Messages in this thread Patch in this message | | | Date | Mon, 11 Dec 2006 23:02:58 +0900 | From | Tejun Heo <> | Subject | [PATCH] libata: don't initialize sg in ata_exec_internal() if DMA_NONE |
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Calling sg_init_one() with NULL buf causes oops on certain configurations. Don't initialize sg in ata_exec_internal() if DMA_NONE and make the function complain if @buf is NULL when dma_dir isn't DMA_NONE. While at it, fix comment.
The problem is discovered and initial patch was submitted by Arnd Bergmann.
Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Arnd Bergmann <arnd.bergmann@de.ibm.com> ---
Hello, Arnd Bergmann.
Thanks for spotting and fixing this but ata_exec_internal_nodma() is almost identical to ata_do_simple_cmd() and ata_exec_internal() itself needs fixing anyway. This patch just fixes ata_exec_internal(). I'll follow up with conversion to ata_do_simple_cmd().
Thanks.
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 011c0a8..70e02e9 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -1332,7 +1332,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev, } /** - * ata_exec_internal_sg - execute libata internal command + * ata_exec_internal - execute libata internal command * @dev: Device to which the command is sent * @tf: Taskfile registers for the command and the result * @cdb: CDB for packet command @@ -1354,10 +1354,15 @@ unsigned ata_exec_internal(struct ata_device *dev, int dma_dir, void *buf, unsigned int buflen) { struct scatterlist sg; + unsigned int n_elem = 0; - sg_init_one(&sg, buf, buflen); + if (dma_dir != DMA_NONE) { + WARN_ON(!buf); + sg_init_one(&sg, buf, buflen); + n_elem++; + } - return ata_exec_internal_sg(dev, tf, cdb, dma_dir, &sg, 1); + return ata_exec_internal_sg(dev, tf, cdb, dma_dir, &sg, n_elem); } /** - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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