diff options
| author | Oleg Nesterov <oleg@tv-sign.ru> | 2007-10-16 23:27:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 08:42:53 -0700 |
| commit | 0840a90d943bcde2fbfeabd3c256236eed2273cd (patch) | |
| tree | d423a5b7576f6ba35494aac06c97c6c21dac9bcf /fs/exec.c | |
| parent | 2b47c3611de05c585e2d81204f6c7e3e255a3461 (diff) | |
| download | lwn-0840a90d943bcde2fbfeabd3c256236eed2273cd.tar.gz lwn-0840a90d943bcde2fbfeabd3c256236eed2273cd.zip | |
exec: simplify ->sighand switching
There is no any reason to do recalc_sigpending() after changing ->sighand.
To begin with, recalc_sigpending() does not take ->sighand into account.
This means we don't need to take newsighand->siglock while changing sighands.
rcu_assign_pointer() provides a necessary barrier, and if another process
reads the new ->sighand it should either take tasklist_lock or it should use
lock_task_sighand() which has a corresponding smp_read_barrier_depends().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/fs/exec.c b/fs/exec.c index 59c0038baa4f..7f325df5e014 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -916,12 +916,7 @@ no_thread_group: write_lock_irq(&tasklist_lock); spin_lock(&oldsighand->siglock); - spin_lock_nested(&newsighand->siglock, SINGLE_DEPTH_NESTING); - rcu_assign_pointer(tsk->sighand, newsighand); - recalc_sigpending(); - - spin_unlock(&newsighand->siglock); spin_unlock(&oldsighand->siglock); write_unlock_irq(&tasklist_lock); @@ -931,12 +926,11 @@ no_thread_group: BUG_ON(!thread_group_leader(tsk)); return 0; } - + /* * These functions flushes out all traces of the currently running executable * so that a new one can be started */ - static void flush_old_files(struct files_struct * files) { long j = -1; |