpf_verifier_env *env;
 	struct bpf_verifier_log *log;
 	int i, len, ret = -EINVAL;
@@ -7899,7 +7924,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 		ret = -EINVAL;
 		/* log attributes have to be sane */
 		if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
-		    !log->level || !log->ubuf)
+		    !log->level || !log->ubuf || log->level & ~BPF_LOG_MASK)
 			goto err_unlock;
 	}
 
@@ -7980,6 +8005,9 @@ skip_full_check:
 	if (ret == 0)
 		ret = fixup_call_args(env);
 
+	env->verification_time = ktime_get_ns() - start_time;
+	print_verification_stats(env);
+
 	if (log->level && bpf_verifier_log_full(log))
 		ret = -ENOSPC;
 	if (log->level && !log->ubuf) {
-- 
cgit v1.2.3


From 9f4686c41bdff051f557accb531af79dd1773687 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Apr 2019 21:27:41 -0700
Subject: bpf: improve verification speed by droping states

Branch instructions, branch targets and calls in a bpf program are
the places where the verifier remembers states that led to successful
verification of the program.
These states are used to prune brute force program analysis.
For unprivileged programs there is a limit of 64 states per such
'branching' instructions (maximum length is tracked by max_states_per_insn
counter introduced in the previous patch).
Simply reducing this threshold to 32 or lower increases insn_processed
metric to the point that small valid programs get rejected.
For root programs there is no limit and cilium programs can have
max_states_per_insn to be 100 or higher.
Walking 100+ states multiplied by number of 'branching' insns during
verification consumes significant amount of cpu time.
Turned out simple LRU-like mechanism can be used to remove states
that unlikely will be helpful in future search pruning.
This patch introduces hit_cnt and miss_cnt counters:
hit_cnt - this many times this state successfully pruned the search
miss_cnt - this many times this state was not equivalent to other states
(and that other states were added to state list)

The heuristic introduced in this patch is:
if (sl->miss_cnt > sl->hit_cnt * 3 + 3)
  /* drop this state from future considerations */

Higher numbers increase max_states_per_insn (allow more states to be
considered for pruning) and slow verification speed, but do not meaningfully
reduce insn_processed metric.
Lower numbers drop too many states and insn_processed increases too much.
Many different formulas were considered.
This one is simple and works well enough in practice.
(the analysis was done on selftests/progs/* and on cilium programs)

The end result is this heuristic improves verification speed by 10 times.
Large synthetic programs that used to take a second more now take
1/10 of a second.
In cases where max_states_per_insn used to be 100 or more, now it's ~10.

There is a slight increase in insn_processed for cilium progs:
                       before   after
bpf_lb-DLB_L3.o 	1831	1838
bpf_lb-DLB_L4.o 	3029	3218
bpf_lb-DUNKNOWN.o 	1064	1064
bpf_lxc-DDROP_ALL.o	26309	26935
bpf_lxc-DUNKNOWN.o	33517	34439
bpf_netdev.o		9713	9721
bpf_overlay.o		6184	6184
bpf_lcx_jit.o		37335	39389
And 2-3 times improvement in the verification speed.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 44 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 41 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index e2001c1e40b3..a636db4a7a4e 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6152,11 +6152,13 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 {
 	struct bpf_verifier_state_list *new_sl;
-	struct bpf_verifier_state_list *sl;
+	struct bpf_verifier_state_list *sl, **pprev;
 	struct bpf_verifier_state *cur = env->cur_state, *new;
 	int i, j, err, states_cnt = 0;
 
-	sl = env->explored_states[insn_idx];
+	pprev = &env->explored_states[insn_idx];
+	sl = *pprev;
+
 	if (!sl)
 		/* this 'insn_idx' instruction wasn't marked, so we will not
 		 * be doing state search here
@@ -6167,6 +6169,7 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 
 	while (sl != STATE_LIST_MARK) {
 		if (states_equal(env, &sl->state, cur)) {
+			sl->hit_cnt++;
 			/* reached equivalent register/stack state,
 			 * prune the search.
 			 * Registers read by the continuation are read by us.
@@ -6182,8 +6185,35 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 				return err;
 			return 1;
 		}
-		sl = sl->next;
 		states_cnt++;
+		sl->miss_cnt++;
+		/* heuristic to determine whether this state is beneficial
+		 * to keep checking from state equivalence point of view.
+		 * Higher numbers increase max_states_per_insn and verification time,
+		 * but do not meaningfully decrease insn_processed.
+		 */
+		if (sl->miss_cnt > sl->hit_cnt * 3 + 3) {
+			/* the state is unlikely to be useful. Remove it to
+			 * speed up verification
+			 */
+			*pprev = sl->next;
+			if (sl->state.frame[0]->regs[0].live & REG_LIVE_DONE) {
+				free_verifier_state(&sl->state, false);
+				kfree(sl);
+				env->peak_states--;
+			} else {
+				/* cannot free this state, since parentage chain may
+				 * walk it later. Add it for free_list instead to
+				 * be freed at the end of verification
+				 */
+				sl->next = env->free_list;
+				env->free_list = sl;
+			}
+			sl = *pprev;
+			continue;
+		}
+		pprev = &sl->next;
+		sl = *pprev;
 	}
 
 	if (env->max_states_per_insn < states_cnt)
@@ -7836,6 +7866,14 @@ static void free_states(struct bpf_verifier_env *env)
 	struct bpf_verifier_state_list *sl, *sln;
 	int i;
 
+	sl = env->free_list;
+	while (sl) {
+		sln = sl->next;
+		free_verifier_state(&sl->state, false);
+		kfree(sl);
+		sl = sln;
+	}
+
 	if (!env->explored_states)
 		return;
 
-- 
cgit v1.2.3


From 25af32dad8047d180e70e233c85b909dd6587cc5 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Apr 2019 21:27:42 -0700
Subject: bpf: improve verification speed by not remarking live_read

With large verifier speed improvement brought by the previous patch
mark_reg_read() becomes the hottest function during verification.
On a typical program it consumes 40% of cpu.
mark_reg_read() walks parentage chain of registers to mark parents as LIVE_READ.
Once the register is marked there is no need to remark it again in the future.
Hence stop walking the chain once first LIVE_READ is seen.
This optimization drops mark_reg_read() time from 40% of cpu to <1%
and overall 2x improvement of verification speed.
For some programs the longest_mark_read_walk counter improves from ~500 to ~5

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a636db4a7a4e..94cf6efc5df6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1151,6 +1151,15 @@ static int mark_reg_read(struct bpf_verifier_env *env,
 				parent->var_off.value, parent->off);
 			return -EFAULT;
 		}
+		if (parent->live & REG_LIVE_READ)
+			/* The parentage chain never changes and
+			 * this parent was already marked as LIVE_READ.
+			 * There is no need to keep walking the chain again and
+			 * keep re-marking all parents as LIVE_READ.
+			 * This case happens when the same register is read
+			 * multiple times without writes into it in-between.
+			 */
+			break;
 		/* ... then we depend on parent's value */
 		parent->live |= REG_LIVE_READ;
 		state = parent;
-- 
cgit v1.2.3


From 71dde681a8cea1ccff2c7b3be83c043ab6b2a977 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Apr 2019 21:27:43 -0700
Subject: bpf: convert temp arrays to kvcalloc

Temporary arrays used during program verification need to be vmalloc-ed
to support large bpf programs.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 94cf6efc5df6..ad3494a881da 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5313,13 +5313,13 @@ static int check_cfg(struct bpf_verifier_env *env)
 	int ret = 0;
 	int i, t;
 
-	insn_state = kcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+	insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
 	if (!insn_state)
 		return -ENOMEM;
 
-	insn_stack = kcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+	insn_stack = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
 	if (!insn_stack) {
-		kfree(insn_state);
+		kvfree(insn_state);
 		return -ENOMEM;
 	}
 
@@ -5417,8 +5417,8 @@ check_state:
 	ret = 0; /* cfg looks good */
 
 err_free:
-	kfree(insn_state);
-	kfree(insn_stack);
+	kvfree(insn_state);
+	kvfree(insn_stack);
 	return ret;
 }
 
@@ -7898,7 +7898,7 @@ static void free_states(struct bpf_verifier_env *env)
 			}
 	}
 
-	kfree(env->explored_states);
+	kvfree(env->explored_states);
 }
 
 static void print_verification_stats(struct bpf_verifier_env *env)
@@ -7994,7 +7994,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 			goto skip_full_check;
 	}
 
-	env->explored_states = kcalloc(env->prog->len,
+	env->explored_states = kvcalloc(env->prog->len,
 				       sizeof(struct bpf_verifier_state_list *),
 				       GFP_USER);
 	ret = -ENOMEM;
-- 
cgit v1.2.3


From 4f73379ec5c2891598aa715c6df7ac9afdc86fbf Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Apr 2019 21:27:44 -0700
Subject: bpf: verbose jump offset overflow check

Larger programs may trigger 16-bit jump offset overflow check
during instruction patching. Make this error verbose otherwise
users cannot decipher error code without printks in the verifier.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/core.c     | 11 ++++++-----
 kernel/bpf/verifier.c |  7 ++++++-
 2 files changed, 12 insertions(+), 6 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index ff09d32a8a1b..2966cb368bf4 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -438,6 +438,7 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 	u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
 	const u32 cnt_max = S16_MAX;
 	struct bpf_prog *prog_adj;
+	int err;
 
 	/* Since our patchlet doesn't expand the image, we're done. */
 	if (insn_delta == 0) {
@@ -453,8 +454,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 	 * we afterwards may not fail anymore.
 	 */
 	if (insn_adj_cnt > cnt_max &&
-	    bpf_adj_branches(prog, off, off + 1, off + len, true))
-		return NULL;
+	    (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
+		return ERR_PTR(err);
 
 	/* Several new instructions need to be inserted. Make room
 	 * for them. Likely, there's no need for a new allocation as
@@ -463,7 +464,7 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 	prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
 				    GFP_USER);
 	if (!prog_adj)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	prog_adj->len = insn_adj_cnt;
 
@@ -1096,13 +1097,13 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
 			continue;
 
 		tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
-		if (!tmp) {
+		if (IS_ERR(tmp)) {
 			/* Patching may have repointed aux->prog during
 			 * realloc from the original one, so we need to
 			 * fix it up here on error.
 			 */
 			bpf_jit_prog_release_other(prog, clone);
-			return ERR_PTR(-ENOMEM);
+			return tmp;
 		}
 
 		clone = tmp;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ad3494a881da..6dcfeb44bb8e 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6932,8 +6932,13 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of
 	struct bpf_prog *new_prog;
 
 	new_prog = bpf_patch_insn_single(env->prog, off, patch, len);
-	if (!new_prog)
+	if (IS_ERR(new_prog)) {
+		if (PTR_ERR(new_prog) == -ERANGE)
+			verbose(env,
+				"insn %d cannot be patched due to 16-bit range\n",
+				env->insn_aux_data[off].orig_idx);
 		return NULL;
+	}
 	if (adjust_insn_aux_data(env, new_prog->len, off, len))
 		return NULL;
 	adjust_subprog_starts(env, off, len);
-- 
cgit v1.2.3


From c04c0d2b968ac45d6ef020316808ef6c82325a82 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Apr 2019 21:27:45 -0700
Subject: bpf: increase complexity limit and maximum program size

Large verifier speed improvements allow to increase
verifier complexity limit.
Now regardless of the program composition and its size it takes
little time for the verifier to hit insn_processed limit.
On typical x86 machine non-debug kernel processes 1M instructions
in 1/10 of a second.
(before these speed improvements specially crafted programs
could be hitting multi-second verification times)
Full kasan kernel with debug takes ~1 second for the same 1M insns.
Hence bump the BPF_COMPLEXITY_LIMIT_INSNS limit to 1M.
Also increase the number of instructions per program
from 4k to internal BPF_COMPLEXITY_LIMIT_INSNS limit.
4k limit was confusing to users, since small programs with hundreds
of insns could be hitting BPF_COMPLEXITY_LIMIT_INSNS limit.
Sometimes adding more insns and bpf_trace_printk debug statements
would make the verifier accept the program while removing
code would make the verifier reject it.
Some user space application started to add #define MAX_FOO to
their programs and do:
  MAX_FOO=100;
again:
  compile with MAX_FOO;
  try to load;
  if (fails_to_load) { reduce MAX_FOO; goto again; }
to be able to fit maximum amount of processing into single program.
Other users artificially split their single program into a set of programs
and use all 32 iterations of tail_calls to increase compute limits.
And the most advanced folks used unlimited tc-bpf filter list
to execute many bpf programs.
Essentially the users managed to workaround 4k insn limit.
This patch removes the limit for root programs from uapi.
BPF_COMPLEXITY_LIMIT_INSNS is the kernel internal limit
and success to load the program no longer depends on program size,
but on 'smartness' of the verifier only.
The verifier will continue to get smarter with every kernel release.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/syscall.c  | 3 ++-
 kernel/bpf/verifier.c | 1 -
 2 files changed, 2 insertions(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index afca36f53c49..1d65e56594db 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1557,7 +1557,8 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
 	is_gpl = license_is_gpl_compatible(license);
 
-	if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
+	if (attr->insn_cnt == 0 ||
+	    attr->insn_cnt > (capable(CAP_SYS_ADMIN) ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
 		return -E2BIG;
 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6dcfeb44bb8e..b631e89e7a51 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -176,7 +176,6 @@ struct bpf_verifier_stack_elem {
 	struct bpf_verifier_stack_elem *next;
 };
 
-#define BPF_COMPLEXITY_LIMIT_INSNS	131072
 #define BPF_COMPLEXITY_LIMIT_STACK	1024
 #define BPF_COMPLEXITY_LIMIT_STATES	64
 
-- 
cgit v1.2.3


From 7a9f5c65abcc9644b11738ca0815510cb5510eaf Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Apr 2019 21:27:46 -0700
Subject: bpf: increase verifier log limit

The existing 16Mbyte verifier log limit is not enough for log_level=2
even for small programs. Increase it to 1Gbyte.
Note it's not a kernel memory limit.
It's an amount of memory user space provides to store
the verifier log. The kernel populates it 1k at a time.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b631e89e7a51..bb27b675923c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -7974,7 +7974,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 
 		ret = -EINVAL;
 		/* log attributes have to be sane */
-		if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
+		if (log->len_total < 128 || log->len_total > UINT_MAX >> 2 ||
 		    !log->level || !log->ubuf || log->level & ~BPF_LOG_MASK)
 			goto err_unlock;
 	}
-- 
cgit v1.2.3


From f2bcd05ec7b839ff826d2008506ad2d2dff46a59 Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Wed, 3 Apr 2019 23:22:37 -0700
Subject: bpf: Reject indirect var_off stack access in raw mode

It's hard to guarantee that whole memory is marked as initialized on
helper return if uninitialized stack is accessed with variable offset
since specific bounds are unknown to verifier. This may cause
uninitialized stack leaking.

Reject such an access in check_stack_boundary to prevent possible
leaking.

There are no known use-cases for indirect uninitialized stack access
with variable offset so it shouldn't break anything.

Fixes: 2011fccfb61b ("bpf: Support variable offset stack access from helpers")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index bb27b675923c..0f12fda35626 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2226,6 +2226,15 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		if (err)
 			return err;
 	} else {
+		/* Only initialized buffer on stack is allowed to be accessed
+		 * with variable offset. With uninitialized buffer it's hard to
+		 * guarantee that whole memory is marked as initialized on
+		 * helper return since specific bounds are unknown what may
+		 * cause uninitialized stack leaking.
+		 */
+		if (meta && meta->raw_mode)
+			meta = NULL;
+
 		min_off = reg->smin_value + reg->off;
 		max_off = reg->umax_value + reg->off;
 		err = __check_stack_boundary(env, regno, min_off, access_size,
-- 
cgit v1.2.3


From 088ec26d9c2da9d879ab73e3f4117f9df6c566ee Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Wed, 3 Apr 2019 23:22:39 -0700
Subject: bpf: Reject indirect var_off stack access in unpriv mode

Proper support of indirect stack access with variable offset in
unprivileged mode (!root) requires corresponding support in Spectre
masking for stack ALU in retrieve_ptr_limit().

There are no use-case for variable offset in unprivileged mode though so
make verifier reject such accesses for simplicity.

Pointer arithmetics is one (and only?) way to cause variable offset and
it's already rejected in unpriv mode so that verifier won't even get to
helper function whose argument contains variable offset, e.g.:

  0: (7a) *(u64 *)(r10 -16) = 0
  1: (7a) *(u64 *)(r10 -8) = 0
  2: (61) r2 = *(u32 *)(r1 +0)
  3: (57) r2 &= 4
  4: (17) r2 -= 16
  5: (0f) r2 += r10
  variable stack access var_off=(0xfffffffffffffff0; 0x4) off=-16 size=1R2
  stack pointer arithmetic goes out of range, prohibited for !root

Still it looks like a good idea to reject variable offset indirect stack
access for unprivileged mode in check_stack_boundary() explicitly.

Fixes: 2011fccfb61b ("bpf: Support variable offset stack access from helpers")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 0f12fda35626..8400c1f33cd4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2226,6 +2226,19 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		if (err)
 			return err;
 	} else {
+		/* Variable offset is prohibited for unprivileged mode for
+		 * simplicity since it requires corresponding support in
+		 * Spectre masking for stack ALU.
+		 * See also retrieve_ptr_limit().
+		 */
+		if (!env->allow_ptr_leaks) {
+			char tn_buf[48];
+
+			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+			verbose(env, "R%d indirect variable offset stack access prohibited for !root, var_off=%s\n",
+				regno, tn_buf);
+			return -EACCES;
+		}
 		/* Only initialized buffer on stack is allowed to be accessed
 		 * with variable offset. With uninitialized buffer it's hard to
 		 * guarantee that whole memory is marked as initialized on
@@ -3339,6 +3352,9 @@ static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg,
 
 	switch (ptr_reg->type) {
 	case PTR_TO_STACK:
+		/* Indirect variable offset stack access is prohibited in
+		 * unprivileged mode so it's not handled here.
+		 */
 		off = ptr_reg->off + ptr_reg->var_off.value;
 		if (mask_to_left)
 			*ptr_limit = MAX_BPF_STACK + off;
-- 
cgit v1.2.3


From 107c26a70ca81bfc33657366ad69d02fdc9efc9d Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Wed, 3 Apr 2019 23:22:41 -0700
Subject: bpf: Sanity check max value for var_off stack access

As discussed in [1] max value of variable offset has to be checked for
overflow on stack access otherwise verifier would accept code like this:

  0: (b7) r2 = 6
  1: (b7) r3 = 28
  2: (7a) *(u64 *)(r10 -16) = 0
  3: (7a) *(u64 *)(r10 -8) = 0
  4: (79) r4 = *(u64 *)(r1 +168)
  5: (c5) if r4 s< 0x0 goto pc+4
   R1=ctx(id=0,off=0,imm=0) R2=inv6 R3=inv28
   R4=inv(id=0,umax_value=9223372036854775807,var_off=(0x0;
   0x7fffffffffffffff)) R10=fp0,call_-1 fp-8=mmmmmmmm fp-16=mmmmmmmm
  6: (17) r4 -= 16
  7: (0f) r4 += r10
  8: (b7) r5 = 8
  9: (85) call bpf_getsockopt#57
  10: (b7) r0 = 0
  11: (95) exit

, where R4 obviosly has unbounded max value.

Fix it by checking that reg->smax_value is inside (-BPF_MAX_VAR_OFF;
BPF_MAX_VAR_OFF) range.

reg->smax_value is used instead of reg->umax_value because stack
pointers are calculated using negative offset from fp. This is opposite
to e.g. map access where offset must be non-negative and where
umax_value is used.

Also dedicated verbose logs are added for both min and max bound check
failures to have diagnostics consistent with variable offset handling in
check_map_access().

