diff options
author | Peter Zijlstra <peterz@infradead.org> | 2014-10-02 16:17:02 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-09 12:23:47 -0700 |
commit | 54a9ae913f324df56734a57af9dea94f14362cf4 (patch) | |
tree | 857f2d0c02e9611418832f1b712e3b639ae1085d /kernel | |
parent | 8f805204b5b0595140be2b33e2297d8ba1c7fc13 (diff) |
perf: fix perf bug in fork()
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>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/events/core.c | 4 | ||||
-rw-r--r-- | kernel/fork.c | 5 |
2 files changed, 6 insertions, 3 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index f626c9f1f3c0..2065959042ea 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7921,8 +7921,10 @@ int perf_event_init_task(struct task_struct *child) 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; diff --git a/kernel/fork.c b/kernel/fork.c index 6a13c46cd87d..b41958b0cb67 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1326,7 +1326,7 @@ 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 */ retval = copy_semundo(clone_flags, p); if (retval) @@ -1525,8 +1525,9 @@ 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: |