Hi Dmitry,
shm locking differs too much from msg/sem locking, I never looked at it
in depth, so I'm not able to perform a proper review.
Except for the obvious: Races that can be triggered from user space are
inacceptable.
Regardless if there is a BUG_ON, a WARN_ON or nothing at all.
On 12/21/2015 04:44 PM, Dmitry Vyukov wrote:
+
+/* This is called by fork, once for every shm attach. */
+static void shm_open(struct vm_area_struct *vma)
+{
+ int err = __shm_open(vma);
+ /*
+ * We raced in the idr lookup or with shm_destroy().
+ * Either way, the ID is busted.
+ */
+ WARN_ON_ONCE(err);
}
Is it possible to trigger this race? Parallel IPC_RMID & fork()?
--
Manfred
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>