fs: no games with DCACHE_UNHASHED

[linux-2.6-block.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index c0c636e34f60f5b347407f1c43599e088d7fedca..623a5cc3076a114af8808ca030f04bdd82638829 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -923,6 +923,15 @@ char *get_task_comm(char *buf, struct task_struct *tsk)
 void set_task_comm(struct task_struct *tsk, char *buf)
 {
        task_lock(tsk);
+
+       /*
+        * Threads may access current->comm without holding
+        * the task lock, so write the string carefully.
+        * Readers without a lock may see incomplete new
+        * names but are safe from non-terminating string reads.
+        */
+       memset(tsk->comm, 0, TASK_COMM_LEN);
+       wmb();
        strlcpy(tsk->comm, buf, sizeof(tsk->comm));
        task_unlock(tsk);
        perf_event_comm(tsk);