PM / Hibernate: Implement compat_ioctl for /dev/snapshot

This allows uswsusp built for i386 to run on an x86_64 kernel (tested
with Debian package version 1.0+20110509-2).

References: http://bugs.debian.org/502816
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Ben Hutchings 2011-12-27 22:54:52 +01:00 committed by Rafael J. Wysocki
parent 90363ddf0a
commit c336078bf6

View file

@ -21,6 +21,7 @@
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/fs.h>
#include <linux/compat.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/freezer.h>
@ -380,6 +381,66 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
return error;
}
#ifdef CONFIG_COMPAT
struct compat_resume_swap_area {
compat_loff_t offset;
u32 dev;
} __packed;
static long
snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
switch (cmd) {
case SNAPSHOT_GET_IMAGE_SIZE:
case SNAPSHOT_AVAIL_SWAP_SIZE:
case SNAPSHOT_ALLOC_SWAP_PAGE: {
compat_loff_t __user *uoffset = compat_ptr(arg);
loff_t offset;
mm_segment_t old_fs;
int err;
old_fs = get_fs();
set_fs(KERNEL_DS);
err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
set_fs(old_fs);
if (!err && put_user(offset, uoffset))
err = -EFAULT;
return err;
}
case SNAPSHOT_CREATE_IMAGE:
return snapshot_ioctl(file, cmd,
(unsigned long) compat_ptr(arg));
case SNAPSHOT_SET_SWAP_AREA: {
struct compat_resume_swap_area __user *u_swap_area =
compat_ptr(arg);
struct resume_swap_area swap_area;
mm_segment_t old_fs;
int err;
err = get_user(swap_area.offset, &u_swap_area->offset);
err |= get_user(swap_area.dev, &u_swap_area->dev);
if (err)
return -EFAULT;
old_fs = get_fs();
set_fs(KERNEL_DS);
err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
(unsigned long) &swap_area);
set_fs(old_fs);
return err;
}
default:
return snapshot_ioctl(file, cmd, arg);
}
}
#endif /* CONFIG_COMPAT */
static const struct file_operations snapshot_fops = {
.open = snapshot_open,
.release = snapshot_release,
@ -387,6 +448,9 @@ static const struct file_operations snapshot_fops = {
.write = snapshot_write,
.llseek = no_llseek,
.unlocked_ioctl = snapshot_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = snapshot_compat_ioctl,
#endif
};
static struct miscdevice snapshot_device = {