From: Al Viro Date: Mon, 20 Aug 2012 13:59:25 +0000 (+0100) Subject: perf_event: Switch to internal refcount, fix race with close() X-Git-Tag: v3.2.30~44 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f8112ffff6bacaad4fcdf144fee23d1b1be74f9a;p=pandora-kernel.git perf_event: Switch to internal refcount, fix race with close() commit a6fa941d94b411bbd2b6421ffbde6db3c93e65ab upstream. Don't mess with file refcounts (or keep a reference to file, for that matter) in perf_event. Use explicit refcount of its own instead. Deal with the race between the final reference to event going away and new children getting created for it by use of atomic_long_inc_not_zero() in inherit_event(); just have the latter free what it had allocated and return NULL, that works out just fine (children of siblings of something doomed are created as singletons, same as if the child of leader had been created and immediately killed). Signed-off-by: Al Viro Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20120820135925.GG23464@ZenIV.linux.org.uk Signed-off-by: Ingo Molnar Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed