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| author | Daniel Borkmann <daniel@iogearbox.net> | 2016-09-09 02:45:29 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-09 19:36:04 -0700 |
| commit | f035a51536af9802f55d8c79bd87f184ebffb093 (patch) | |
| tree | b10ca650031a03f3752a1ea9f7178282e8eb0a75 /kernel/trace/bpf_trace.c | |
| parent | 6088b5823b4cb132a838878747384cbfb5ce6646 (diff) | |
| download | lwn-f035a51536af9802f55d8c79bd87f184ebffb093.tar.gz lwn-f035a51536af9802f55d8c79bd87f184ebffb093.zip | |
bpf: add BPF_SIZEOF and BPF_FIELD_SIZEOF macros
Add BPF_SIZEOF() and BPF_FIELD_SIZEOF() macros to improve the code a bit
which otherwise often result in overly long bytes_to_bpf_size(sizeof())
and bytes_to_bpf_size(FIELD_SIZEOF()) lines. So place them into a macro
helper instead. Moreover, we currently have a BUILD_BUG_ON(BPF_FIELD_SIZEOF())
check in convert_bpf_extensions(), but we should rather make that generic
as well and add a BUILD_BUG_ON() test in all BPF_SIZEOF()/BPF_FIELD_SIZEOF()
users to detect any rewriter size issues at compile time. Note, there are
currently none, but we want to assert that it stays this way.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/trace/bpf_trace.c')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index d3869b03d9fe..e63d7d435796 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -583,18 +583,18 @@ static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, int dst_reg, switch (ctx_off) { case offsetof(struct bpf_perf_event_data, sample_period): BUILD_BUG_ON(FIELD_SIZEOF(struct perf_sample_data, period) != sizeof(u64)); - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct bpf_perf_event_data_kern, data)), - dst_reg, src_reg, + + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, + data), dst_reg, src_reg, offsetof(struct bpf_perf_event_data_kern, data)); *insn++ = BPF_LDX_MEM(BPF_DW, dst_reg, dst_reg, offsetof(struct perf_sample_data, period)); break; default: - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct bpf_perf_event_data_kern, regs)), - dst_reg, src_reg, + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, + regs), dst_reg, src_reg, offsetof(struct bpf_perf_event_data_kern, regs)); - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(sizeof(long)), - dst_reg, dst_reg, ctx_off); + *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), dst_reg, dst_reg, ctx_off); break; } |