[1] https://marc.info/?l=linux-netdev&m=155433357510597&w=2

Fixes: 2011fccfb61b ("bpf: Support variable offset stack access from helpers")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 8400c1f33cd4..f2d600199e66 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2248,16 +2248,28 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 		if (meta && meta->raw_mode)
 			meta = NULL;
 
+		if (reg->smax_value >= BPF_MAX_VAR_OFF ||
+		    reg->smax_value <= -BPF_MAX_VAR_OFF) {
+			verbose(env, "R%d unbounded indirect variable offset stack access\n",
+				regno);
+			return -EACCES;
+		}
 		min_off = reg->smin_value + reg->off;
-		max_off = reg->umax_value + reg->off;
+		max_off = reg->smax_value + reg->off;
 		err = __check_stack_boundary(env, regno, min_off, access_size,
 					     zero_size_allowed);
-		if (err)
+		if (err) {
+			verbose(env, "R%d min value is outside of stack bound\n",
+				regno);
 			return err;
+		}
 		err = __check_stack_boundary(env, regno, max_off, access_size,
 					     zero_size_allowed);
-		if (err)
+		if (err) {
+			verbose(env, "R%d max value is outside of stack bound\n",
+				regno);
 			return err;
+		}
 	}
 
 	if (meta && meta->raw_mode) {
-- 
cgit v1.2.3


From 1fbd20f8b77b366ea4aeb92ade72daa7f36a7e3b Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Wed, 3 Apr 2019 23:22:43 -0700
Subject: bpf: Add missed newline in verifier verbose log

check_stack_access() that prints verbose log is used in
adjust_ptr_min_max_vals() that prints its own verbose log and now they
stick together, e.g.:

  variable stack access var_off=(0xfffffffffffffff0; 0x4) off=-16
  size=1R2 stack pointer arithmetic goes out of range, prohibited for
  !root

Add missing newline so that log is more readable:
  variable stack access var_off=(0xfffffffffffffff0; 0x4) off=-16 size=1
  R2 stack pointer arithmetic goes out of range, prohibited for !root

Fixes: f1174f77b50c ("bpf/verifier: rework value tracking")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index f2d600199e66..48718e1da16d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1426,7 +1426,7 @@ static int check_stack_access(struct bpf_verifier_env *env,
 		char tn_buf[48];
 
 		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-		verbose(env, "variable stack access var_off=%s off=%d size=%d",
+		verbose(env, "variable stack access var_off=%s off=%d size=%d\n",
 			tn_buf, off, size);
 		return -EACCES;
 	}
-- 
cgit v1.2.3


From 3b15d09f7e6db44065aaba5fd16dc7420035c5ad Mon Sep 17 00:00:00 2001
From: Li RongQing <lirongqing@baidu.com>
Date: Thu, 28 Feb 2019 13:13:26 +0800
Subject: time: Introduce jiffies64_to_msecs()

there is a similar helper in net/netfilter/nf_tables_api.c,
this maybe become a common request someday, so move it to
time.c

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 kernel/time/time.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'kernel')

diff --git a/kernel/time/time.c b/kernel/time/time.c
index c3f756f8534b..9e3f79d4f5a8 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -783,6 +783,16 @@ u64 jiffies64_to_nsecs(u64 j)
 }
 EXPORT_SYMBOL(jiffies64_to_nsecs);
 
+u64 jiffies64_to_msecs(const u64 j)
+{
+#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
+	return (MSEC_PER_SEC / HZ) * j;
+#else
+	return div_u64(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN);
+#endif
+}
+EXPORT_SYMBOL(jiffies64_to_msecs);
+
 /**
  * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64
  *
-- 
cgit v1.2.3


From d8eca5bbb2be9bc7546f9e733786fa2f1a594c67 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 9 Apr 2019 23:20:03 +0200
Subject: bpf: implement lookup-free direct value access for maps

This generic extension to BPF maps allows for directly loading
an address residing inside a BPF map value as a single BPF
ldimm64 instruction!

The idea is similar to what BPF_PSEUDO_MAP_FD does today, which
is a special src_reg flag for ldimm64 instruction that indicates
that inside the first part of the double insns's imm field is a
file descriptor which the verifier then replaces as a full 64bit
address of the map into both imm parts. For the newly added
BPF_PSEUDO_MAP_VALUE src_reg flag, the idea is the following:
the first part of the double insns's imm field is again a file
descriptor corresponding to the map, and the second part of the
imm field is an offset into the value. The verifier will then
replace both imm parts with an address that points into the BPF
map value at the given value offset for maps that support this
operation. Currently supported is array map with single entry.
It is possible to support more than just single map element by
reusing both 16bit off fields of the insns as a map index, so
full array map lookup could be expressed that way. It hasn't
been implemented here due to lack of concrete use case, but
could easily be done so in future in a compatible way, since
both off fields right now have to be 0 and would correctly
denote a map index 0.

The BPF_PSEUDO_MAP_VALUE is a distinct flag as otherwise with
BPF_PSEUDO_MAP_FD we could not differ offset 0 between load of
map pointer versus load of map's value at offset 0, and changing
BPF_PSEUDO_MAP_FD's encoding into off by one to differ between
regular map pointer and map value pointer would add unnecessary
complexity and increases barrier for debugability thus less
suitable. Using the second part of the imm field as an offset
into the value does /not/ come with limitations since maximum
possible value size is in u32 universe anyway.

This optimization allows for efficiently retrieving an address
to a map value memory area without having to issue a helper call
which needs to prepare registers according to calling convention,
etc, without needing the extra NULL test, and without having to
add the offset in an additional instruction to the value base
pointer. The verifier then treats the destination register as
PTR_TO_MAP_VALUE with constant reg->off from the user passed
offset from the second imm field, and guarantees that this is
within bounds of the map value. Any subsequent operations are
normally treated as typical map value handling without anything
extra needed from verification side.

The two map operations for direct value access have been added to
array map for now. In future other types could be supported as
well depending on the use case. The main use case for this commit
is to allow for BPF loader support for global variables that
reside in .data/.rodata/.bss sections such that we can directly
load the address of them with minimal additional infrastructure
required. Loader support has been added in subsequent commits for
libbpf library.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/arraymap.c | 32 +++++++++++++++++++
 kernel/bpf/core.c     |  3 +-
 kernel/bpf/disasm.c   |  5 +--
 kernel/bpf/syscall.c  | 28 ++++++++++++-----
 kernel/bpf/verifier.c | 86 +++++++++++++++++++++++++++++++++++++++------------
 5 files changed, 124 insertions(+), 30 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index c72e0d8e1e65..1a6e9861d554 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -160,6 +160,36 @@ static void *array_map_lookup_elem(struct bpf_map *map, void *key)
 	return array->value + array->elem_size * (index & array->index_mask);
 }
 
+static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
+				       u32 off)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+
+	if (map->max_entries != 1)
+		return -ENOTSUPP;
+	if (off >= map->value_size)
+		return -EINVAL;
+
+	*imm = (unsigned long)array->value;
+	return 0;
+}
+
+static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
+				       u32 *off)
+{
+	struct bpf_array *array = container_of(map, struct bpf_array, map);
+	u64 base = (unsigned long)array->value;
+	u64 range = array->elem_size;
+
+	if (map->max_entries != 1)
+		return -ENOTSUPP;
+	if (imm < base || imm >= base + range)
+		return -ENOENT;
+
+	*off = imm - base;
+	return 0;
+}
+
 /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
 static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
 {
@@ -419,6 +449,8 @@ const struct bpf_map_ops array_map_ops = {
 	.map_update_elem = array_map_update_elem,
 	.map_delete_elem = array_map_delete_elem,
 	.map_gen_lookup = array_map_gen_lookup,
+	.map_direct_value_addr = array_map_direct_value_addr,
+	.map_direct_value_meta = array_map_direct_value_meta,
 	.map_seq_show_elem = array_map_seq_show_elem,
 	.map_check_btf = array_map_check_btf,
 };
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 2966cb368bf4..ace8c22c8b0e 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -292,7 +292,8 @@ int bpf_prog_calc_tag(struct bpf_prog *fp)
 		dst[i] = fp->insnsi[i];
 		if (!was_ld_map &&
 		    dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
-		    dst[i].src_reg == BPF_PSEUDO_MAP_FD) {
+		    (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
+		     dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
 			was_ld_map = true;
 			dst[i].imm = 0;
 		} else if (was_ld_map &&
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
index de73f55e42fd..d9ce383c0f9c 100644
--- a/kernel/bpf/disasm.c
+++ b/kernel/bpf/disasm.c
@@ -205,10 +205,11 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs,
 			 * part of the ldimm64 insn is accessible.
 			 */
 			u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
-			bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD;
+			bool is_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD ||
+				      insn->src_reg == BPF_PSEUDO_MAP_VALUE;
 			char tmp[64];
 
-			if (map_ptr && !allow_ptr_leaks)
+			if (is_ptr && !allow_ptr_leaks)
 				imm = 0;
 
 			verbose(cbs->private_data, "(%02x) r%d = %s\n",
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 1d65e56594db..828518bb947b 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2072,13 +2072,26 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
 }
 
 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
-					      unsigned long addr)
+					      unsigned long addr, u32 *off,
+					      u32 *type)
 {
+	const struct bpf_map *map;
 	int i;
 
-	for (i = 0; i < prog->aux->used_map_cnt; i++)
-		if (prog->aux->used_maps[i] == (void *)addr)
-			return prog->aux->used_maps[i];
+	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
+		map = prog->aux->used_maps[i];
+		if (map == (void *)addr) {
+			*type = BPF_PSEUDO_MAP_FD;
+			return map;
+		}
+		if (!map->ops->map_direct_value_meta)
+			continue;
+		if (!map->ops->map_direct_value_meta(map, addr, off)) {
+			*type = BPF_PSEUDO_MAP_VALUE;
+			return map;
+		}
+	}
+
 	return NULL;
 }
 
@@ -2086,6 +2099,7 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
 {
 	const struct bpf_map *map;
 	struct bpf_insn *insns;
+	u32 off, type;
 	u64 imm;
 	int i;
 
@@ -2113,11 +2127,11 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
 			continue;
 
 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
-		map = bpf_map_from_imm(prog, imm);
+		map = bpf_map_from_imm(prog, imm, &off, &type);
 		if (map) {
-			insns[i].src_reg = BPF_PSEUDO_MAP_FD;
+			insns[i].src_reg = type;
 			insns[i].imm = map->id;
-			insns[i + 1].imm = 0;
+			insns[i + 1].imm = off;
 			continue;
 		}
 	}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 48718e1da16d..6ab7a23fc924 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5056,18 +5056,12 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 	return 0;
 }
 
-/* return the map pointer stored inside BPF_LD_IMM64 instruction */
-static struct bpf_map *ld_imm64_to_map_ptr(struct bpf_insn *insn)
-{
-	u64 imm64 = ((u64) (u32) insn[0].imm) | ((u64) (u32) insn[1].imm) << 32;
-
-	return (struct bpf_map *) (unsigned long) imm64;
-}
-
 /* verify BPF_LD_IMM64 instruction */
 static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
 {
+	struct bpf_insn_aux_data *aux = cur_aux(env);
 	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_map *map;
 	int err;
 
 	if (BPF_SIZE(insn->code) != BPF_DW) {
@@ -5091,11 +5085,22 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
 		return 0;
 	}
 
-	/* replace_map_fd_with_map_ptr() should have caught bad ld_imm64 */
-	BUG_ON(insn->src_reg != BPF_PSEUDO_MAP_FD);
+	map = env->used_maps[aux->map_index];
+	mark_reg_known_zero(env, regs, insn->dst_reg);
+	regs[insn->dst_reg].map_ptr = map;
+
+	if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) {
+		regs[insn->dst_reg].type = PTR_TO_MAP_VALUE;
+		regs[insn->dst_reg].off = aux->map_off;
+		if (map_value_has_spin_lock(map))
+			regs[insn->dst_reg].id = ++env->id_gen;
+	} else if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+		regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
+	} else {
+		verbose(env, "bpf verifier is misconfigured\n");
+		return -EINVAL;
+	}
 
-	regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
-	regs[insn->dst_reg].map_ptr = ld_imm64_to_map_ptr(insn);
 	return 0;
 }
 
@@ -6803,8 +6808,10 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 		}
 
 		if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW)) {
+			struct bpf_insn_aux_data *aux;
 			struct bpf_map *map;
 			struct fd f;
+			u64 addr;
 
 			if (i == insn_cnt - 1 || insn[1].code != 0 ||
 			    insn[1].dst_reg != 0 || insn[1].src_reg != 0 ||
@@ -6813,13 +6820,19 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 				return -EINVAL;
 			}
 
-			if (insn->src_reg == 0)
+			if (insn[0].src_reg == 0)
 				/* valid generic load 64-bit imm */
 				goto next_insn;
 
-			if (insn[0].src_reg != BPF_PSEUDO_MAP_FD ||
-			    insn[1].imm != 0) {
-				verbose(env, "unrecognized bpf_ld_imm64 insn\n");
+			/* In final convert_pseudo_ld_imm64() step, this is
+			 * converted into regular 64-bit imm load insn.
+			 */
+			if ((insn[0].src_reg != BPF_PSEUDO_MAP_FD &&
+			     insn[0].src_reg != BPF_PSEUDO_MAP_VALUE) ||
+			    (insn[0].src_reg == BPF_PSEUDO_MAP_FD &&
+			     insn[1].imm != 0)) {
+				verbose(env,
+					"unrecognized bpf_ld_imm64 insn\n");
 				return -EINVAL;
 			}
 
@@ -6837,16 +6850,47 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 				return err;
 			}
 
-			/* store map pointer inside BPF_LD_IMM64 instruction */
-			insn[0].imm = (u32) (unsigned long) map;
-			insn[1].imm = ((u64) (unsigned long) map) >> 32;
+			aux = &env->insn_aux_data[i];
+			if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+				addr = (unsigned long)map;
+			} else {
+				u32 off = insn[1].imm;
+
+				if (off >= BPF_MAX_VAR_OFF) {
+					verbose(env, "direct value offset of %u is not allowed\n", off);
+					fdput(f);
+					return -EINVAL;
+				}
+
+				if (!map->ops->map_direct_value_addr) {
+					verbose(env, "no direct value access support for this map type\n");
+					fdput(f);
+					return -EINVAL;
+				}
+
+				err = map->ops->map_direct_value_addr(map, &addr, off);
+				if (err) {
+					verbose(env, "invalid access to map value pointer, value_size=%u off=%u\n",
+						map->value_size, off);
+					fdput(f);
+					return err;
+				}
+
+				aux->map_off = off;
+				addr += off;
+			}
+
+			insn[0].imm = (u32)addr;
+			insn[1].imm = addr >> 32;
 
 			/* check whether we recorded this map already */
-			for (j = 0; j < env->used_map_cnt; j++)
+			for (j = 0; j < env->used_map_cnt; j++) {
 				if (env->used_maps[j] == map) {
+					aux->map_index = j;
 					fdput(f);
 					goto next_insn;
 				}
+			}
 
 			if (env->used_map_cnt >= MAX_USED_MAPS) {
 				fdput(f);
@@ -6863,6 +6907,8 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 				fdput(f);
 				return PTR_ERR(map);
 			}
+
+			aux->map_index = env->used_map_cnt;
 			env->used_maps[env->used_map_cnt++] = map;
 
 			if (bpf_map_is_cgroup_storage(map) &&
-- 
cgit v1.2.3


From be70bcd53de66e86f2726e576307cbdaebd3b1a5 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 9 Apr 2019 23:20:04 +0200
Subject: bpf: do not retain flags that are not tied to map lifetime

Both BPF_F_WRONLY / BPF_F_RDONLY flags are tied to the map file
descriptor, but not to the map object itself! Meaning, at map
creation time BPF_F_RDONLY can be set to make the map read-only
from syscall side, but this holds only for the returned fd, so
any other fd either retrieved via bpf file system or via map id
for the very same underlying map object can have read-write access
instead.

Given that, keeping the two flags around in the map_flags attribute
and exposing them to user space upon map dump is misleading and
may lead to false conclusions. Since these two flags are not
tied to the map object lets also not store them as map property.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/syscall.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 828518bb947b..56b4b0e08b3b 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -166,13 +166,25 @@ void bpf_map_area_free(void *area)
 	kvfree(area);
 }
 
+static u32 bpf_map_flags_retain_permanent(u32 flags)
+{
+	/* Some map creation flags are not tied to the map object but
+	 * rather to the map fd instead, so they have no meaning upon
+	 * map object inspection since multiple file descriptors with
+	 * different (access) properties can exist here. Thus, given
+	 * this has zero meaning for the map itself, lets clear these
+	 * from here.
+	 */
+	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
+}
+
 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
 {
 	map->map_type = attr->map_type;
 	map->key_size = attr->key_size;
 	map->value_size = attr->value_size;
 	map->max_entries = attr->max_entries;
-	map->map_flags = attr->map_flags;
+	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
 	map->numa_node = bpf_map_attr_numa_node(attr);
 }
 
-- 
cgit v1.2.3


From 591fe9888d7809d9ee5c828020b6c6ae27c37229 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 9 Apr 2019 23:20:05 +0200
Subject: bpf: add program side {rd, wr}only support for maps

This work adds two new map creation flags BPF_F_RDONLY_PROG
and BPF_F_WRONLY_PROG in order to allow for read-only or
write-only BPF maps from a BPF program side.

Today we have BPF_F_RDONLY and BPF_F_WRONLY, but this only
applies to system call side, meaning the BPF program has full
read/write access to the map as usual while bpf(2) calls with
map fd can either only read or write into the map depending
on the flags. BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG allows
for the exact opposite such that verifier is going to reject
program loads if write into a read-only map or a read into a
write-only map is detected. For read-only map case also some
helpers are forbidden for programs that would alter the map
state such as map deletion, update, etc. As opposed to the two
BPF_F_RDONLY / BPF_F_WRONLY flags, BPF_F_RDONLY_PROG as well
as BPF_F_WRONLY_PROG really do correspond to the map lifetime.

