[PATCH 1/5] perf event: Check ref_reloc_sym before using it

From: Igor Lubashev
Date: Mon Aug 26 2019 - 21:40:30 EST


Check for ref_reloc_sym before using it instead of checking
symbol_conf.kptr_restrict and relying solely on that check.

Signed-off-by: Igor Lubashev <ilubashe@xxxxxxxxxx>
Reported-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
tools/perf/util/event.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index f440fdc3e953..b84f5f3c9651 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -913,11 +913,13 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
int err;
union perf_event *event;

- if (symbol_conf.kptr_restrict)
- return -1;
if (map == NULL)
return -1;

+ kmap = map__kmap(map);
+ if (!kmap->ref_reloc_sym)
+ return -1;
+
/*
* We should get this from /sys/kernel/sections/.text, but till that is
* available use this, and after it is use this as a fallback for older
@@ -940,7 +942,6 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
}

- kmap = map__kmap(map);
size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
size = PERF_ALIGN(size, sizeof(u64));
--
2.7.4