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ide: avoid DMA on the stack for REQ_TYPE_ATA_PC

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Some REQ_TYPE_ATA_PC commands uses the stack buffers for DMA, which
leads to memory corruption on a non-coherent platform.

With regard to alignment and padding, ide-cd has the the dma safe
check for sg requests and REQ_TYPE_ATA_PC. This adds the stack buffer
check to that check.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Borislav Petkov <petkovbb@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
This commit is contained in:
FUJITA Tomonori 2008-07-16 20:33:35 +02:00 committed by Bartlomiej Zolnierkiewicz
parent 84e0f3f6c1
commit 0b6abc1770
1 changed files with 5 additions and 0 deletions
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5
drivers/ide/ide-cd.c
View file

@ -1195,6 +1195,7 @@ static ide_startstop_t cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
int mask = drive->queue->dma_alignment;
unsigned long addr =
(unsigned long)page_address(bio_page(rq->bio));
unsigned long stack_mask = ~(THREAD_SIZE - 1);
info->dma = drive->using_dma;
@ -1206,6 +1207,10 @@ static ide_startstop_t cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
*/
if ((rq->data_len & 15) || (addr & mask))
info->dma = 0;
if (!((addr & stack_mask) ^
((unsigned long)current->stack & stack_mask)))
info->dma = 0;
}
/* start sending the command to the drive */