[PATCH] cleanup __exit_signal->cleanup_sighand path

Move 'tsk->sighand = NULL' from cleanup_sighand() to __exit_signal().  This
makes the exit path more understandable and allows us to do
cleanup_sighand() outside of ->siglock protected section.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 99855f6..d04186d 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1151,7 +1151,7 @@ extern void exit_thread(void);
 
 extern void exit_files(struct task_struct *);
 extern void __cleanup_signal(struct signal_struct *);
-extern void cleanup_sighand(struct task_struct *);
+extern void __cleanup_sighand(struct sighand_struct *);
 extern void exit_itimers(struct signal_struct *);
 
 extern NORET_TYPE void do_group_exit(int);

diff --git a/kernel/exit.c b/kernel/exit.c
index 22399ca..bc0ec67 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -114,10 +114,11 @@ static void __exit_signal(struct task_struct *tsk)
        __unhash_process(tsk);
 
        tsk->signal = NULL;
-       cleanup_sighand(tsk);
+       tsk->sighand = NULL;
        spin_unlock(&sighand->siglock);
        rcu_read_unlock();
 
+       __cleanup_sighand(sighand);
        clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
        flush_sigqueue(&tsk->pending);
        if (sig) {

diff --git a/kernel/fork.c b/kernel/fork.c
index aa50c84..b3f7a1b 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -803,12 +803,8 @@ static inline int copy_sighand(unsigned long clone_flags, struct task_struct * t
        return 0;
 }
 
-void cleanup_sighand(struct task_struct *tsk)
+void __cleanup_sighand(struct sighand_struct *sighand)
 {
-       struct sighand_struct * sighand = tsk->sighand;
-
-       /* Ok, we're done with the signal handlers */
-       tsk->sighand = NULL;
        if (atomic_dec_and_test(&sighand->count))
                kmem_cache_free(sighand_cachep, sighand);
 }
@@ -1233,7 +1229,7 @@ bad_fork_cleanup_mm:
 bad_fork_cleanup_signal:
        cleanup_signal(p);
 bad_fork_cleanup_sighand:
-       cleanup_sighand(p);
+       __cleanup_sighand(p->sighand);
 bad_fork_cleanup_fs:
        exit_fs(p); /* blocking */
 bad_fork_cleanup_files: