In the v5.4 merge window, a cleanup patch from Al Viro conflicted with my rework of the compat handling for sg.c read(). Linus Torvalds did a correct merge but pointed out that the resulting code is still unsatisfactory.

I later noticed that the sg_new_read() function still gets the compat mode wrong, when the 'count' argument is large enough to pass a compat_sg_io_hdr object, but not a nativ sg_io_hdr.

To address both of these, move the definition of compat_sg_io_hdr into a scsi/sg.h to make it visible to sg.c and rewrite the logic for reading req_pack_id as well as the size check to a simpler version that gets the expected results.

Fixes: c35a5cfb4150 ("scsi: sg: sg_read(): simplify reading ->pack_id of userland sg_io_hdr_t") Fixes: 98aaaec4a150 ("compat_ioctl: reimplement SG_IO handling") Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/scsi_ioctl.c | 29 +---------- drivers/scsi/sg.c | 125 +++++++++++++++++++++------------------------ include/scsi/sg.h | 30 +++++++++++ 3 files changed, 89 insertions(+), 95 deletions(-)

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 650bade5ea5a..b61dbf4d8443 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -20,6 +20,7 @@ #include <scsi/scsi.h> #include <scsi/scsi_ioctl.h> #include <scsi/scsi_cmnd.h> +#include <scsi/sg.h>

struct blk_cmd_filter { unsigned long read_ok[BLK_SCSI_CMD_PER_LONG]; @@ -550,34 +551,6 @@ static inline int blk_send_start_stop(struct request_queue *q, return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data); }

-#ifdef CONFIG_COMPAT -struct compat_sg_io_hdr { - compat_int_t interface_id; /* [i] 'S' for SCSI generic (required) */ - compat_int_t dxfer_direction; /* [i] data transfer direction */ - unsigned char cmd_len; /* [i] SCSI command length ( <= 16 bytes) */ - unsigned char mx_sb_len; /* [i] max length to write to sbp */ - unsigned short iovec_count; /* [i] 0 implies no scatter gather */ - compat_uint_t dxfer_len; /* [i] byte count of data transfer */ - compat_uint_t dxferp; /* [i], [*io] points to data transfer memory - or scatter gather list */ - compat_uptr_t cmdp; /* [i], [*i] points to command to perform */ - compat_uptr_t sbp; /* [i], [*o] points to sense_buffer memory */ - compat_uint_t timeout; /* [i] MAX_UINT->no timeout (unit: millisec) */ - compat_uint_t flags; /* [i] 0 -> default, see SG_FLAG... */ - compat_int_t pack_id; /* [i->o] unused internally (normally) */ - compat_uptr_t usr_ptr; /* [i->o] unused internally */ - unsigned char status; /* [o] scsi status */ - unsigned char masked_status; /* [o] shifted, masked scsi status */ - unsigned char msg_status; /* [o] messaging level data (optional) */ - unsigned char sb_len_wr; /* [o] byte count actually written to sbp */ - unsigned short host_status; /* [o] errors from host adapter */ - unsigned short driver_status; /* [o] errors from software driver */ - compat_int_t resid; /* [o] dxfer_len - actual_transferred */ - compat_uint_t duration; /* [o] time taken by cmd (unit: millisec) */ - compat_uint_t info; /* [o] auxiliary information */ -}; -#endif - int put_sg_io_hdr(const struct sg_io_hdr *hdr, void __user *argp) { #ifdef CONFIG_COMPAT diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 160748ad9c0f..985546aac236 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -198,6 +198,7 @@ static void sg_device_destroy(struct kref *kref);

#define SZ_SG_HEADER sizeof(struct sg_header) #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t) +#define SZ_COMPAT_SG_IO_HDR sizeof(struct compat_sg_io_hdr) #define SZ_SG_IOVEC sizeof(sg_iovec_t) #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)

@@ -405,6 +406,36 @@ sg_release(struct inode *inode, struct file *filp) return 0; }

+static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count) +{ + struct sg_header __user *old_hdr = buf; + int reply_len; + + if (count < SZ_SG_HEADER) + goto unknown_id; + + /* negative reply_len means v3 format, otherwise v1/v2 */ + if (get_user(reply_len, &old_hdr->reply_len)) + return -EFAULT; + if (reply_len >= 0) + return get_user(*pack_id, &old_hdr->pack_id); + + if (in_compat_syscall() && count >= SZ_COMPAT_SG_IO_HDR) { + struct compat_sg_io_hdr __user *hp = buf; + return get_user(*pack_id, &hp->pack_id); + } + + if (count >= SZ_SG_IO_HDR) { + struct sg_io_hdr __user *hp = buf; + return get_user(*pack_id, &hp->pack_id); + } + +unknown_id: + /* no valid header was passed, so ignore the pack_id */ + *pack_id = -1; + return 0; +} + static ssize_t sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) { @@ -413,8 +444,8 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) Sg_request *srp; int req_pack_id = -1; sg_io_hdr_t *hp; - struct sg_header *old_hdr = NULL; - int retval = 0; + struct sg_header *old_hdr; + int retval;

/* * This could cause a response to be stranded. Close the associated @@ -429,79 +460,34 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_read: count=%d\n", (int) count));

