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> --- 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 b525a09..d02c95c 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); -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
