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| author |   Dave Marchevsky <davemarchevsky@fb.com> | 2021-09-17 11:29:05 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2021-09-17 14:02:05 -0700 |
| commit | 10aceb629e198429c849d5e995c3bb1ba7a9aaa3 (patch) | |
| tree | 1aa48fcb75302b3a2b2ec4f515f456bac55c4ea9 /kernel/bpf | |
| parent | selftests/bpf: Stop using bpf_program__load (diff) | |
| download | linux-dev-10aceb629e198429c849d5e995c3bb1ba7a9aaa3.tar.xz linux-dev-10aceb629e198429c849d5e995c3bb1ba7a9aaa3.zip | |
bpf: Add bpf_trace_vprintk helper
This helper is meant to be "bpf_trace_printk, but with proper vararg
support". Follow bpf_snprintf's example and take a u64 pseudo-vararg
array. Write to /sys/kernel/debug/tracing/trace_pipe using the same
mechanism as bpf_trace_printk. The functionality of this helper was
requested in the libbpf issue tracker [0].
[0] Closes: https://github.com/libbpf/libbpf/issues/315
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-4-davemarchevsky@fb.com
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 5 | ||||
| -rw-r--r-- | kernel/bpf/helpers.c | 2 |
2 files changed, 7 insertions, 0 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 9f4636d021b1..6fddc13fe67f 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2357,6 +2357,11 @@ const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) return NULL; } +const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void) +{ + return NULL; +} + u64 __weak bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 8f9f392c1322..2c604ff8c7fb 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1435,6 +1435,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_snprintf_proto; case BPF_FUNC_task_pt_regs: return &bpf_task_pt_regs_proto; + case BPF_FUNC_trace_vprintk: + return bpf_get_trace_vprintk_proto(); default: return NULL; } |