Reset to 3.12.19

1 files changed, 17 insertions, 118 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 3d32f54..ded28b9 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -14,7 +14,6 @@
 #include <linux/export.h>
 #include <linux/init.h>
 #include <linux/sched.h>
-#include <linux/sched/rt.h>
 #include <linux/fs.h>
 #include <linux/tty.h>
 #include <linux/binfmts.h>
@@ -350,45 +349,13 @@ static bool task_participate_group_stop(struct task_struct *task)
 	return false;
 }
 
-#ifdef __HAVE_ARCH_CMPXCHG
-static inline struct sigqueue *get_task_cache(struct task_struct *t)
-{
-	struct sigqueue *q = t->sigqueue_cache;
-
-	if (cmpxchg(&t->sigqueue_cache, q, NULL) != q)
-		return NULL;
-	return q;
-}
-
-static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
-{
-	if (cmpxchg(&t->sigqueue_cache, NULL, q) == NULL)
-		return 0;
-	return 1;
-}
-
-#else
-
-static inline struct sigqueue *get_task_cache(struct task_struct *t)
-{
-	return NULL;
-}
-
-static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
-{
-	return 1;
-}
-
-#endif
-
 /*
  * allocate a new signal queue record
  * - this may be called without locks if and only if t == current, otherwise an
  *   appropriate lock must be held to stop the target task from exiting
  */
 static struct sigqueue *
-__sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags,
-		    int override_rlimit, int fromslab)
+__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit)
 {
 	struct sigqueue *q = NULL;
 	struct user_struct *user;
@@ -405,10 +372,7 @@ __sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags,
 	if (override_rlimit ||
 	    atomic_read(&user->sigpending) <=
 			task_rlimit(t, RLIMIT_SIGPENDING)) {
-		if (!fromslab)
-			q = get_task_cache(t);
-		if (!q)
-			q = kmem_cache_alloc(sigqueue_cachep, flags);
+		q = kmem_cache_alloc(sigqueue_cachep, flags);
 	} else {
 		print_dropped_signal(sig);
 	}
@@ -425,13 +389,6 @@ __sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags,
 	return q;
 }
 
-static struct sigqueue *
-__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags,
-		 int override_rlimit)
-{
-	return __sigqueue_do_alloc(sig, t, flags, override_rlimit, 0);
-}
-
 static void __sigqueue_free(struct sigqueue *q)
 {
 	if (q->flags & SIGQUEUE_PREALLOC)
@@ -441,21 +398,6 @@ static void __sigqueue_free(struct sigqueue *q)
 	kmem_cache_free(sigqueue_cachep, q);
 }
 
-static void sigqueue_free_current(struct sigqueue *q)
-{
-	struct user_struct *up;
-
-	if (q->flags & SIGQUEUE_PREALLOC)
-		return;
-
-	up = q->user;
-	if (rt_prio(current->normal_prio) && !put_task_cache(current, q)) {
-		atomic_dec(&up->sigpending);
-		free_uid(up);
-	} else
-		  __sigqueue_free(q);
-}
-
 void flush_sigqueue(struct sigpending *queue)
 {
 	struct sigqueue *q;
@@ -469,21 +411,6 @@ void flush_sigqueue(struct sigpending *queue)
 }
 
 /*
- * Called from __exit_signal. Flush tsk->pending and
- * tsk->sigqueue_cache
- */
-void flush_task_sigqueue(struct task_struct *tsk)
-{
-	struct sigqueue *q;
-
-	flush_sigqueue(&tsk->pending);
-
-	q = get_task_cache(tsk);
-	if (q)
-		kmem_cache_free(sigqueue_cachep, q);
-}
-
-/*
  * Flush all pending signals for a task.
  */
 void __flush_signals(struct task_struct *t)
@@ -635,7 +562,7 @@ static void collect_signal(int sig, struct sigpending *list, siginfo_t *info)
 still_pending:
 		list_del_init(&first->list);
 		copy_siginfo(info, &first->info);
-		sigqueue_free_current(first);
+		__sigqueue_free(first);
 	} else {
 		/*
 		 * Ok, it wasn't in the queue.  This must be
@@ -681,8 +608,6 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 {
 	int signr;
 
-	WARN_ON_ONCE(tsk != current);
-
 	/* We only dequeue private signals from ourselves, we don't let
 	 * signalfd steal them
 	 */
@@ -1305,8 +1230,8 @@ int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
  * We don't want to have recursive SIGSEGV's etc, for example,
  * that is why we also clear SIGNAL_UNKILLABLE.
  */
-static int
-do_force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+int
+force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 {
 	unsigned long int flags;
 	int ret, blocked, ignored;
@@ -1331,39 +1256,6 @@ do_force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 	return ret;
 }
 
-int force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
-{
-/*
- * On some archs, PREEMPT_RT has to delay sending a signal from a trap
- * since it can not enable preemption, and the signal code's spin_locks
- * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will
- * send the signal on exit of the trap.
- */
-#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
-	if (in_atomic()) {
-		if (WARN_ON_ONCE(t != current))
-			return 0;
-		if (WARN_ON_ONCE(t->forced_info.si_signo))
-			return 0;
-
-		if (is_si_special(info)) {
-			WARN_ON_ONCE(info != SEND_SIG_PRIV);
-			t->forced_info.si_signo = sig;
-			t->forced_info.si_errno = 0;
-			t->forced_info.si_code = SI_KERNEL;
-			t->forced_info.si_pid = 0;
-			t->forced_info.si_uid = 0;
-		} else {
-			t->forced_info = *info;
-		}
-
-		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
-		return 0;
-	}
-#endif
-	return do_force_sig_info(sig, info, t);
-}
-
 /*
  * Nuke all other threads in the group.
  */
@@ -1394,12 +1286,12 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
 	struct sighand_struct *sighand;
 
 	for (;;) {
-		local_irq_save_nort(*flags);
+		local_irq_save(*flags);
 		rcu_read_lock();
 		sighand = rcu_dereference(tsk->sighand);
 		if (unlikely(sighand == NULL)) {
 			rcu_read_unlock();
-			local_irq_restore_nort(*flags);
+			local_irq_restore(*flags);
 			break;
 		}
 
@@ -1410,7 +1302,7 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
 		}
 		spin_unlock(&sighand->siglock);
 		rcu_read_unlock();
-		local_irq_restore_nort(*flags);
+		local_irq_restore(*flags);
 	}
 
 	return sighand;
@@ -1655,8 +1547,7 @@ EXPORT_SYMBOL(kill_pid);
  */
 struct sigqueue *sigqueue_alloc(void)
 {
-	/* Preallocated sigqueue objects always from the slabcache ! */
-	struct sigqueue *q = __sigqueue_do_alloc(-1, current, GFP_KERNEL, 0, 1);
+	struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0);
 
 	if (q)
 		q->flags |= SIGQUEUE_PREALLOC;
@@ -2017,7 +1908,15 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info)
 		if (gstop_done && ptrace_reparented(current))
 			do_notify_parent_cldstop(current, false, why);
 
+		/*
+		 * Don't want to allow preemption here, because
+		 * sys_ptrace() needs this task to be inactive.
+		 *
+		 * XXX: implement read_unlock_no_resched().
+		 */
+		preempt_disable();
 		read_unlock(&tasklist_lock);
+		preempt_enable_no_resched();
 		freezable_schedule();
 	} else {
 		/*