From 07bf9627d5f1c0334fc543a5435a31a3b5907944 Mon Sep 17 00:00:00 2001 From: Andrew Boyer Date: Mon, 5 Dec 2016 08:43:20 -0500 Subject: [PATCH] IB/rxe: Wait for tasklets to finish before tearing down QP The system may crash when a malformed request is received and the error is detected by the responder. NodeA: $ ibv_rc_pingpong -g 0 -d rxe0 -i 1 -n 1 -s 50000 NodeB: $ ibv_rc_pingpong -g 0 -d rxe0 -i 1 -n 1 -s 1024 The responder generates a receive error on node B since the incoming SEND is oversized. If the client tears down the QP before the responder or the completer finish running, a page fault may occur. The fix makes the destroy operation spin until the tasks complete, which appears to be original intent of the design. Signed-off-by: Andrew Boyer Reviewed-by: Yuval Shaia Signed-off-by: Doug Ledford --- drivers/infiniband/sw/rxe/rxe_task.c | 19 +++++++++++++++++++ drivers/infiniband/sw/rxe/rxe_task.h | 1 + 2 files changed, 20 insertions(+) diff --git a/drivers/infiniband/sw/rxe/rxe_task.c b/drivers/infiniband/sw/rxe/rxe_task.c index 1e19bf828a6e..d2a14a1bdc7f 100644 --- a/drivers/infiniband/sw/rxe/rxe_task.c +++ b/drivers/infiniband/sw/rxe/rxe_task.c @@ -121,6 +121,7 @@ int rxe_init_task(void *obj, struct rxe_task *task, task->arg = arg; task->func = func; snprintf(task->name, sizeof(task->name), "%s", name); + task->destroyed = false; tasklet_init(&task->tasklet, rxe_do_task, (unsigned long)task); @@ -132,11 +133,29 @@ int rxe_init_task(void *obj, struct rxe_task *task, void rxe_cleanup_task(struct rxe_task *task) { + unsigned long flags; + bool idle; + + /* + * Mark the task, then wait for it to finish. It might be + * running in a non-tasklet (direct call) context. + */ + task->destroyed = true; + + do { + spin_lock_irqsave(&task->state_lock, flags); + idle = (task->state == TASK_STATE_START); + spin_unlock_irqrestore(&task->state_lock, flags); + } while (!idle); + tasklet_kill(&task->tasklet); } void rxe_run_task(struct rxe_task *task, int sched) { + if (task->destroyed) + return; + if (sched) tasklet_schedule(&task->tasklet); else diff --git a/drivers/infiniband/sw/rxe/rxe_task.h b/drivers/infiniband/sw/rxe/rxe_task.h index d14aa6daed05..08ff42d451c6 100644 --- a/drivers/infiniband/sw/rxe/rxe_task.h +++ b/drivers/infiniband/sw/rxe/rxe_task.h @@ -54,6 +54,7 @@ struct rxe_task { int (*func)(void *arg); int ret; char name[16]; + bool destroyed; }; /*