From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Oleg Nesterov <oleg@redhat.com>,
Sylvain ythier Hitier <sylvain.hitier@gmail.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 3.10 02/13] perf: fix perf bug in fork()
Date: Tue, 7 Oct 2014 16:20:07 -0700 [thread overview]
Message-ID: <20141007231919.997655907@linuxfoundation.org> (raw)
In-Reply-To: <20141007231919.924479934@linuxfoundation.org>
3.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Peter Zijlstra <peterz@infradead.org>
commit 6c72e3501d0d62fc064d3680e5234f3463ec5a86 upstream.
Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by
calling perf_event_free_task() when failing sched_fork() we will not yet
have done the memset() on ->perf_event_ctxp[] and will therefore try and
'free' the inherited contexts, which are still in use by the parent
process. This is bad..
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/events/core.c | 4 +++-
kernel/fork.c | 5 +++--
2 files changed, 6 insertions(+), 3 deletions(-)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7482,8 +7482,10 @@ int perf_event_init_task(struct task_str
for_each_task_context_nr(ctxn) {
ret = perf_event_init_context(child, ctxn);
- if (ret)
+ if (ret) {
+ perf_event_free_task(child);
return ret;
+ }
}
return 0;
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1324,7 +1324,7 @@ static struct task_struct *copy_process(
goto bad_fork_cleanup_policy;
retval = audit_alloc(p);
if (retval)
- goto bad_fork_cleanup_policy;
+ goto bad_fork_cleanup_perf;
/* copy all the process information */
retval = copy_semundo(clone_flags, p);
if (retval)
@@ -1522,8 +1522,9 @@ bad_fork_cleanup_semundo:
exit_sem(p);
bad_fork_cleanup_audit:
audit_free(p);
-bad_fork_cleanup_policy:
+bad_fork_cleanup_perf:
perf_event_free_task(p);
+bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
next prev parent reply other threads:[~2014-10-07 23:20 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-07 23:20 [PATCH 3.10 00/13] 3.10.57-stable review Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 01/13] udf: Avoid infinite loop when processing indirect ICBs Greg Kroah-Hartman
2014-10-07 23:20 ` Greg Kroah-Hartman [this message]
2014-10-07 23:20 ` [PATCH 3.10 03/13] init/Kconfig: Fix HAVE_FUTEX_CMPXCHG to not break up the EXPERT menu Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 04/13] ring-buffer: Fix infinite spin in reading buffer Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 05/13] mm, thp: move invariant bug check out of loop in __split_huge_page_map Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 06/13] mm: numa: Do not mark PTEs pte_numa when splitting huge pages Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 07/13] media: vb2: fix VBI/poll regression Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 08/13] md/raid5: disable DISCARD by default due to safety concerns Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 09/13] jiffies: Fix timeval conversion to jiffies Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 10/13] drbd: fix regression out of mem, failed to invoke fence-peer helper Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 11/13] nl80211: clear skb cb before passing to netlink Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 12/13] cpufreq: Fix wrong time unit conversion Greg Kroah-Hartman
2014-10-07 23:20 ` [PATCH 3.10 13/13] cpufreq: ondemand: Change the calculation of target frequency Greg Kroah-Hartman
2014-10-08 2:49 ` [PATCH 3.10 00/13] 3.10.57-stable review Guenter Roeck
2014-10-08 20:06 ` Shuah Khan
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