From 4d220ed0f8140c478ab7b0a14d96821da639b646 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Sat, 28 Apr 2018 19:56:37 -0700 Subject: bpf: remove tracepoints from bpf core tracepoints to bpf core were added as a way to provide introspection to bpf programs and maps, but after some time it became clear that this approach is inadequate, so prog_id, map_id and corresponding get_next_id, get_fd_by_id, get_info_by_fd, prog_query APIs were introduced and fully adopted by bpftool and other applications. The tracepoints in bpf core started to rot and causing syzbot warnings: WARNING: CPU: 0 PID: 3008 at kernel/trace/trace_event_perf.c:274 Kernel panic - not syncing: panic_on_warn set ... perf_trace_bpf_map_keyval+0x260/0xbd0 include/trace/events/bpf.h:228 trace_bpf_map_update_elem include/trace/events/bpf.h:274 [inline] map_update_elem kernel/bpf/syscall.c:597 [inline] SYSC_bpf kernel/bpf/syscall.c:1478 [inline] Hence this patch deletes tracepoints in bpf core. Reported-by: Eric Biggers Reported-by: syzbot Signed-off-by: Alexei Starovoitov Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- kernel/bpf/syscall.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) (limited to 'kernel/bpf/syscall.c') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 0bd2944eafb9..263e13ede029 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -503,7 +503,6 @@ static int map_create(union bpf_attr *attr) return err; } - trace_bpf_map_create(map, err); return err; free_map: @@ -663,7 +662,6 @@ static int map_lookup_elem(union bpf_attr *attr) if (copy_to_user(uvalue, value, value_size) != 0) goto free_value; - trace_bpf_map_lookup_elem(map, ufd, key, value); err = 0; free_value: @@ -760,8 +758,6 @@ static int map_update_elem(union bpf_attr *attr) __this_cpu_dec(bpf_prog_active); preempt_enable(); out: - if (!err) - trace_bpf_map_update_elem(map, ufd, key, value); free_value: kfree(value); free_key: @@ -814,8 +810,6 @@ static int map_delete_elem(union bpf_attr *attr) __this_cpu_dec(bpf_prog_active); preempt_enable(); out: - if (!err) - trace_bpf_map_delete_elem(map, ufd, key); kfree(key); err_put: fdput(f); @@ -879,7 +873,6 @@ out: if (copy_to_user(unext_key, next_key, map->key_size) != 0) goto free_next_key; - trace_bpf_map_next_key(map, ufd, key, next_key); err = 0; free_next_key: @@ -1027,7 +1020,6 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) if (atomic_dec_and_test(&prog->aux->refcnt)) { int i; - trace_bpf_prog_put_rcu(prog); /* bpf_prog_free_id() must be called first */ bpf_prog_free_id(prog, do_idr_lock); @@ -1194,11 +1186,7 @@ struct bpf_prog *bpf_prog_get(u32 ufd) struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, bool attach_drv) { - struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv); - - if (!IS_ERR(prog)) - trace_bpf_prog_get_type(prog); - return prog; + return __bpf_prog_get(ufd, &type, attach_drv); } EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); @@ -1373,7 +1361,6 @@ static int bpf_prog_load(union bpf_attr *attr) } bpf_prog_kallsyms_add(prog); - trace_bpf_prog_load(prog, err); return err; free_used_maps: -- cgit v1.2.3 From 630a4d3874a06aa9f9481cbfc688981aad7a834c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 3 May 2018 18:37:09 -0700 Subject: nfp: bpf: record offload neutral maps in the driver For asynchronous events originating from the device, like perf event output, we need to be able to make sure that objects being referred to by the FW message are valid on the host. FW events can get queued and reordered. Even if we had a FW message "barrier" we should still protect ourselves from bogus FW output. Add a reverse-mapping hash table and record in it all raw map pointers FW may refer to. Only record neutral maps, i.e. perf event arrays. These are currently the only objects FW can refer to. Use RCU protection on the read side, update side is under RTNL. Since program vs map destruction order is slightly painful for offload simply take an extra reference on all the recorded maps to make sure they don't disappear. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- kernel/bpf/syscall.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/bpf/syscall.c') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 263e13ede029..9b87198deea2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -282,6 +282,7 @@ void bpf_map_put(struct bpf_map *map) { __bpf_map_put(map, true); } +EXPORT_SYMBOL_GPL(bpf_map_put); void bpf_map_put_with_uref(struct bpf_map *map) { @@ -543,6 +544,7 @@ struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref) atomic_inc(&map->usercnt); return map; } +EXPORT_SYMBOL_GPL(bpf_map_inc); struct bpf_map *bpf_map_get_with_uref(u32 ufd) { -- cgit v1.2.3