The patch titled
drivers/ata/libata: Move dereference after NULL test
has been added to the -mm tree. Its filename is
drivers-ata-libata-move-dereference-after-null-test.patch
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See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: drivers/ata/libata: Move dereference after NULL test
From: Julia Lawall <julia@xxxxxxx>
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@xxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Jeff Garzik <jeff@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/ata/libata-core.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff -puN drivers/ata/libata-core.c~drivers-ata-libata-move-dereference-after-null-test drivers/ata/libata-core.c
--- a/drivers/ata/libata-core.c~drivers-ata-libata-move-dereference-after-null-test
+++ a/drivers/ata/libata-core.c
@@ -4919,10 +4919,11 @@ struct ata_queued_cmd *ata_qc_new_init(s
*/
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 *
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);
_
Patches currently in -mm which might be from julia@xxxxxxx are
origin.patch
linux-next.patch
drivers-scsi-libsas-use-sam_good.patch
drivers-block-dac960c-use-dac960_v2_controller.patch
drivers-char-ipmi-use-kcs_idle_state.patch
drivers-message-move-dereference-after-null-test.patch
drivers-acpi-move-dereference-after-null-test.patch
drivers-media-video-move-dereference-after-null-test.patch
drivers-mmc-move-dereference-after-null-test.patch
drivers-cpuidle-move-dereference-after-null-test.patch
drivers-video-move-dereference-after-null-test.patch
drivers-ata-libata-move-dereference-after-null-test.patch
drivers-scsi-remove-unnecessary-null-test.patch
arch-arm-plat-omap-drop-an-unnecessary-null-test.patch
arch-arm-plat-s3c24xx-move-dereference-after-null-test.patch
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