Gitweb: http://git.kernel.org/linus/8f76d151b010980d137bfdc736d1d8f64b489165
Commit: 8f76d151b010980d137bfdc736d1d8f64b489165
Parent: dd406ef8950e76b17d74c5764a1e3d3a87d4a855
Author: Dave Hansen <dave@linux.vnet.ibm.com>
AuthorDate: Tue Apr 21 16:43:27 2009 -0700
Committer: James Bottomley <James.Bottomley@HansenPartnership.com>
CommitDate: Mon Apr 27 10:36:07 2009 -0500
[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>
---
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 3fcb64b..8404423 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 "
--
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