bpf: Add verifier tests for the bpf_sk_storage

This patch adds verifier tests for the bpf_sk_storage:
1. ARG_PTR_TO_MAP_VALUE_OR_NULL
2. Map and helper compatibility (e.g. disallow bpf_map_loookup_elem)

It also takes this chance to remove the unused struct btf_raw_data
and uses the BTF encoding macros from "test_btf.h".

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

2 files changed, 152 insertions, 19 deletions

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index ed9e894afef3..ccd896b98cac 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -47,12 +47,13 @@
 #include "bpf_rlimit.h"
 #include "bpf_rand.h"
 #include "bpf_util.h"
+#include "test_btf.h"
 #include "../../../include/linux/filter.h"
 
 #define MAX_INSNS	BPF_MAXINSNS
 #define MAX_TEST_INSNS	1000000
 #define MAX_FIXUPS	8
-#define MAX_NR_MAPS	17
+#define MAX_NR_MAPS	18
 #define MAX_TEST_RUNS	8
 #define POINTER_VALUE	0xcafe4all
 #define TEST_DATA_LEN	64
@@ -85,6 +86,7 @@ struct bpf_test {
 	int fixup_map_array_ro[MAX_FIXUPS];
 	int fixup_map_array_wo[MAX_FIXUPS];
 	int fixup_map_array_small[MAX_FIXUPS];
+	int fixup_sk_storage_map[MAX_FIXUPS];
 	const char *errstr;
 	const char *errstr_unpriv;
 	uint32_t retval, retval_unpriv, insn_processed;
@@ -497,24 +499,6 @@ static int create_cgroup_storage(bool percpu)
 	return fd;
 }
 
-#define BTF_INFO_ENC(kind, kind_flag, vlen) \
-	((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN))
-#define BTF_TYPE_ENC(name, info, size_or_type) \
-	(name), (info), (size_or_type)
-#define BTF_INT_ENC(encoding, bits_offset, nr_bits) \
-	((encoding) << 24 | (bits_offset) << 16 | (nr_bits))
-#define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \
-	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \
-	BTF_INT_ENC(encoding, bits_offset, bits)
-#define BTF_MEMBER_ENC(name, type, bits_offset) \
-	(name), (type), (bits_offset)
-
-struct btf_raw_data {
-	__u32 raw_types[64];
-	const char *str_sec;
-	__u32 str_sec_size;
-};
-
 /* struct bpf_spin_lock {
  *   int val;
  * };
@@ -589,6 +573,31 @@ static int create_map_spin_lock(void)
 	return fd;
 }
 
+static int create_sk_storage_map(void)
+{
+	struct bpf_create_map_attr attr = {
+		.name = "test_map",
+		.map_type = BPF_MAP_TYPE_SK_STORAGE,
+		.key_size = 4,
+		.value_size = 8,
+		.max_entries = 0,
+		.map_flags = BPF_F_NO_PREALLOC,
+		.btf_key_type_id = 1,
+		.btf_value_type_id = 3,
+	};
+	int fd, btf_fd;
+
+	btf_fd = load_btf();
+	if (btf_fd < 0)
+		return -1;
+	attr.btf_fd = btf_fd;
+	fd = bpf_create_map_xattr(&attr);
+	close(attr.btf_fd);
+	if (fd < 0)
+		printf("Failed to create sk_storage_map\n");
+	return fd;
+}
+
 static char bpf_vlog[UINT_MAX >> 8];
 
 static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
@@ -611,6 +620,7 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 	int *fixup_map_array_ro = test->fixup_map_array_ro;
 	int *fixup_map_array_wo = test->fixup_map_array_wo;
 	int *fixup_map_array_small = test->fixup_map_array_small;
+	int *fixup_sk_storage_map = test->fixup_sk_storage_map;
 
 	if (test->fill_helper) {
 		test->fill_insns = calloc(MAX_TEST_INSNS, sizeof(struct bpf_insn));
@@ -765,6 +775,13 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 			fixup_map_array_small++;
 		} while (*fixup_map_array_small);
 	}
+	if (*fixup_sk_storage_map) {
+		map_fds[17] = create_sk_storage_map();
+		do {
+			prog[*fixup_sk_storage_map].imm = map_fds[17];
+			fixup_sk_storage_map++;
+		} while (*fixup_sk_storage_map);
+	}
 }
 
 static int set_admin(bool admin)
diff --git a/tools/testing/selftests/bpf/verifier/sock.c b/tools/testing/selftests/bpf/verifier/sock.c
index 416436231fab..b31cd2cf50d0 100644
--- a/tools/testing/selftests/bpf/verifier/sock.c
+++ b/tools/testing/selftests/bpf/verifier/sock.c
@@ -382,3 +382,119 @@
 	.result = REJECT,
 	.errstr = "reference has not been acquired before",
 },
+{
+	"sk_storage_get(map, skb->sk, NULL, 0): value == NULL",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_MOV64_IMM(BPF_REG_3, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_storage_get),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_sk_storage_map = { 11 },
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+},
+{
+	"sk_storage_get(map, skb->sk, 1, 1): value == 1",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_IMM(BPF_REG_4, 1),
+	BPF_MOV64_IMM(BPF_REG_3, 1),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_storage_get),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_sk_storage_map = { 11 },
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = REJECT,
+	.errstr = "R3 type=inv expected=fp",
+},
+{
+	"sk_storage_get(map, skb->sk, &stack_value, 1): stack_value",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -8),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_IMM(BPF_REG_4, 1),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -8),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_storage_get),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_sk_storage_map = { 14 },
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+},
+{
+	"sk_storage_get(map, skb->sk, &stack_value, 1): partially init stack_value",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -8),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_EMIT_CALL(BPF_FUNC_sk_fullsock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_IMM(BPF_REG_4, 1),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -8),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_storage_get),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_sk_storage_map = { 14 },
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = REJECT,
+	.errstr = "invalid indirect read from stack",
+},
+{
+	"bpf_map_lookup_elem(smap, &key)",
+	.insns = {
+	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_sk_storage_map = { 3 },
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = REJECT,
+	.errstr = "cannot pass map_type 24 into func bpf_map_lookup_elem",
+},