[PATCH] perf script report: fix segfault when using DWARF mode

[Andreas Gerstmayr]

When running perf script report with a Python script and a callgraph in
DWARF mode, intr_regs->regs can be 0 and therefore crashing the regs_map
function.

Added a check for this condition (same check as in builtin-script.c:595).

Signed-off-by: Andreas Gerstmayr <agerstmayr@xxxxxxxxxx>
---
 tools/perf/util/scripting-engines/trace-event-python.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 8c1b27cd8b99..2c372cf5495e 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -694,6 +694,9 @@ static int regs_map(struct regs_dump *regs, uint64_t mask, char *bf, int size)
 
 	bf[0] = 0;
 
+	if (!regs || !regs->regs)
+		return 0;
+
 	for_each_set_bit(r, (unsigned long *) &mask, sizeof(mask) * 8) {
 		u64 val = regs->regs[i++];
 
-- 
2.25.1