IB/mthca: Don't cancel commands on a signal
We have run into the following problem: if a task receives a signal
while in the process of e.g. destroying a resource (which could be
because the relevant file was closed) mthca could bail out from trying
to take a command interface semaphore without performing the
appropriate command to tell hardware that the resource is being
destroyed.
As a result we see messages like
ib_mthca 0000:04:00.0: HW2SW_CQ failed (-4)
In this case, hardware could access the resource after the memory has
been freed, possibly causing memory corruption.
A simple solution is to replace down_interruptible() by down() in
command interface activation.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
[ It's also not safe to bail out on multicast table operations, since
they may be invoked on the cleanup path too. So use down() for
mcg_table.sem too. ]
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_cmd.c b/drivers/infiniband/hw/mthca/mthca_cmd.c
index be1791b..69128fe 100644
--- a/drivers/infiniband/hw/mthca/mthca_cmd.c
+++ b/drivers/infiniband/hw/mthca/mthca_cmd.c
@@ -199,8 +199,7 @@
{
int err = 0;
- if (down_interruptible(&dev->cmd.hcr_sem))
- return -EINTR;
+ down(&dev->cmd.hcr_sem);
if (event) {
unsigned long end = jiffies + GO_BIT_TIMEOUT;
@@ -255,8 +254,7 @@
int err = 0;
unsigned long end;
- if (down_interruptible(&dev->cmd.poll_sem))
- return -EINTR;
+ down(&dev->cmd.poll_sem);
err = mthca_cmd_post(dev, in_param,
out_param ? *out_param : 0,
@@ -333,8 +331,7 @@
int err = 0;
struct mthca_cmd_context *context;
- if (down_interruptible(&dev->cmd.event_sem))
- return -EINTR;
+ down(&dev->cmd.event_sem);
spin_lock(&dev->cmd.context_lock);
BUG_ON(dev->cmd.free_head < 0);