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authorJulia Lawall <julia@diku.dk>2009-10-17 08:41:47 +0200
committerJeff Garzik <jgarzik@redhat.com>2009-11-03 14:26:12 -0500
commita1104016ce8f7750ecd8ca6129786bc549aa5c38 (patch)
tree362350c913218858952d4c09b18bd3cd59969958
parente65cc194f7628ecaa02462f22f42fb09b50dcd49 (diff)
drivers/ata/libata: Move dereference after NULL test
In each case, if the NULL test on qc is needed, then the derefernce should be after the NULL test. A simplified version of the semantic match that detects this problem is as follows (http://coccinelle.lip6.fr/): // <smpl> @match exists@ expression x, E; identifier fld; @@ * x->fld ... when != \(x = E\|&x\) * x == NULL // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
-rw-r--r--drivers/ata/libata-core.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index d7f0f1b..dc72690 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4919,10 +4919,11 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
*/
void ata_qc_free(struct ata_queued_cmd *qc)
{
- struct ata_port *ap = qc->ap;
+ struct ata_port *ap;
unsigned int tag;
WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
+ ap = qc->ap;
qc->flags = 0;
tag = qc->tag;
@@ -4934,11 +4935,13 @@ void ata_qc_free(struct ata_queued_cmd *qc)
void __ata_qc_complete(struct ata_queued_cmd *qc)
{
- struct ata_port *ap = qc->ap;
- struct ata_link *link = qc->dev->link;
+ struct ata_port *ap;
+ struct ata_link *link;
WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_ACTIVE));
+ ap = qc->ap;
+ link = qc->dev->link;
if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
ata_sg_clean(qc);