Commit-ID: f3ae75de98c4bac145a87d830c156c96f9414022 Gitweb: http://git.kernel.org/tip/f3ae75de98c4bac145a87d830c156c96f9414022 Author: Stephane Eranian <eran...@google.com> AuthorDate: Wed, 8 Jan 2014 11:15:52 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 12 Jan 2014 10:16:07 +0100
perf/x86: Fix active_entry initialization This patch fixes a problem with the initialization of the struct perf_event active_entry field. It is defined inside an anonymous union and was initialized in perf_event_alloc() using INIT_LIST_HEAD(). However at that time, we do not know whether the event is going to use active_entry or hlist_entry (SW). Or at last, we don't want to make that determination there. The problem is that hlist and list_head are not initialized the same way. One is okay with NULL (from kzmalloc), the other needs to pointers to point to self. This patch resolves this problem by dropping the union. This will avoid problems later on, if someone starts using active_entry or hlist_entry without verifying that they actually overlap. This also solves the initialization problem. Signed-off-by: Stephane Eranian <eran...@google.com> Cc: a...@linux.intel.com Cc: a...@redhat.com Cc: jo...@redhat.com Cc: zheng.z....@intel.com Cc: b...@alien8.de Cc: vincent.wea...@maine.edu Cc: maria.n.dimakopou...@gmail.com Signed-off-by: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/1389176153-3128-2-git-send-email-eran...@google.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- include/linux/perf_event.h | 6 ++---- kernel/events/core.c | 2 ++ 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 8f4a70f..e56b07f 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -319,10 +319,8 @@ struct perf_event { */ struct list_head migrate_entry; - union { - struct hlist_node hlist_entry; - struct list_head active_entry; - }; + struct hlist_node hlist_entry; + struct list_head active_entry; int nr_siblings; int group_flags; struct perf_event *group_leader; diff --git a/kernel/events/core.c b/kernel/events/core.c index 89d34f9..c3b6c27 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6670,6 +6670,8 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, INIT_LIST_HEAD(&event->sibling_list); INIT_LIST_HEAD(&event->rb_entry); INIT_LIST_HEAD(&event->active_entry); + INIT_HLIST_NODE(&event->hlist_entry); + init_waitqueue_head(&event->waitq); init_irq_work(&event->pending, perf_pending_event); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
