From: Dean Luick <dean.luick@xxxxxxxxxxxxxxxxxxxx>
Commit 13bac861952a ("IB/hfi1: Fix abba locking issue with
sc_disable()") incorrectly tries to move a list from one list
head to another. The result is a kernel crash.
The crash is triggered when a link goes down and there are
waiters for a send to complete. The following signature is
seen:
BUG: kernel NULL pointer dereference, address: 0000000000000030
[...]
Call Trace:
<TASK>
sc_disable+0x1ba/0x240 [hfi1]
pio_freeze+0x3d/0x60 [hfi1]
handle_freeze+0x27/0x1b0 [hfi1]
process_one_work+0x1b0/0x380
? process_one_work+0x380/0x380
worker_thread+0x30/0x360
? process_one_work+0x380/0x380
kthread+0xd7/0x100
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x1f/0x30
</TASK>
The fix is to use the correct call to move the list.
Fixes: 13bac861952a ("IB/hfi1: Fix abba locking issue with sc_disable()")
Signed-off-by: Dean Luick <dean.luick@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxxxxxxxxxxxxx>
---
drivers/infiniband/hw/hfi1/pio.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c
index 3d42bd2b36bd..51ae58c02b15 100644
--- a/drivers/infiniband/hw/hfi1/pio.c
+++ b/drivers/infiniband/hw/hfi1/pio.c
@@ -913,8 +913,7 @@ void sc_disable(struct send_context *sc)
spin_unlock(&sc->release_lock);
write_seqlock(&sc->waitlock);
- if (!list_empty(&sc->piowait))
- list_move(&sc->piowait, &wake_list);
+ list_splice_init(&sc->piowait, &wake_list);
write_sequnlock(&sc->waitlock);
while (!list_empty(&wake_list)) {
struct iowait *wait;
