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| author | Dave Hansen <dave@linux.vnet.ibm.com> | 2009-04-21 16:43:27 -0700 |
|---|---|---|
| committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2009-04-27 10:36:07 -0500 |
| commit | 8f76d151b010980d137bfdc736d1d8f64b489165 (patch) | |
| tree | b8e1f221b37f091eea027032d81a2ac2aea33ab9 | |
| parent | dd406ef8950e76b17d74c5764a1e3d3a87d4a855 (diff) | |
| download | linux-8f76d151b010980d137bfdc736d1d8f64b489165.tar.gz linux-8f76d151b010980d137bfdc736d1d8f64b489165.tar.bz2 linux-8f76d151b010980d137bfdc736d1d8f64b489165.zip | |
[SCSI] fix sign extension with 1.5TB usb-storage LBD=y
Shifting an unsigned char implicitly casts it to a signed int. This
caused 'lba' to sign-extend and Linux would then try READ CAPACITY 16
which was not supported by at least one drive. Using the
get_unaligned_be*() helpers keeps us from having to worry about how the
extension might occur.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
| -rw-r--r-- | drivers/scsi/sd.c | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3fcb64b91c43..84044233b637 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -50,6 +50,7 @@ #include <linux/string_helpers.h> #include <linux/async.h> #include <asm/uaccess.h> +#include <asm/unaligned.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -1344,12 +1345,8 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, return -EINVAL; } - sector_size = (buffer[8] << 24) | (buffer[9] << 16) | - (buffer[10] << 8) | buffer[11]; - lba = (((u64)buffer[0] << 56) | ((u64)buffer[1] << 48) | - ((u64)buffer[2] << 40) | ((u64)buffer[3] << 32) | - ((u64)buffer[4] << 24) | ((u64)buffer[5] << 16) | - ((u64)buffer[6] << 8) | (u64)buffer[7]); + sector_size = get_unaligned_be32(&buffer[8]); + lba = get_unaligned_be64(&buffer[0]); sd_read_protection_type(sdkp, buffer); @@ -1400,10 +1397,8 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp, return -EINVAL; } - sector_size = (buffer[4] << 24) | (buffer[5] << 16) | - (buffer[6] << 8) | buffer[7]; - lba = (buffer[0] << 24) | (buffer[1] << 16) | - (buffer[2] << 8) | buffer[3]; + sector_size = get_unaligned_be32(&buffer[4]); + lba = get_unaligned_be32(&buffer[0]); if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " |