Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

1 files changed, 10 insertions, 6 deletions

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 0a5df5f82fb..5a4c23d8989 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -810,12 +810,16 @@ static void ptrace_bts_untrace(struct task_struct *child)
 
 static void ptrace_bts_detach(struct task_struct *child)
 {
-	if (unlikely(child->bts)) {
-		ds_release_bts(child->bts);
-		child->bts = NULL;
-
-		ptrace_bts_free_buffer(child);
-	}
+	/*
+	 * Ptrace_detach() races with ptrace_untrace() in case
+	 * the child dies and is reaped by another thread.
+	 *
+	 * We only do the memory accounting at this point and
+	 * leave the buffer deallocation and the bts tracer
+	 * release to ptrace_bts_untrace() which will be called
+	 * later on with tasklist_lock held.
+	 */
+	release_locked_buffer(child->bts_buffer, child->bts_size);
 }
 #else
 static inline void ptrace_bts_fork(struct task_struct *tsk) {}