We've enabled this generic map extension to various non-special
maps holding normal user data: array, hash, lru, lpm, local
storage, queue and stack. Further generic map types could be
followed up in future depending on use-case. Main use case
here is to forbid writes into .rodata map values from verifier
side.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/arraymap.c         |  6 +++++-
 kernel/bpf/hashtab.c          |  6 +++---
 kernel/bpf/local_storage.c    |  6 +++---
 kernel/bpf/lpm_trie.c         |  3 ++-
 kernel/bpf/queue_stack_maps.c |  6 +++---
 kernel/bpf/syscall.c          |  2 ++
 kernel/bpf/verifier.c         | 46 +++++++++++++++++++++++++++++++++++++++++--
 7 files changed, 62 insertions(+), 13 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 1a6e9861d554..217b10bd9f48 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -22,7 +22,7 @@
 #include "map_in_map.h"
 
 #define ARRAY_CREATE_FLAG_MASK \
-	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 static void bpf_array_free_percpu(struct bpf_array *array)
 {
@@ -63,6 +63,7 @@ int array_map_alloc_check(union bpf_attr *attr)
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
 	    attr->value_size == 0 ||
 	    attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags) ||
 	    (percpu && numa_node != NUMA_NO_NODE))
 		return -EINVAL;
 
@@ -472,6 +473,9 @@ static int fd_array_map_alloc_check(union bpf_attr *attr)
 	/* only file descriptors can be stored in this type of map */
 	if (attr->value_size != sizeof(u32))
 		return -EINVAL;
+	/* Program read-only/write-only not supported for special maps yet. */
+	if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
+		return -EINVAL;
 	return array_map_alloc_check(attr);
 }
 
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index fed15cf94dca..192d32e77db3 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -23,7 +23,7 @@
 
 #define HTAB_CREATE_FLAG_MASK						\
 	(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE |	\
-	 BPF_F_RDONLY | BPF_F_WRONLY | BPF_F_ZERO_SEED)
+	 BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED)
 
 struct bucket {
 	struct hlist_nulls_head head;
@@ -262,8 +262,8 @@ static int htab_map_alloc_check(union bpf_attr *attr)
 		/* Guard against local DoS, and discourage production use. */
 		return -EPERM;
 
-	if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK)
-		/* reserved bits should not be used */
+	if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
 		return -EINVAL;
 
 	if (!lru && percpu_lru)
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index 6b572e2de7fb..980e8f1f6cb5 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -14,7 +14,7 @@ DEFINE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STO
 #ifdef CONFIG_CGROUP_BPF
 
 #define LOCAL_STORAGE_CREATE_FLAG_MASK					\
-	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 struct bpf_cgroup_storage_map {
 	struct bpf_map map;
@@ -282,8 +282,8 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
 	if (attr->value_size > PAGE_SIZE)
 		return ERR_PTR(-E2BIG);
 
-	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK)
-		/* reserved bits should not be used */
+	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
 		return ERR_PTR(-EINVAL);
 
 	if (attr->max_entries)
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index 93a5cbbde421..e61630c2e50b 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -538,7 +538,7 @@ out:
 #define LPM_KEY_SIZE_MIN	LPM_KEY_SIZE(LPM_DATA_SIZE_MIN)
 
 #define LPM_CREATE_FLAG_MASK	(BPF_F_NO_PREALLOC | BPF_F_NUMA_NODE |	\
-				 BPF_F_RDONLY | BPF_F_WRONLY)
+				 BPF_F_ACCESS_MASK)
 
 static struct bpf_map *trie_alloc(union bpf_attr *attr)
 {
@@ -553,6 +553,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
 	if (attr->max_entries == 0 ||
 	    !(attr->map_flags & BPF_F_NO_PREALLOC) ||
 	    attr->map_flags & ~LPM_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags) ||
 	    attr->key_size < LPM_KEY_SIZE_MIN ||
 	    attr->key_size > LPM_KEY_SIZE_MAX ||
 	    attr->value_size < LPM_VAL_SIZE_MIN ||
diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
index b384ea9f3254..0b140d236889 100644
--- a/kernel/bpf/queue_stack_maps.c
+++ b/kernel/bpf/queue_stack_maps.c
@@ -11,8 +11,7 @@
 #include "percpu_freelist.h"
 
 #define QUEUE_STACK_CREATE_FLAG_MASK \
-	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
-
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 struct bpf_queue_stack {
 	struct bpf_map map;
@@ -52,7 +51,8 @@ static int queue_stack_map_alloc_check(union bpf_attr *attr)
 	/* check sanity of attributes */
 	if (attr->max_entries == 0 || attr->key_size != 0 ||
 	    attr->value_size == 0 ||
-	    attr->map_flags & ~QUEUE_STACK_CREATE_FLAG_MASK)
+	    attr->map_flags & ~QUEUE_STACK_CREATE_FLAG_MASK ||
+	    !bpf_map_flags_access_ok(attr->map_flags))
 		return -EINVAL;
 
 	if (attr->value_size > KMALLOC_MAX_SIZE)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 56b4b0e08b3b..0c9276b54c88 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -501,6 +501,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 	map->spin_lock_off = btf_find_spin_lock(btf, value_type);
 
 	if (map_value_has_spin_lock(map)) {
+		if (map->map_flags & BPF_F_RDONLY_PROG)
+			return -EACCES;
 		if (map->map_type != BPF_MAP_TYPE_HASH &&
 		    map->map_type != BPF_MAP_TYPE_ARRAY &&
 		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6ab7a23fc924..b747434df89c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1439,6 +1439,28 @@ static int check_stack_access(struct bpf_verifier_env *env,
 	return 0;
 }
 
+static int check_map_access_type(struct bpf_verifier_env *env, u32 regno,
+				 int off, int size, enum bpf_access_type type)
+{
+	struct bpf_reg_state *regs = cur_regs(env);
+	struct bpf_map *map = regs[regno].map_ptr;
+	u32 cap = bpf_map_flags_to_cap(map);
+
+	if (type == BPF_WRITE && !(cap & BPF_MAP_CAN_WRITE)) {
+		verbose(env, "write into map forbidden, value_size=%d off=%d size=%d\n",
+			map->value_size, off, size);
+		return -EACCES;
+	}
+
+	if (type == BPF_READ && !(cap & BPF_MAP_CAN_READ)) {
+		verbose(env, "read from map forbidden, value_size=%d off=%d size=%d\n",
+			map->value_size, off, size);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
 /* check read/write into map element returned by bpf_map_lookup_elem() */
 static int __check_map_access(struct bpf_verifier_env *env, u32 regno, int off,
 			      int size, bool zero_size_allowed)
@@ -2024,7 +2046,9 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
 			verbose(env, "R%d leaks addr into map\n", value_regno);
 			return -EACCES;
 		}
-
+		err = check_map_access_type(env, regno, off, size, t);
+		if (err)
+			return err;
 		err = check_map_access(env, regno, off, size, false);
 		if (!err && t == BPF_READ && value_regno >= 0)
 			mark_reg_unknown(env, regs, value_regno);
@@ -2327,6 +2351,10 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
 		return check_packet_access(env, regno, reg->off, access_size,
 					   zero_size_allowed);
 	case PTR_TO_MAP_VALUE:
+		if (check_map_access_type(env, regno, reg->off, access_size,
+					  meta && meta->raw_mode ? BPF_WRITE :
+					  BPF_READ))
+			return -EACCES;
 		return check_map_access(env, regno, reg->off, access_size,
 					zero_size_allowed);
 	default: /* scalar_value|ptr_to_stack or invalid ptr */
@@ -3059,6 +3087,7 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 		int func_id, int insn_idx)
 {
 	struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
+	struct bpf_map *map = meta->map_ptr;
 
 	if (func_id != BPF_FUNC_tail_call &&
 	    func_id != BPF_FUNC_map_lookup_elem &&
@@ -3069,11 +3098,24 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
 	    func_id != BPF_FUNC_map_peek_elem)
 		return 0;
 
-	if (meta->map_ptr == NULL) {
+	if (map == NULL) {
 		verbose(env, "kernel subsystem misconfigured verifier\n");
 		return -EINVAL;
 	}
 
+	/* In case of read-only, some additional restrictions
+	 * need to be applied in order to prevent altering the
+	 * state of the map from program side.
+	 */
+	if ((map->map_flags & BPF_F_RDONLY_PROG) &&
+	    (func_id == BPF_FUNC_map_delete_elem ||
+	     func_id == BPF_FUNC_map_update_elem ||
+	     func_id == BPF_FUNC_map_push_elem ||
+	     func_id == BPF_FUNC_map_pop_elem)) {
+		verbose(env, "write into map forbidden\n");
+		return -EACCES;
+	}
+
 	if (!BPF_MAP_PTR(aux->map_state))
 		bpf_map_ptr_store(aux, meta->map_ptr,
 				  meta->map_ptr->unpriv_array);
-- 
cgit v1.2.3


From 87df15de441bd4add7876ef584da8cabdd9a042a Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 9 Apr 2019 23:20:06 +0200
Subject: bpf: add syscall side map freeze support

This patch adds a new BPF_MAP_FREEZE command which allows to
"freeze" the map globally as read-only / immutable from syscall
side.

Map permission handling has been refactored into map_get_sys_perms()
and drops FMODE_CAN_WRITE in case of locked map. Main use case is
to allow for setting up .rodata sections from the BPF ELF which
are loaded into the kernel, meaning BPF loader first allocates
map, sets up map value by copying .rodata section into it and once
complete, it calls BPF_MAP_FREEZE on the map fd to prevent further
modifications.

Right now BPF_MAP_FREEZE only takes map fd as argument while remaining
bpf_attr members are required to be zero. I didn't add write-only
locking here as counterpart since I don't have a concrete use-case
for it on my side, and I think it makes probably more sense to wait
once there is actually one. In that case bpf_attr can be extended
as usual with a flag field and/or others where flag 0 means that
we lock the map read-only hence this doesn't prevent to add further
extensions to BPF_MAP_FREEZE upon need.

A map creation flag like BPF_F_WRONCE was not considered for couple
of reasons: i) in case of a generic implementation, a map can consist
of more than just one element, thus there could be multiple map
updates needed to set the map into a state where it can then be
made immutable, ii) WRONCE indicates exact one-time write before
it is then set immutable. A generic implementation would set a bit
atomically on map update entry (if unset), indicating that every
subsequent update from then onwards will need to bail out there.
However, map updates can fail, so upon failure that flag would need
to be unset again and the update attempt would need to be repeated
for it to be eventually made immutable. While this can be made
race-free, this approach feels less clean and in combination with
reason i), it's not generic enough. A dedicated BPF_MAP_FREEZE
command directly sets the flag and caller has the guarantee that
map is immutable from syscall side upon successful return for any
future syscall invocations that would alter the map state, which
is also more intuitive from an API point of view. A command name
such as BPF_MAP_LOCK has been avoided as it's too close with BPF
map spin locks (which already has BPF_F_LOCK flag). BPF_MAP_FREEZE
is so far only enabled for privileged users.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/syscall.c | 66 ++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 54 insertions(+), 12 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0c9276b54c88..b3ce516e5a20 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -355,6 +355,18 @@ static int bpf_map_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
+{
+	fmode_t mode = f.file->f_mode;
+
+	/* Our file permissions may have been overridden by global
+	 * map permissions facing syscall side.
+	 */
+	if (READ_ONCE(map->frozen))
+		mode &= ~FMODE_CAN_WRITE;
+	return mode;
+}
+
 #ifdef CONFIG_PROC_FS
 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 {
@@ -376,14 +388,16 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 		   "max_entries:\t%u\n"
 		   "map_flags:\t%#x\n"
 		   "memlock:\t%llu\n"
-		   "map_id:\t%u\n",
+		   "map_id:\t%u\n"
+		   "frozen:\t%u\n",
 		   map->map_type,
 		   map->key_size,
 		   map->value_size,
 		   map->max_entries,
 		   map->map_flags,
 		   map->pages * 1ULL << PAGE_SHIFT,
-		   map->id);
+		   map->id,
+		   READ_ONCE(map->frozen));
 
 	if (owner_prog_type) {
 		seq_printf(m, "owner_prog_type:\t%u\n",
@@ -727,8 +741,7 @@ static int map_lookup_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_READ)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -857,8 +870,7 @@ static int map_update_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -969,8 +981,7 @@ static int map_delete_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -1021,8 +1032,7 @@ static int map_get_next_key(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_READ)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -1089,8 +1099,7 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
 	map = __bpf_map_get(f);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
-
-	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
 		err = -EPERM;
 		goto err_put;
 	}
@@ -1132,6 +1141,36 @@ err_put:
 	return err;
 }
 
+#define BPF_MAP_FREEZE_LAST_FIELD map_fd
+
+static int map_freeze(const union bpf_attr *attr)
+{
+	int err = 0, ufd = attr->map_fd;
+	struct bpf_map *map;
+	struct fd f;
+
+	if (CHECK_ATTR(BPF_MAP_FREEZE))
+		return -EINVAL;
+
+	f = fdget(ufd);
+	map = __bpf_map_get(f);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+	if (READ_ONCE(map->frozen)) {
+		err = -EBUSY;
+		goto err_put;
+	}
+	if (!capable(CAP_SYS_ADMIN)) {
+		err = -EPERM;
+		goto err_put;
+	}
+
+	WRITE_ONCE(map->frozen, true);
+err_put:
+	fdput(f);
+	return err;
+}
+
 static const struct bpf_prog_ops * const bpf_prog_types[] = {
 #define BPF_PROG_TYPE(_id, _name) \
 	[_id] = & _name ## _prog_ops,
@@ -2735,6 +2774,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
 	case BPF_MAP_GET_NEXT_KEY:
 		err = map_get_next_key(&attr);
 		break;
+	case BPF_MAP_FREEZE:
+		err = map_freeze(&attr);
+		break;
 	case BPF_PROG_LOAD:
 		err = bpf_prog_load(&attr, uattr);
 		break;
-- 
cgit v1.2.3


From 3e0ddc4f3ff1436970e96e76f3df3c3b5f5173b6 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 9 Apr 2019 23:20:07 +0200
Subject: bpf: allow . char as part of the object name

Trivial addition to allow '.' aside from '_' as "special" characters
in the object name. Used to allow for substrings in maps from loader
side such as ".bss", ".data", ".rodata", but could also be useful for
other purposes.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/syscall.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index b3ce516e5a20..198c9680bf0d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -474,10 +474,10 @@ static int bpf_obj_name_cpy(char *dst, const char *src)
 	const char *end = src + BPF_OBJ_NAME_LEN;
 
 	memset(dst, 0, BPF_OBJ_NAME_LEN);
-
-	/* Copy all isalnum() and '_' char */
+	/* Copy all isalnum(), '_' and '.' chars. */
 	while (src < end && *src) {
-		if (!isalnum(*src) && *src != '_')
+		if (!isalnum(*src) &&
+		    *src != '_' && *src != '.')
 			return -EINVAL;
 		*dst++ = *src++;
 	}
-- 
cgit v1.2.3


From 1dc92851849cc2235a1efef8f8d5a9255efc5f13 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 9 Apr 2019 23:20:09 +0200
Subject: bpf: kernel side support for BTF Var and DataSec

This work adds kernel-side verification, logging and seq_show dumping
of BTF Var and DataSec kinds which are emitted with latest LLVM. The
following constraints apply:

BTF Var must have:

- Its kind_flag is 0
- Its vlen is 0
- Must point to a valid type
- Type must not resolve to a forward type
- Size of underlying type must be > 0
- Must have a valid name
- Can only be a source type, not sink or intermediate one
- Name may include dots (e.g. in case of static variables
  inside functions)
- Cannot be a member of a struct/union
- Linkage so far can either only be static or global/allocated

BTF DataSec must have:

- Its kind_flag is 0
- Its vlen cannot be 0
- Its size cannot be 0
- Must have a valid name
- Can only be a source type, not sink or intermediate one
- Name may include dots (e.g. to represent .bss, .data, .rodata etc)
- Cannot be a member of a struct/union
- Inner btf_var_secinfo array with {type,offset,size} triple
  must be sorted by offset in ascending order
- Type must always point to BTF Var
- BTF resolved size of Var must be <= size provided by triple
- DataSec size must be >= sum of triple sizes (thus holes
  are allowed)

btf_var_resolve(), btf_ptr_resolve() and btf_modifier_resolve()
are on a high level quite similar but each come with slight,
subtle differences. They could potentially be a bit refactored
in future which hasn't been done here to ease review.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/btf.c | 417 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 397 insertions(+), 20 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index bd3921b1514b..0cecf6bab61b 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -185,6 +185,16 @@
 	     i < btf_type_vlen(struct_type);				\
 	     i++, member++)
 
+#define for_each_vsi(i, struct_type, member)			\
+	for (i = 0, member = btf_type_var_secinfo(struct_type);	\
+	     i < btf_type_vlen(struct_type);			\
+	     i++, member++)
+
+#define for_each_vsi_from(i, from, struct_type, member)				\
+	for (i = from, member = btf_type_var_secinfo(struct_type) + from;	\
+	     i < btf_type_vlen(struct_type);					\
+	     i++, member++)
+
 static DEFINE_IDR(btf_idr);
 static DEFINE_SPINLOCK(btf_idr_lock);
 
@@ -262,6 +272,8 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_RESTRICT]	= "RESTRICT",
 	[BTF_KIND_FUNC]		= "FUNC",
 	[BTF_KIND_FUNC_PROTO]	= "FUNC_PROTO",
+	[BTF_KIND_VAR]		= "VAR",
+	[BTF_KIND_DATASEC]	= "DATASEC",
 };
 
 struct btf_kind_operations {
@@ -375,13 +387,36 @@ static bool btf_type_is_int(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
 }
 
+static bool btf_type_is_var(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
+}
+
+static bool btf_type_is_datasec(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
+}
+
+/* Types that act only as a source, not sink or intermediate
+ * type when resolving.
+ */
+static bool btf_type_is_resolve_source_only(const struct btf_type *t)
+{
+	return btf_type_is_var(t) ||
+	       btf_type_is_datasec(t);
+}
+
 /* What types need to be resolved?
  *
  * btf_type_is_modifier() is an obvious one.
  *
  * btf_type_is_struct() because its member refers to
  * another type (through member->type).
-
+ *
+ * btf_type_is_var() because the variable refers to
+ * another type. btf_type_is_datasec() holds multiple
+ * btf_type_is_var() types that need resolving.
+ *
  * btf_type_is_array() because its element (array->type)
  * refers to another type.  Array can be thought of a
  * special case of struct while array just has the same
@@ -390,9 +425,11 @@ static bool btf_type_is_int(const struct btf_type *t)
 static bool btf_type_needs_resolve(const struct btf_type *t)
 {
 	return btf_type_is_modifier(t) ||
-		btf_type_is_ptr(t) ||
-		btf_type_is_struct(t) ||
-		btf_type_is_array(t);
+	       btf_type_is_ptr(t) ||
+	       btf_type_is_struct(t) ||
+	       btf_type_is_array(t) ||
+	       btf_type_is_var(t) ||
+	       btf_type_is_datasec(t);
 }
 
 /* t->size can be used */
@@ -403,6 +440,7 @@ static bool btf_type_has_size(const struct btf_type *t)
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_DATASEC:
 		return true;
 	}
 
@@ -467,6 +505,16 @@ static const struct btf_enum *btf_type_enum(const struct btf_type *t)
 	return (const struct btf_enum *)(t + 1);
 }
 
+static const struct btf_var *btf_type_var(const struct btf_type *t)
+{
+	return (const struct btf_var *)(t + 1);
+}
+
+static const struct btf_var_secinfo *btf_type_var_secinfo(const struct btf_type *t)
+{
+	return (const struct btf_var_secinfo *)(t + 1);
+}
+
 static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
 {
 	return kind_ops[BTF_INFO_KIND(t->info)];
@@ -478,23 +526,31 @@ static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
 		offset < btf->hdr.str_len;
 }
 
-/* Only C-style identifier is permitted. This can be relaxed if
- * necessary.
- */
-static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
+static bool __btf_name_char_ok(char c, bool first, bool dot_ok)
+{
+	if ((first ? !isalpha(c) :
+		     !isalnum(c)) &&
+	    c != '_' &&
+	    ((c == '.' && !dot_ok) ||
+	      c != '.'))
+		return false;
+	return true;
+}
+
+static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok)
 {
 	/* offset must be valid */
 	const char *src = &btf->strings[offset];
 	const char *src_limit;
 
-	if (!isalpha(*src) && *src != '_')
+	if (!__btf_name_char_ok(*src, true, dot_ok))
 		return false;
 
 	/* set a limit on identifier length */
 	src_limit = src + KSYM_NAME_LEN;
 	src++;
 	while (*src && src < src_limit) {
-		if (!isalnum(*src) && *src != '_')
+		if (!__btf_name_char_ok(*src, false, dot_ok))
 			return false;
 		src++;
 	}
@@ -502,6 +558,19 @@ static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
 	return !*src;
 }
 
+/* Only C-style identifier is permitted. This can be relaxed if
+ * necessary.
+ */
+static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
+{
+	return __btf_name_valid(btf, offset, false);
+}
+
+static bool btf_name_valid_section(const struct btf *btf, u32 offset)
+{
+	return __btf_name_valid(btf, offset, true);
+}
+
 static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
 {
 	if (!offset)
@@ -697,6 +766,32 @@ static void btf_verifier_log_member(struct btf_verifier_env *env,
 	__btf_verifier_log(log, "\n");
 }
 
