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 a6fe71fd5d1b..713098ee5a02 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 382109b5baeb..a7267bfd3765 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 d82142be8dd2..26e08754744f 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 e4dcfb2272a4..9147a3190c9d 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 a5e74ddee0e2..c0fa54b276d9 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 3dcaa1661357..874ecf1307ae 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 c9dcf98b4463..bece7c0b67b2 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 a728976a3a6c..419a39d0988f 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 3b05c2b088d2..3cb1849f5989 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 21a5ca849514..83c4417b6a3c 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 1ce5dc6372b8..a884c09006c4 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) {