diff options
author | Alexei Starovoitov <ast@fb.com> | 2016-04-06 18:43:27 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-04-07 21:04:26 -0400 |
commit | 9940d67c93b5bb7ddcf862b41b1847cb728186c4 (patch) | |
tree | e5b9a36df5bc8bde9b7435cda796d2cefe686e45 | |
parent | 9fd82b610ba3351f05a59c3e9117cfefe82f7751 (diff) | |
download | linux-9940d67c93b5bb7ddcf862b41b1847cb728186c4.tar.bz2 |
bpf: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint programs
needs two wrapper functions to fetch 'struct pt_regs *' to convert
tracepoint bpf context into kprobe bpf context to reuse existing
helper functions
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | include/linux/bpf.h | 1 | ||||
-rw-r--r-- | kernel/bpf/stackmap.c | 2 | ||||
-rw-r--r-- | kernel/trace/bpf_trace.c | 42 |
3 files changed, 43 insertions, 2 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 21ee41b92e8a..198f6ace70ec 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -160,6 +160,7 @@ struct bpf_array { #define MAX_TAIL_CALL_CNT 32 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); +u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); void bpf_fd_array_map_clear(struct bpf_map *map); bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp); const struct bpf_func_proto *bpf_get_trace_printk_proto(void); diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 499d9e933f8e..35114725cf30 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -116,7 +116,7 @@ free_smap: return ERR_PTR(err); } -static u64 bpf_get_stackid(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5) +u64 bpf_get_stackid(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5) { struct pt_regs *regs = (struct pt_regs *) (long) r1; struct bpf_map *map = (struct bpf_map *) (long) r2; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 3e5ebe3254d2..413ec5614180 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -340,12 +340,52 @@ static struct bpf_prog_type_list kprobe_tl = { .type = BPF_PROG_TYPE_KPROBE, }; +static u64 bpf_perf_event_output_tp(u64 r1, u64 r2, u64 index, u64 r4, u64 size) +{ + /* + * r1 points to perf tracepoint buffer where first 8 bytes are hidden + * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it + * from there and call the same bpf_perf_event_output() helper + */ + u64 ctx = *(long *)r1; + + return bpf_perf_event_output(ctx, r2, index, r4, size); +} + +static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { + .func = bpf_perf_event_output_tp, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_STACK, + .arg5_type = ARG_CONST_STACK_SIZE, +}; + +static u64 bpf_get_stackid_tp(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) +{ + u64 ctx = *(long *)r1; + + return bpf_get_stackid(ctx, r2, r3, r4, r5); +} + +static const struct bpf_func_proto bpf_get_stackid_proto_tp = { + .func = bpf_get_stackid_tp, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto *tp_prog_func_proto(enum bpf_func_id func_id) { switch (func_id) { case BPF_FUNC_perf_event_output: + return &bpf_perf_event_output_proto_tp; case BPF_FUNC_get_stackid: - return NULL; + return &bpf_get_stackid_proto_tp; default: return tracing_func_proto(func_id); } |