+__printf(4, 5)
+static void btf_verifier_log_vsi(struct btf_verifier_env *env,
+				 const struct btf_type *datasec_type,
+				 const struct btf_var_secinfo *vsi,
+				 const char *fmt, ...)
+{
+	struct bpf_verifier_log *log = &env->log;
+	va_list args;
+
+	if (!bpf_verifier_log_needed(log))
+		return;
+	if (env->phase != CHECK_META)
+		btf_verifier_log_type(env, datasec_type, NULL);
+
+	__btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
+			   vsi->type, vsi->offset, vsi->size);
+	if (fmt && *fmt) {
+		__btf_verifier_log(log, " ");
+		va_start(args, fmt);
+		bpf_verifier_vlog(log, fmt, args);
+		va_end(args);
+	}
+
+	__btf_verifier_log(log, "\n");
+}
+
 static void btf_verifier_log_hdr(struct btf_verifier_env *env,
 				 u32 btf_data_size)
 {
@@ -974,7 +1069,8 @@ const struct btf_type *btf_type_id_size(const struct btf *btf,
 	} else if (btf_type_is_ptr(size_type)) {
 		size = sizeof(void *);
 	} else {
-		if (WARN_ON_ONCE(!btf_type_is_modifier(size_type)))
+		if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
+				 !btf_type_is_var(size_type)))
 			return NULL;
 
 		size = btf->resolved_sizes[size_type_id];
@@ -1509,7 +1605,7 @@ static int btf_modifier_resolve(struct btf_verifier_env *env,
 	u32 next_type_size = 0;
 
 	next_type = btf_type_by_id(btf, next_type_id);
-	if (!next_type) {
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
 		btf_verifier_log_type(env, v->t, "Invalid type_id");
 		return -EINVAL;
 	}
@@ -1542,6 +1638,53 @@ static int btf_modifier_resolve(struct btf_verifier_env *env,
 	return 0;
 }
 
+static int btf_var_resolve(struct btf_verifier_env *env,
+			   const struct resolve_vertex *v)
+{
+	const struct btf_type *next_type;
+	const struct btf_type *t = v->t;
+	u32 next_type_id = t->type;
+	struct btf *btf = env->btf;
+	u32 next_type_size;
+
+	next_type = btf_type_by_id(btf, next_type_id);
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	if (!env_type_is_resolve_sink(env, next_type) &&
+	    !env_type_is_resolved(env, next_type_id))
+		return env_stack_push(env, next_type, next_type_id);
+
+	if (btf_type_is_modifier(next_type)) {
+		const struct btf_type *resolved_type;
+		u32 resolved_type_id;
+
+		resolved_type_id = next_type_id;
+		resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
+
+		if (btf_type_is_ptr(resolved_type) &&
+		    !env_type_is_resolve_sink(env, resolved_type) &&
+		    !env_type_is_resolved(env, resolved_type_id))
+			return env_stack_push(env, resolved_type,
+					      resolved_type_id);
+	}
+
+	/* We must resolve to something concrete at this point, no
+	 * forward types or similar that would resolve to size of
+	 * zero is allowed.
+	 */
+	if (!btf_type_id_size(btf, &next_type_id, &next_type_size)) {
+		btf_verifier_log_type(env, v->t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	env_stack_pop_resolved(env, next_type_id, next_type_size);
+
+	return 0;
+}
+
 static int btf_ptr_resolve(struct btf_verifier_env *env,
 			   const struct resolve_vertex *v)
 {
@@ -1551,7 +1694,7 @@ static int btf_ptr_resolve(struct btf_verifier_env *env,
 	struct btf *btf = env->btf;
 
 	next_type = btf_type_by_id(btf, next_type_id);
-	if (!next_type) {
+	if (!next_type || btf_type_is_resolve_source_only(next_type)) {
 		btf_verifier_log_type(env, v->t, "Invalid type_id");
 		return -EINVAL;
 	}
@@ -1609,6 +1752,15 @@ static void btf_modifier_seq_show(const struct btf *btf,
 	btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
 }
 
+static void btf_var_seq_show(const struct btf *btf, const struct btf_type *t,
+			     u32 type_id, void *data, u8 bits_offset,
+			     struct seq_file *m)
+{
+	t = btf_type_id_resolve(btf, &type_id);
+
+	btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m);
+}
+
 static void btf_ptr_seq_show(const struct btf *btf, const struct btf_type *t,
 			     u32 type_id, void *data, u8 bits_offset,
 			     struct seq_file *m)
@@ -1776,7 +1928,8 @@ static int btf_array_resolve(struct btf_verifier_env *env,
 	/* Check array->index_type */
 	index_type_id = array->index_type;
 	index_type = btf_type_by_id(btf, index_type_id);
-	if (btf_type_nosize_or_null(index_type)) {
+	if (btf_type_is_resolve_source_only(index_type) ||
+	    btf_type_nosize_or_null(index_type)) {
 		btf_verifier_log_type(env, v->t, "Invalid index");
 		return -EINVAL;
 	}
@@ -1795,7 +1948,8 @@ static int btf_array_resolve(struct btf_verifier_env *env,
 	/* Check array->type */
 	elem_type_id = array->type;
 	elem_type = btf_type_by_id(btf, elem_type_id);
-	if (btf_type_nosize_or_null(elem_type)) {
+	if (btf_type_is_resolve_source_only(elem_type) ||
+	    btf_type_nosize_or_null(elem_type)) {
 		btf_verifier_log_type(env, v->t,
 				      "Invalid elem");
 		return -EINVAL;
@@ -2016,7 +2170,8 @@ static int btf_struct_resolve(struct btf_verifier_env *env,
 		const struct btf_type *member_type = btf_type_by_id(env->btf,
 								member_type_id);
 
-		if (btf_type_nosize_or_null(member_type)) {
+		if (btf_type_is_resolve_source_only(member_type) ||
+		    btf_type_nosize_or_null(member_type)) {
 			btf_verifier_log_member(env, v->t, member,
 						"Invalid member");
 			return -EINVAL;
@@ -2411,6 +2566,222 @@ static struct btf_kind_operations func_ops = {
 	.seq_show = btf_df_seq_show,
 };
 
+static s32 btf_var_check_meta(struct btf_verifier_env *env,
+			      const struct btf_type *t,
+			      u32 meta_left)
+{
+	const struct btf_var *var;
+	u32 meta_needed = sizeof(*var);
+
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen != 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (!t->name_off ||
+	    !__btf_name_valid(env->btf, t->name_off, true)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	/* A var cannot be in type void */
+	if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
+		btf_verifier_log_type(env, t, "Invalid type_id");
+		return -EINVAL;
+	}
+
+	var = btf_type_var(t);
+	if (var->linkage != BTF_VAR_STATIC &&
+	    var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
+		btf_verifier_log_type(env, t, "Linkage not supported");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	return meta_needed;
+}
+
+static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
+{
+	const struct btf_var *var = btf_type_var(t);
+
+	btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
+}
+
+static const struct btf_kind_operations var_ops = {
+	.check_meta		= btf_var_check_meta,
+	.resolve		= btf_var_resolve,
+	.check_member		= btf_df_check_member,
+	.check_kflag_member	= btf_df_check_kflag_member,
+	.log_details		= btf_var_log,
+	.seq_show		= btf_var_seq_show,
+};
+
+static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
+				  const struct btf_type *t,
+				  u32 meta_left)
+{
+	const struct btf_var_secinfo *vsi;
+	u64 last_vsi_end_off = 0, sum = 0;
+	u32 i, meta_needed;
+
+	meta_needed = btf_type_vlen(t) * sizeof(*vsi);
+	if (meta_left < meta_needed) {
+		btf_verifier_log_basic(env, t,
+				       "meta_left:%u meta_needed:%u",
+				       meta_left, meta_needed);
+		return -EINVAL;
+	}
+
+	if (!btf_type_vlen(t)) {
+		btf_verifier_log_type(env, t, "vlen == 0");
+		return -EINVAL;
+	}
+
+	if (!t->size) {
+		btf_verifier_log_type(env, t, "size == 0");
+		return -EINVAL;
+	}
+
+	if (btf_type_kflag(t)) {
+		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+		return -EINVAL;
+	}
+
+	if (!t->name_off ||
+	    !btf_name_valid_section(env->btf, t->name_off)) {
+		btf_verifier_log_type(env, t, "Invalid name");
+		return -EINVAL;
+	}
+
+	btf_verifier_log_type(env, t, NULL);
+
+	for_each_vsi(i, t, vsi) {
+		/* A var cannot be in type void */
+		if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid type_id");
+			return -EINVAL;
+		}
+
+		if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid offset");
+			return -EINVAL;
+		}
+
+		if (!vsi->size || vsi->size > t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid size");
+			return -EINVAL;
+		}
+
+		last_vsi_end_off = vsi->offset + vsi->size;
+		if (last_vsi_end_off > t->size) {
+			btf_verifier_log_vsi(env, t, vsi,
+					     "Invalid offset+size");
+			return -EINVAL;
+		}
+
+		btf_verifier_log_vsi(env, t, vsi, NULL);
+		sum += vsi->size;
+	}
+
+	if (t->size < sum) {
+		btf_verifier_log_type(env, t, "Invalid btf_info size");
+		return -EINVAL;
+	}
+
+	return meta_needed;
+}
+
+static int btf_datasec_resolve(struct btf_verifier_env *env,
+			       const struct resolve_vertex *v)
+{
+	const struct btf_var_secinfo *vsi;
+	struct btf *btf = env->btf;
+	u16 i;
+
+	for_each_vsi_from(i, v->next_member, v->t, vsi) {
+		u32 var_type_id = vsi->type, type_id, type_size = 0;
+		const struct btf_type *var_type = btf_type_by_id(env->btf,
+								 var_type_id);
+		if (!var_type || !btf_type_is_var(var_type)) {
+			btf_verifier_log_vsi(env, v->t, vsi,
+					     "Not a VAR kind member");
+			return -EINVAL;
+		}
+
+		if (!env_type_is_resolve_sink(env, var_type) &&
+		    !env_type_is_resolved(env, var_type_id)) {
+			env_stack_set_next_member(env, i + 1);
+			return env_stack_push(env, var_type, var_type_id);
+		}
+
+		type_id = var_type->type;
+		if (!btf_type_id_size(btf, &type_id, &type_size)) {
+			btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
+			return -EINVAL;
+		}
+
+		if (vsi->size < type_size) {
+			btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
+			return -EINVAL;
+		}
+	}
+
+	env_stack_pop_resolved(env, 0, 0);
+	return 0;
+}
+
+static void btf_datasec_log(struct btf_verifier_env *env,
+			    const struct btf_type *t)
+{
+	btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+static void btf_datasec_seq_show(const struct btf *btf,
+				 const struct btf_type *t, u32 type_id,
+				 void *data, u8 bits_offset,
+				 struct seq_file *m)
+{
+	const struct btf_var_secinfo *vsi;
+	const struct btf_type *var;
+	u32 i;
+
+	seq_printf(m, "section (\"%s\") = {", __btf_name_by_offset(btf, t->name_off));
+	for_each_vsi(i, t, vsi) {
+		var = btf_type_by_id(btf, vsi->type);
+		if (i)
+			seq_puts(m, ",");
+		btf_type_ops(var)->seq_show(btf, var, vsi->type,
+					    data + vsi->offset, bits_offset, m);
+	}
+	seq_puts(m, "}");
+}
+
+static const struct btf_kind_operations datasec_ops = {
+	.check_meta		= btf_datasec_check_meta,
+	.resolve		= btf_datasec_resolve,
+	.check_member		= btf_df_check_member,
+	.check_kflag_member	= btf_df_check_kflag_member,
+	.log_details		= btf_datasec_log,
+	.seq_show		= btf_datasec_seq_show,
+};
+
 static int btf_func_proto_check(struct btf_verifier_env *env,
 				const struct btf_type *t)
 {
@@ -2542,6 +2913,8 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
 	[BTF_KIND_RESTRICT] = &modifier_ops,
 	[BTF_KIND_FUNC] = &func_ops,
 	[BTF_KIND_FUNC_PROTO] = &func_proto_ops,
+	[BTF_KIND_VAR] = &var_ops,
+	[BTF_KIND_DATASEC] = &datasec_ops,
 };
 
 static s32 btf_check_meta(struct btf_verifier_env *env,
@@ -2622,13 +2995,17 @@ static bool btf_resolve_valid(struct btf_verifier_env *env,
 	if (!env_type_is_resolved(env, type_id))
 		return false;
 
-	if (btf_type_is_struct(t))
+	if (btf_type_is_struct(t) || btf_type_is_datasec(t))
 		return !btf->resolved_ids[type_id] &&
-			!btf->resolved_sizes[type_id];
+		       !btf->resolved_sizes[type_id];
 
-	if (btf_type_is_modifier(t) || btf_type_is_ptr(t)) {
+	if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
+	    btf_type_is_var(t)) {
 		t = btf_type_id_resolve(btf, &type_id);
-		return t && !btf_type_is_modifier(t);
+		return t &&
+		       !btf_type_is_modifier(t) &&
+		       !btf_type_is_var(t) &&
+		       !btf_type_is_datasec(t);
 	}
 
 	if (btf_type_is_array(t)) {
-- 
cgit v1.2.3


From 2824ecb7010f6a20e9a4140512b798469ab066cc Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Tue, 9 Apr 2019 23:20:10 +0200
Subject: bpf: allow for key-less BTF in array map

Given we'll be reusing BPF array maps for global data/bss/rodata
sections, we need a way to associate BTF DataSec type as its map
value type. In usual cases we have this ugly BPF_ANNOTATE_KV_PAIR()
macro hack e.g. via 38d5d3b3d5db ("bpf: Introduce BPF_ANNOTATE_KV_PAIR")
to get initial map to type association going. While more use cases
for it are discouraged, this also won't work for global data since
the use of array map is a BPF loader detail and therefore unknown
at compilation time. For array maps with just a single entry we make
an exception in terms of BTF in that key type is declared optional
if value type is of DataSec type. The latter LLVM is guaranteed to
emit and it also aligns with how we regard global data maps as just
a plain buffer area reusing existing map facilities for allowing
things like introspection with existing tools.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/arraymap.c | 15 ++++++++++++++-
 kernel/bpf/btf.c      |  2 +-
 kernel/bpf/syscall.c  | 15 +++++++++++----
 3 files changed, 26 insertions(+), 6 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 217b10bd9f48..584636c9e2eb 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -391,7 +391,8 @@ static void array_map_seq_show_elem(struct bpf_map *map, void *key,
 		return;
 	}
 
-	seq_printf(m, "%u: ", *(u32 *)key);
+	if (map->btf_key_type_id)
+		seq_printf(m, "%u: ", *(u32 *)key);
 	btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
 	seq_puts(m, "\n");
 
@@ -428,6 +429,18 @@ static int array_map_check_btf(const struct bpf_map *map,
 {
 	u32 int_data;
 
+	/* One exception for keyless BTF: .bss/.data/.rodata map */
+	if (btf_type_is_void(key_type)) {
+		if (map->map_type != BPF_MAP_TYPE_ARRAY ||
+		    map->max_entries != 1)
+			return -EINVAL;
+
+		if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
+			return -EINVAL;
+
+		return 0;
+	}
+
 	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
 		return -EINVAL;
 
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 0cecf6bab61b..cad09858a5f2 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -326,7 +326,7 @@ static bool btf_type_is_modifier(const struct btf_type *t)
 	return false;
 }
 
-static bool btf_type_is_void(const struct btf_type *t)
+bool btf_type_is_void(const struct btf_type *t)
 {
 	return t == &btf_void;
 }
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 198c9680bf0d..438199e2eca4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -504,9 +504,16 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 	u32 key_size, value_size;
 	int ret = 0;
 
-	key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
-	if (!key_type || key_size != map->key_size)
-		return -EINVAL;
+	/* Some maps allow key to be unspecified. */
+	if (btf_key_id) {
+		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
+		if (!key_type || key_size != map->key_size)
+			return -EINVAL;
+	} else {
+		key_type = btf_type_by_id(btf, 0);
+		if (!map->ops->map_check_btf)
+			return -EINVAL;
+	}
 
 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
 	if (!value_type || value_size != map->value_size)
@@ -573,7 +580,7 @@ static int map_create(union bpf_attr *attr)
 	if (attr->btf_key_type_id || attr->btf_value_type_id) {
 		struct btf *btf;
 
-		if (!attr->btf_key_type_id || !attr->btf_value_type_id) {
+		if (!attr->btf_value_type_id) {
 			err = -EINVAL;
 			goto free_map_nouncharge;
 		}
-- 
cgit v1.2.3


From b0b9395d865e3060d97658fbc9ba3f77fecc8da1 Mon Sep 17 00:00:00 2001
From: Stanislav Fomichev <sdf@google.com>
Date: Tue, 9 Apr 2019 11:49:09 -0700
Subject: bpf: support input __sk_buff context in BPF_PROG_TEST_RUN

Add new set of arguments to bpf_attr for BPF_PROG_TEST_RUN:
* ctx_in/ctx_size_in - input context
* ctx_out/ctx_size_out - output context

The intended use case is to pass some meta data to the test runs that
operate on skb (this has being brought up on recent LPC).

For programs that use bpf_prog_test_run_skb, support __sk_buff input and
output. Initially, from input __sk_buff, copy _only_ cb and priority into
skb, all other non-zero fields are prohibited (with EINVAL).
If the user has set ctx_out/ctx_size_out, copy the potentially modified
__sk_buff back to the userspace.

We require all fields of input __sk_buff except the ones we explicitly
support to be set to zero. The expectation is that in the future we might
add support for more fields and we want to fail explicitly if the user
runs the program on the kernel where we don't yet support them.

The API is intentionally vague (i.e. we don't explicitly add __sk_buff
to bpf_attr, but ctx_in) to potentially let other test_run types use
this interface in the future (this can be xdp_md for xdp types for
example).

v4:
  * don't copy more than allowed in bpf_ctx_init [Martin]

v3:
  * handle case where ctx_in is NULL, but ctx_out is not [Martin]
  * convert size==0 checks to ptr==NULL checks and add some extra ptr
    checks [Martin]

v2:
  * Addressed comments from Martin Lau

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/syscall.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 438199e2eca4..d995eedfdd16 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2009,7 +2009,7 @@ static int bpf_prog_query(const union bpf_attr *attr,
 	return cgroup_bpf_prog_query(attr, uattr);
 }
 
-#define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
+#define BPF_PROG_TEST_RUN_LAST_FIELD test.ctx_out
 
 static int bpf_prog_test_run(const union bpf_attr *attr,
 			     union bpf_attr __user *uattr)
@@ -2022,6 +2022,14 @@ static int bpf_prog_test_run(const union bpf_attr *attr,
 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
 		return -EINVAL;
 
+	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
+	    (!attr->test.ctx_size_in && attr->test.ctx_in))
+		return -EINVAL;
+
+	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
+	    (!attr->test.ctx_size_out && attr->test.ctx_out))
+		return -EINVAL;
+
 	prog = bpf_prog_get(attr->test.prog_fd);
 	if (IS_ERR(prog))
 		return PTR_ERR(prog);
-- 
cgit v1.2.3


From b1cd609d9b517f01867c211bd520cc805db3068a Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Tue, 12 Mar 2019 09:27:09 -0700
Subject: bpf: Add base proto function for cgroup-bpf programs

Currently kernel/bpf/cgroup.c contains only one program type and one
proto function cgroup_dev_func_proto(). It'd be useful to have base
proto function that can be reused for new cgroup-bpf program types
coming soon.

Introduce cgroup_base_func_proto().

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 4e807973aa80..f6cd38746df2 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -701,7 +701,7 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
 EXPORT_SYMBOL(__cgroup_bpf_check_dev_permission);
 
 static const struct bpf_func_proto *
-cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
 	switch (func_id) {
 	case BPF_FUNC_map_lookup_elem:
@@ -725,6 +725,12 @@ cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	}
 }
 
+static const struct bpf_func_proto *
+cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	return cgroup_base_func_proto(func_id, prog);
+}
+
 static bool cgroup_dev_is_valid_access(int off, int size,
 				       enum bpf_access_type type,
 				       const struct bpf_prog *prog,
-- 
cgit v1.2.3


From 7b146cebe30cb481b0f70d85779da938da818637 Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Wed, 27 Feb 2019 12:59:24 -0800
Subject: bpf: Sysctl hook

Containerized applications may run as root and it may create problems
for whole host. Specifically such applications may change a sysctl and
affect applications in other containers.