- if (sfp->force_packid && (count >= SZ_SG_HEADER)) { - old_hdr = memdup_user(buf, SZ_SG_HEADER); - if (IS_ERR(old_hdr)) - return PTR_ERR(old_hdr); - if (old_hdr->reply_len < 0) { - if (count >= SZ_SG_IO_HDR) { - /* - * This is stupid. - * - * We're copying the whole sg_io_hdr_t from user - * space just to get the 'pack_id' field. But the - * field is at different offsets for the compat - * case, so we'll use "get_sg_io_hdr()" to copy - * the whole thing and convert it. - * - * We could do something like just calculating the - * offset based of 'in_compat_syscall()', but the - * 'compat_sg_io_hdr' definition is in the wrong - * place for that. - */ - sg_io_hdr_t *new_hdr; - new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL); - if (!new_hdr) { - retval = -ENOMEM; - goto free_old_hdr; - } - retval = get_sg_io_hdr(new_hdr, buf); - req_pack_id = new_hdr->pack_id; - kfree(new_hdr); - if (retval) { - retval = -EFAULT; - goto free_old_hdr; - } - } - } else - req_pack_id = old_hdr->pack_id; - } + if (sfp->force_packid) + retval = get_sg_io_pack_id(&req_pack_id, buf, count); + if (retval) + return retval; + srp = sg_get_rq_mark(sfp, req_pack_id); if (!srp) { /* now wait on packet to arrive */ - if (atomic_read(&sdp->detaching)) { - retval = -ENODEV; - goto free_old_hdr; - } - if (filp->f_flags & O_NONBLOCK) { - retval = -EAGAIN; - goto free_old_hdr; - } + if (atomic_read(&sdp->detaching)) + return -ENODEV; + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; retval = wait_event_interruptible(sfp->read_wait, (atomic_read(&sdp->detaching) || (srp = sg_get_rq_mark(sfp, req_pack_id)))); - if (atomic_read(&sdp->detaching)) { - retval = -ENODEV; - goto free_old_hdr; - } - if (retval) { + if (atomic_read(&sdp->detaching)) + return -ENODEV; + if (retval) /* -ERESTARTSYS as signal hit process */ - goto free_old_hdr; - } - } - if (srp->header.interface_id != '\0') { - retval = sg_new_read(sfp, buf, count, srp); - goto free_old_hdr; + return retval; } + if (srp->header.interface_id != '\0') + return sg_new_read(sfp, buf, count, srp);

hp = &srp->header; - if (old_hdr == NULL) { - old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL); - if (! old_hdr) { - retval = -ENOMEM; - goto free_old_hdr; - } - } - memset(old_hdr, 0, SZ_SG_HEADER); + old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL); + if (!old_hdr) + return -ENOMEM; + old_hdr->reply_len = (int) hp->timeout; old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */ old_hdr->pack_id = hp->pack_id; @@ -575,7 +561,12 @@ sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp) int err = 0, err2; int len;

- if (count < SZ_SG_IO_HDR) { + if (in_compat_syscall()) { + if (count < SZ_COMPAT_SG_IO_HDR) { + err = -EINVAL; + goto err_out; + } + } else if (count < SZ_SG_IO_HDR) { err = -EINVAL; goto err_out; } diff --git a/include/scsi/sg.h b/include/scsi/sg.h index f91bcca604e4..29c7ad04d2e2 100644 --- a/include/scsi/sg.h +++ b/include/scsi/sg.h @@ -68,6 +68,36 @@ typedef struct sg_io_hdr unsigned int info; /* [o] auxiliary information */ } sg_io_hdr_t; /* 64 bytes long (on i386) */

+#if defined(__KERNEL__) +#include <linux/compat.h> + +struct compat_sg_io_hdr { + compat_int_t interface_id; /* [i] 'S' for SCSI generic (required) */ + compat_int_t dxfer_direction; /* [i] data transfer direction */ + unsigned char cmd_len; /* [i] SCSI command length ( <= 16 bytes) */ + unsigned char mx_sb_len; /* [i] max length to write to sbp */ + unsigned short iovec_count; /* [i] 0 implies no scatter gather */ + compat_uint_t dxfer_len; /* [i] byte count of data transfer */ + compat_uint_t dxferp; /* [i], [*io] points to data transfer memory + or scatter gather list */ + compat_uptr_t cmdp; /* [i], [*i] points to command to perform */ + compat_uptr_t sbp; /* [i], [*o] points to sense_buffer memory */ + compat_uint_t timeout; /* [i] MAX_UINT->no timeout (unit: millisec) */ + compat_uint_t flags; /* [i] 0 -> default, see SG_FLAG... */ + compat_int_t pack_id; /* [i->o] unused internally (normally) */ + compat_uptr_t usr_ptr; /* [i->o] unused internally */ + unsigned char status; /* [o] scsi status */ + unsigned char masked_status; /* [o] shifted, masked scsi status */ + unsigned char msg_status; /* [o] messaging level data (optional) */ + unsigned char sb_len_wr; /* [o] byte count actually written to sbp */ + unsigned short host_status; /* [o] errors from host adapter */ + unsigned short driver_status; /* [o] errors from software driver */ + compat_int_t resid; /* [o] dxfer_len - actual_transferred */ + compat_uint_t duration; /* [o] time taken by cmd (unit: millisec) */ + compat_uint_t info; /* [o] auxiliary information */ +}; +#endif + #define SG_INTERFACE_ID_ORIG 'S'

/* Use negative values to flag difference from original sg_header structure */

These drivers implement the HDIO_GET_IDENTITY and CDROMVOLREAD ioctl commands, which are compatible between 32-bit and 64-bit user space and traditionally handled by compat_blkdev_driver_ioctl().

As a prerequisite to removing that function, make both drivers use blkdev_compat_ptr_ioctl() as their .compat_ioctl callback.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- arch/um/drivers/ubd_kern.c | 1 + drivers/block/aoe/aoeblk.c | 1 + 2 files changed, 2 insertions(+)

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 6627d7c30f37..582eb5b1f09b 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -113,6 +113,7 @@ static const struct block_device_operations ubd_blops = { .open = ubd_open, .release = ubd_release, .ioctl = ubd_ioctl, + .compat_ioctl = blkdev_compat_ptr_ioctl, .getgeo = ubd_getgeo, };

diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index bd19f8af950b..7b32fb673375 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -329,6 +329,7 @@ static const struct block_device_operations aoe_bdops = { .open = aoeblk_open, .release = aoeblk_release, .ioctl = aoeblk_ioctl, + .compat_ioctl = blkdev_compat_ptr_ioctl, .getgeo = aoeblk_getgeo, .owner = THIS_MODULE, };

Again, there is only one file that needs this, so move the conversion handler into the native implementation.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/compat_ioctl.c | 36 ------------------------------------ drivers/cdrom/cdrom.c | 28 +++++++++++++++++++++++++--- 2 files changed, 25 insertions(+), 39 deletions(-)

diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index 578e04f94619..cf136bc2c9fc 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -95,40 +95,6 @@ static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode, return error; }

