[PATCH 21/22] perf script: Fix brstackinsn for AUXTRACE

From: Arnaldo Carvalho de Melo
Date: Thu Nov 28 2019 - 08:41:47 EST


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

brstackinsn must be allowed to be set by the user when AUX area data has
been captured because, in that case, the branch stack might be
synthesized on the fly. This fixes the following error:

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
Display of branch stack assembler requested, but non all-branch filter set
Hint: run 'perf record -b ...'

After:

$ 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

Fixes: 48d02a1d5c13 ("perf script: Add 'brstackinsn' for branch stacks")
Reported-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20191127095322.15417-1-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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 7b2f0922050c..e8db26b9b29e 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -448,7 +448,7 @@ static int perf_evsel__check_attr(struct evsel *evsel,
"selected. Hence, no address to lookup the source line number.\n");
return -EINVAL;
}
- if (PRINT_FIELD(BRSTACKINSN) &&
+ if (PRINT_FIELD(BRSTACKINSN) && !allow_user_set &&
!(perf_evlist__combined_branch_type(session->evlist) &
PERF_SAMPLE_BRANCH_ANY)) {
pr_err("Display of branch stack assembler requested, but non all-branch filter set\n"
--
2.21.0