Furthermore in existing infrastructure it may not be possible to just
completely disable writing to sysctl, instead such a process should be
gradual with ability to log what sysctl are being changed by a
container, investigate, limit the set of writable sysctl to currently
used ones (so that new ones can not be changed) and eventually reduce
this set to zero.

The patch introduces new program type BPF_PROG_TYPE_CGROUP_SYSCTL and
attach type BPF_CGROUP_SYSCTL to solve these problems on cgroup basis.

New program type has access to following minimal context:
	struct bpf_sysctl {
		__u32	write;
	};

Where @write indicates whether sysctl is being read (= 0) or written (=
1).

Helpers to access sysctl name and value will be introduced separately.

BPF_CGROUP_SYSCTL attach point is added to sysctl code right before
passing control to ctl_table->proc_handler so that BPF program can
either allow or deny access to sysctl.

Suggested-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c   | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/bpf/syscall.c  |  7 ++++
 kernel/bpf/verifier.c |  1 +
 3 files changed, 100 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index f6cd38746df2..610491b5f0aa 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -11,7 +11,9 @@
 #include <linux/kernel.h>
 #include <linux/atomic.h>
 #include <linux/cgroup.h>
+#include <linux/filter.h>
 #include <linux/slab.h>
+#include <linux/sysctl.h>
 #include <linux/bpf.h>
 #include <linux/bpf-cgroup.h>
 #include <net/sock.h>
@@ -768,3 +770,93 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
 	.get_func_proto		= cgroup_dev_func_proto,
 	.is_valid_access	= cgroup_dev_is_valid_access,
 };
+
+/**
+ * __cgroup_bpf_run_filter_sysctl - Run a program on sysctl
+ *
+ * @head: sysctl table header
+ * @table: sysctl table
+ * @write: sysctl is being read (= 0) or written (= 1)
+ * @type: type of program to be executed
+ *
+ * Program is run when sysctl is being accessed, either read or written, and
+ * can allow or deny such access.
+ *
+ * This function will return %-EPERM if an attached program is found and
+ * returned value != 1 during execution. In all other cases 0 is returned.
+ */
+int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
+				   struct ctl_table *table, int write,
+				   enum bpf_attach_type type)
+{
+	struct bpf_sysctl_kern ctx = {
+		.head = head,
+		.table = table,
+		.write = write,
+	};
+	struct cgroup *cgrp;
+	int ret;
+
+	rcu_read_lock();
+	cgrp = task_dfl_cgroup(current);
+	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN);
+	rcu_read_unlock();
+
+	return ret == 1 ? 0 : -EPERM;
+}
+EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl);
+
+static const struct bpf_func_proto *
+sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	return cgroup_base_func_proto(func_id, prog);
+}
+
+static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
+				   const struct bpf_prog *prog,
+				   struct bpf_insn_access_aux *info)
+{
+	const int size_default = sizeof(__u32);
+
+	if (off < 0 || off + size > sizeof(struct bpf_sysctl) ||
+	    off % size || type != BPF_READ)
+		return false;
+
+	switch (off) {
+	case offsetof(struct bpf_sysctl, write):
+		bpf_ctx_record_field_size(info, size_default);
+		return bpf_ctx_narrow_access_ok(off, size, size_default);
+	default:
+		return false;
+	}
+}
+
+static u32 sysctl_convert_ctx_access(enum bpf_access_type type,
+				     const struct bpf_insn *si,
+				     struct bpf_insn *insn_buf,
+				     struct bpf_prog *prog, u32 *target_size)
+{
+	struct bpf_insn *insn = insn_buf;
+
+	switch (si->off) {
+	case offsetof(struct bpf_sysctl, write):
+		*insn++ = BPF_LDX_MEM(
+			BPF_SIZE(si->code), si->dst_reg, si->src_reg,
+			bpf_target_off(struct bpf_sysctl_kern, write,
+				       FIELD_SIZEOF(struct bpf_sysctl_kern,
+						    write),
+				       target_size));
+		break;
+	}
+
+	return insn - insn_buf;
+}
+
+const struct bpf_verifier_ops cg_sysctl_verifier_ops = {
+	.get_func_proto		= sysctl_func_proto,
+	.is_valid_access	= sysctl_is_valid_access,
+	.convert_ctx_access	= sysctl_convert_ctx_access,
+};
+
+const struct bpf_prog_ops cg_sysctl_prog_ops = {
+};
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index d995eedfdd16..92c9b8a32b50 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1888,6 +1888,9 @@ static int bpf_prog_attach(const union bpf_attr *attr)
 	case BPF_FLOW_DISSECTOR:
 		ptype = BPF_PROG_TYPE_FLOW_DISSECTOR;
 		break;
+	case BPF_CGROUP_SYSCTL:
+		ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1966,6 +1969,9 @@ static int bpf_prog_detach(const union bpf_attr *attr)
 		return lirc_prog_detach(attr);
 	case BPF_FLOW_DISSECTOR:
 		return skb_flow_dissector_bpf_prog_detach(attr);
+	case BPF_CGROUP_SYSCTL:
+		ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1999,6 +2005,7 @@ static int bpf_prog_query(const union bpf_attr *attr,
 	case BPF_CGROUP_UDP6_SENDMSG:
 	case BPF_CGROUP_SOCK_OPS:
 	case BPF_CGROUP_DEVICE:
+	case BPF_CGROUP_SYSCTL:
 		break;
 	case BPF_LIRC_MODE2:
 		return lirc_prog_query(attr, uattr);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index f25b7c9c20ba..20808e3c95a8 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5267,6 +5267,7 @@ static int check_return_code(struct bpf_verifier_env *env)
 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
 	case BPF_PROG_TYPE_SOCK_OPS:
 	case BPF_PROG_TYPE_CGROUP_DEVICE:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
 		break;
 	default:
 		return 0;
-- 
cgit v1.2.3


From 808649fb787d918a48a360a668ee4ee9023f0c11 Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Wed, 27 Feb 2019 13:28:48 -0800
Subject: bpf: Introduce bpf_sysctl_get_name helper

Add bpf_sysctl_get_name() helper to copy sysctl name (/proc/sys/ entry)
into provided by BPF_PROG_TYPE_CGROUP_SYSCTL program buffer.

By default full name (w/o /proc/sys/) is copied, e.g. "net/ipv4/tcp_mem".

If BPF_F_SYSCTL_BASE_NAME flag is set, only base name will be copied,
e.g. "tcp_mem".

Documentation for the new helper is provided in bpf.h UAPI.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 610491b5f0aa..a68387043244 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -14,6 +14,7 @@
 #include <linux/filter.h>
 #include <linux/slab.h>
 #include <linux/sysctl.h>
+#include <linux/string.h>
 #include <linux/bpf.h>
 #include <linux/bpf-cgroup.h>
 #include <net/sock.h>
@@ -806,10 +807,77 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 }
 EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl);
 
+static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
+			      size_t *lenp)
+{
+	ssize_t tmp_ret = 0, ret;
+
+	if (dir->header.parent) {
+		tmp_ret = sysctl_cpy_dir(dir->header.parent, bufp, lenp);
+		if (tmp_ret < 0)
+			return tmp_ret;
+	}
+
+	ret = strscpy(*bufp, dir->header.ctl_table[0].procname, *lenp);
+	if (ret < 0)
+		return ret;
+	*bufp += ret;
+	*lenp -= ret;
+	ret += tmp_ret;
+
+	/* Avoid leading slash. */
+	if (!ret)
+		return ret;
+
+	tmp_ret = strscpy(*bufp, "/", *lenp);
+	if (tmp_ret < 0)
+		return tmp_ret;
+	*bufp += tmp_ret;
+	*lenp -= tmp_ret;
+
+	return ret + tmp_ret;
+}
+
+BPF_CALL_4(bpf_sysctl_get_name, struct bpf_sysctl_kern *, ctx, char *, buf,
+	   size_t, buf_len, u64, flags)
+{
+	ssize_t tmp_ret = 0, ret;
+
+	if (!buf)
+		return -EINVAL;
+
+	if (!(flags & BPF_F_SYSCTL_BASE_NAME)) {
+		if (!ctx->head)
+			return -EINVAL;
+		tmp_ret = sysctl_cpy_dir(ctx->head->parent, &buf, &buf_len);
+		if (tmp_ret < 0)
+			return tmp_ret;
+	}
+
+	ret = strscpy(buf, ctx->table->procname, buf_len);
+
+	return ret < 0 ? ret : tmp_ret + ret;
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
+	.func		= bpf_sysctl_get_name,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+	.arg4_type	= ARG_ANYTHING,
+};
+
 static const struct bpf_func_proto *
 sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
-	return cgroup_base_func_proto(func_id, prog);
+	switch (func_id) {
+	case BPF_FUNC_sysctl_get_name:
+		return &bpf_sysctl_get_name_proto;
+	default:
+		return cgroup_base_func_proto(func_id, prog);
+	}
 }
 
 static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
-- 
cgit v1.2.3


From 1d11b3016cec4ed9770b98e82a61708c8f4926e7 Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Thu, 28 Feb 2019 19:22:15 -0800
Subject: bpf: Introduce bpf_sysctl_get_current_value helper

Add bpf_sysctl_get_current_value() helper to copy current sysctl value
into provided by BPF_PROG_TYPE_CGROUP_SYSCTL program buffer.

It provides same string as user space can see by reading corresponding
file in /proc/sys/, including new line, etc.

Documentation for the new helper is provided in bpf.h UAPI.

Since current value is kept in ctl_table->data in a parsed form,
ctl_table->proc_handler() with write=0 is called to read that data and
convert it to a string. Such a string can later be parsed by a program
using helpers that will be introduced separately.

Unfortunately it's not trivial to provide API to access parsed data due to
variety of data representations (string, intvec, uintvec, ulongvec,
custom structures, even NULL, etc). Instead it's assumed that user know
how to handle specific sysctl they're interested in and appropriate
helpers can be used.

Since ctl_table->proc_handler() expects __user buffer, conversion to
__user happens for kernel allocated one where the value is stored.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index a68387043244..c6b2cf29a54b 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -794,15 +794,37 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 		.head = head,
 		.table = table,
 		.write = write,
+		.cur_val = NULL,
+		.cur_len = PAGE_SIZE,
 	};
 	struct cgroup *cgrp;
 	int ret;
 
+	ctx.cur_val = kmalloc_track_caller(ctx.cur_len, GFP_KERNEL);
+	if (ctx.cur_val) {
+		mm_segment_t old_fs;
+		loff_t pos = 0;
+
+		old_fs = get_fs();
+		set_fs(KERNEL_DS);
+		if (table->proc_handler(table, 0, (void __user *)ctx.cur_val,
+					&ctx.cur_len, &pos)) {
+			/* Let BPF program decide how to proceed. */
+			ctx.cur_len = 0;
+		}
+		set_fs(old_fs);
+	} else {
+		/* Let BPF program decide how to proceed. */
+		ctx.cur_len = 0;
+	}
+
 	rcu_read_lock();
 	cgrp = task_dfl_cgroup(current);
 	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN);
 	rcu_read_unlock();
 
+	kfree(ctx.cur_val);
+
 	return ret == 1 ? 0 : -EPERM;
 }
 EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl);
@@ -869,12 +891,55 @@ static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
 	.arg4_type	= ARG_ANYTHING,
 };
 
+static int copy_sysctl_value(char *dst, size_t dst_len, char *src,
+			     size_t src_len)
+{
+	if (!dst)
+		return -EINVAL;
+
+	if (!dst_len)
+		return -E2BIG;
+
+	if (!src || !src_len) {
+		memset(dst, 0, dst_len);
+		return -EINVAL;
+	}
+
+	memcpy(dst, src, min(dst_len, src_len));
+
+	if (dst_len > src_len) {
+		memset(dst + src_len, '\0', dst_len - src_len);
+		return src_len;
+	}
+
+	dst[dst_len - 1] = '\0';
+
+	return -E2BIG;
+}
+
+BPF_CALL_3(bpf_sysctl_get_current_value, struct bpf_sysctl_kern *, ctx,
+	   char *, buf, size_t, buf_len)
+{
+	return copy_sysctl_value(buf, buf_len, ctx->cur_val, ctx->cur_len);
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_current_value_proto = {
+	.func		= bpf_sysctl_get_current_value,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+};
+
 static const struct bpf_func_proto *
 sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
 	switch (func_id) {
 	case BPF_FUNC_sysctl_get_name:
 		return &bpf_sysctl_get_name_proto;
+	case BPF_FUNC_sysctl_get_current_value:
+		return &bpf_sysctl_get_current_value_proto;
 	default:
 		return cgroup_base_func_proto(func_id, prog);
 	}
-- 
cgit v1.2.3


From 4e63acdff864654cee0ac5aaeda3913798ee78f6 Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Thu, 7 Mar 2019 18:38:43 -0800
Subject: bpf: Introduce bpf_sysctl_{get,set}_new_value helpers

Add helpers to work with new value being written to sysctl by user
space.

bpf_sysctl_get_new_value() copies value being written to sysctl into
provided buffer.

bpf_sysctl_set_new_value() overrides new value being written by user
space with a one from provided buffer. Buffer should contain string
representation of the value, similar to what can be seen in /proc/sys/.

Both helpers can be used only on sysctl write.

File position matters and can be managed by an interface that will be
introduced separately. E.g. if user space calls sys_write to a file in
/proc/sys/ at file position = X, where X > 0, then the value set by
bpf_sysctl_set_new_value() will be written starting from X. If program
wants to override whole value with specified buffer, file position has
to be set to zero.

Documentation for the new helpers is provided in bpf.h UAPI.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index c6b2cf29a54b..ba4e21986760 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -778,6 +778,13 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  * @head: sysctl table header
  * @table: sysctl table
  * @write: sysctl is being read (= 0) or written (= 1)
+ * @buf: pointer to buffer passed by user space
+ * @pcount: value-result argument: value is size of buffer pointed to by @buf,
+ *	result is size of @new_buf if program set new value, initial value
+ *	otherwise
+ * @new_buf: pointer to pointer to new buffer that will be allocated if program
+ *	overrides new value provided by user space on sysctl write
+ *	NOTE: it's caller responsibility to free *new_buf if it was set
  * @type: type of program to be executed
  *
  * Program is run when sysctl is being accessed, either read or written, and
@@ -788,7 +795,8 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  */
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   struct ctl_table *table, int write,
-				   enum bpf_attach_type type)
+				   void __user *buf, size_t *pcount,
+				   void **new_buf, enum bpf_attach_type type)
 {
 	struct bpf_sysctl_kern ctx = {
 		.head = head,
@@ -796,6 +804,9 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 		.write = write,
 		.cur_val = NULL,
 		.cur_len = PAGE_SIZE,
+		.new_val = NULL,
+		.new_len = 0,
+		.new_updated = 0,
 	};
 	struct cgroup *cgrp;
 	int ret;
@@ -818,6 +829,18 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 		ctx.cur_len = 0;
 	}
 
+	if (write && buf && *pcount) {
+		/* BPF program should be able to override new value with a
+		 * buffer bigger than provided by user.
+		 */
+		ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
+		ctx.new_len = min(PAGE_SIZE, *pcount);
+		if (!ctx.new_val ||
+		    copy_from_user(ctx.new_val, buf, ctx.new_len))
+			/* Let BPF program decide how to proceed. */
+			ctx.new_len = 0;
+	}
+
 	rcu_read_lock();
 	cgrp = task_dfl_cgroup(current);
 	ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN);
@@ -825,6 +848,13 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 
 	kfree(ctx.cur_val);
 
+	if (ret == 1 && ctx.new_updated) {
+		*new_buf = ctx.new_val;
+		*pcount = ctx.new_len;
+	} else {
+		kfree(ctx.new_val);
+	}
+
 	return ret == 1 ? 0 : -EPERM;
 }
 EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl);
@@ -932,6 +962,51 @@ static const struct bpf_func_proto bpf_sysctl_get_current_value_proto = {
 	.arg3_type	= ARG_CONST_SIZE,
 };
 
+BPF_CALL_3(bpf_sysctl_get_new_value, struct bpf_sysctl_kern *, ctx, char *, buf,
+	   size_t, buf_len)
+{
+	if (!ctx->write) {
+		if (buf && buf_len)
+			memset(buf, '\0', buf_len);
+		return -EINVAL;
+	}
+	return copy_sysctl_value(buf, buf_len, ctx->new_val, ctx->new_len);
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_new_value_proto = {
+	.func		= bpf_sysctl_get_new_value,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+};
+
+BPF_CALL_3(bpf_sysctl_set_new_value, struct bpf_sysctl_kern *, ctx,
+	   const char *, buf, size_t, buf_len)
+{
+	if (!ctx->write || !ctx->new_val || !ctx->new_len || !buf || !buf_len)
+		return -EINVAL;
+
+	if (buf_len > PAGE_SIZE - 1)
+		return -E2BIG;
+
+	memcpy(ctx->new_val, buf, buf_len);
+	ctx->new_len = buf_len;
+	ctx->new_updated = 1;
+
+	return 0;
+}
+
+static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = {
+	.func		= bpf_sysctl_set_new_value,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_PTR_TO_MEM,
+	.arg3_type	= ARG_CONST_SIZE,
+};
+
 static const struct bpf_func_proto *
 sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -940,6 +1015,10 @@ sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_sysctl_get_name_proto;
 	case BPF_FUNC_sysctl_get_current_value:
 		return &bpf_sysctl_get_current_value_proto;
+	case BPF_FUNC_sysctl_get_new_value:
+		return &bpf_sysctl_get_new_value_proto;
+	case BPF_FUNC_sysctl_set_new_value:
+		return &bpf_sysctl_set_new_value_proto;
 	default:
 		return cgroup_base_func_proto(func_id, prog);
 	}
-- 
cgit v1.2.3


From e1550bfe0de47e30484ba91de1e50a91ec1c31f5 Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Thu, 7 Mar 2019 18:50:52 -0800
Subject: bpf: Add file_pos field to bpf_sysctl ctx

Add file_pos field to bpf_sysctl context to read and write sysctl file
position at which sysctl is being accessed (read or written).

