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| author | Christoph Hellwig <hch@lst.de> | 2019-07-22 11:20:38 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2019-07-23 04:05:48 +0200 |
| commit | 1b5d9a6e98350e0713b4faa1b04e8f239f63b581 (patch) | |
| tree | 8433fa141ffb58e7d4343a1d18d4b3da9d1e3a05 /drivers/scsi/scsi_lib.c | |
| parent | scsi: fdomain: fix building pcmcia front-end (diff) | |
| download | linux-1b5d9a6e98350e0713b4faa1b04e8f239f63b581.tar.xz linux-1b5d9a6e98350e0713b4faa1b04e8f239f63b581.zip | |
scsi: core: fix the dma_max_mapping_size call
We should only call dma_max_mapping_size for devices that have a DMA mask
set, otherwise we can run into a NULL pointer dereference that will crash
the system.
Also we need to do right shift to get the sectors from the size in bytes,
not a left shift.
Fixes: bdd17bdef7d8 ("scsi: core: take the DMA max mapping size into account")
Reported-by: Bart Van Assche <bvanassche@acm.org>
Reported-by: Ming Lei <tom.leiming@gmail.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9381171c2fc0..11e64b50497f 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1784,8 +1784,10 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); } - shost->max_sectors = min_t(unsigned int, shost->max_sectors, - dma_max_mapping_size(dev) << SECTOR_SHIFT); + if (dev->dma_mask) { + shost->max_sectors = min_t(unsigned int, shost->max_sectors, + dma_max_mapping_size(dev) >> SECTOR_SHIFT); + } blk_queue_max_hw_sectors(q, shost->max_sectors); if (shost->unchecked_isa_dma) blk_queue_bounce_limit(q, BLK_BOUNCE_ISA); |