From: Adrian Hunter adrian.hunter@intel.com
[ Upstream commit 5172672da02e483d9b3c4d814c3482d0c8ffb1a6 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/builtin-script.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 67be8d31afab6..6dba8b728d232 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -1084,7 +1084,7 @@ 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"); }