The field can be used to e.g. override whole sysctl value on write to
sysctl even when sys_write is called by user space with file_pos > 0. Or
BPF program may reject such accesses.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 51 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index ba4e21986760..b2adf22139b3 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -782,6 +782,9 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  * @pcount: value-result argument: value is size of buffer pointed to by @buf,
  *	result is size of @new_buf if program set new value, initial value
  *	otherwise
+ * @ppos: value-result argument: value is position at which read from or write
+ *	to sysctl is happening, result is new position if program overrode it,
+ *	initial value otherwise
  * @new_buf: pointer to pointer to new buffer that will be allocated if program
  *	overrides new value provided by user space on sysctl write
  *	NOTE: it's caller responsibility to free *new_buf if it was set
@@ -796,12 +799,14 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   struct ctl_table *table, int write,
 				   void __user *buf, size_t *pcount,
-				   void **new_buf, enum bpf_attach_type type)
+				   loff_t *ppos, void **new_buf,
+				   enum bpf_attach_type type)
 {
 	struct bpf_sysctl_kern ctx = {
 		.head = head,
 		.table = table,
 		.write = write,
+		.ppos = ppos,
 		.cur_val = NULL,
 		.cur_len = PAGE_SIZE,
 		.new_val = NULL,
@@ -1030,14 +1035,22 @@ static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
 {
 	const int size_default = sizeof(__u32);
 
-	if (off < 0 || off + size > sizeof(struct bpf_sysctl) ||
-	    off % size || type != BPF_READ)
+	if (off < 0 || off + size > sizeof(struct bpf_sysctl) || off % size)
 		return false;
 
 	switch (off) {
 	case offsetof(struct bpf_sysctl, write):
+		if (type != BPF_READ)
+			return false;
 		bpf_ctx_record_field_size(info, size_default);
 		return bpf_ctx_narrow_access_ok(off, size, size_default);
+	case offsetof(struct bpf_sysctl, file_pos):
+		if (type == BPF_READ) {
+			bpf_ctx_record_field_size(info, size_default);
+			return bpf_ctx_narrow_access_ok(off, size, size_default);
+		} else {
+			return size == size_default;
+		}
 	default:
 		return false;
 	}
@@ -1059,6 +1072,41 @@ static u32 sysctl_convert_ctx_access(enum bpf_access_type type,
 						    write),
 				       target_size));
 		break;
+	case offsetof(struct bpf_sysctl, file_pos):
+		/* ppos is a pointer so it should be accessed via indirect
+		 * loads and stores. Also for stores additional temporary
+		 * register is used since neither src_reg nor dst_reg can be
+		 * overridden.
+		 */
+		if (type == BPF_WRITE) {
+			int treg = BPF_REG_9;
+
+			if (si->src_reg == treg || si->dst_reg == treg)
+				--treg;
+			if (si->src_reg == treg || si->dst_reg == treg)
+				--treg;
+			*insn++ = BPF_STX_MEM(
+				BPF_DW, si->dst_reg, treg,
+				offsetof(struct bpf_sysctl_kern, tmp_reg));
+			*insn++ = BPF_LDX_MEM(
+				BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
+				treg, si->dst_reg,
+				offsetof(struct bpf_sysctl_kern, ppos));
+			*insn++ = BPF_STX_MEM(
+				BPF_SIZEOF(u32), treg, si->src_reg, 0);
+			*insn++ = BPF_LDX_MEM(
+				BPF_DW, treg, si->dst_reg,
+				offsetof(struct bpf_sysctl_kern, tmp_reg));
+		} else {
+			*insn++ = BPF_LDX_MEM(
+				BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
+				si->dst_reg, si->src_reg,
+				offsetof(struct bpf_sysctl_kern, ppos));
+			*insn++ = BPF_LDX_MEM(
+				BPF_SIZE(si->code), si->dst_reg, si->dst_reg, 0);
+		}
+		*target_size = sizeof(u32);
+		break;
 	}
 
 	return insn - insn_buf;
-- 
cgit v1.2.3


From 57c3bb725a3dd97d960d7e1cd0845d88de53217f Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Mon, 18 Mar 2019 16:57:10 -0700
Subject: bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types

Currently the way to pass result from BPF helper to BPF program is to
provide memory area defined by pointer and size: func(void *, size_t).

It works great for generic use-case, but for simple types, such as int,
it's overkill and consumes two arguments when it could use just one.

Introduce new argument types ARG_PTR_TO_INT and ARG_PTR_TO_LONG to be
able to pass result from helper to program via pointer to int and long
correspondingly: func(int *) or func(long *).

New argument types are similar to ARG_PTR_TO_MEM with the following
differences:
* they don't require corresponding ARG_CONST_SIZE argument, predefined
  access sizes are used instead (32bit for int, 64bit for long);
* it's possible to use more than one such an argument in a helper;
* provided pointers have to be aligned.

It's easy to introduce similar ARG_PTR_TO_CHAR and ARG_PTR_TO_SHORT
argument types. It's not done due to lack of use-case though.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 20808e3c95a8..15ab6fa817ce 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2462,6 +2462,22 @@ static bool arg_type_is_mem_size(enum bpf_arg_type type)
 	       type == ARG_CONST_SIZE_OR_ZERO;
 }
 
+static bool arg_type_is_int_ptr(enum bpf_arg_type type)
+{
+	return type == ARG_PTR_TO_INT ||
+	       type == ARG_PTR_TO_LONG;
+}
+
+static int int_ptr_type_to_size(enum bpf_arg_type type)
+{
+	if (type == ARG_PTR_TO_INT)
+		return sizeof(u32);
+	else if (type == ARG_PTR_TO_LONG)
+		return sizeof(u64);
+
+	return -EINVAL;
+}
+
 static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 			  enum bpf_arg_type arg_type,
 			  struct bpf_call_arg_meta *meta)
@@ -2554,6 +2570,12 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 			 type != expected_type)
 			goto err_type;
 		meta->raw_mode = arg_type == ARG_PTR_TO_UNINIT_MEM;
+	} else if (arg_type_is_int_ptr(arg_type)) {
+		expected_type = PTR_TO_STACK;
+		if (!type_is_pkt_pointer(type) &&
+		    type != PTR_TO_MAP_VALUE &&
+		    type != expected_type)
+			goto err_type;
 	} else {
 		verbose(env, "unsupported arg_type %d\n", arg_type);
 		return -EFAULT;
@@ -2635,6 +2657,13 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 		err = check_helper_mem_access(env, regno - 1,
 					      reg->umax_value,
 					      zero_size_allowed, meta);
+	} else if (arg_type_is_int_ptr(arg_type)) {
+		int size = int_ptr_type_to_size(arg_type);
+
+		err = check_helper_mem_access(env, regno, size, false, meta);
+		if (err)
+			return err;
+		err = check_ptr_alignment(env, reg, 0, size, true);
 	}
 
 	return err;
-- 
cgit v1.2.3


From d7a4cb9b6705a89937d12c8158a35a3145dc967a Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Mon, 18 Mar 2019 17:55:26 -0700
Subject: bpf: Introduce bpf_strtol and bpf_strtoul helpers

Add bpf_strtol and bpf_strtoul to convert a string to long and unsigned
long correspondingly. It's similar to user space strtol(3) and
strtoul(3) with a few changes to the API:

* instead of NUL-terminated C string the helpers expect buffer and
  buffer length;

* resulting long or unsigned long is returned in a separate
  result-argument;

* return value is used to indicate success or failure, on success number
  of consumed bytes is returned that can be used to identify position to
  read next if the buffer is expected to contain multiple integers;

* instead of *base* argument, *flags* is used that provides base in 5
  LSB, other bits are reserved for future use;

* number of supported bases is limited.

Documentation for the new helpers is provided in bpf.h UAPI.

The helpers are made available to BPF_PROG_TYPE_CGROUP_SYSCTL programs to
be able to convert string input to e.g. "ulongvec" output.

E.g. "net/ipv4/tcp_mem" consists of three ulong integers. They can be
parsed by calling to bpf_strtoul three times.

Implementation notes:

Implementation includes "../../lib/kstrtox.h" to reuse integer parsing
functions. It's done exactly same way as fs/proc/base.c already does.

Unfortunately existing kstrtoX function can't be used directly since
they fail if any invalid character is present right after integer in the
string. Existing simple_strtoX functions can't be used either since
they're obsolete and don't handle overflow properly.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c  |   4 ++
 kernel/bpf/helpers.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 135 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index b2adf22139b3..789d4ab2336e 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1016,6 +1016,10 @@ static const struct bpf_func_proto *
 sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
 	switch (func_id) {
+	case BPF_FUNC_strtol:
+		return &bpf_strtol_proto;
+	case BPF_FUNC_strtoul:
+		return &bpf_strtoul_proto;
 	case BPF_FUNC_sysctl_get_name:
 		return &bpf_sysctl_get_name_proto;
 	case BPF_FUNC_sysctl_get_current_value:
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index a411fc17d265..4266ffde07ca 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -18,6 +18,9 @@
 #include <linux/sched.h>
 #include <linux/uidgid.h>
 #include <linux/filter.h>
+#include <linux/ctype.h>
+
+#include "../../lib/kstrtox.h"
 
 /* If kernel subsystem is allowing eBPF programs to call this function,
  * inside its own verifier_ops->get_func_proto() callback it should return
@@ -363,4 +366,132 @@ const struct bpf_func_proto bpf_get_local_storage_proto = {
 	.arg2_type	= ARG_ANYTHING,
 };
 #endif
+
+#define BPF_STRTOX_BASE_MASK 0x1F
+
+static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
+			  unsigned long long *res, bool *is_negative)
+{
+	unsigned int base = flags & BPF_STRTOX_BASE_MASK;
+	const char *cur_buf = buf;
+	size_t cur_len = buf_len;
+	unsigned int consumed;
+	size_t val_len;
+	char str[64];
+
+	if (!buf || !buf_len || !res || !is_negative)
+		return -EINVAL;
+
+	if (base != 0 && base != 8 && base != 10 && base != 16)
+		return -EINVAL;
+
+	if (flags & ~BPF_STRTOX_BASE_MASK)
+		return -EINVAL;
+
+	while (cur_buf < buf + buf_len && isspace(*cur_buf))
+		++cur_buf;
+
+	*is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
+	if (*is_negative)
+		++cur_buf;
+
+	consumed = cur_buf - buf;
+	cur_len -= consumed;
+	if (!cur_len)
+		return -EINVAL;
+
+	cur_len = min(cur_len, sizeof(str) - 1);
+	memcpy(str, cur_buf, cur_len);
+	str[cur_len] = '\0';
+	cur_buf = str;
+
+	cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
+	val_len = _parse_integer(cur_buf, base, res);
+
+	if (val_len & KSTRTOX_OVERFLOW)
+		return -ERANGE;
+
+	if (val_len == 0)
+		return -EINVAL;
+
+	cur_buf += val_len;
+	consumed += cur_buf - str;
+
+	return consumed;
+}
+
+static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
+			 long long *res)
+{
+	unsigned long long _res;
+	bool is_negative;
+	int err;
+
+	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
+	if (err < 0)
+		return err;
+	if (is_negative) {
+		if ((long long)-_res > 0)
+			return -ERANGE;
+		*res = -_res;
+	} else {
+		if ((long long)_res < 0)
+			return -ERANGE;
+		*res = _res;
+	}
+	return err;
+}
+
+BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
+	   long *, res)
+{
+	long long _res;
+	int err;
+
+	err = __bpf_strtoll(buf, buf_len, flags, &_res);
+	if (err < 0)
+		return err;
+	if (_res != (long)_res)
+		return -ERANGE;
+	*res = _res;
+	return err;
+}
+
+const struct bpf_func_proto bpf_strtol_proto = {
+	.func		= bpf_strtol,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_MEM,
+	.arg2_type	= ARG_CONST_SIZE,
+	.arg3_type	= ARG_ANYTHING,
+	.arg4_type	= ARG_PTR_TO_LONG,
+};
+
+BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
+	   unsigned long *, res)
+{
+	unsigned long long _res;
+	bool is_negative;
+	int err;
+
+	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
+	if (err < 0)
+		return err;
+	if (is_negative)
+		return -EINVAL;
+	if (_res != (unsigned long)_res)
+		return -ERANGE;
+	*res = _res;
+	return err;
+}
+
+const struct bpf_func_proto bpf_strtoul_proto = {
+	.func		= bpf_strtoul,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_MEM,
+	.arg2_type	= ARG_CONST_SIZE,
+	.arg3_type	= ARG_ANYTHING,
+	.arg4_type	= ARG_PTR_TO_LONG,
+};
 #endif
-- 
cgit v1.2.3


From 51356ac89b5a15e5207e8740d5f4f8b71cb7332f Mon Sep 17 00:00:00 2001
From: Andrey Ignatov <rdna@fb.com>
Date: Fri, 12 Apr 2019 16:01:01 -0700
Subject: bpf: Fix distinct pointer types warning for ARCH=i386

Fix a new warning reported by kbuild for make ARCH=i386:

   In file included from kernel/bpf/cgroup.c:11:0:
   kernel/bpf/cgroup.c: In function '__cgroup_bpf_run_filter_sysctl':
   include/linux/kernel.h:827:29: warning: comparison of distinct pointer types lacks a cast
      (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                                ^
   include/linux/kernel.h:841:4: note: in expansion of macro '__typecheck'
      (__typecheck(x, y) && __no_side_effects(x, y))
       ^~~~~~~~~~~
   include/linux/kernel.h:851:24: note: in expansion of macro '__safe_cmp'
     __builtin_choose_expr(__safe_cmp(x, y), \
                           ^~~~~~~~~~
   include/linux/kernel.h:860:19: note: in expansion of macro '__careful_cmp'
    #define min(x, y) __careful_cmp(x, y, <)
                      ^~~~~~~~~~~~~
>> kernel/bpf/cgroup.c:837:17: note: in expansion of macro 'min'
      ctx.new_len = min(PAGE_SIZE, *pcount);
                    ^~~

Fixes: 4e63acdff864 ("bpf: Introduce bpf_sysctl_{get,set}_new_value helpers")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 789d4ab2336e..e58a6c247f56 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -839,7 +839,7 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 		 * buffer bigger than provided by user.
 		 */
 		ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
-		ctx.new_len = min(PAGE_SIZE, *pcount);
+		ctx.new_len = min_t(size_t, PAGE_SIZE, *pcount);
 		if (!ctx.new_val ||
 		    copy_from_user(ctx.new_val, buf, ctx.new_len))
 			/* Let BPF program decide how to proceed. */
-- 
cgit v1.2.3


From 1b04aee7e2182454a663950e68084fa5ada9625a Mon Sep 17 00:00:00 2001
From: Jiong Wang <jiong.wang@netronome.com>
Date: Fri, 12 Apr 2019 22:59:34 +0100
Subject: bpf: refactor propagate_liveness to eliminate duplicated for loop

Propagation for register and stack slot are finished in separate for loop,
while they are perfect to be put into a single loop.

This could also let them share some common variables in later patches.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 15ab6fa817ce..da285df492fd 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6254,10 +6254,8 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 					return err;
 			}
 		}
-	}
 
-	/* ... and stack slots */
-	for (frame = 0; frame <= vstate->curframe; frame++) {
+		/* Propagate stack slots. */
 		state = vstate->frame[frame];
 		parent = vparent->frame[frame];
 		for (i = 0; i < state->allocated_stack / BPF_REG_SIZE &&
-- 
cgit v1.2.3


From 3f8cafa4131f67d47c8de326c7dcd561cc65fb38 Mon Sep 17 00:00:00 2001
From: Jiong Wang <jiong.wang@netronome.com>
Date: Fri, 12 Apr 2019 22:59:35 +0100
Subject: bpf: refactor propagate_liveness to eliminate code redundance

Access to reg states were not factored out, the consequence is long code
for dereferencing them which made the indentation not good for reading.

This patch factor out these code so the core code in the loop could be
easier to follow.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index da285df492fd..6fd36a8ba1a0 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6232,8 +6232,9 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 			      const struct bpf_verifier_state *vstate,
 			      struct bpf_verifier_state *vparent)
 {
-	int i, frame, err = 0;
+	struct bpf_reg_state *state_reg, *parent_reg;
 	struct bpf_func_state *state, *parent;
+	int i, frame, err = 0;
 
 	if (vparent->curframe != vstate->curframe) {
 		WARN(1, "propagate_live: parent frame %d current frame %d\n",
@@ -6243,28 +6244,33 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 	/* Propagate read liveness of registers... */
 	BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
 	for (frame = 0; frame <= vstate->curframe; frame++) {
+		parent = vparent->frame[frame];
+		state = vstate->frame[frame];
+		parent_reg = parent->regs;
+		state_reg = state->regs;
 		/* We don't need to worry about FP liveness, it's read-only */
 		for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) {
-			if (vparent->frame[frame]->regs[i].live & REG_LIVE_READ)
+			if (parent_reg[i].live & REG_LIVE_READ)
 				continue;
-			if (vstate->frame[frame]->regs[i].live & REG_LIVE_READ) {
-				err = mark_reg_read(env, &vstate->frame[frame]->regs[i],
-						    &vparent->frame[frame]->regs[i]);
-				if (err)
-					return err;
-			}
+			if (!(state_reg[i].live & REG_LIVE_READ))
+				continue;
+			err = mark_reg_read(env, &state_reg[i], &parent_reg[i]);
+			if (err)
+				return err;
 		}
 
 		/* Propagate stack slots. */
-		state = vstate->frame[frame];
-		parent = vparent->frame[frame];
 		for (i = 0; i < state->allocated_stack / BPF_REG_SIZE &&
 			    i < parent->allocated_stack / BPF_REG_SIZE; i++) {
-			if (parent->stack[i].spilled_ptr.live & REG_LIVE_READ)
+			parent_reg = &parent->stack[i].spilled_ptr;
+			state_reg = &state->stack[i].spilled_ptr;
+			if (parent_reg->live & REG_LIVE_READ)
 				continue;
-			if (state->stack[i].spilled_ptr.live & REG_LIVE_READ)
-				mark_reg_read(env, &state->stack[i].spilled_ptr,
-					      &parent->stack[i].spilled_ptr);
+			if (!(state_reg->live & REG_LIVE_READ))
+				continue;
+			err = mark_reg_read(env, state_reg, parent_reg);
+			if (err)
+				return err;
 		}
 	}
 	return err;
-- 
cgit v1.2.3


From 55e7f3b5ac94a8c9f2e35961a45e9aa526a9e41d Mon Sep 17 00:00:00 2001
From: Jiong Wang <jiong.wang@netronome.com>
Date: Fri, 12 Apr 2019 22:59:36 +0100
Subject: bpf: factor out reg and stack slot propagation into
 "propagate_liveness_reg"

After code refactor in previous patches, the propagation logic inside the
for loop in "propagate_liveness" becomes clear that they are good enough to
be factored out into a common function "propagate_liveness_reg".

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6fd36a8ba1a0..3fdb301c4f8c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6221,6 +6221,22 @@ static bool states_equal(struct bpf_verifier_env *env,
 	return true;
 }
 
+static int propagate_liveness_reg(struct bpf_verifier_env *env,
+				  struct bpf_reg_state *reg,
+				  struct bpf_reg_state *parent_reg)
+{
+	int err;
+
+	if (parent_reg->live & REG_LIVE_READ || !(reg->live & REG_LIVE_READ))
+		return 0;
+
+	err = mark_reg_read(env, reg, parent_reg);
+	if (err)
+		return err;
+
+	return 0;
+}
+
 /* A write screens off any subsequent reads; but write marks come from the
  * straight-line code between a state and its parent.  When we arrive at an
  * equivalent state (jump target or such) we didn't arrive by the straight-line
@@ -6250,11 +6266,8 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 		state_reg = state->regs;
 		/* We don't need to worry about FP liveness, it's read-only */
 		for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) {
-			if (parent_reg[i].live & REG_LIVE_READ)
-				continue;
-			if (!(state_reg[i].live & REG_LIVE_READ))
-				continue;
-			err = mark_reg_read(env, &state_reg[i], &parent_reg[i]);
+			err = propagate_liveness_reg(env, &state_reg[i],
+						     &parent_reg[i]);
 			if (err)
 				return err;
 		}
@@ -6264,11 +6277,8 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 			    i < parent->allocated_stack / BPF_REG_SIZE; i++) {
 			parent_reg = &parent->stack[i].spilled_ptr;
 			state_reg = &state->stack[i].spilled_ptr;
-			if (parent_reg->live & REG_LIVE_READ)
-				continue;
-			if (!(state_reg->live & REG_LIVE_READ))
-				continue;
-			err = mark_reg_read(env, state_reg, parent_reg);
+			err = propagate_liveness_reg(env, state_reg,
+						     parent_reg);
 			if (err)
 				return err;
 		}
-- 
cgit v1.2.3


From c342dc109aa5a4f0bb36335cb441aaafc98b98ef Mon Sep 17 00:00:00 2001
From: Jiong Wang <jiong.wang@netronome.com>
Date: Fri, 12 Apr 2019 22:59:37 +0100
Subject: bpf: refactor "check_reg_arg" to eliminate code redundancy

There are a few "regs[regno]" here are there across "check_reg_arg", this
patch factor it out into a simple "reg" pointer. The intention is to
simplify code indentation and make the later patches in this set look
cleaner.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 3fdb301c4f8c..c7220153c5b1 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1177,30 +1177,32 @@ static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
 {
 	struct bpf_verifier_state *vstate = env->cur_state;
 	struct bpf_func_state *state = vstate->frame[vstate->curframe];
-	struct bpf_reg_state *regs = state->regs;
+	struct bpf_reg_state *reg, *regs = state->regs;
 
 	if (regno >= MAX_BPF_REG) {
 		verbose(env, "R%d is invalid\n", regno);
 		return -EINVAL;
 	}
 
+	reg = &regs[regno];
 	if (t == SRC_OP) {
 		/* check whether register used as source operand can be read */
-		if (regs[regno].type == NOT_INIT) {
+		if (reg->type == NOT_INIT) {
 			verbose(env, "R%d !read_ok\n", regno);
 			return -EACCES;
 		}
 		/* We don't need to worry about FP liveness because it's read-only */
-		if (regno != BPF_REG_FP)
-			return mark_reg_read(env, &regs[regno],
-					     regs[regno].parent);
+		if (regno == BPF_REG_FP)
+			return 0;
+
+		return mark_reg_read(env, reg, reg->parent);
 	} else {
 		/* check whether register used as dest operand can be written to */
 		if (regno == BPF_REG_FP) {
 			verbose(env, "frame pointer is read only\n");
 			return -EACCES;
 		}
-		regs[regno].live |= REG_LIVE_WRITTEN;
+		reg->live |= REG_LIVE_WRITTEN;
 		if (t == DST_OP)
 			mark_reg_unknown(env, regs, regno);
 	}
-- 
cgit v1.2.3


From 02a8c817a31606b6b37c2b755f6569903f44241e Mon Sep 17 00:00:00 2001
From: Alban Crequy <alban@kinvolk.io>
Date: Sun, 14 Apr 2019 18:58:46 +0200
Subject: bpf: add map helper functions push, pop, peek in more BPF programs

commit f1a2e44a3aec ("bpf: add queue and stack maps") introduced new BPF
helper functions:
- BPF_FUNC_map_push_elem
- BPF_FUNC_map_pop_elem
- BPF_FUNC_map_peek_elem

but they were made available only for network BPF programs. This patch
makes them available for tracepoint, cgroup and lirc programs.

