[tip:perf/core] perf report: Don't call map__kmap if map is NULL.

From: tip-bot for Wang Nan
Date: Wed Apr 08 2015 - 11:15:46 EST

Commit-ID: f6fcc1433a4a9057b2977313f31eadbc1c84268b
Gitweb: http://git.kernel.org/tip/f6fcc1433a4a9057b2977313f31eadbc1c84268b
Author: Wang Nan <wangnan0@xxxxxxxxxx>
AuthorDate: Wed, 8 Apr 2015 10:59:32 +0000
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 8 Apr 2015 11:00:00 -0300

perf report: Don't call map__kmap if map is NULL.

report__warn_kptr_restrict() calls map__kmap(kernel_map) before checking
kernel_map againest NULL.

Which is dangerous, since map__kmap() will return a invalid and not NULL

It will trigger a warning message in map__kmap() after the patch "perf:
kmaps: enforce usage of kmaps to protect futher bugs." was applied.

This patch fixes it by adding the missing checking.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1428490772-135393-1-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
tools/perf/builtin-report.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index b5b2ad4..476cdf7 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -347,7 +347,7 @@ static int perf_evlist__tty_browse_hists(struct perf_evlist *evlist,
static void report__warn_kptr_restrict(const struct report *rep)
struct map *kernel_map = rep->session->machines.host.vmlinux_maps[MAP__FUNCTION];
- struct kmap *kernel_kmap = map__kmap(kernel_map);
+ struct kmap *kernel_kmap = kernel_map ? map__kmap(kernel_map) : NULL;

if (kernel_map == NULL ||
(kernel_map->dso->hit &&
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/