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| author | Teng Qin <qinteng@fb.com> | 2018-03-06 10:55:01 -0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-08 02:22:34 +0100 |
| commit | 95da0cdb723260362fc126a563285ac66a193da7 (patch) | |
| tree | db1eb572476d510c1a2e06c18c3ad6d4a79a0060 | |
| parent | a366e300ae9fc466d333e6d8f2bc5d58ed248041 (diff) | |
| download | linux-95da0cdb723260362fc126a563285ac66a193da7.tar.gz linux-95da0cdb723260362fc126a563285ac66a193da7.tar.bz2 linux-95da0cdb723260362fc126a563285ac66a193da7.zip | |
bpf: add support to read sample address in bpf program
This commit adds new field "addr" to bpf_perf_event_data which could be
read and used by bpf programs attached to perf events. The value of the
field is copied from bpf_perf_event_data_kern.addr and contains the
address value recorded by specifying sample_type with PERF_SAMPLE_ADDR
when calling perf_event_open.
Signed-off-by: Teng Qin <qinteng@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | include/uapi/linux/bpf_perf_event.h | 1 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 20 |
2 files changed, 17 insertions, 4 deletions
diff --git a/include/uapi/linux/bpf_perf_event.h b/include/uapi/linux/bpf_perf_event.h index 8f95303f9d80..eb1b9d21250c 100644 --- a/include/uapi/linux/bpf_perf_event.h +++ b/include/uapi/linux/bpf_perf_event.h @@ -13,6 +13,7 @@ struct bpf_perf_event_data { bpf_user_pt_regs_t regs; __u64 sample_period; + __u64 addr; }; #endif /* _UAPI__LINUX_BPF_PERF_EVENT_H__ */ diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index c0a9e310d715..c634e093951f 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -726,8 +726,7 @@ const struct bpf_prog_ops tracepoint_prog_ops = { static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, struct bpf_insn_access_aux *info) { - const int size_sp = FIELD_SIZEOF(struct bpf_perf_event_data, - sample_period); + const int size_u64 = sizeof(u64); if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) return false; @@ -738,8 +737,13 @@ static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type switch (off) { case bpf_ctx_range(struct bpf_perf_event_data, sample_period): - bpf_ctx_record_field_size(info, size_sp); - if (!bpf_ctx_narrow_access_ok(off, size, size_sp)) + bpf_ctx_record_field_size(info, size_u64); + if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) + return false; + break; + case bpf_ctx_range(struct bpf_perf_event_data, addr): + bpf_ctx_record_field_size(info, size_u64); + if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) return false; break; default: @@ -766,6 +770,14 @@ static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, bpf_target_off(struct perf_sample_data, period, 8, target_size)); break; + case offsetof(struct bpf_perf_event_data, addr): + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, + data), si->dst_reg, si->src_reg, + offsetof(struct bpf_perf_event_data_kern, data)); + *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, + bpf_target_off(struct perf_sample_data, addr, 8, + target_size)); + break; default: *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, regs), si->dst_reg, si->src_reg, |