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ide: fix ->io_32bit race in ide_taskfile_ioctl() 

In ide_taskfile_ioctl(), there was a race condition involving
drive->io_32bit.  It was cleared and restored during ioctl
requests but there was no synchronization with other requests.
So, other requests could execute with the altered ->io_32bit
setting or updated drive->io_32bit could be overwritten by
ide_taskfile_ioctl().

This patch adds IDE_TFLAG_IO_16BIT flag to indicate to
ide_pio_datablock() that 16-bit I/O is needed regardless of
drive->io_32bit settting.

Bart:
- ported it over recent IDE changes

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
This commit is contained in:
Tejun Heo 2008-01-26 20:13:10 +01:00 committed by Bartlomiej Zolnierkiewicz
parent 63c4467805
commit 35cf2b94d0
2 changed files with 14 additions and 5 deletions
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17
drivers/ide/ide-taskfile.c
View File

@ -346,9 +346,18 @@ static void ide_pio_multi(ide_drive_t *drive, unsigned int write)
static void ide_pio_datablock(ide_drive_t *drive, struct request *rq,
unsigned int write)
{
u8 saved_io_32bit = drive->io_32bit;
if (rq->bio) /* fs request */
rq->errors = 0;
if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
ide_task_t *task = rq->special;
if (task->tf_flags & IDE_TFLAG_IO_16BIT)
drive->io_32bit = 0;
}
touch_softlockup_watchdog();
switch (drive->hwif->data_phase) {
@ -360,6 +369,8 @@ static void ide_pio_datablock(ide_drive_t *drive, struct request *rq,
ide_pio_sector(drive, write);
break;
}
drive->io_32bit = saved_io_32bit;
}
static ide_startstop_t task_error(ide_drive_t *drive, struct request *rq,
@ -555,7 +566,6 @@ int ide_taskfile_ioctl (ide_drive_t *drive, unsigned int cmd, unsigned long arg)
unsigned int taskin = 0;
unsigned int taskout = 0;
u16 nsect = 0;
u8 io_32bit = drive->io_32bit;
char __user *buf = (char __user *)arg;
// printk("IDE Taskfile ...\n");
@ -608,7 +618,7 @@ int ide_taskfile_ioctl (ide_drive_t *drive, unsigned int cmd, unsigned long arg)
args.data_phase = req_task->data_phase;
args.tf_flags = IDE_TFLAG_OUT_DEVICE;
args.tf_flags = IDE_TFLAG_IO_16BIT | IDE_TFLAG_OUT_DEVICE;
if (drive->addressing == 1)
args.tf_flags |= IDE_TFLAG_LBA48;
@ -646,7 +656,6 @@ int ide_taskfile_ioctl (ide_drive_t *drive, unsigned int cmd, unsigned long arg)
if (req_task->in_flags.b.data)
args.tf_flags |= IDE_TFLAG_IN_DATA;
drive->io_32bit = 0;
switch(req_task->data_phase) {
case TASKFILE_MULTI_OUT:
if (!drive->mult_count) {
@ -742,8 +751,6 @@ int ide_taskfile_ioctl (ide_drive_t *drive, unsigned int cmd, unsigned long arg)
// printk("IDE Taskfile ioctl ended. rc = %i\n", err);
drive->io_32bit = io_32bit;
return err;
}
#endif

2
include/linux/ide.h
View File

@ -931,6 +931,8 @@ enum {
IDE_TFLAG_IN_TF = IDE_TFLAG_IN_NSECT |
IDE_TFLAG_IN_LBA,
IDE_TFLAG_IN_DEVICE = (1 << 29),
/* force 16-bit I/O operations */
IDE_TFLAG_IO_16BIT = (1 << 30),
};
struct ide_taskfile {