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authorOleg Nesterov <oleg@tv-sign.ru>2008-04-30 03:52:56 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 11:29:36 -0400
commite62e6650e99a3dffcd0bf0d063cd818fbc13fa95 (patch)
tree75f79d45eb89fb75014117b6fdc67bae1608f826 /kernel
parent4cd4b6d4e0372075f846feb85aea016cbdbfec4c (diff)
signals: unify send_sigqueue/send_group_sigqueue completely
Suggested by Pavel Emelyanov. send_sigqueue/send_group_sigqueue are only differ in how they lock ->siglock. Unify them. send_group_sigqueue() uses spin_lock() because it knows the task can't exit, but in that case lock_task_sighand() can't fail and doesn't hurt. Note that the "sig" argument is ignored, it is always equal to ->si_signo. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> 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 'kernel')
-rw-r--r--kernel/signal.c58
1 files changed, 21 insertions, 37 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 87424f7a4f3d..367c6662b12f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1240,14 +1240,27 @@ void sigqueue_free(struct sigqueue *q)
1240 __sigqueue_free(q); 1240 __sigqueue_free(q);
1241} 1241}
1242 1242
1243static int do_send_sigqueue(int sig, struct sigqueue *q, struct task_struct *t, 1243static int do_send_sigqueue(struct sigqueue *q, struct task_struct *t,
1244 int group) 1244 int group)
1245{ 1245{
1246 int sig = q->info.si_signo;
1246 struct sigpending *pending; 1247 struct sigpending *pending;
1248 unsigned long flags;
1249 int ret;
1247 1250
1248 BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); 1251 BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
1252
1253 ret = -1;
1254 if (!likely(lock_task_sighand(t, &flags)))
1255 goto ret;
1256
1249 handle_stop_signal(sig, t); 1257 handle_stop_signal(sig, t);
1250 1258
1259 ret = 1;
1260 if (sig_ignored(t, sig))
1261 goto out;
1262
1263 ret = 0;
1251 if (unlikely(!list_empty(&q->list))) { 1264 if (unlikely(!list_empty(&q->list))) {
1252 /* 1265 /*
1253 * If an SI_TIMER entry is already queue just increment 1266 * If an SI_TIMER entry is already queue just increment
@@ -1256,58 +1269,29 @@ static int do_send_sigqueue(int sig, struct sigqueue *q, struct task_struct *t,
1256 1269
1257 BUG_ON(q->info.si_code != SI_TIMER); 1270 BUG_ON(q->info.si_code != SI_TIMER);
1258 q->info.si_overrun++; 1271 q->info.si_overrun++;
1259 return 0; 1272 goto out;
1260 } 1273 }
1261 1274
1262 if (sig_ignored(t, sig))
1263 return 1;
1264
1265 signalfd_notify(t, sig); 1275 signalfd_notify(t, sig);
1266 pending = group ? &t->signal->shared_pending : &t->pending; 1276 pending = group ? &t->signal->shared_pending : &t->pending;
1267 list_add_tail(&q->list, &pending->list); 1277 list_add_tail(&q->list, &pending->list);
1268 sigaddset(&pending->signal, sig); 1278 sigaddset(&pending->signal, sig);
1269 complete_signal(sig, t, group); 1279 complete_signal(sig, t, group);
1270 1280out:
1271 return 0; 1281 unlock_task_sighand(t, &flags);
1282ret:
1283 return ret;
1272} 1284}
1273 1285
1274int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) 1286int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
1275{ 1287{
1276 unsigned long flags; 1288 return do_send_sigqueue(q, p, 0);
1277 int ret = -1;
1278
1279 /*
1280 * The rcu based delayed sighand destroy makes it possible to
1281 * run this without tasklist lock held. The task struct itself
1282 * cannot go away as create_timer did get_task_struct().
1283 *
1284 * We return -1, when the task is marked exiting, so
1285 * posix_timer_event can redirect it to the group leader
1286 */
1287 if (!likely(lock_task_sighand(p, &flags)))
1288 goto out_err;
1289
1290 ret = do_send_sigqueue(sig, q, p, 0);
1291
1292 unlock_task_sighand(p, &flags);
1293out_err:
1294 return ret;
1295} 1289}
1296 1290
1297int 1291int
1298send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) 1292send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
1299{ 1293{
1300 unsigned long flags; 1294 return do_send_sigqueue(q, p, 1);
1301 int ret;
1302
1303 /* Since it_lock is held, p->sighand cannot be NULL. */
1304 spin_lock_irqsave(&p->sighand->siglock, flags);
1305
1306 ret = do_send_sigqueue(sig, q, p, 1);
1307
1308 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1309
1310 return ret;
1311} 1295}
1312 1296
1313/* 1297/*