* [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less()
@ 2020-03-12 10:56 Dan Carpenter
2020-03-13 12:27 ` Peter Zijlstra
2020-03-20 12:58 ` [tip: perf/core] " tip-bot2 for Dan Carpenter
0 siblings, 2 replies; 4+ messages in thread
From: Dan Carpenter @ 2020-03-12 10:56 UTC (permalink / raw)
To: Peter Zijlstra, Ian Rogers
Cc: Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
Alexander Shishkin, Jiri Olsa, Namhyung Kim, linux-kernel,
kernel-janitors
This NULL check is reversed so it leads to a Smatch warning and
presumably a NULL dereference.
kernel/events/core.c:1598 perf_event_groups_less()
error: we previously assumed 'right->cgrp->css.cgroup' could be null
(see line 1590)
Fixes: 95ed6c707f26 ("perf/cgroup: Order events in RB tree by cgroup id")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6a47c3e54fe9..607c04ec7cfa 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1587,7 +1587,7 @@ perf_event_groups_less(struct perf_event *left, struct perf_event *right)
*/
return true;
}
- if (!right->cgrp || right->cgrp->css.cgroup) {
+ if (!right->cgrp || !right->cgrp->css.cgroup) {
/*
* Right has no cgroup but left does, no cgroups come
* first.
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less()
2020-03-12 10:56 [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less() Dan Carpenter
@ 2020-03-13 12:27 ` Peter Zijlstra
2020-03-21 2:24 ` Ian Rogers
2020-03-20 12:58 ` [tip: perf/core] " tip-bot2 for Dan Carpenter
1 sibling, 1 reply; 4+ messages in thread
From: Peter Zijlstra @ 2020-03-13 12:27 UTC (permalink / raw)
To: Dan Carpenter
Cc: Ian Rogers, Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
Alexander Shishkin, Jiri Olsa, Namhyung Kim, linux-kernel,
kernel-janitors
On Thu, Mar 12, 2020 at 01:56:37PM +0300, Dan Carpenter wrote:
> This NULL check is reversed so it leads to a Smatch warning and
> presumably a NULL dereference.
>
> kernel/events/core.c:1598 perf_event_groups_less()
> error: we previously assumed 'right->cgrp->css.cgroup' could be null
> (see line 1590)
>
> Fixes: 95ed6c707f26 ("perf/cgroup: Order events in RB tree by cgroup id")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> kernel/events/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 6a47c3e54fe9..607c04ec7cfa 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -1587,7 +1587,7 @@ perf_event_groups_less(struct perf_event *left, struct perf_event *right)
> */
> return true;
> }
> - if (!right->cgrp || right->cgrp->css.cgroup) {
> + if (!right->cgrp || !right->cgrp->css.cgroup) {
> /*
> * Right has no cgroup but left does, no cgroups come
> * first.
Thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less()
2020-03-13 12:27 ` Peter Zijlstra
@ 2020-03-21 2:24 ` Ian Rogers
0 siblings, 0 replies; 4+ messages in thread
From: Ian Rogers @ 2020-03-21 2:24 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Dan Carpenter, Ingo Molnar, Arnaldo Carvalho de Melo,
Mark Rutland, Alexander Shishkin, Jiri Olsa, Namhyung Kim, LKML,
kernel-janitors
On Fri, Mar 13, 2020 at 5:27 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Thu, Mar 12, 2020 at 01:56:37PM +0300, Dan Carpenter wrote:
> > This NULL check is reversed so it leads to a Smatch warning and
> > presumably a NULL dereference.
> >
> > kernel/events/core.c:1598 perf_event_groups_less()
> > error: we previously assumed 'right->cgrp->css.cgroup' could be null
> > (see line 1590)
> >
> > Fixes: 95ed6c707f26 ("perf/cgroup: Order events in RB tree by cgroup id")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > kernel/events/core.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/events/core.c b/kernel/events/core.c
> > index 6a47c3e54fe9..607c04ec7cfa 100644
> > --- a/kernel/events/core.c
> > +++ b/kernel/events/core.c
> > @@ -1587,7 +1587,7 @@ perf_event_groups_less(struct perf_event *left, struct perf_event *right)
> > */
> > return true;
> > }
> > - if (!right->cgrp || right->cgrp->css.cgroup) {
> > + if (!right->cgrp || !right->cgrp->css.cgroup) {
> > /*
> > * Right has no cgroup but left does, no cgroups come
> > * first.
>
> Thanks!
Also much thanks!
Ian
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip: perf/core] perf/core: Fix reversed NULL check in perf_event_groups_less()
2020-03-12 10:56 [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less() Dan Carpenter
2020-03-13 12:27 ` Peter Zijlstra
@ 2020-03-20 12:58 ` tip-bot2 for Dan Carpenter
1 sibling, 0 replies; 4+ messages in thread
From: tip-bot2 for Dan Carpenter @ 2020-03-20 12:58 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Dan Carpenter, Peter Zijlstra (Intel), x86, LKML
The following commit has been merged into the perf/core branch of tip:
Commit-ID: a6763625ae6f8aa5ee82fcd8fa4e5e38db20dbc6
Gitweb: https://git.kernel.org/tip/a6763625ae6f8aa5ee82fcd8fa4e5e38db20dbc6
Author: Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Thu, 12 Mar 2020 13:56:37 +03:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 20 Mar 2020 13:06:22 +01:00
perf/core: Fix reversed NULL check in perf_event_groups_less()
This NULL check is reversed so it leads to a Smatch warning and
presumably a NULL dereference.
kernel/events/core.c:1598 perf_event_groups_less()
error: we previously assumed 'right->cgrp->css.cgroup' could be null
(see line 1590)
Fixes: 95ed6c707f26 ("perf/cgroup: Order events in RB tree by cgroup id")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200312105637.GA8960@mwanda
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b5a68d2..d22e4ba 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1586,7 +1586,7 @@ perf_event_groups_less(struct perf_event *left, struct perf_event *right)
*/
return true;
}
- if (!right->cgrp || right->cgrp->css.cgroup) {
+ if (!right->cgrp || !right->cgrp->css.cgroup) {
/*
* Right has no cgroup but left does, no cgroups come
* first.
^ permalink raw reply related [flat|nested] 4+ messages in thread
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2020-03-12 10:56 [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less() Dan Carpenter
2020-03-13 12:27 ` Peter Zijlstra
2020-03-21 2:24 ` Ian Rogers
2020-03-20 12:58 ` [tip: perf/core] " tip-bot2 for Dan Carpenter
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