2015-04-08 10:59:48

by Wang Nan

Subject: [PATCH] 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 address. It will trigger
a warning message in map__kmap() after patch "perf: kmaps: enforce
usage of kmaps to protect futher bugs."

This patch fixes it by adding the missing checking.

Signed-off-by: Wang Nan <[email protected]>
---
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 &&
--
1.8.3.4

2015-04-08 12:56:38

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] perf: report: don't call map__kmap if map is NULL.

Em Wed, Apr 08, 2015 at 10:59:32AM +0000, Wang Nan escreveu:
> 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 address. It will trigger
> a warning message in map__kmap() after patch "perf: kmaps: enforce
> usage of kmaps to protect futher bugs."
>
> This patch fixes it by adding the missing checking.
>
> Signed-off-by: Wang Nan <[email protected]>
> ---
> 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 &&

Thanks, applied.

2015-04-08 15:15:42

by tip-bot for Vasyl Gomonovych

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

Commit-ID: f6fcc1433a4a9057b2977313f31eadbc1c84268b
Gitweb: http://git.kernel.org/tip/f6fcc1433a4a9057b2977313f31eadbc1c84268b
Author: Wang Nan <[email protected]>
AuthorDate: Wed, 8 Apr 2015 10:59:32 +0000
Committer: Arnaldo Carvalho de Melo <[email protected]>
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
address.

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 <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Zefan Li <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
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 &&