-struct compat_cdrom_read_audio { - union cdrom_addr addr; - u8 addr_format; - compat_int_t nframes; - compat_caddr_t buf; -}; - -static int compat_cdrom_read_audio(struct block_device *bdev, fmode_t mode, - unsigned int cmd, unsigned long arg) -{ - struct cdrom_read_audio __user *cdread_audio; - struct compat_cdrom_read_audio __user *cdread_audio32; - __u32 data; - void __user *datap; - - cdread_audio = compat_alloc_user_space(sizeof(*cdread_audio)); - cdread_audio32 = compat_ptr(arg); - - if (copy_in_user(&cdread_audio->addr, - &cdread_audio32->addr, - (sizeof(*cdread_audio32) - - sizeof(compat_caddr_t)))) - return -EFAULT; - - if (get_user(data, &cdread_audio32->buf)) - return -EFAULT; - datap = compat_ptr(data); - if (put_user(datap, &cdread_audio->buf)) - return -EFAULT; - - return __blkdev_driver_ioctl(bdev, mode, cmd, - (unsigned long)cdread_audio); -} - struct compat_blkpg_ioctl_arg { compat_int_t op; compat_int_t flags; @@ -178,8 +144,6 @@ static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode, case HDIO_GET_ADDRESS: case HDIO_GET_BUSSTATE: return compat_hdio_ioctl(bdev, mode, cmd, arg); - case CDROMREADAUDIO: - return compat_cdrom_read_audio(bdev, mode, cmd, arg);

/* * No handler required for the ones below, we just need to diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index eebdcbef0578..48095025e588 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -3017,9 +3017,31 @@ static noinline int mmc_ioctl_cdrom_read_audio(struct cdrom_device_info *cdi, struct cdrom_read_audio ra; int lba;

- if (copy_from_user(&ra, (struct cdrom_read_audio __user *)arg, - sizeof(ra))) - return -EFAULT; +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) { + struct compat_cdrom_read_audio { + union cdrom_addr addr; + u8 addr_format; + compat_int_t nframes; + compat_caddr_t buf; + } ra32; + + if (copy_from_user(&ra32, arg, sizeof(ra32))) + return -EFAULT; + + ra = (struct cdrom_read_audio) { + .addr = ra32.addr, + .addr_format = ra32.addr_format, + .nframes = ra32.nframes, + .buf = compat_ptr(ra32.buf), + }; + } else +#endif + { + if (copy_from_user(&ra, (struct cdrom_read_audio __user *)arg, + sizeof(ra))) + return -EFAULT; + }

if (ra.addr_format == CDROM_MSF) lba = msf_to_lba(ra.addr.msf.minute,

Various block drivers implement the CDROMMULTISESSION, CDROM_GET_CAPABILITY, and CDROMEJECT ioctl commands, relying on the block layer to handle compat_ioctl mode for them.

Move this into the drivers directly as a preparation for simplifying the block layer later.

Since some of these commands need a compat_ptr() conversion, introduce a blkdev_compat_ptr_ioctl() helper function that can be used as the .compat_ioctl callback for those drivers that only support compatible commands.

The actual CD-ROM drivers that call cdrom_ioctl() are converted in a separate patch.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/ioctl.c | 21 +++++++++++++++++++++ drivers/block/floppy.c | 3 +++ drivers/block/paride/pd.c | 1 + drivers/block/paride/pf.c | 1 + drivers/block/sunvdc.c | 1 + drivers/block/xen-blkfront.c | 1 + include/linux/blkdev.h | 7 +++++++ 7 files changed, 35 insertions(+)

diff --git a/block/ioctl.c b/block/ioctl.c index 5de98b97af2a..e728331d1a5b 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/capability.h> +#include <linux/compat.h> #include <linux/blkdev.h> #include <linux/export.h> #include <linux/gfp.h> @@ -285,6 +286,26 @@ int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode, */ EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);

+#ifdef CONFIG_COMPAT +/* + * This is the equivalent of compat_ptr_ioctl(), to be used by block + * drivers that implement only commands that are completely compatible + * between 32-bit and 64-bit user space + */ +int blkdev_compat_ptr_ioctl(struct block_device *bdev, fmode_t mode, + unsigned cmd, unsigned long arg) +{ + struct gendisk *disk = bdev->bd_disk; + + if (disk->fops->ioctl) + return disk->fops->ioctl(bdev, mode, cmd, + (unsigned long)compat_ptr(arg)); + + return -ENOIOCTLCMD; +} +EXPORT_SYMBOL(blkdev_compat_ptr_ioctl); +#endif + static int blkdev_pr_register(struct block_device *bdev, struct pr_registration __user *arg) { diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 485865fd0412..cd3612e4e2e1 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3879,6 +3879,9 @@ static int fd_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned int { int drive = (long)bdev->bd_disk->private_data; switch (cmd) { + case CDROMEJECT: /* CD-ROM eject */ + case 0x6470: /* SunOS floppy eject */ + case FDMSGON: case FDMSGOFF: case FDSETEMSGTRESH: diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c index 6f9ad3fc716f..c0967507d085 100644 --- a/drivers/block/paride/pd.c +++ b/drivers/block/paride/pd.c @@ -874,6 +874,7 @@ static const struct block_device_operations pd_fops = { .open = pd_open, .release = pd_release, .ioctl = pd_ioctl, + .compat_ioctl = pd_ioctl, .getgeo = pd_getgeo, .check_events = pd_check_events, .revalidate_disk= pd_revalidate diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c index 6b7d4cab3687..bb09f21ce21a 100644 --- a/drivers/block/paride/pf.c +++ b/drivers/block/paride/pf.c @@ -276,6 +276,7 @@ static const struct block_device_operations pf_fops = { .open = pf_open, .release = pf_release, .ioctl = pf_ioctl, + .compat_ioctl = pf_ioctl, .getgeo = pf_getgeo, .check_events = pf_check_events, }; diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c index 571612e233fe..39aeebc6837d 100644 --- a/drivers/block/sunvdc.c +++ b/drivers/block/sunvdc.c @@ -171,6 +171,7 @@ static const struct block_device_operations vdc_fops = { .owner = THIS_MODULE, .getgeo = vdc_getgeo, .ioctl = vdc_ioctl, + .compat_ioctl = blkdev_compat_ptr_ioctl, };

static void vdc_blk_queue_start(struct vdc_port *port) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index a74d03913822..23c86350a5ab 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -2632,6 +2632,7 @@ static const struct block_device_operations xlvbd_block_fops = .release = blkif_release, .getgeo = blkif_getgeo, .ioctl = blkif_ioctl, + .compat_ioctl = blkdev_compat_ptr_ioctl, };

