diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/perf_event.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 80f40da9a01e..3ede0981f4ac 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1782,6 +1782,7 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) *enabled = 0; *running = 0; + mutex_lock(&event->child_mutex); total += perf_event_read(event); *enabled += event->total_time_enabled + atomic64_read(&event->child_total_time_enabled); @@ -1793,6 +1794,7 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) *enabled += child->total_time_enabled; *running += child->total_time_running; } + mutex_unlock(&event->child_mutex); return total; } @@ -1802,10 +1804,12 @@ static int perf_event_read_group(struct perf_event *event, u64 read_format, char __user *buf) { struct perf_event *leader = event->group_leader, *sub; - int n = 0, size = 0, ret = 0; + int n = 0, size = 0, ret = -EFAULT; + struct perf_event_context *ctx = leader->ctx; u64 values[5]; u64 count, enabled, running; + mutex_lock(&ctx->mutex); count = perf_event_read_value(leader, &enabled, &running); values[n++] = 1 + leader->nr_siblings; @@ -1820,9 +1824,9 @@ static int perf_event_read_group(struct perf_event *event, size = n * sizeof(u64); if (copy_to_user(buf, values, size)) - return -EFAULT; + goto unlock; - ret += size; + ret = size; list_for_each_entry(sub, &leader->sibling_list, group_entry) { n = 0; @@ -1833,11 +1837,15 @@ static int perf_event_read_group(struct perf_event *event, size = n * sizeof(u64); - if (copy_to_user(buf + size, values, size)) - return -EFAULT; + if (copy_to_user(buf + size, values, size)) { + ret = -EFAULT; + goto unlock; + } ret += size; } +unlock: + mutex_unlock(&ctx->mutex); return ret; } @@ -1884,12 +1892,10 @@ perf_read_hw(struct perf_event *event, char __user *buf, size_t count) return -ENOSPC; WARN_ON_ONCE(event->ctx->parent_ctx); - mutex_lock(&event->child_mutex); if (read_format & PERF_FORMAT_GROUP) ret = perf_event_read_group(event, read_format, buf); else ret = perf_event_read_one(event, read_format, buf); - mutex_unlock(&event->child_mutex); return ret; } |