diff options
| author | Julia Lawall <julia@diku.dk> | 2009-10-17 10:41:47 +0400 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2009-11-03 22:26:12 +0300 |
| commit | a1104016ce8f7750ecd8ca6129786bc549aa5c38 (patch) | |
| tree | 362350c913218858952d4c09b18bd3cd59969958 | |
| parent | e65cc194f7628ecaa02462f22f42fb09b50dcd49 (diff) | |
| download | linux-a1104016ce8f7750ecd8ca6129786bc549aa5c38.tar.xz | |
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.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index d7f0f1b1ae3e..dc72690ed5db 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); |