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perf script: Fix invalid LBR/binary mismatch error

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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: e98df280bc ("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>
This commit is contained in:
Adrian Hunter 2019-11-27 11:56:31 +02:00 committed by Arnaldo Carvalho de Melo
parent 0cd032d3b5
commit 5172672da0
1 changed files with 1 additions and 1 deletions
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2
tools/perf/builtin-script.c
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@ -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");
}