nvme: Add compat_ioctl handler for NVME_IOCTL_SUBMIT_IO

Currently 32 bit application gets ENOTTY when it calls
compat_ioctl with NVME_IOCTL_SUBMIT_IO in 64 bit kernel.

The cause is that the results of sizeof(struct nvme_user_io),
which is used to define NVME_IOCTL_SUBMIT_IO,
are not same between 32 bit compiler and 64 bit compiler.

* 32 bit: the result of sizeof nvme_user_io is 44.
* 64 bit: the result of sizeof nvme_user_io is 48.

64 bit compiler seems to add 32 bit padding for multiple of 8 bytes.

This patch adds a compat_ioctl handler.
The handler replaces NVME_IOCTL_SUBMIT_IO32 with NVME_IOCTL_SUBMIT_IO
in case 32 bit application calls compat_ioctl for submit in 64 bit kernel.
Then, it calls nvme_ioctl as usual.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada (KIOXIA) <masahiro31.yamada@kioxia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This commit is contained in:
masahiro31.yamada@kioxia.com 2020-03-05 11:13:29 +00:00 committed by Keith Busch
parent e90d172b11
commit c225b61031

View File

@ -1585,6 +1585,47 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
return ret;
}
#ifdef CONFIG_COMPAT
struct nvme_user_io32 {
__u8 opcode;
__u8 flags;
__u16 control;
__u16 nblocks;
__u16 rsvd;
__u64 metadata;
__u64 addr;
__u64 slba;
__u32 dsmgmt;
__u32 reftag;
__u16 apptag;
__u16 appmask;
} __attribute__((__packed__));
#define NVME_IOCTL_SUBMIT_IO32 _IOW('N', 0x42, struct nvme_user_io32)
static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
/*
* Corresponds to the difference of NVME_IOCTL_SUBMIT_IO
* between 32 bit programs and 64 bit kernel.
* The cause is that the results of sizeof(struct nvme_user_io),
* which is used to define NVME_IOCTL_SUBMIT_IO,
* are not same between 32 bit compiler and 64 bit compiler.
* NVME_IOCTL_SUBMIT_IO32 is for 64 bit kernel handling
* NVME_IOCTL_SUBMIT_IO issued from 32 bit programs.
* Other IOCTL numbers are same between 32 bit and 64 bit.
* So there is nothing to do regarding to other IOCTL numbers.
*/
if (cmd == NVME_IOCTL_SUBMIT_IO32)
return nvme_ioctl(bdev, mode, NVME_IOCTL_SUBMIT_IO, arg);
return nvme_ioctl(bdev, mode, cmd, arg);
}
#else
#define nvme_compat_ioctl NULL
#endif /* CONFIG_COMPAT */
static int nvme_open(struct block_device *bdev, fmode_t mode)
{
struct nvme_ns *ns = bdev->bd_disk->private_data;
@ -2028,7 +2069,7 @@ EXPORT_SYMBOL_GPL(nvme_sec_submit);
static const struct block_device_operations nvme_fops = {
.owner = THIS_MODULE,
.ioctl = nvme_ioctl,
.compat_ioctl = nvme_ioctl,
.compat_ioctl = nvme_compat_ioctl,
.open = nvme_open,
.release = nvme_release,
.getgeo = nvme_getgeo,
@ -2056,7 +2097,7 @@ const struct block_device_operations nvme_ns_head_ops = {
.open = nvme_ns_head_open,
.release = nvme_ns_head_release,
.ioctl = nvme_ioctl,
.compat_ioctl = nvme_ioctl,
.compat_ioctl = nvme_compat_ioctl,
.getgeo = nvme_getgeo,
.pr_ops = &nvme_pr_ops,
};