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 47eb22a3b7f9..3e0408618da7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1711,6 +1711,13 @@ struct block_device_operations { const struct pr_ops *pr_ops; };

+#ifdef CONFIG_COMPAT +extern int blkdev_compat_ptr_ioctl(struct block_device *, fmode_t, + unsigned int, unsigned long); +#else +#define blkdev_compat_ptr_ioctl NULL +#endif + extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long); extern int bdev_read_page(struct block_device *, sector_t, struct page *);

bsg_ioctl() calls into scsi_cmd_ioctl() for a couple of generic commands and relies on fs/compat_ioctl.c to handle it correctly in compat mode.

Adding a private compat_ioctl() handler avoids that round-trip and lets us get rid of the generic emulation once this is done.

Note that bsg implements an SG_IO command that is different from the other drivers and does not need emulation.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/bsg.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/block/bsg.c b/block/bsg.c index 833c44b3d458..d7bae94b64d9 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -382,6 +382,7 @@ static const struct file_operations bsg_fops = { .open = bsg_open, .release = bsg_release, .unlocked_ioctl = bsg_ioctl, + .compat_ioctl = compat_ptr_ioctl, .owner = THIS_MODULE, .llseek = default_llseek, };

Each driver calling scsi_ioctl() gets an equivalent compat_ioctl() handler that implements the same commands by calling scsi_compat_ioctl().

The scsi_cmd_ioctl() and scsi_cmd_blk_ioctl() functions are compatible at this point, so any driver that calls those can do so for both native and compat mode, with the argument passed through compat_ptr().

With this, we can remove the entries from fs/compat_ioctl.c. The new code is larger, but should be easier to maintain and keep updated with newly added commands.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/block/virtio_blk.c | 3 + drivers/scsi/ch.c | 9 ++- drivers/scsi/sd.c | 50 ++++++-------- drivers/scsi/sg.c | 44 ++++++++----- drivers/scsi/sr.c | 57 ++++++++++++++-- drivers/scsi/st.c | 51 ++++++++------ fs/compat_ioctl.c | 132 +------------------------------------ 7 files changed, 142 insertions(+), 204 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 7ffd719d89de..fbbf18ac1d5d 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -405,6 +405,9 @@ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)

static const struct block_device_operations virtblk_fops = { .ioctl = virtblk_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = blkdev_compat_ptr_ioctl, +#endif .owner = THIS_MODULE, .getgeo = virtblk_getgeo, }; diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c index 76751d6c7f0d..ed5f4a6ae270 100644 --- a/drivers/scsi/ch.c +++ b/drivers/scsi/ch.c @@ -872,6 +872,10 @@ static long ch_ioctl_compat(struct file * file, unsigned int cmd, unsigned long arg) { scsi_changer *ch = file->private_data; + int retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd, + file->f_flags & O_NDELAY); + if (retval) + return retval;

switch (cmd) { case CHIOGPARAMS: @@ -883,7 +887,7 @@ static long ch_ioctl_compat(struct file * file, case CHIOINITELEM: case CHIOSVOLTAG: /* compatible */ - return ch_ioctl(file, cmd, arg); + return ch_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); case CHIOGSTATUS32: { struct changer_element_status32 ces32; @@ -898,8 +902,7 @@ static long ch_ioctl_compat(struct file * file, return ch_gstatus(ch, ces32.ces_type, data); } default: - // return scsi_ioctl_compat(ch->device, cmd, (void*)arg); - return -ENOIOCTLCMD; + return scsi_compat_ioctl(ch->device, cmd, compat_ptr(arg));

} } diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index cea625906440..5afb0046b12a 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1465,13 +1465,12 @@ static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo) * Note: most ioctls are forward onto the block subsystem or further * down in the scsi subsystem. **/ -static int sd_ioctl(struct block_device *bdev, fmode_t mode, - unsigned int cmd, unsigned long arg) +static int sd_ioctl_common(struct block_device *bdev, fmode_t mode, + unsigned int cmd, void __user *p) { struct gendisk *disk = bdev->bd_disk; struct scsi_disk *sdkp = scsi_disk(disk); struct scsi_device *sdp = sdkp->device; - void __user *p = (void __user *)arg; int error;

SCSI_LOG_IOCTL(1, sd_printk(KERN_INFO, sdkp, "sd_ioctl: disk=%s, " @@ -1507,9 +1506,6 @@ static int sd_ioctl(struct block_device *bdev, fmode_t mode, break; default: error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p); - if (error != -ENOTTY) - break; - error = scsi_ioctl(sdp, cmd, p); break; } out: @@ -1691,39 +1687,31 @@ static void sd_rescan(struct device *dev) revalidate_disk(sdkp->disk); }

+static int sd_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + void __user *p = (void __user *)arg; + int ret; + + ret = sd_ioctl_common(bdev, mode, cmd, p); + if (ret != -ENOTTY) + return ret; + + return scsi_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p); +}

#ifdef CONFIG_COMPAT -/* - * This gets directly called from VFS. When the ioctl - * is not recognized we go back to the other translation paths. - */ static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { - struct gendisk *disk = bdev->bd_disk; - struct scsi_disk *sdkp = scsi_disk(disk); - struct scsi_device *sdev = sdkp->device; void __user *p = compat_ptr(arg); - int error; - - error = scsi_verify_blk_ioctl(bdev, cmd); - if (error < 0) - return error; + int ret;

- error = scsi_ioctl_block_when_processing_errors(sdev, cmd, - (mode & FMODE_NDELAY) != 0); - if (error) - return error; + ret = sd_ioctl_common(bdev, mode, cmd, p); + if (ret != -ENOTTY) + return ret;

