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author | Peter Zijlstra <peterz@infradead.org> | 2014-10-02 16:17:02 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-02 16:28:44 -0700 |
commit | 6c72e3501d0d62fc064d3680e5234f3463ec5a86 (patch) | |
tree | 48b15a8bc67816fe492e1323580bf8ee99b29e81 /kernel/fork.c | |
parent | cba5b1c6e2c42152135a85b90bf820b77d6527da (diff) | |
download | lwn-6c72e3501d0d62fc064d3680e5234f3463ec5a86.tar.gz lwn-6c72e3501d0d62fc064d3680e5234f3463ec5a86.zip |
perf: fix perf bug in fork()
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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r-- | kernel/fork.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 0cf9cdb6e491..a91e47d86de2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1360,7 +1360,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, 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 */ shm_init_task(p); retval = copy_semundo(clone_flags, p); @@ -1566,8 +1566,9 @@ 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_threadgroup_lock: |