Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Validate cpu early in perf_event_alloc()
  perf: Find_get_context: fix the per-cpu-counter check
  perf: Fix contexted inheritance

diff --combined kernel/perf_event.c
index 05ebe84,67d9bd7..84522c7
--- 1/kernel/perf_event.c
--- 2/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@@ -2228,14 -2228,11 +2228,11 @@@ find_get_context(struct pmu *pmu, struc
        unsigned long flags;
        int ctxn, err;
  
-       if (!task && cpu != -1) {
+       if (!task) {
                /* Must be root to operate on a CPU event: */
                if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
                        return ERR_PTR(-EACCES);
  
-               if (cpu < 0 || cpu >= nr_cpumask_bits)
-                       return ERR_PTR(-EINVAL);
- 
                /*
                 * We could be clever and allow to attach a event to an
                 * offline CPU and activate it when the CPU comes up, but
@@@ -4664,7 -4661,7 +4661,7 @@@ int perf_swevent_get_recursion_context(
  }
  EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
  
 -void inline perf_swevent_put_recursion_context(int rctx)
 +inline void perf_swevent_put_recursion_context(int rctx)
  {
        struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
  
@@@ -5541,6 -5538,11 +5538,11 @@@ perf_event_alloc(struct perf_event_att
        struct hw_perf_event *hwc;
        long err;
  
+       if ((unsigned)cpu >= nr_cpu_ids) {
+               if (!task || cpu != -1)
+                       return ERR_PTR(-EINVAL);
+       }
+ 
        event = kzalloc(sizeof(*event), GFP_KERNEL);
        if (!event)
                return ERR_PTR(-ENOMEM);
@@@ -5589,7 -5591,7 +5591,7 @@@
  
        if (!overflow_handler && parent_event)
                overflow_handler = parent_event->overflow_handler;
-       
+ 
        event->overflow_handler = overflow_handler;
  
        if (attr->disabled)
@@@ -6494,7 -6496,6 +6496,6 @@@ int perf_event_init_context(struct task
  
        raw_spin_lock_irqsave(&parent_ctx->lock, flags);
        parent_ctx->rotate_disable = 0;
-       raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
  
        child_ctx = child->perf_event_ctxp[ctxn];
  
@@@ -6502,12 -6503,11 +6503,11 @@@
                /*
                 * Mark the child context as a clone of the parent
                 * context, or of whatever the parent is a clone of.
-                * Note that if the parent is a clone, it could get
-                * uncloned at any point, but that doesn't matter
-                * because the list of events and the generation
-                * count can't have changed since we took the mutex.
+                *
+                * Note that if the parent is a clone, the holding of
+                * parent_ctx->lock avoids it from being uncloned.
                 */
-               cloned_ctx = rcu_dereference(parent_ctx->parent_ctx);
+               cloned_ctx = parent_ctx->parent_ctx;
                if (cloned_ctx) {
                        child_ctx->parent_ctx = cloned_ctx;
                        child_ctx->parent_gen = parent_ctx->parent_gen;
@@@ -6518,6 -6518,7 +6518,7 @@@
                get_ctx(child_ctx->parent_ctx);
        }
  
+       raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
        mutex_unlock(&parent_ctx->mutex);
  
        perf_unpin_context(parent_ctx);