- if (is_sed_ioctl(cmd)) - return sed_ioctl(sdkp->opal_dev, cmd, p); - - /* - * Let the static ioctl translation table take care of it. - */ - if (!sdev->host->hostt->compat_ioctl) - return -ENOIOCTLCMD; - return sdev->host->hostt->compat_ioctl(sdev, cmd, p); + return scsi_compat_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p); } #endif

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 985546aac236..08efcee7a34d 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -910,19 +910,14 @@ static int put_compat_request_table(struct compat_sg_req_info __user *o, #endif

static long -sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) +sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp, + unsigned int cmd_in, void __user *p) { - void __user *p = (void __user *)arg; int __user *ip = p; int result, val, read_only; - Sg_device *sdp; - Sg_fd *sfp; Sg_request *srp; unsigned long iflags;

- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) - return -ENXIO; - SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_ioctl: cmd=0x%x\n", (int) cmd_in)); read_only = (O_RDWR != (filp->f_flags & O_ACCMODE)); @@ -1145,29 +1140,44 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) cmd_in, filp->f_flags & O_NDELAY); if (result) return result; + + return -ENOIOCTLCMD; +} + +static long +sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) +{ + void __user *p = (void __user *)arg; + Sg_device *sdp; + Sg_fd *sfp; + int ret; + + if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) + return -ENXIO; + + ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p); + if (ret != -ENOIOCTLCMD) + return ret; + return scsi_ioctl(sdp->device, cmd_in, p); }

#ifdef CONFIG_COMPAT static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) { + void __user *p = compat_ptr(arg); Sg_device *sdp; Sg_fd *sfp; - struct scsi_device *sdev; + int ret;

if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO;

- sdev = sdp->device; - if (sdev->host->hostt->compat_ioctl) { - int ret; - - ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg); - + ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p); + if (ret != -ENOIOCTLCMD) return ret; - } - - return -ENOIOCTLCMD; + + return scsi_compat_ioctl(sdp->device, cmd_in, p); } #endif

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 4664fdf75c0f..6033a886c42c 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -38,6 +38,7 @@ #include <linux/kernel.h> #include <linux/mm.h> #include <linux/bio.h> +#include <linux/compat.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/cdrom.h> @@ -598,6 +599,55 @@ static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, return ret; }

+#ifdef CONFIG_COMPAT +static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, + unsigned long arg) +{ + struct scsi_cd *cd = scsi_cd(bdev->bd_disk); + struct scsi_device *sdev = cd->device; + void __user *argp = compat_ptr(arg); + int ret; + + mutex_lock(&sr_mutex); + + ret = scsi_ioctl_block_when_processing_errors(sdev, cmd, + (mode & FMODE_NDELAY) != 0); + if (ret) + goto out; + + scsi_autopm_get_device(sdev); + + /* + * Send SCSI addressing ioctls directly to mid level, send other + * ioctls to cdrom/block level. + */ + switch (cmd) { + case SCSI_IOCTL_GET_IDLUN: + case SCSI_IOCTL_GET_BUS_NUMBER: + ret = scsi_compat_ioctl(sdev, cmd, argp); + goto put; + } + + /* + * CDROM ioctls are handled in the block layer, but + * do the scsi blk ioctls here. + */ + ret = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp); + if (ret != -ENOTTY) + return ret; + + ret = scsi_compat_ioctl(sdev, cmd, argp); + +put: + scsi_autopm_put_device(sdev); + +out: + mutex_unlock(&sr_mutex); + return ret; + +} +#endif + static unsigned int sr_block_check_events(struct gendisk *disk, unsigned int clearing) { @@ -641,12 +691,11 @@ static const struct block_device_operations sr_bdops = .open = sr_block_open, .release = sr_block_release, .ioctl = sr_block_ioctl, +#ifdef CONFIG_COMPAT + .ioctl = sr_block_compat_ioctl, +#endif .check_events = sr_block_check_events, .revalidate_disk = sr_block_revalidate_disk, - /* - * No compat_ioctl for now because sr_block_ioctl never - * seems to pass arbitrary ioctls down to host drivers. - */ };

static int sr_open(struct cdrom_device_info *cdi, int purpose) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 9e3fff2de83e..393f3019ccac 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -3501,7 +3501,7 @@ static int partition_tape(struct scsi_tape *STp, int size)

/* The ioctl command */ -static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) +static long st_ioctl_common(struct file *file, unsigned int cmd_in, void __user *p) { int i, cmd_nr, cmd_type, bt; int retval = 0; @@ -3509,7 +3509,6 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) struct scsi_tape *STp = file->private_data; struct st_modedef *STm; struct st_partstat *STps; - void __user *p = (void __user *)arg;

if (mutex_lock_interruptible(&STp->lock)) return -ERESTARTSYS; @@ -3824,9 +3823,19 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) } mutex_unlock(&STp->lock); switch (cmd_in) { + case SCSI_IOCTL_STOP_UNIT: + /* unload */ + retval = scsi_ioctl(STp->device, cmd_in, p); + if (!retval) { + STp->rew_at_close = 0; + STp->ready = ST_NO_TAPE; + } + return retval; + case SCSI_IOCTL_GET_IDLUN: case SCSI_IOCTL_GET_BUS_NUMBER: break; + default: if ((cmd_in == SG_IO || cmd_in == SCSI_IOCTL_SEND_COMMAND || @@ -3840,42 +3849,46 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) return i; break; } - retval = scsi_ioctl(STp->device, cmd_in, p); - if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */ - STp->rew_at_close = 0; - STp->ready = ST_NO_TAPE; - } - return retval; + return -ENOTTY;

out: mutex_unlock(&STp->lock); return retval; }

+static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) +{ + void __user *p = (void __user *)arg; + struct scsi_tape *STp = file->private_data; + int ret; + + ret = st_ioctl_common(file, cmd_in, p); + if (ret != -ENOTTY) + return ret; + + return scsi_ioctl(STp->device, cmd_in, p); +} + #ifdef CONFIG_COMPAT static long st_compat_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) { void __user *p = compat_ptr(arg); struct scsi_tape *STp = file->private_data; - struct scsi_device *sdev = STp->device; - int ret = -ENOIOCTLCMD; + int ret;

