Merge commit 'v2.6.30-rc6' into perfcounters/core

Merge reason: this branch was on an -rc4 base, merge it up to -rc6
              to get the latest upstream fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

11 files changed, 58 insertions, 50 deletions

diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index a6fe71fd5d1..713098ee5a0 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1028,7 +1028,7 @@ static void audit_update_watch(struct audit_parent *parent,
 
 		if (audit_enabled) {
 			struct audit_buffer *ab;
-			ab = audit_log_start(NULL, GFP_KERNEL,
+			ab = audit_log_start(NULL, GFP_NOFS,
 				AUDIT_CONFIG_CHANGE);
 			audit_log_format(ab, "auid=%u ses=%u",
 				audit_get_loginuid(current),
@@ -1067,7 +1067,7 @@ static void audit_remove_parent_watches(struct audit_parent *parent)
 			e = container_of(r, struct audit_entry, rule);
 			if (audit_enabled) {
 				struct audit_buffer *ab;
-				ab = audit_log_start(NULL, GFP_KERNEL,
+				ab = audit_log_start(NULL, GFP_NOFS,
 					AUDIT_CONFIG_CHANGE);
 				audit_log_format(ab, "auid=%u ses=%u",
 					audit_get_loginuid(current),
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 382109b5bae..a7267bfd376 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1133,8 +1133,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
  free_cg_links:
 	free_cg_links(&tmp_cg_links);
  drop_new_super:
-	up_write(&sb->s_umount);
-	deactivate_super(sb);
+	deactivate_locked_super(sb);
 	return ret;
 }
 
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index d82142be8dd..26e08754744 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -363,8 +363,6 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
 	irqreturn_t ret, retval = IRQ_NONE;
 	unsigned int status = 0;
 
-	WARN_ONCE(!in_irq(), "BUG: IRQ handler called from non-hardirq context!");
-
 	if (!(action->flags & IRQF_DISABLED))
 		local_irq_enable_in_hardirq();
 
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index e4dcfb2272a..9147a3190c9 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -1583,8 +1583,8 @@ static void sysrq_handle_gdb(int key, struct tty_struct *tty)
 
 static struct sysrq_key_op sysrq_gdb_op = {
 	.handler	= sysrq_handle_gdb,
-	.help_msg	= "Gdb",
-	.action_msg	= "GDB",
+	.help_msg	= "debug(G)",
+	.action_msg	= "DEBUG",
 };
 #endif
 
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a5e74ddee0e..c0fa54b276d 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -319,6 +319,22 @@ struct kprobe __kprobes *get_kprobe(void *addr)
 	return NULL;
 }
 
+/* Arm a kprobe with text_mutex */
+static void __kprobes arm_kprobe(struct kprobe *kp)
+{
+	mutex_lock(&text_mutex);
+	arch_arm_kprobe(kp);
+	mutex_unlock(&text_mutex);
+}
+
+/* Disarm a kprobe with text_mutex */
+static void __kprobes disarm_kprobe(struct kprobe *kp)
+{
+	mutex_lock(&text_mutex);
+	arch_disarm_kprobe(kp);
+	mutex_unlock(&text_mutex);
+}
+
 /*
  * Aggregate handlers for multiple kprobes support - these handlers
  * take care of invoking the individual kprobe handlers on p->list
@@ -538,7 +554,7 @@ static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p)
 		ap->flags &= ~KPROBE_FLAG_DISABLED;
 		if (!kprobes_all_disarmed)
 			/* Arm the breakpoint again. */
-			arch_arm_kprobe(ap);
+			arm_kprobe(ap);
 	}
 	return 0;
 }
@@ -789,11 +805,8 @@ static int __kprobes __unregister_kprobe_top(struct kprobe *p)
 		 * enabled and not gone - otherwise, the breakpoint would
 		 * already have been removed. We save on flushing icache.
 		 */
-		if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) {
-			mutex_lock(&text_mutex);
-			arch_disarm_kprobe(p);
-			mutex_unlock(&text_mutex);
-		}
+		if (!kprobes_all_disarmed && !kprobe_disabled(old_p))
+			disarm_kprobe(p);
 		hlist_del_rcu(&old_p->hlist);
 	} else {
 		if (p->break_handler && !kprobe_gone(p))
@@ -810,7 +823,7 @@ noclean:
 		if (!kprobe_disabled(old_p)) {
 			try_to_disable_aggr_kprobe(old_p);
 			if (!kprobes_all_disarmed && kprobe_disabled(old_p))
-				arch_disarm_kprobe(old_p);
+				disarm_kprobe(old_p);
 		}
 	}
 	return 0;
@@ -1364,7 +1377,7 @@ int __kprobes disable_kprobe(struct kprobe *kp)
 		try_to_disable_aggr_kprobe(p);
 
 	if (!kprobes_all_disarmed && kprobe_disabled(p))
-		arch_disarm_kprobe(p);
+		disarm_kprobe(p);
 out:
 	mutex_unlock(&kprobe_mutex);
 	return ret;
@@ -1393,7 +1406,7 @@ int __kprobes enable_kprobe(struct kprobe *kp)
 	}
 
 	if (!kprobes_all_disarmed && kprobe_disabled(p))
-		arch_arm_kprobe(p);
+		arm_kprobe(p);
 
 	p->flags &= ~KPROBE_FLAG_DISABLED;
 	if (p != kp)
diff --git a/kernel/panic.c b/kernel/panic.c
index 3dcaa166135..874ecf1307a 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -340,7 +340,7 @@ void oops_exit(void)
 }
 
