diff options
| -rw-r--r-- | kernel/events/core.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index ca4c1242c29b..773875aaa291 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6680,7 +6680,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) unsigned long vma_size; unsigned long nr_pages; long user_extra = 0, extra = 0; - int ret = 0, flags = 0; + int ret, flags = 0; /* * Don't allow mmap() of inherited per-task counters. This would @@ -6708,6 +6708,9 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) user_extra = nr_pages; + mutex_lock(&event->mmap_mutex); + ret = -EINVAL; + if (vma->vm_pgoff == 0) { nr_pages -= 1; @@ -6716,16 +6719,13 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) * can do bitmasks instead of modulo. */ if (nr_pages != 0 && !is_power_of_2(nr_pages)) - return -EINVAL; + goto unlock; WARN_ON_ONCE(event->ctx->parent_ctx); - mutex_lock(&event->mmap_mutex); if (event->rb) { - if (data_page_nr(event->rb) != nr_pages) { - ret = -EINVAL; + if (data_page_nr(event->rb) != nr_pages) goto unlock; - } if (atomic_inc_not_zero(&event->rb->mmap_count)) { /* @@ -6754,12 +6754,6 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) */ u64 aux_offset, aux_size; - if (!event->rb) - return -EINVAL; - - mutex_lock(&event->mmap_mutex); - ret = -EINVAL; - rb = event->rb; if (!rb) goto aux_unlock; @@ -6869,6 +6863,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) rb->aux_mmap_locked = extra; } + ret = 0; + unlock: if (!ret) { atomic_long_add(user_extra, &user->locked_vm); |