/* argument conversion is handled using put_user_mtpos/put_user_mtget */ switch (cmd_in) { - case MTIOCTOP: - return st_ioctl(file, MTIOCTOP, (unsigned long)p); case MTIOCPOS32: - return st_ioctl(file, MTIOCPOS, (unsigned long)p); + return st_ioctl_common(file, MTIOCPOS, p); case MTIOCGET32: - return st_ioctl(file, MTIOCGET, (unsigned long)p); + return st_ioctl_common(file, MTIOCGET, p); }

- if (sdev->host->hostt->compat_ioctl) { + ret = st_ioctl_common(file, cmd_in, p); + if (ret != -ENOTTY) + return ret;

- ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg); - - } - return ret; + return scsi_compat_ioctl(STp->device, cmd_in, p); } #endif

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index 358ea2ecf36b..ab4471f469e6 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -36,109 +36,11 @@

#include "internal.h"

-#ifdef CONFIG_BLOCK -#include <linux/cdrom.h> -#include <linux/fd.h> -#include <scsi/scsi.h> -#include <scsi/scsi_ioctl.h> -#include <scsi/sg.h> -#endif - #include <linux/uaccess.h> #include <linux/watchdog.h>

#include <linux/hiddev.h>

- -#include <linux/sort.h> - -/* - * simple reversible transform to make our table more evenly - * distributed after sorting. - */ -#define XFORM(i) (((i) ^ ((i) << 27) ^ ((i) << 17)) & 0xffffffff) - -#define COMPATIBLE_IOCTL(cmd) XFORM((u32)cmd), -static unsigned int ioctl_pointer[] = { -#ifdef CONFIG_BLOCK -/* Big S */ -COMPATIBLE_IOCTL(SCSI_IOCTL_GET_IDLUN) -COMPATIBLE_IOCTL(SCSI_IOCTL_DOORLOCK) -COMPATIBLE_IOCTL(SCSI_IOCTL_DOORUNLOCK) -COMPATIBLE_IOCTL(SCSI_IOCTL_TEST_UNIT_READY) -COMPATIBLE_IOCTL(SCSI_IOCTL_GET_BUS_NUMBER) -COMPATIBLE_IOCTL(SCSI_IOCTL_SEND_COMMAND) -COMPATIBLE_IOCTL(SCSI_IOCTL_PROBE_HOST) -COMPATIBLE_IOCTL(SCSI_IOCTL_GET_PCI) -#endif -#ifdef CONFIG_BLOCK -/* SG stuff */ -COMPATIBLE_IOCTL(SG_IO) -COMPATIBLE_IOCTL(SG_GET_REQUEST_TABLE) -COMPATIBLE_IOCTL(SG_SET_TIMEOUT) -COMPATIBLE_IOCTL(SG_GET_TIMEOUT) -COMPATIBLE_IOCTL(SG_EMULATED_HOST) -COMPATIBLE_IOCTL(SG_GET_TRANSFORM) -COMPATIBLE_IOCTL(SG_SET_RESERVED_SIZE) -COMPATIBLE_IOCTL(SG_GET_RESERVED_SIZE) -COMPATIBLE_IOCTL(SG_GET_SCSI_ID) -COMPATIBLE_IOCTL(SG_SET_FORCE_LOW_DMA) -COMPATIBLE_IOCTL(SG_GET_LOW_DMA) -COMPATIBLE_IOCTL(SG_SET_FORCE_PACK_ID) -COMPATIBLE_IOCTL(SG_GET_PACK_ID) -COMPATIBLE_IOCTL(SG_GET_NUM_WAITING) -COMPATIBLE_IOCTL(SG_SET_DEBUG) -COMPATIBLE_IOCTL(SG_GET_SG_TABLESIZE) -COMPATIBLE_IOCTL(SG_GET_COMMAND_Q) -COMPATIBLE_IOCTL(SG_SET_COMMAND_Q) -COMPATIBLE_IOCTL(SG_GET_VERSION_NUM) -COMPATIBLE_IOCTL(SG_NEXT_CMD_LEN) -COMPATIBLE_IOCTL(SG_SCSI_RESET) -COMPATIBLE_IOCTL(SG_GET_REQUEST_TABLE) -COMPATIBLE_IOCTL(SG_SET_KEEP_ORPHAN) -COMPATIBLE_IOCTL(SG_GET_KEEP_ORPHAN) -#endif -}; - -/* - * Convert common ioctl arguments based on their command number - * - * Please do not add any code in here. Instead, implement - * a compat_ioctl operation in the place that handleѕ the - * ioctl for the native case. - */ -static long do_ioctl_trans(unsigned int cmd, - unsigned long arg, struct file *file) -{ - return -ENOIOCTLCMD; -} - -static int compat_ioctl_check_table(unsigned int xcmd) -{ -#ifdef CONFIG_BLOCK - int i; - const int max = ARRAY_SIZE(ioctl_pointer) - 1; - - BUILD_BUG_ON(max >= (1 << 16)); - - /* guess initial offset into table, assuming a - normalized distribution */ - i = ((xcmd >> 16) * max) >> 16; - - /* do linear search up first, until greater or equal */ - while (ioctl_pointer[i] < xcmd && i < max) - i++; - - /* then do linear search down */ - while (ioctl_pointer[i] > xcmd && i > 0) - i--; - - return ioctl_pointer[i] == xcmd; -#else - return 0; -#endif -} - COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, compat_ulong_t, arg32) { @@ -216,19 +118,9 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, goto out_fput; }

- if (!f.file->f_op->unlocked_ioctl) - goto do_ioctl; - break; - } - - if (compat_ioctl_check_table(XFORM(cmd))) - goto found_handler; - - error = do_ioctl_trans(cmd, arg, f.file); - if (error == -ENOIOCTLCMD) error = -ENOTTY; - - goto out_fput; + goto out_fput; + }

found_handler: arg = (unsigned long)compat_ptr(arg); @@ -239,23 +131,3 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, out: return error; } - -static int __init init_sys32_ioctl_cmp(const void *p, const void *q) -{ - unsigned int a, b; - a = *(unsigned int *)p; - b = *(unsigned int *)q; - if (a > b) - return 1; - if (a < b) - return -1; - return 0; -} - -static int __init init_sys32_ioctl(void) -{ - sort(ioctl_pointer, ARRAY_SIZE(ioctl_pointer), sizeof(*ioctl_pointer), - init_sys32_ioctl_cmp, NULL); - return 0; -} -__initcall(init_sys32_ioctl);

