Merge commit 'v2.6.33' into perf/core

Merge reason:
	__percpu annotations need the corresponding sparse address
space definition upstream.

Conflicts:
	tools/perf/util/probe-event.c (trivial)

1 files changed, 43 insertions, 11 deletions

diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index c030ae657f20..967e66143e11 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -243,38 +243,70 @@ static void toggle_bp_slot(struct perf_event *bp, bool enable)
  *       ((per_cpu(nr_bp_flexible, *) > 1) + max(per_cpu(nr_cpu_bp_pinned, *))
  *            + max(per_cpu(nr_task_bp_pinned, *))) < HBP_NUM
  */
-int reserve_bp_slot(struct perf_event *bp)
+static int __reserve_bp_slot(struct perf_event *bp)
 {
         struct bp_busy_slots slots = {0};
-        int ret = 0;
-
-        mutex_lock(&nr_bp_mutex);
 
         fetch_bp_busy_slots(&slots, bp);
 
         /* Flexible counters need to keep at least one slot */
-        if (slots.pinned + (!!slots.flexible) == HBP_NUM) {
-                ret = -ENOSPC;
-                goto end;
-        }
+        if (slots.pinned + (!!slots.flexible) == HBP_NUM)
+                return -ENOSPC;
 
         toggle_bp_slot(bp, true);
 
-end:
+        return 0;
+}
+
+int reserve_bp_slot(struct perf_event *bp)
+{
+        int ret;
+
+        mutex_lock(&nr_bp_mutex);
+
+        ret = __reserve_bp_slot(bp);
+
         mutex_unlock(&nr_bp_mutex);
 
         return ret;
 }
 
+static void __release_bp_slot(struct perf_event *bp)
+{
+        toggle_bp_slot(bp, false);
+}
+
 void release_bp_slot(struct perf_event *bp)
 {
         mutex_lock(&nr_bp_mutex);
 
-        toggle_bp_slot(bp, false);
+        __release_bp_slot(bp);
 
         mutex_unlock(&nr_bp_mutex);
 }
 
+/*
+ * Allow the kernel debugger to reserve breakpoint slots without
+ * taking a lock using the dbg_* variant of for the reserve and
+ * release breakpoint slots.
+ */
+int dbg_reserve_bp_slot(struct perf_event *bp)
+{
+        if (mutex_is_locked(&nr_bp_mutex))
+                return -1;
+
+        return __reserve_bp_slot(bp);
+}
+
+int dbg_release_bp_slot(struct perf_event *bp)
+{
+        if (mutex_is_locked(&nr_bp_mutex))
+                return -1;
+
+        __release_bp_slot(bp);
+
+        return 0;
+}
 
 int register_perf_hw_breakpoint(struct perf_event *bp)
 {
@@ -328,8 +360,8 @@ EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
 int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
 {
         u64 old_addr = bp->attr.bp_addr;
+        u64 old_len = bp->attr.bp_len;
         int old_type = bp->attr.bp_type;
-        int old_len = bp->attr.bp_len;
         int err = 0;
 
         perf_event_disable(bp);