From: Oleg Nesterov Date: Fri, 26 Jul 2013 17:25:43 +0000 (+0200) Subject: tracing: Change f_start() to take event_mutex and verify i_private != NULL X-Git-Tag: v3.11-rc5~28^2~13 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5a44a1200c6eda2202434f25325e8ad19533fca;p=pandora-kernel.git tracing: Change f_start() to take event_mutex and verify i_private != NULL trace_format_open() and trace_format_seq_ops are racy, nothing protects ftrace_event_call from trace_remove_event_call(). Change f_start() to take event_mutex and verify i_private != NULL, change f_stop() to drop this lock. This fixes nothing, but now we can change debugfs_remove("format") callers to nullify ->i_private and fix the the problem. Note: the usage of event_mutex is sub-optimal but simple, we can change this later. Link: http://lkml.kernel.org/r/20130726172543.GA3622@redhat.com Reviewed-by: Masami Hiramatsu Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt --- Reading git-diff-tree failed