From 5172672da02e483d9b3c4d814c3482d0c8ffb1a6 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 27 Nov 2019 11:56:31 +0200 Subject: 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 Signed-off-by: Adrian Hunter Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20191127095631.15663-1-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-script.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools') 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"); } -- cgit v1.2.3