The rest of the fs/compat_ioctl.c file is no longer useful now, so move the actual syscall as planned.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- fs/Makefile | 2 +- fs/compat_ioctl.c | 133 ---------------------------------------------- fs/ioctl.c | 90 +++++++++++++++++++++++++++++++ 3 files changed, 91 insertions(+), 134 deletions(-) delete mode 100644 fs/compat_ioctl.c

diff --git a/fs/Makefile b/fs/Makefile index 1148c555c4d3..98be354fdb61 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -37,7 +37,7 @@ obj-$(CONFIG_FS_DAX) += dax.o obj-$(CONFIG_FS_ENCRYPTION) += crypto/ obj-$(CONFIG_FS_VERITY) += verity/ obj-$(CONFIG_FILE_LOCKING) += locks.o -obj-$(CONFIG_COMPAT) += compat.o compat_ioctl.o +obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_BINFMT_AOUT) += binfmt_aout.o obj-$(CONFIG_BINFMT_EM86) += binfmt_em86.o obj-$(CONFIG_BINFMT_MISC) += binfmt_misc.o diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c deleted file mode 100644 index ab4471f469e6..000000000000 --- a/fs/compat_ioctl.c +++ /dev/null @@ -1,133 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * ioctl32.c: Conversion between 32bit and 64bit native ioctls. - * - * Copyright (C) 1997-2000 Jakub Jelinek (jakub@redhat.com) - * Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be) - * Copyright (C) 2001,2002 Andi Kleen, SuSE Labs - * Copyright (C) 2003 Pavel Machek (pavel@ucw.cz) - * - * These routines maintain argument size conversion between 32bit and 64bit - * ioctls. - */ - -#include <linux/types.h> -#include <linux/compat.h> -#include <linux/kernel.h> -#include <linux/capability.h> -#include <linux/compiler.h> -#include <linux/sched.h> -#include <linux/smp.h> -#include <linux/ioctl.h> -#include <linux/if.h> -#include <linux/raid/md_u.h> -#include <linux/falloc.h> -#include <linux/file.h> -#include <linux/ppp-ioctl.h> -#include <linux/if_pppox.h> -#include <linux/tty.h> -#include <linux/vt_kern.h> -#include <linux/blkdev.h> -#include <linux/serial.h> -#include <linux/ctype.h> -#include <linux/syscalls.h> -#include <linux/gfp.h> -#include <linux/cec.h> - -#include "internal.h" - -#include <linux/uaccess.h> -#include <linux/watchdog.h> - -#include <linux/hiddev.h> - -COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, - compat_ulong_t, arg32) -{ - unsigned long arg = arg32; - struct fd f = fdget(fd); - int error = -EBADF; - if (!f.file) - goto out; - - /* RED-PEN how should LSM module know it's handling 32bit? */ - error = security_file_ioctl(f.file, cmd, arg); - if (error) - goto out_fput; - - switch (cmd) { - /* these are never seen by ->ioctl(), no argument or int argument */ - case FIOCLEX: - case FIONCLEX: - case FIFREEZE: - case FITHAW: - case FICLONE: - goto do_ioctl; - /* these are never seen by ->ioctl(), pointer argument */ - case FIONBIO: - case FIOASYNC: - case FIOQSIZE: - case FS_IOC_FIEMAP: - case FIGETBSZ: - case FICLONERANGE: - case FIDEDUPERANGE: - goto found_handler; - /* - * The next group is the stuff handled inside file_ioctl(). - * For regular files these never reach ->ioctl(); for - * devices, sockets, etc. they do and one (FIONREAD) is - * even accepted in some cases. In all those cases - * argument has the same type, so we can handle these - * here, shunting them towards do_vfs_ioctl(). - * ->compat_ioctl() will never see any of those. - */ - /* pointer argument, never actually handled by ->ioctl() */ - case FIBMAP: - goto found_handler; - /* handled by some ->ioctl(); always a pointer to int */ - case FIONREAD: - goto found_handler; - /* these get messy on amd64 due to alignment differences */ -#if defined(CONFIG_X86_64) - case FS_IOC_RESVSP_32: - case FS_IOC_RESVSP64_32: - error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg)); - goto out_fput; - case FS_IOC_UNRESVSP_32: - case FS_IOC_UNRESVSP64_32: - error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE, - compat_ptr(arg)); - goto out_fput; - case FS_IOC_ZERO_RANGE_32: - error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE, - compat_ptr(arg)); - goto out_fput; -#else - case FS_IOC_RESVSP: - case FS_IOC_RESVSP64: - case FS_IOC_UNRESVSP: - case FS_IOC_UNRESVSP64: - case FS_IOC_ZERO_RANGE: - goto found_handler; -#endif - - default: - if (f.file->f_op->compat_ioctl) { - error = f.file->f_op->compat_ioctl(f.file, cmd, arg); - if (error != -ENOIOCTLCMD) - goto out_fput; - } - - error = -ENOTTY; - goto out_fput; - } - - found_handler: - arg = (unsigned long)compat_ptr(arg); - do_ioctl: - error = do_vfs_ioctl(f.file, fd, cmd, arg); - out_fput: - fdput(f); - out: - return error; -} diff --git a/fs/ioctl.c b/fs/ioctl.c index 2f5e4e5b97e1..8f22f7817edb 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -788,4 +788,94 @@ long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); } EXPORT_SYMBOL(compat_ptr_ioctl); + +COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, + compat_ulong_t, arg32) +{ + unsigned long arg = arg32; + struct fd f = fdget(fd); + int error = -EBADF; + if (!f.file) + goto out; + + /* RED-PEN how should LSM module know it's handling 32bit? */ + error = security_file_ioctl(f.file, cmd, arg); + if (error) + goto out_fput; + + switch (cmd) { + /* these are never seen by ->ioctl(), no argument or int argument */ + case FIOCLEX: + case FIONCLEX: + case FIFREEZE: + case FITHAW: + case FICLONE: + goto do_ioctl; + /* these are never seen by ->ioctl(), pointer argument */ + case FIONBIO: + case FIOASYNC: + case FIOQSIZE: + case FS_IOC_FIEMAP: + case FIGETBSZ: + case FICLONERANGE: + case FIDEDUPERANGE: + goto found_handler; + /* + * The next group is the stuff handled inside file_ioctl(). + * For regular files these never reach ->ioctl(); for + * devices, sockets, etc. they do and one (FIONREAD) is + * even accepted in some cases. In all those cases + * argument has the same type, so we can handle these + * here, shunting them towards do_vfs_ioctl(). + * ->compat_ioctl() will never see any of those. + */ + /* pointer argument, never actually handled by ->ioctl() */ + case FIBMAP: + goto found_handler; + /* handled by some ->ioctl(); always a pointer to int */ + case FIONREAD: + goto found_handler; + /* these get messy on amd64 due to alignment differences */ +#if defined(CONFIG_X86_64) + case FS_IOC_RESVSP_32: + case FS_IOC_RESVSP64_32: + error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg)); + goto out_fput; + case FS_IOC_UNRESVSP_32: + case FS_IOC_UNRESVSP64_32: + error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE, + compat_ptr(arg)); + goto out_fput; + case FS_IOC_ZERO_RANGE_32: + error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE, + compat_ptr(arg)); + goto out_fput; +#else + case FS_IOC_RESVSP: + case FS_IOC_RESVSP64: + case FS_IOC_UNRESVSP: + case FS_IOC_UNRESVSP64: + case FS_IOC_ZERO_RANGE: + goto found_handler; +#endif + + default: + if (f.file->f_op->compat_ioctl) { + error = f.file->f_op->compat_ioctl(f.file, cmd, arg); + if (error != -ENOIOCTLCMD) + goto out_fput; + } + error = -ENOTTY; + goto out_fput; + } + + found_handler: + arg = (unsigned long)compat_ptr(arg); + do_ioctl: + error = do_vfs_ioctl(f.file, fd, cmd, arg); + out_fput: + fdput(f); + out: + return error; +} #endif