 #ifdef WANT_WARN_ON_SLOWPATH
-void warn_slowpath(const char *file, int line, const char *fmt, ...)
+void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
 {
 	va_list args;
 	char function[KSYM_SYMBOL_LEN];
@@ -356,7 +356,7 @@ void warn_slowpath(const char *file, int line, const char *fmt, ...)
 	if (board)
 		printk(KERN_WARNING "Hardware name: %s\n", board);
 
-	if (fmt) {
+	if (*fmt) {
 		va_start(args, fmt);
 		vprintk(fmt, args);
 		va_end(args);
@@ -367,7 +367,14 @@ void warn_slowpath(const char *file, int line, const char *fmt, ...)
 	print_oops_end_marker();
 	add_taint(TAINT_WARN);
 }
-EXPORT_SYMBOL(warn_slowpath);
+EXPORT_SYMBOL(warn_slowpath_fmt);
+
+void warn_slowpath_null(const char *file, int line)
+{
+	static const char *empty = "";
+	warn_slowpath_fmt(file, line, empty);
+}
+EXPORT_SYMBOL(warn_slowpath_null);
 #endif
 
 #ifdef CONFIG_CC_STACKPROTECTOR
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index c9dcf98b446..bece7c0b67b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1420,19 +1420,19 @@ void run_posix_cpu_timers(struct task_struct *tsk)
 	 * timer call will interfere.
 	 */
 	list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
-		int firing;
+		int cpu_firing;
+
 		spin_lock(&timer->it_lock);
 		list_del_init(&timer->it.cpu.entry);
-		firing = timer->it.cpu.firing;
+		cpu_firing = timer->it.cpu.firing;
 		timer->it.cpu.firing = 0;
 		/*
 		 * The firing flag is -1 if we collided with a reset
 		 * of the timer, which already reported this
 		 * almost-firing as an overrun.  So don't generate an event.
 		 */
-		if (likely(firing >= 0)) {
+		if (likely(cpu_firing >= 0))
 			cpu_timer_fire(timer);
-		}
 		spin_unlock(&timer->it_lock);
 	}
 }
diff --git a/kernel/sched.c b/kernel/sched.c
index a728976a3a6..419a39d0988 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4769,7 +4769,7 @@ void account_process_tick(struct task_struct *p, int user_tick)
 
 	if (user_tick)
 		account_user_time(p, one_jiffy, one_jiffy_scaled);
-	else if (p != rq->idle)
+	else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
 		account_system_time(p, HARDIRQ_OFFSET, one_jiffy,
 				    one_jiffy_scaled);
 	else
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 3b05c2b088d..3cb1849f598 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -102,7 +102,9 @@ static int __maybe_unused one = 1;
 static int __maybe_unused two = 2;
 static unsigned long one_ul = 1;
 static int one_hundred = 100;
-static int one_thousand = 1000;
+
+/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
+static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 
 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 static int maxolduid = 65535;
@@ -1025,7 +1027,7 @@ static struct ctl_table vm_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &dirty_bytes_handler,
 		.strategy	= &sysctl_intvec,
-		.extra1		= &one_ul,
+		.extra1		= &dirty_bytes_min,
 	},
 	{
 		.procname	= "dirty_writeback_centisecs",
@@ -1050,28 +1052,6 @@ static struct ctl_table vm_table[] = {
 		.proc_handler	= &proc_dointvec,
 	},
 	{
-		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "nr_pdflush_threads_min",
-		.data		= &nr_pdflush_threads_min,
-		.maxlen		= sizeof nr_pdflush_threads_min,
-		.mode		= 0644 /* read-write */,
-		.proc_handler	= &proc_dointvec_minmax,
-		.strategy	= &sysctl_intvec,
-		.extra1		= &one,
-		.extra2		= &nr_pdflush_threads_max,
-	},
-	{
-		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "nr_pdflush_threads_max",
-		.data		= &nr_pdflush_threads_max,
-		.maxlen		= sizeof nr_pdflush_threads_max,
-		.mode		= 0644 /* read-write */,
-		.proc_handler	= &proc_dointvec_minmax,
-		.strategy	= &sysctl_intvec,
-		.extra1		= &nr_pdflush_threads_min,
-		.extra2		= &one_thousand,
-	},
-	{
 		.ctl_name	= VM_SWAPPINESS,
 		.procname	= "swappiness",
 		.data		= &vm_swappiness,
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 21a5ca84951..83c4417b6a3 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -93,7 +93,17 @@ void tick_handle_periodic(struct clock_event_device *dev)
 	for (;;) {
 		if (!clockevents_program_event(dev, next, ktime_get()))
 			return;
-		tick_periodic(cpu);
+		/*
+		 * Have to be careful here. If we're in oneshot mode,
+		 * before we call tick_periodic() in a loop, we need
+		 * to be sure we're using a real hardware clocksource.
+		 * Otherwise we could get trapped in an infinite
+		 * loop, as the tick_periodic() increments jiffies,
+		 * when then will increment time, posibly causing
+		 * the loop to trigger again and again.
+		 */
+		if (timekeeping_valid_for_hres())
+			tick_periodic(cpu);
 		next = ktime_add(next, tick_period);
 	}
 }
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1ce5dc6372b..a884c09006c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3448,6 +3448,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 		if (!ref)
 			break;
 
+		ref->ref = 1;
 		ref->buffer = info->tr->buffer;
 		ref->page = ring_buffer_alloc_read_page(ref->buffer);
 		if (!ref->page) {