BUG/MEDIUM: tasks: Make sure we switch wait queues in task_set_affinity().
In task_set_affinity(), leave the wait_queue if any before changing the
affinity, and re-enter a wait queue once it is done. If we don't do that,
the task may stay in the wait queue of another thread, and we later may
end up modifying that wait queue while holding no lock, which could lead
to memory corruption.
THis should be backported to 2.1, 2.0 and 1.9.
(cherry picked from commit 0742c314c35c2c96b72e42076c76d6a6786045ba)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 279698ebdef2c00e7a01544af0321438b69ea7d1)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/include/proto/task.h b/include/proto/task.h
index 4044bd4..ae8fbab 100644
--- a/include/proto/task.h
+++ b/include/proto/task.h
@@ -103,6 +103,8 @@
__decl_hathreads(extern HA_SPINLOCK_T rq_lock); /* spin lock related to run queue */
__decl_hathreads(extern HA_RWLOCK_T wq_lock); /* RW lock related to the wait queue */
+static inline struct task *task_unlink_wq(struct task *t);
+static inline void task_queue(struct task *task);
/* return 0 if task is in run queue, otherwise non-zero */
static inline int task_in_rq(struct task *t)
@@ -151,7 +153,11 @@
/* change the thread affinity of a task to <thread_mask> */
static inline void task_set_affinity(struct task *t, unsigned long thread_mask)
{
+ if (task_in_wq(t))
+ task_unlink_wq(t);
t->thread_mask = thread_mask;
+ if (t->expire != TICK_ETERNITY)
+ task_queue(t);
}
/*