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| author | Adrian Hunter <adrian.hunter@intel.com> | 2019-11-27 11:56:31 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-11-28 08:08:38 -0300 |
| commit | 5172672da02e483d9b3c4d814c3482d0c8ffb1a6 (patch) | |
| tree | d5ab3518545317132705791bbbf09017e4f2bafe /tools | |
| parent | 0cd032d3b5fcebf5454315400ab310746a81ca53 (diff) | |
| download | linux-5172672da02e483d9b3c4d814c3482d0c8ffb1a6.tar.gz linux-5172672da02e483d9b3c4d814c3482d0c8ffb1a6.tar.bz2 linux-5172672da02e483d9b3c4d814c3482d0c8ffb1a6.zip | |
perf script: Fix invalid LBR/binary mismatch error
The 'len' returned by grab_bb() includes an extra MAXINSN bytes to allow
for the last instruction, so the the final 'offs' will not be 'len'.
Fix the error condition logic accordingly.
Before:
$ perf record -e '{intel_pt//,cpu/mem_inst_retired.all_loads,aux-sample-size=8192/pp}:u' grep -rqs jhgjhg /boot
[ perf record: Woken up 19 times to write data ]
[ perf record: Captured and wrote 2.274 MB perf.data ]
$ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
grep 13759 [002] 8091.310257: 1862 instructions:uH: 5641d58069eb bmexec+0x86b (/bin/grep)
bmexec+2485:
00005641d5806b35 jnz 0x5641d5806bd0 # MISPRED
00005641d5806bd0 movzxb (%r13,%rdx,1), %eax
00005641d5806bd6 add %rdi, %rax
00005641d5806bd9 movzxb -0x1(%rax), %edx
00005641d5806bdd cmp %rax, %r14
00005641d5806be0 jnb 0x5641d58069c0 # MISPRED
mismatch of LBR data and executable
00005641d58069c0 movzxb (%r13,%rdx,1), %edi
After:
$ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
grep 13759 [002] 8091.310257: 1862 instructions:uH: 5641d58069eb bmexec+0x86b (/bin/grep)
bmexec+2485:
00005641d5806b35 jnz 0x5641d5806bd0 # MISPRED
00005641d5806bd0 movzxb (%r13,%rdx,1), %eax
00005641d5806bd6 add %rdi, %rax
00005641d5806bd9 movzxb -0x1(%rax), %edx
00005641d5806bdd cmp %rax, %r14
00005641d5806be0 jnb 0x5641d58069c0 # MISPRED
00005641d58069c0 movzxb (%r13,%rdx,1), %edi
00005641d58069c6 add %rax, %rdi
Fixes: e98df280bc2a ("perf script brstackinsn: Fix recovery from LBR/binary mismatch")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191127095631.15663-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/builtin-script.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index e8db26b9b29e..e2406b291c1c 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -1126,7 +1126,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample, insn++; } } - if (off != (unsigned)len) + if (off != end - start) printed += fprintf(fp, "\tmismatch of LBR data and executable\n"); } |