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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-18 14:29:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-18 14:29:37 -0800
commit335bc70b6b5fdc9b4e28cb56c27f10124064f9da (patch)
tree7f5a1594a09cdcb2ea9a5d768ea72c0256f6aa3c /kernel
parent404cbbd52f10d1d5719ad82ce8ba903890779255 (diff)
parent66832eb4baaaa9abe4c993ddf9113a79e39b9915 (diff)
downloadlinux-linaro-precise-335bc70b6b5fdc9b4e28cb56c27f10124064f9da.tar.gz
Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* '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
Diffstat (limited to 'kernel')
-rw-r--r--kernel/perf_event.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 05ebe841270..84522c79698 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2228,14 +2228,11 @@ find_get_context(struct pmu *pmu, struct task_struct *task, int cpu)
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
@@ -5541,6 +5538,11 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
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 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
if (!overflow_handler && parent_event)
overflow_handler = parent_event->overflow_handler;
-
+
event->overflow_handler = overflow_handler;
if (attr->disabled)
@@ -6494,7 +6496,6 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
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 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
/*
* 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 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
get_ctx(child_ctx->parent_ctx);
}
+ raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
mutex_unlock(&parent_ctx->mutex);
perf_unpin_context(parent_ctx);