printk: fix lockdep instrumentation of console_sem
authorJan Kara <jack@suse.cz>
Wed, 4 Jun 2014 23:11:36 +0000 (16:11 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 4 Jun 2014 23:54:16 +0000 (16:54 -0700)
commitbd8d7cf5b8410fe98eba06a9aaa90efe88815d8a
treec00e0af9d7fbed0b5e6d89d7b2b8348513103328
parent608873cacb9d0d2811586fcc79a38b64eabd6d32
printk: fix lockdep instrumentation of console_sem

Printk calls mutex_acquire() / mutex_release() by hand to instrument
lockdep about console_sem.  However in some corner cases the
instrumentation is missing.  Fix the problem by creating helper functions
for locking / unlocking console_sem which take care of lockdep
instrumentation as well.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Fabio Estevam <festevam@gmail.com>
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <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>
kernel/printk/printk.c