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-rw-r--r--tools/perf/builtin-script.c17
-rw-r--r--tools/perf/util/dump-insn.c8
-rw-r--r--tools/perf/util/dump-insn.h2
-rw-r--r--tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c8
4 files changed, 34 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);
}
diff --git a/tools/perf/util/dump-insn.c b/tools/perf/util/dump-insn.c
index 10988d3de7ce..2bd8585db93c 100644
--- a/tools/perf/util/dump-insn.c
+++ b/tools/perf/util/dump-insn.c
@@ -13,3 +13,11 @@ const char *dump_insn(struct perf_insn *x __maybe_unused,
*lenp = 0;
return "?";
}
+
+__weak
+int arch_is_branch(const unsigned char *buf __maybe_unused,
+ size_t len __maybe_unused,
+ int x86_64 __maybe_unused)
+{
+ return 0;
+}
diff --git a/tools/perf/util/dump-insn.h b/tools/perf/util/dump-insn.h
index 0e06280a8860..650125061530 100644
--- a/tools/perf/util/dump-insn.h
+++ b/tools/perf/util/dump-insn.h
@@ -20,4 +20,6 @@ struct perf_insn {
const char *dump_insn(struct perf_insn *x, u64 ip,
u8 *inbuf, int inlen, int *lenp);
+int arch_is_branch(const unsigned char *buf, size_t len, int x86_64);
+
#endif
diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c
index 54818828023b..1c0e289f01e6 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c
@@ -180,6 +180,14 @@ int intel_pt_get_insn(const unsigned char *buf, size_t len, int x86_64,
return 0;
}
+int arch_is_branch(const unsigned char *buf, size_t len, int x86_64)
+{
+ struct intel_pt_insn in;
+ if (intel_pt_get_insn(buf, len, x86_64, &in) < 0)
+ return -1;
+ return in.branch != INTEL_PT_BR_NO_BRANCH;
+}
+
const char *dump_insn(struct perf_insn *x, uint64_t ip __maybe_unused,
u8 *inbuf, int inlen, int *lenp)
{