[openib-general] [PATCH 1 of 53] ipath - fix spinlock recursion bug

[Bryan O'Sullivan]

The local loopback path for RC can lock the rkey table lock without
blocking interrupts.  The receive interrupt path can then call
ipath_rkey_ok() and deadlock.  Since the lock only protects a 64 bit read,
the lock isn't needed.

Signed-off-by: Bryan O'Sullivan <bos at pathscale.com>

diff -r 89f7c69a68bf -r 9b9f24aab350 drivers/infiniband/hw/ipath/ipath_keys.c
--- a/drivers/infiniband/hw/ipath/ipath_keys.c	Fri May 12 15:55:27 2006 -0700
+++ b/drivers/infiniband/hw/ipath/ipath_keys.c	Fri May 12 15:55:27 2006 -0700
@@ -136,9 +136,7 @@ int ipath_lkey_ok(struct ipath_lkey_tabl
 		ret = 1;
 		goto bail;
 	}
-	spin_lock(&rkt->lock);
 	mr = rkt->table[(sge->lkey >> (32 - ib_ipath_lkey_table_size))];
-	spin_unlock(&rkt->lock);
 	if (unlikely(mr == NULL || mr->lkey != sge->lkey)) {
 		ret = 0;
 		goto bail;
@@ -184,8 +182,6 @@ bail:
  * @acc: access flags
  *
  * Return 1 if successful, otherwise 0.
- *
- * The QP r_rq.lock should be held.
  */
 int ipath_rkey_ok(struct ipath_ibdev *dev, struct ipath_sge_state *ss,
 		  u32 len, u64 vaddr, u32 rkey, int acc)
@@ -196,9 +192,7 @@ int ipath_rkey_ok(struct ipath_ibdev *de
 	size_t off;
 	int ret;
 
-	spin_lock(&rkt->lock);
 	mr = rkt->table[(rkey >> (32 - ib_ipath_lkey_table_size))];
-	spin_unlock(&rkt->lock);
 	if (unlikely(mr == NULL || mr->lkey != rkey)) {
 		ret = 0;
 		goto bail;