From 5fb889f587fa2ae486e067d8a00df955ae6492b3 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 28 Nov 2019 11:28:41 +0100 Subject: [PATCH] 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 Signed-off-by: Arnd Bergmann --- block/ioctl.c | 74 ++++++++++++++++++++++++++++++----------------------------- 1 file changed, 38 insertions(+), 36 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index f8c4e26..d6911a1 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -12,12 +12,12 @@ #include #include -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) -- 2.7.4