From 8f76d151b010980d137bfdc736d1d8f64b489165 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Tue, 21 Apr 2009 16:43:27 -0700 Subject: [PATCH] [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 Reviewed-by: Matthew Wilcox Signed-off-by: James Bottomley --- drivers/scsi/sd.c | 15 +++++---------- 1 file 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 #include #include +#include #include #include @@ -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 " -- 2.11.4.GIT