Signed-off-by: Alban Crequy <alban@kinvolk.io>
Cc: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/cgroup.c      | 6 ++++++
 kernel/trace/bpf_trace.c | 6 ++++++
 2 files changed, 12 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index e58a6c247f56..fcde0f7b2585 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -713,6 +713,12 @@ cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_map_update_elem_proto;
 	case BPF_FUNC_map_delete_elem:
 		return &bpf_map_delete_elem_proto;
+	case BPF_FUNC_map_push_elem:
+		return &bpf_map_push_elem_proto;
+	case BPF_FUNC_map_pop_elem:
+		return &bpf_map_pop_elem_proto;
+	case BPF_FUNC_map_peek_elem:
+		return &bpf_map_peek_elem_proto;
 	case BPF_FUNC_get_current_uid_gid:
 		return &bpf_get_current_uid_gid_proto;
 	case BPF_FUNC_get_local_storage:
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d64c00afceb5..91800be0c8eb 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -569,6 +569,12 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_map_update_elem_proto;
 	case BPF_FUNC_map_delete_elem:
 		return &bpf_map_delete_elem_proto;
+	case BPF_FUNC_map_push_elem:
+		return &bpf_map_push_elem_proto;
+	case BPF_FUNC_map_pop_elem:
+		return &bpf_map_pop_elem_proto;
+	case BPF_FUNC_map_peek_elem:
+		return &bpf_map_peek_elem_proto;
 	case BPF_FUNC_probe_read:
 		return &bpf_probe_read_proto;
 	case BPF_FUNC_ktime_get_ns:
-- 
cgit v1.2.3


From 0d306c31b2f77391dacdeaad4470c577f2aecc4f Mon Sep 17 00:00:00 2001
From: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Date: Tue, 16 Apr 2019 18:13:01 +0900
Subject: bpf: use BPF_CAST_CALL for casting bpf call

verifier.c uses BPF_CAST_CALL for casting bpf call except at one
place in jit_subprogs(). Let's use the macro for consistency.

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/verifier.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c7220153c5b1..db301e9b5295 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -7647,9 +7647,8 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 			    insn->src_reg != BPF_PSEUDO_CALL)
 				continue;
 			subprog = insn->off;
-			insn->imm = (u64 (*)(u64, u64, u64, u64, u64))
-				func[subprog]->bpf_func -
-				__bpf_call_base;
+			insn->imm = BPF_CAST_CALL(func[subprog]->bpf_func) -
+				    __bpf_call_base;
 		}
 
 		/* we use the aux data to keep a list of the start addresses
-- 
cgit v1.2.3


From 77361825bb01ecadf3ac8622e2e4dbc28806e858 Mon Sep 17 00:00:00 2001
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Fri, 12 Apr 2019 17:07:32 +0200
Subject: bpf: cpumap use ptr_ring_consume_batched

Move ptr_ring dequeue outside loop, that allocate SKBs and calls network
stack, as these operations that can take some time. The ptr_ring is a
communication channel between CPUs, where we want to reduce/limit any
cacheline bouncing.

Do a concentrated bulk dequeue via ptr_ring_consume_batched, to shorten the
period and times the remote cacheline in ptr_ring is read

Batch size 8 is both to (1) limit BH-disable period, and (2) consume one
cacheline on 64-bit archs. After reducing the BH-disable section further
then we can consider changing this, while still thinking about L1 cacheline
size being active.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cpumap.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 3c18260403dd..430103e182a0 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -240,6 +240,8 @@ static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
 	}
 }
 
+#define CPUMAP_BATCH 8
+
 static int cpu_map_kthread_run(void *data)
 {
 	struct bpf_cpu_map_entry *rcpu = data;
@@ -252,8 +254,9 @@ static int cpu_map_kthread_run(void *data)
 	 * kthread_stop signal until queue is empty.
 	 */
 	while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) {
-		unsigned int processed = 0, drops = 0, sched = 0;
-		struct xdp_frame *xdpf;
+		unsigned int drops = 0, sched = 0;
+		void *frames[CPUMAP_BATCH];
+		int i, n;
 
 		/* Release CPU reschedule checks */
 		if (__ptr_ring_empty(rcpu->queue)) {
@@ -269,14 +272,16 @@ static int cpu_map_kthread_run(void *data)
 			sched = cond_resched();
 		}
 
-		/* Process packets in rcpu->queue */
-		local_bh_disable();
 		/*
 		 * The bpf_cpu_map_entry is single consumer, with this
 		 * kthread CPU pinned. Lockless access to ptr_ring
 		 * consume side valid as no-resize allowed of queue.
 		 */
-		while ((xdpf = __ptr_ring_consume(rcpu->queue))) {
+		n = ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH);
+
+		local_bh_disable();
+		for (i = 0; i < n; i++) {
+			struct xdp_frame *xdpf = frames[i];
 			struct sk_buff *skb;
 			int ret;
 
@@ -290,13 +295,9 @@ static int cpu_map_kthread_run(void *data)
 			ret = netif_receive_skb_core(skb);
 			if (ret == NET_RX_DROP)
 				drops++;
-
-			/* Limit BH-disable period */
-			if (++processed == 8)
-				break;
 		}
 		/* Feedback loop via tracepoint */
-		trace_xdp_cpumap_kthread(rcpu->map_id, processed, drops, sched);
+		trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched);
 
 		local_bh_enable(); /* resched point, may call do_softirq() */
 	}
-- 
cgit v1.2.3


From 8f0504a97e1ba6b70e1c8b5a88255c280f263287 Mon Sep 17 00:00:00 2001
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Fri, 12 Apr 2019 17:07:43 +0200
Subject: bpf: cpumap do bulk allocation of SKBs

As cpumap now batch consume xdp_frame's from the ptr_ring, it knows how many
SKBs it need to allocate. Thus, lets bulk allocate these SKBs via
kmem_cache_alloc_bulk() API, and use the previously introduced function
build_skb_around().

Notice that the flag __GFP_ZERO asks the slab/slub allocator to clear the
memory for us. This does clear a larger area than needed, but my micro
benchmarks on Intel CPUs show that this is slightly faster due to being a
cacheline aligned area is cleared for the SKBs. (For SLUB allocator, there
is a future optimization potential, because SKBs will with high probability
originate from same page. If we can find/identify continuous memory areas
then the Intel CPU memset rep stos will have a real performance gain.)

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cpumap.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 430103e182a0..732d6ced3987 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -160,12 +160,12 @@ static void cpu_map_kthread_stop(struct work_struct *work)
 }
 
 static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
-					 struct xdp_frame *xdpf)
+					 struct xdp_frame *xdpf,
+					 struct sk_buff *skb)
 {
 	unsigned int hard_start_headroom;
 	unsigned int frame_size;
 	void *pkt_data_start;
-	struct sk_buff *skb;
 
 	/* Part of headroom was reserved to xdpf */
 	hard_start_headroom = sizeof(struct xdp_frame) +  xdpf->headroom;
@@ -191,8 +191,8 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
 		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 
 	pkt_data_start = xdpf->data - hard_start_headroom;
-	skb = build_skb(pkt_data_start, frame_size);
-	if (!skb)
+	skb = build_skb_around(skb, pkt_data_start, frame_size);
+	if (unlikely(!skb))
 		return NULL;
 
 	skb_reserve(skb, hard_start_headroom);
@@ -256,7 +256,9 @@ static int cpu_map_kthread_run(void *data)
 	while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) {
 		unsigned int drops = 0, sched = 0;
 		void *frames[CPUMAP_BATCH];
-		int i, n;
+		void *skbs[CPUMAP_BATCH];
+		gfp_t gfp = __GFP_ZERO | GFP_ATOMIC;
+		int i, n, m;
 
 		/* Release CPU reschedule checks */
 		if (__ptr_ring_empty(rcpu->queue)) {
@@ -278,14 +280,20 @@ static int cpu_map_kthread_run(void *data)
 		 * consume side valid as no-resize allowed of queue.
 		 */
 		n = ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH);
+		m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, n, skbs);
+		if (unlikely(m == 0)) {
+			for (i = 0; i < n; i++)
+				skbs[i] = NULL; /* effect: xdp_return_frame */
+			drops = n;
+		}
 
 		local_bh_disable();
 		for (i = 0; i < n; i++) {
 			struct xdp_frame *xdpf = frames[i];
-			struct sk_buff *skb;
+			struct sk_buff *skb = skbs[i];
 			int ret;
 
-			skb = cpu_map_build_skb(rcpu, xdpf);
+			skb = cpu_map_build_skb(rcpu, xdpf, skb);
 			if (!skb) {
 				xdp_return_frame(xdpf);
 				continue;
-- 
cgit v1.2.3


From 86d231459d6dc9094e70c35c3517f4ef860b2f1e Mon Sep 17 00:00:00 2001
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Fri, 12 Apr 2019 17:07:48 +0200
Subject: bpf: cpumap memory prefetchw optimizations for struct page

A lot of the performance gain comes from this patch.

While analysing performance overhead it was found that the largest CPU
stalls were caused when touching the struct page area. It is first read with
a READ_ONCE from build_skb_around via page_is_pfmemalloc(), and when freed
written by page_frag_free() call.

Measurements show that the prefetchw (W) variant operation is needed to
achieve the performance gain. We believe this optimization it two fold,
first the W-variant saves one step in the cache-coherency protocol, and
second it helps us to avoid the non-temporal prefetch HW optimizations and
bring this into all cache-levels. It might be worth investigating if
prefetch into L2 will have the same benefit.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/cpumap.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 732d6ced3987..cf727d77c6c6 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -280,6 +280,18 @@ static int cpu_map_kthread_run(void *data)
 		 * consume side valid as no-resize allowed of queue.
 		 */
 		n = ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH);
+
+		for (i = 0; i < n; i++) {
+			void *f = frames[i];
+			struct page *page = virt_to_page(f);
+
+			/* Bring struct page memory area to curr CPU. Read by
+			 * build_skb_around via page_is_pfmemalloc(), and when
+			 * freed written by page_frag_free call.
+			 */
+			prefetchw(page);
+		}
+
 		m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, n, skbs);
 		if (unlikely(m == 0)) {
 			for (i = 0; i < n; i++)
-- 
cgit v1.2.3


From 0bc199854405543b0debe67c735c0aae94f1d319 Mon Sep 17 00:00:00 2001
From: Stephen Suryaputra <ssuryaextr@gmail.com>
Date: Wed, 17 Apr 2019 16:35:49 -0400
Subject: ipv6: Add rate limit mask for ICMPv6 messages

To make ICMPv6 closer to ICMPv4, add ratemask parameter. Since the ICMP
message types use larger numeric values, a simple bitmask doesn't fit.
I use large bitmap. The input and output are the in form of list of
ranges. Set the default to rate limit all error messages but Packet Too
Big. For Packet Too Big, use ratemask instead of hard-coded.

There are functions where icmpv6_xrlim_allow() and icmpv6_global_allow()
aren't called. This patch only adds them to icmpv6_echo_reply().

Rate limiting error messages is mandated by RFC 4443 but RFC 4890 says
that it is also acceptable to rate limit informational messages. Thus,
I removed the current hard-coded behavior of icmpv6_mask_allow() that
doesn't rate limit informational messages.

v2: Add dummy function proc_do_large_bitmap() if CONFIG_PROC_SYSCTL
    isn't defined, expand the description in ip-sysctl.txt and remove
    unnecessary conditional before kfree().
v3: Inline the bitmap instead of dynamically allocated. Still is a
    pointer to it is needed because of the way proc_do_large_bitmap work.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 kernel/sysctl.c | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'kernel')

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c9ec050bcf46..599510a3355e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -3326,6 +3326,11 @@ int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
     return -ENOSYS;
 }
 
+int proc_do_large_bitmap(struct ctl_table *table, int write,
+			 void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
 
 #endif /* CONFIG_PROC_SYSCTL */
 
@@ -3366,3 +3371,4 @@ EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
 EXPORT_SYMBOL(proc_dostring);
 EXPORT_SYMBOL(proc_doulongvec_minmax);
 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
+EXPORT_SYMBOL(proc_do_large_bitmap);
-- 
cgit v1.2.3


From 7df737e991069d75eec1ded1c8b37e81b8c54df9 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Fri, 19 Apr 2019 07:44:54 -0700
Subject: bpf: remove global variables

Move three global variables protected by bpf_verifier_lock into
'struct bpf_verifier_env' to allow parallel verification.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index db301e9b5295..5f0eb5bd5589 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5369,10 +5369,6 @@ enum {
 
 #define STATE_LIST_MARK ((struct bpf_verifier_state_list *) -1L)
 
-static int *insn_stack;	/* stack of insns to process */
-static int cur_stack;	/* current stack index */
-static int *insn_state;
-
 /* t, w, e - match pseudo-code above:
  * t - index of current instruction
  * w - next instruction
@@ -5380,6 +5376,9 @@ static int *insn_state;
  */
 static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)
 {
+	int *insn_stack = env->cfg.insn_stack;
+	int *insn_state = env->cfg.insn_state;
+
 	if (e == FALLTHROUGH && insn_state[t] >= (DISCOVERED | FALLTHROUGH))
 		return 0;
 
@@ -5400,9 +5399,9 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)
 		/* tree-edge */
 		insn_state[t] = DISCOVERED | e;
 		insn_state[w] = DISCOVERED;
-		if (cur_stack >= env->prog->len)
+		if (env->cfg.cur_stack >= env->prog->len)
 			return -E2BIG;
-		insn_stack[cur_stack++] = w;
+		insn_stack[env->cfg.cur_stack++] = w;
 		return 1;
 	} else if ((insn_state[w] & 0xF0) == DISCOVERED) {
 		verbose_linfo(env, t, "%d: ", t);
@@ -5426,14 +5425,15 @@ static int check_cfg(struct bpf_verifier_env *env)
 {
 	struct bpf_insn *insns = env->prog->insnsi;
 	int insn_cnt = env->prog->len;
+	int *insn_stack, *insn_state;
 	int ret = 0;
 	int i, t;
 
-	insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+	insn_state = env->cfg.insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
 	if (!insn_state)
 		return -ENOMEM;
 
-	insn_stack = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+	insn_stack = env->cfg.insn_stack = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
 	if (!insn_stack) {
 		kvfree(insn_state);
 		return -ENOMEM;
@@ -5441,12 +5441,12 @@ static int check_cfg(struct bpf_verifier_env *env)
 
 	insn_state[0] = DISCOVERED; /* mark 1st insn as discovered */
 	insn_stack[0] = 0; /* 0 is the first instruction */
-	cur_stack = 1;
+	env->cfg.cur_stack = 1;
 
 peek_stack:
-	if (cur_stack == 0)
+	if (env->cfg.cur_stack == 0)
 		goto check_state;
-	t = insn_stack[cur_stack - 1];
+	t = insn_stack[env->cfg.cur_stack - 1];
 
 	if (BPF_CLASS(insns[t].code) == BPF_JMP ||
 	    BPF_CLASS(insns[t].code) == BPF_JMP32) {
@@ -5515,7 +5515,7 @@ peek_stack:
 
 mark_explored:
 	insn_state[t] = EXPLORED;
-	if (cur_stack-- <= 0) {
+	if (env->cfg.cur_stack-- <= 0) {
 		verbose(env, "pop stack internal bug\n");
 		ret = -EFAULT;
 		goto err_free;
@@ -5535,6 +5535,7 @@ check_state:
 err_free:
 	kvfree(insn_state);
 	kvfree(insn_stack);
+	env->cfg.insn_state = env->cfg.insn_stack = NULL;
 	return ret;
 }
 
-- 
cgit v1.2.3


From 45a73c17bfb92c3ceebedc80a750ef2c2931c26b Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Fri, 19 Apr 2019 07:44:55 -0700
Subject: bpf: drop bpf_verifier_lock

Drop bpf_verifier_lock for root to avoid being DoS-ed by unprivileged.
The BPF verifier is now fully parallel.
All unpriv users are still serialized by bpf_verifier_lock to avoid
exhausting kernel memory by running N parallel verifications.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/verifier.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5f0eb5bd5589..423f242a5efb 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -8132,9 +8132,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 		env->insn_aux_data[i].orig_idx = i;
 	env->prog = *prog;
 	env->ops = bpf_verifier_ops[env->prog->type];
+	is_priv = capable(CAP_SYS_ADMIN);
 
 	/* grab the mutex to protect few globals used by verifier */
-	mutex_lock(&bpf_verifier_lock);
+	if (!is_priv)
+		mutex_lock(&bpf_verifier_lock);
 
 	if (attr->log_level || attr->log_buf || attr->log_size) {
 		/* user requested verbose verifier output
@@ -8157,7 +8159,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 	if (attr->prog_flags & BPF_F_ANY_ALIGNMENT)
 		env->strict_alignment = false;
 
-	is_priv = capable(CAP_SYS_ADMIN);
 	env->allow_ptr_leaks = is_priv;
 
 	ret = replace_map_fd_with_map_ptr(env);
@@ -8270,7 +8271,8 @@ err_release_maps:
 		release_maps(env);
 	*prog = env->prog;
 err_unlock:
-	mutex_unlock(&bpf_verifier_lock);
+	if (!is_priv)
+		mutex_unlock(&bpf_verifier_lock);
 	vfree(env->insn_aux_data);
 err_free_env:
 	kfree(env);
-- 
cgit v1.2.3


From 118c8e9ae629d35fa9b3d27a7b9d59298b1b4183 Mon Sep 17 00:00:00 2001
From: Stanislav Fomichev <sdf@google.com>
Date: Thu, 25 Apr 2019 14:37:23 -0700
Subject: bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type

target_fd is target namespace. If there is a flow dissector BPF program
attached to that namespace, its (single) id is returned.

v5:
* drop net ref right after rcu unlock (Daniel Borkmann)

v4:
* add missing put_net (Jann Horn)

v3:
* add missing inline to skb_flow_dissector_prog_query static def
  (kbuild test robot <lkp@intel.com>)

v2:
* don't sleep in rcu critical section (Jakub Kicinski)
* check input prog_cnt (exit early)

Cc: Jann Horn <jannh@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/syscall.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 92c9b8a32b50..b0de49598341 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2009,6 +2009,8 @@ static int bpf_prog_query(const union bpf_attr *attr,
 		break;
 	case BPF_LIRC_MODE2:
 		return lirc_prog_query(attr, uattr);
+	case BPF_FLOW_DISSECTOR:
+		return skb_flow_dissector_prog_query(attr, uattr);
 	default:
 		return -EINVAL;
 	}
-- 
cgit v1.2.3


From 9df1c28bb75217b244257152ab7d788bb2a386d0 Mon Sep 17 00:00:00 2001
From: Matt Mullins <mmullins@fb.com>
Date: Fri, 26 Apr 2019 11:49:47 -0700
Subject: bpf: add writable context for raw tracepoints

This is an opt-in interface that allows a tracepoint to provide a safe
buffer that can be written from a BPF_PROG_TYPE_RAW_TRACEPOINT program.
The size of the buffer must be a compile-time constant, and is checked
before allowing a BPF program to attach to a tracepoint that uses this
feature.

