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-rw-r--r--tools/perf/builtin-script.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 3728b50e52e2..88d52ed85ffc 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1073,9 +1073,18 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
/*
* Print final block upto sample
+ *
+ * Due to pipeline delays the LBRs might be missing a branch
+ * or two, which can result in very large or negative blocks
+ * between final branch and sample. When this happens just
+ * continue walking after the last TO until we hit a branch.
*/
start = br->entries[0].to;
end = sample->ip;
+ if (end < start) {
+ /* Missing jump. Scan 128 bytes for the next branch */
+ end = start + 128;
+ }
len = grab_bb(buffer, start, end, machine, thread, &x.is64bit, &x.cpumode, true);
printed += ip__fprintf_sym(start, thread, x.cpumode, x.cpu, &lastsym, attr, fp);
if (len <= 0) {
@@ -1084,7 +1093,6 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
machine, thread, &x.is64bit, &x.cpumode, false);
if (len <= 0)
goto out;
-
printed += fprintf(fp, "\t%016" PRIx64 "\t%s\n", sample->ip,
dump_insn(&x, sample->ip, buffer, len, NULL));
if (PRINT_FIELD(SRCCODE))
@@ -1096,6 +1104,13 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
dump_insn(&x, start + off, buffer + off, len - off, &ilen));
if (ilen == 0)
break;
+ if (arch_is_branch(buffer + off, len - off, x.is64bit) && start + off != sample->ip) {
+ /*
+ * Hit a missing branch. Just stop.
+ */
+ printed += fprintf(fp, "\t... not reaching sample ...\n");
+ break;
+ }
if (PRINT_FIELD(SRCCODE))
print_srccode(thread, x.cpumode, start + off);
}