perf: Find task before event alloc

So that we can pass the task pointer to the event allocation, so that
we can use task associated data during event initialization.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.340789919@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 11 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index f928878a1c17..b21d06aaef60 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -5551,10 +5551,18 @@ SYSCALL_DEFINE5(perf_event_open,
                         group_leader = NULL;
         }
 
+        if (pid != -1) {
+                task = find_lively_task_by_vpid(pid);
+                if (IS_ERR(task)) {
+                        err = PTR_ERR(task);
+                        goto err_group_fd;
+                }
+        }
+
         event = perf_event_alloc(&attr, cpu, group_leader, NULL, NULL);
         if (IS_ERR(event)) {
                 err = PTR_ERR(event);
-                goto err_fd;
+                goto err_task;
         }
 
         /*
@@ -5586,21 +5594,13 @@ SYSCALL_DEFINE5(perf_event_open,
                 }
         }
 
-        if (pid != -1) {
-                task = find_lively_task_by_vpid(pid);
-                if (IS_ERR(task)) {
-                        err = PTR_ERR(task);
-                        goto err_group_fd;
-                }
-        }
-
         /*
          * Get the target context (task or percpu):
          */
         ctx = find_get_context(pmu, task, cpu);
         if (IS_ERR(ctx)) {
                 err = PTR_ERR(ctx);
-                goto err_task;
+                goto err_alloc;
         }
 
         /*
@@ -5696,12 +5696,13 @@ SYSCALL_DEFINE5(perf_event_open,
 
 err_context:
         put_ctx(ctx);
+err_alloc:
+        free_event(event);
 err_task:
         if (task)
                 put_task_struct(task);
 err_group_fd:
         fput_light(group_file, fput_needed);
-        free_event(event);
 err_fd:
         put_unused_fd(event_fd);
         return err;