The pointer to this buffer will be the first argument of tracepoints
that opt in; the pointer is valid and can be bpf_probe_read() by both
BPF_PROG_TYPE_RAW_TRACEPOINT and BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE
programs that attach to such a tracepoint, but the buffer to which it
points may only be written by the latter.

Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/syscall.c     |  8 ++++++--
 kernel/bpf/verifier.c    | 31 +++++++++++++++++++++++++++++++
 kernel/trace/bpf_trace.c | 24 ++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index b0de49598341..ae141e745f92 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1789,12 +1789,16 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
 	}
 	raw_tp->btp = btp;
 
-	prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd,
-				 BPF_PROG_TYPE_RAW_TRACEPOINT);
+	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
 	if (IS_ERR(prog)) {
 		err = PTR_ERR(prog);
 		goto out_free_tp;
 	}
+	if (prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT &&
+	    prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE) {
+		err = -EINVAL;
+		goto out_put_prog;
+	}
 
 	err = bpf_probe_register(raw_tp->btp, prog);
 	if (err)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 423f242a5efb..2ef442c62c0e 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -405,6 +405,7 @@ static const char * const reg_type_str[] = {
 	[PTR_TO_SOCK_COMMON_OR_NULL] = "sock_common_or_null",
 	[PTR_TO_TCP_SOCK]	= "tcp_sock",
 	[PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null",
+	[PTR_TO_TP_BUFFER]	= "tp_buffer",
 };
 
 static char slot_type_char[] = {
@@ -1993,6 +1994,32 @@ static int check_ctx_reg(struct bpf_verifier_env *env,
 	return 0;
 }
 
+static int check_tp_buffer_access(struct bpf_verifier_env *env,
+				  const struct bpf_reg_state *reg,
+				  int regno, int off, int size)
+{
+	if (off < 0) {
+		verbose(env,
+			"R%d invalid tracepoint buffer access: off=%d, size=%d",
+			regno, off, size);
+		return -EACCES;
+	}
+	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose(env,
+			"R%d invalid variable buffer offset: off=%d, var_off=%s",
+			regno, off, tn_buf);
+		return -EACCES;
+	}
+	if (off + size > env->prog->aux->max_tp_access)
+		env->prog->aux->max_tp_access = off + size;
+
+	return 0;
+}
+
+
 /* truncate register to smaller size (in bytes)
  * must be called with size < BPF_REG_SIZE
  */
@@ -2137,6 +2164,10 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
 		err = check_sock_access(env, insn_idx, regno, off, size, t);
 		if (!err && value_regno >= 0)
 			mark_reg_unknown(env, regs, value_regno);
+	} else if (reg->type == PTR_TO_TP_BUFFER) {
+		err = check_tp_buffer_access(env, reg, regno, off, size);
+		if (!err && t == BPF_READ && value_regno >= 0)
+			mark_reg_unknown(env, regs, value_regno);
 	} else {
 		verbose(env, "R%d invalid mem access '%s'\n", regno,
 			reg_type_str[reg->type]);
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 91800be0c8eb..8607aba1d882 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -915,6 +915,27 @@ const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
 };
 
+static bool raw_tp_writable_prog_is_valid_access(int off, int size,
+						 enum bpf_access_type type,
+						 const struct bpf_prog *prog,
+						 struct bpf_insn_access_aux *info)
+{
+	if (off == 0) {
+		if (size != sizeof(u64) || type != BPF_READ)
+			return false;
+		info->reg_type = PTR_TO_TP_BUFFER;
+	}
+	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
+}
+
+const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
+	.get_func_proto  = raw_tp_prog_func_proto,
+	.is_valid_access = raw_tp_writable_prog_is_valid_access,
+};
+
+const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
+};
+
 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
 				    const struct bpf_prog *prog,
 				    struct bpf_insn_access_aux *info)
@@ -1204,6 +1225,9 @@ static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *
 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
 		return -EINVAL;
 
+	if (prog->aux->max_tp_access > btp->writable_size)
+		return -EINVAL;
+
 	return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
 }
 
-- 
cgit v1.2.3


From 6ac99e8f23d4b10258406ca0dd7bffca5f31da9d Mon Sep 17 00:00:00 2001
From: Martin KaFai Lau <kafai@fb.com>
Date: Fri, 26 Apr 2019 16:39:39 -0700
Subject: bpf: Introduce bpf sk local storage
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

After allowing a bpf prog to
- directly read the skb->sk ptr
- get the fullsock bpf_sock by "bpf_sk_fullsock()"
- get the bpf_tcp_sock by "bpf_tcp_sock()"
- get the listener sock by "bpf_get_listener_sock()"
- avoid duplicating the fields of "(bpf_)sock" and "(bpf_)tcp_sock"
  into different bpf running context.

this patch is another effort to make bpf's network programming
more intuitive to do (together with memory and performance benefit).

When bpf prog needs to store data for a sk, the current practice is to
define a map with the usual 4-tuples (src/dst ip/port) as the key.
If multiple bpf progs require to store different sk data, multiple maps
have to be defined.  Hence, wasting memory to store the duplicated
keys (i.e. 4 tuples here) in each of the bpf map.
[ The smallest key could be the sk pointer itself which requires
  some enhancement in the verifier and it is a separate topic. ]

Also, the bpf prog needs to clean up the elem when sk is freed.
Otherwise, the bpf map will become full and un-usable quickly.
The sk-free tracking currently could be done during sk state
transition (e.g. BPF_SOCK_OPS_STATE_CB).

The size of the map needs to be predefined which then usually ended-up
with an over-provisioned map in production.  Even the map was re-sizable,
while the sk naturally come and go away already, this potential re-size
operation is arguably redundant if the data can be directly connected
to the sk itself instead of proxy-ing through a bpf map.

This patch introduces sk->sk_bpf_storage to provide local storage space
at sk for bpf prog to use.  The space will be allocated when the first bpf
prog has created data for this particular sk.

The design optimizes the bpf prog's lookup (and then optionally followed by
an inline update).  bpf_spin_lock should be used if the inline update needs
to be protected.

BPF_MAP_TYPE_SK_STORAGE:
-----------------------
To define a bpf "sk-local-storage", a BPF_MAP_TYPE_SK_STORAGE map (new in
this patch) needs to be created.  Multiple BPF_MAP_TYPE_SK_STORAGE maps can
be created to fit different bpf progs' needs.  The map enforces
BTF to allow printing the sk-local-storage during a system-wise
sk dump (e.g. "ss -ta") in the future.

The purpose of a BPF_MAP_TYPE_SK_STORAGE map is not for lookup/update/delete
a "sk-local-storage" data from a particular sk.
Think of the map as a meta-data (or "type") of a "sk-local-storage".  This
particular "type" of "sk-local-storage" data can then be stored in any sk.

The main purposes of this map are mostly:
1. Define the size of a "sk-local-storage" type.
2. Provide a similar syscall userspace API as the map (e.g. lookup/update,
   map-id, map-btf...etc.)
3. Keep track of all sk's storages of this "type" and clean them up
   when the map is freed.

sk->sk_bpf_storage:
------------------
The main lookup/update/delete is done on sk->sk_bpf_storage (which
is a "struct bpf_sk_storage").  When doing a lookup,
the "map" pointer is now used as the "key" to search on the
sk_storage->list.  The "map" pointer is actually serving
as the "type" of the "sk-local-storage" that is being
requested.

To allow very fast lookup, it should be as fast as looking up an
array at a stable-offset.  At the same time, it is not ideal to
set a hard limit on the number of sk-local-storage "type" that the
system can have.  Hence, this patch takes a cache approach.
The last search result from sk_storage->list is cached in
sk_storage->cache[] which is a stable sized array.  Each
"sk-local-storage" type has a stable offset to the cache[] array.
In the future, a map's flag could be introduced to do cache
opt-out/enforcement if it became necessary.

The cache size is 16 (i.e. 16 types of "sk-local-storage").
Programs can share map.  On the program side, having a few bpf_progs
running in the networking hotpath is already a lot.  The bpf_prog
should have already consolidated the existing sock-key-ed map usage
to minimize the map lookup penalty.  16 has enough runway to grow.

All sk-local-storage data will be removed from sk->sk_bpf_storage
during sk destruction.

bpf_sk_storage_get() and bpf_sk_storage_delete():
------------------------------------------------
Instead of using bpf_map_(lookup|update|delete)_elem(),
the bpf prog needs to use the new helper bpf_sk_storage_get() and
bpf_sk_storage_delete().  The verifier can then enforce the
ARG_PTR_TO_SOCKET argument.  The bpf_sk_storage_get() also allows to
"create" new elem if one does not exist in the sk.  It is done by
the new BPF_SK_STORAGE_GET_F_CREATE flag.  An optional value can also be
provided as the initial value during BPF_SK_STORAGE_GET_F_CREATE.
The BPF_MAP_TYPE_SK_STORAGE also supports bpf_spin_lock.  Together,
it has eliminated the potential use cases for an equivalent
bpf_map_update_elem() API (for bpf_prog) in this patch.

Misc notes:
----------
1. map_get_next_key is not supported.  From the userspace syscall
   perspective,  the map has the socket fd as the key while the map
   can be shared by pinned-file or map-id.

   Since btf is enforced, the existing "ss" could be enhanced to pretty
   print the local-storage.

   Supporting a kernel defined btf with 4 tuples as the return key could
   be explored later also.

2. The sk->sk_lock cannot be acquired.  Atomic operations is used instead.
   e.g. cmpxchg is done on the sk->sk_bpf_storage ptr.
   Please refer to the source code comments for the details in
   synchronization cases and considerations.

3. The mem is charged to the sk->sk_omem_alloc as the sk filter does.

Benchmark:
---------
Here is the benchmark data collected by turning on
the "kernel.bpf_stats_enabled" sysctl.
Two bpf progs are tested:

One bpf prog with the usual bpf hashmap (max_entries = 8192) with the
sk ptr as the key. (verifier is modified to support sk ptr as the key
That should have shortened the key lookup time.)

Another bpf prog is with the new BPF_MAP_TYPE_SK_STORAGE.

Both are storing a "u32 cnt", do a lookup on "egress_skb/cgroup" for
each egress skb and then bump the cnt.  netperf is used to drive
data with 4096 connected UDP sockets.

BPF_MAP_TYPE_HASH with a modifier verifier (152ns per bpf run)
27: cgroup_skb  name egress_sk_map  tag 74f56e832918070b run_time_ns 58280107540 run_cnt 381347633
    loaded_at 2019-04-15T13:46:39-0700  uid 0
    xlated 344B  jited 258B  memlock 4096B  map_ids 16
    btf_id 5

BPF_MAP_TYPE_SK_STORAGE in this patch (66ns per bpf run)
30: cgroup_skb  name egress_sk_stora  tag d4aa70984cc7bbf6 run_time_ns 25617093319 run_cnt 390989739
    loaded_at 2019-04-15T13:47:54-0700  uid 0
    xlated 168B  jited 156B  memlock 4096B  map_ids 17
    btf_id 6

Here is a high-level picture on how are the objects organized:

       sk
    ┌──────┐
    │      │
    │      │
    │      │
    │*sk_bpf_storage─────▶ bpf_sk_storage
    └──────┘                 ┌───────┐
                 ┌───────────┤ list  │
                 │           │       │
                 │           │       │
                 │           │       │
                 │           └───────┘
                 │
                 │     elem
                 │  ┌────────┐
                 ├─▶│ snode  │
                 │  ├────────┤
                 │  │  data  │          bpf_map
                 │  ├────────┤        ┌─────────┐
                 │  │map_node│◀─┬─────┤  list   │
                 │  └────────┘  │     │         │
                 │              │     │         │
                 │     elem     │     │         │
                 │  ┌────────┐  │     └─────────┘
                 └─▶│ snode  │  │
                    ├────────┤  │
   bpf_map          │  data  │  │
 ┌─────────┐        ├────────┤  │
 │  list   ├───────▶│map_node│  │
 │         │        └────────┘  │
 │         │                    │
 │         │           elem     │
 └─────────┘        ┌────────┐  │
                 ┌─▶│ snode  │  │
                 │  ├────────┤  │
                 │  │  data  │  │
                 │  ├────────┤  │
                 │  │map_node│◀─┘
                 │  └────────┘
                 │
                 │
                 │          ┌───────┐
     sk          └──────────│ list  │
  ┌──────┐                  │       │
  │      │                  │       │
  │      │                  │       │
  │      │                  └───────┘
  │*sk_bpf_storage───────▶bpf_sk_storage
  └──────┘

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/syscall.c  |  3 ++-
 kernel/bpf/verifier.c | 27 ++++++++++++++++++++++++---
 2 files changed, 26 insertions(+), 4 deletions(-)

(limited to 'kernel')

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ae141e745f92..ad3ccf82f31d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -526,7 +526,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 			return -EACCES;
 		if (map->map_type != BPF_MAP_TYPE_HASH &&
 		    map->map_type != BPF_MAP_TYPE_ARRAY &&
-		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE)
+		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
+		    map->map_type != BPF_MAP_TYPE_SK_STORAGE)
 			return -ENOTSUPP;
 		if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
 		    map->value_size) {
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2ef442c62c0e..271717246af3 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2543,10 +2543,15 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 
 	if (arg_type == ARG_PTR_TO_MAP_KEY ||
 	    arg_type == ARG_PTR_TO_MAP_VALUE ||
-	    arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE) {
+	    arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE ||
+	    arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL) {
 		expected_type = PTR_TO_STACK;
-		if (!type_is_pkt_pointer(type) && type != PTR_TO_MAP_VALUE &&
-		    type != expected_type)
+		if (register_is_null(reg) &&
+		    arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL)
+			/* final test in check_stack_boundary() */;
+		else if (!type_is_pkt_pointer(type) &&
+			 type != PTR_TO_MAP_VALUE &&
+			 type != expected_type)
 			goto err_type;
 	} else if (arg_type == ARG_CONST_SIZE ||
 		   arg_type == ARG_CONST_SIZE_OR_ZERO) {
@@ -2578,6 +2583,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 			}
 			meta->ref_obj_id = reg->ref_obj_id;
 		}
+	} else if (arg_type == ARG_PTR_TO_SOCKET) {
+		expected_type = PTR_TO_SOCKET;
+		if (type != expected_type)
+			goto err_type;
 	} else if (arg_type == ARG_PTR_TO_SPIN_LOCK) {
 		if (meta->func_id == BPF_FUNC_spin_lock) {
 			if (process_spin_lock(env, regno, true))
@@ -2635,6 +2644,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 					      meta->map_ptr->key_size, false,
 					      NULL);
 	} else if (arg_type == ARG_PTR_TO_MAP_VALUE ||
+		   (arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL &&
+		    !register_is_null(reg)) ||
 		   arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE) {
 		/* bpf_map_xxx(..., map_ptr, ..., value) call:
 		 * check [value, value + map->value_size) validity
@@ -2784,6 +2795,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		    func_id != BPF_FUNC_map_push_elem)
 			goto error;
 		break;
+	case BPF_MAP_TYPE_SK_STORAGE:
+		if (func_id != BPF_FUNC_sk_storage_get &&
+		    func_id != BPF_FUNC_sk_storage_delete)
+			goto error;
+		break;
 	default:
 		break;
 	}
@@ -2847,6 +2863,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		    map->map_type != BPF_MAP_TYPE_STACK)
 			goto error;
 		break;
+	case BPF_FUNC_sk_storage_get:
+	case BPF_FUNC_sk_storage_delete:
+		if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
+			goto error;
+		break;
 	default:
 		break;
 	}
-- 
cgit v1.2.3


From ae0be8de9a53cda3505865c11826d8ff0640237c Mon Sep 17 00:00:00 2001
From: Michal Kubecek <mkubecek@suse.cz>
Date: Fri, 26 Apr 2019 11:13:06 +0200
Subject: netlink: make nla_nest_start() add NLA_F_NESTED flag

Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 kernel/taskstats.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 1b942a7caf26..ef4f9cd980fd 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -375,7 +375,7 @@ static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
 			? TASKSTATS_TYPE_AGGR_PID
 			: TASKSTATS_TYPE_AGGR_TGID;
 
-	na = nla_nest_start(skb, aggr);
+	na = nla_nest_start_noflag(skb, aggr);
 	if (!na)
 		goto err;
 
-- 
cgit v1.2.3


From 8cb081746c031fb164089322e2336a0bf5b3070c Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 26 Apr 2019 14:07:28 +0200
Subject: netlink: make validation more configurable for future strictness

We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type >= max) & NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs > max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -> nla_parse_deprecated
 * nla_parse_strict    -> nla_parse_deprecated_strict
 * nlmsg_parse         -> nlmsg_parse_deprecated
 * nlmsg_parse_strict  -> nlmsg_parse_deprecated_strict
 * nla_parse_nested    -> nla_parse_nested_deprecated
 * nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 kernel/taskstats.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index ef4f9cd980fd..0e347f1c7800 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -677,8 +677,9 @@ static int taskstats_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
 		return -EINVAL;
 	}
 
-	return nlmsg_validate(info->nlhdr, GENL_HDRLEN, TASKSTATS_CMD_ATTR_MAX,
-			      policy, info->extack);
+	return nlmsg_validate_deprecated(info->nlhdr, GENL_HDRLEN,
+					 TASKSTATS_CMD_ATTR_MAX, policy,
+					 info->extack);
 }
 
 static struct genl_family family __ro_after_init = {
-- 
cgit v1.2.3


From ef6243acb4782df587a4d7d6c310fa5b5d82684b Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 26 Apr 2019 14:07:31 +0200
Subject: genetlink: optionally validate strictly/dumps

Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.

Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:

    @@
    identifier ops;
    expression X;
    @@
    struct genl_ops ops[] = {
    ...,
     {
            .cmd = X,
    +       .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
            ...
     },
    ...
    };

For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 kernel/taskstats.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'kernel')

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 0e347f1c7800..5f852b8f59f7 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -649,12 +649,14 @@ err:
 static const struct genl_ops taskstats_ops[] = {
 	{
 		.cmd		= TASKSTATS_CMD_GET,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit		= taskstats_user_cmd,
 		/* policy enforced later */
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_HASPOL,
 	},
 	{
 		.cmd		= CGROUPSTATS_CMD_GET,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit		= cgroupstats_user_cmd,
 		/* policy enforced later */
 		.flags		= GENL_CMD_CAP_HASPOL,
-- 
cgit v1.2.3