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Commit 8f76d151 authored by Dave Hansen's avatar Dave Hansen Committed by James Bottomley
Browse files

[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: default avatarDave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: default avatarMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent dd406ef8

drivers/scsi/sd.c

+5 −10
Original line number Original line Diff line number Diff line
@@ -50,6 +50,7 @@ 
#include <linux/string_helpers.h>

#include <linux/string_helpers.h>

#include <linux/async.h>

#include <linux/async.h>

#include <asm/uaccess.h>

#include <asm/uaccess.h>

#include <asm/unaligned.h>





#include <scsi/scsi.h>

#include <scsi/scsi.h>

#include <scsi/scsi_cmnd.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;

		return -EINVAL;

	}

	}





	sector_size =	(buffer[8] << 24) | (buffer[9] << 16) |

	sector_size = get_unaligned_be32(&buffer[8]);

			(buffer[10] << 8) | buffer[11];

	lba = get_unaligned_be64(&buffer[0]);

	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]);





	sd_read_protection_type(sdkp, buffer);

	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;

		return -EINVAL;

	}

	}





	sector_size =	(buffer[4] << 24) | (buffer[5] << 16) |

	sector_size = get_unaligned_be32(&buffer[4]);

			(buffer[6] << 8) | buffer[7];

	lba = get_unaligned_be32(&buffer[0]);

	lba =	(buffer[0] << 24) | (buffer[1] << 16) |

		(buffer[2] << 8) | buffer[3];





	if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {

	if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {

		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "

		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "