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compat_ioctl: block: simplify compat_blkpg_ioctl() 

There is no need to go through a compat_alloc_user_space()
copy any more, just wrap the function in a small helper that
works the same way for native and compat mode.

Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Arnd Bergmann 2019-11-28 11:28:41 +01:00
parent bdc1ddad3e
commit 5fb889f587
1 changed files with 38 additions and 36 deletions
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74
block/ioctl.c
View File

@ -12,12 +12,12 @@
#include <linux/pr.h>
#include <linux/uaccess.h>
static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
static int blkpg_do_ioctl(struct block_device *bdev,
struct blkpg_partition __user *upart, int op)
{
struct block_device *bdevp;
struct gendisk *disk;
struct hd_struct *part, *lpart;
struct blkpg_ioctl_arg a;
struct blkpg_partition p;
struct disk_part_iter piter;
long long start, length;
@ -25,9 +25,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
return -EFAULT;
if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))
return -EFAULT;
disk = bdev->bd_disk;
if (bdev != bdev->bd_contains)
@ -35,7 +33,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
partno = p.pno;
if (partno <= 0)
return -EINVAL;
switch (a.op) {
switch (op) {
case BLKPG_ADD_PARTITION:
start = p.start >> 9;
length = p.length >> 9;
@ -156,6 +154,39 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
}
}
static int blkpg_ioctl(struct block_device *bdev,
struct blkpg_ioctl_arg __user *arg)
{
struct blkpg_partition __user *udata;
int op;
if (get_user(op, &arg->op) || get_user(udata, &arg->data))
return -EFAULT;
return blkpg_do_ioctl(bdev, udata, op);
}
#ifdef CONFIG_COMPAT
struct compat_blkpg_ioctl_arg {
compat_int_t op;
compat_int_t flags;
compat_int_t datalen;
compat_caddr_t data;
};
static int compat_blkpg_ioctl(struct block_device *bdev,
struct compat_blkpg_ioctl_arg __user *arg)
{
compat_caddr_t udata;
int op;
if (get_user(op, &arg->op) || get_user(udata, &arg->data))
return -EFAULT;
return blkpg_do_ioctl(bdev, compat_ptr(udata), op);
}
#endif
static int blkdev_reread_part(struct block_device *bdev)
{
int ret;
@ -676,35 +707,6 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
EXPORT_SYMBOL_GPL(blkdev_ioctl);
#ifdef CONFIG_COMPAT
struct compat_blkpg_ioctl_arg {
compat_int_t op;
compat_int_t flags;
compat_int_t datalen;
compat_caddr_t data;
};
static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, struct compat_blkpg_ioctl_arg __user *ua32)
{
struct blkpg_ioctl_arg __user *a = compat_alloc_user_space(sizeof(*a));
compat_caddr_t udata;
compat_int_t n;
int err;
err = get_user(n, &ua32->op);
err |= put_user(n, &a->op);
err |= get_user(n, &ua32->flags);
err |= put_user(n, &a->flags);
err |= get_user(n, &ua32->datalen);
err |= put_user(n, &a->datalen);
err |= get_user(udata, &ua32->data);
err |= put_user(compat_ptr(udata), &a->data);
if (err)
return err;
return blkdev_ioctl(bdev, mode, cmd, (unsigned long)a);
}
#define BLKBSZGET_32 _IOR(0x12, 112, int)
#define BLKBSZSET_32 _IOW(0x12, 113, int)
#define BLKGETSIZE64_32 _IOR(0x12, 114, int)
@ -767,7 +769,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
return blkdev_ioctl(bdev, mode, BLKBSZSET,
(unsigned long)compat_ptr(arg));
case BLKPG:
return compat_blkpg_ioctl(bdev, mode, cmd, compat_ptr(arg));
return compat_blkpg_ioctl(bdev, compat_ptr(arg));
case BLKRAGET:
case BLKFRAGET:
if (!arg)