[PATCH] copy_process: cleanup bad_fork_cleanup_sighand
authorOleg Nesterov <oleg@tv-sign.ru>
Wed, 29 Mar 2006 00:11:14 +0000 (16:11 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Wed, 29 Mar 2006 02:36:42 +0000 (18:36 -0800)
commit7001510d0cbf51ad202dd2d0744f54104285cbb9
tree1df2a6930c460c12026231634b86d14b153a4a86
parenta9e88e84b5245da0a1dadb6ccca70ae84e93ccf6
[PATCH] copy_process: cleanup bad_fork_cleanup_sighand

The only caller of exit_sighand(tsk) is copy_process's error path.  We can
call __exit_sighand() directly and kill exit_sighand().

This 'tsk' was not yet registered in pid_hash[] or init_task.tasks, it has no
external references, nobody can see it, and

IF (clone_flags & CLONE_SIGHAND)
At least 'current' has a reference to ->sighand, this
means atomic_dec_and_test(sighand->count) can't be true.

ELSE
Nobody can see this ->sighand, this means we can free it
without any locking.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/linux/sched.h
kernel/fork.c
kernel/signal.c