From: Steven Rostedt Date: Tue, 5 Jul 2011 18:32:51 +0000 (-0400) Subject: tracing: Have "enable" file use refcounts like the "filter" file X-Git-Tag: v3.1-rc1~299^2~11^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=40ee4dffff061399eb9358e0c8fcfbaf8de4c8fe;p=pandora-kernel.git tracing: Have "enable" file use refcounts like the "filter" file The "enable" file for the event system can be removed when a module is unloaded and the event system only has events from that module. As the event system nr_events count goes to zero, it may be freed if its ref_count is also set to zero. Like the "filter" file, the "enable" file may be opened by a task and referenced later, after a module has been unloaded and the events for that event system have been removed. Although the "filter" file referenced the event system structure, the "enable" file only references a pointer to the event system name. Since the name is freed when the event system is removed, it is possible that an access to the "enable" file may reference a freed pointer. Update the "enable" file to use the subsystem_open() routine that the "filter" file uses, to keep a reference to the event system structure while the "enable" file is opened. Cc: Reported-by: Johannes Berg Signed-off-by: Steven Rostedt --- Reading git-diff-tree failed