There is no need for the special cases for the cdrom ioctls any more now, so make sure that each cdrom driver has a .compat_ioctl() callback and calls cdrom_compat_ioctl() directly there.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/compat_ioctl.c | 45 -------------------------------------- drivers/block/paride/pcd.c | 3 +++ drivers/cdrom/gdrom.c | 3 +++ drivers/ide/ide-cd.c | 36 ++++++++++++++++++++++++++++++ drivers/scsi/sr.c | 10 +++------ 5 files changed, 45 insertions(+), 52 deletions(-)

diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index cf136bc2c9fc..7cb534d6e767 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -159,42 +159,6 @@ static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode, case HDIO_DRIVE_CMD: /* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */ case 0x330: - /* CDROM stuff */ - case CDROMPAUSE: - case CDROMRESUME: - case CDROMPLAYMSF: - case CDROMPLAYTRKIND: - case CDROMREADTOCHDR: - case CDROMREADTOCENTRY: - case CDROMSTOP: - case CDROMSTART: - case CDROMEJECT: - case CDROMVOLCTRL: - case CDROMSUBCHNL: - case CDROMMULTISESSION: - case CDROM_GET_MCN: - case CDROMRESET: - case CDROMVOLREAD: - case CDROMSEEK: - case CDROMPLAYBLK: - case CDROMCLOSETRAY: - case CDROM_DISC_STATUS: - case CDROM_CHANGER_NSLOTS: - case CDROM_GET_CAPABILITY: - case CDROM_SEND_PACKET: - /* Ignore cdrom.h about these next 5 ioctls, they absolutely do - * not take a struct cdrom_read, instead they take a struct cdrom_msf - * which is compatible. - */ - case CDROMREADMODE2: - case CDROMREADMODE1: - case CDROMREADRAW: - case CDROMREADCOOKED: - case CDROMREADALL: - /* DVD ioctls */ - case DVD_READ_STRUCT: - case DVD_WRITE_STRUCT: - case DVD_AUTH: arg = (unsigned long)compat_ptr(arg); /* These intepret arg as an unsigned long, not as a pointer, * so we must not do compat_ptr() conversion. */ @@ -210,15 +174,6 @@ static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode, case HDIO_SET_ACOUSTIC: case HDIO_SET_BUSSTATE: case HDIO_SET_ADDRESS: - case CDROMEJECT_SW: - case CDROM_SET_OPTIONS: - case CDROM_CLEAR_OPTIONS: - case CDROM_SELECT_SPEED: - case CDROM_SELECT_DISC: - case CDROM_MEDIA_CHANGED: - case CDROM_DRIVE_STATUS: - case CDROM_LOCKDOOR: - case CDROM_DEBUG: break; default: /* unknown ioctl number */ diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c index 636bfea2de6f..117cfc8cd05a 100644 --- a/drivers/block/paride/pcd.c +++ b/drivers/block/paride/pcd.c @@ -275,6 +275,9 @@ static const struct block_device_operations pcd_bdops = { .open = pcd_block_open, .release = pcd_block_release, .ioctl = pcd_block_ioctl, +#ifdef CONFIG_COMPAT + .ioctl = blkdev_compat_ptr_ioctl, +#endif .check_events = pcd_block_check_events, };

diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c index 5b21dc421c94..886b2638c730 100644 --- a/drivers/cdrom/gdrom.c +++ b/drivers/cdrom/gdrom.c @@ -518,6 +518,9 @@ static const struct block_device_operations gdrom_bdops = { .release = gdrom_bdops_release, .check_events = gdrom_bdops_check_events, .ioctl = gdrom_bdops_ioctl, +#ifdef CONFIG_COMPAT + .ioctl = blkdev_compat_ptr_ioctl, +#endif };

static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 9d117936bee1..2de6e8ace957 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -25,6 +25,7 @@

#define IDECD_VERSION "5.00"

+#include <linux/compat.h> #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> @@ -1710,6 +1711,38 @@ static int idecd_ioctl(struct block_device *bdev, fmode_t mode, return ret; }

+#ifdef CONFIG_COMPAT +static int idecd_locked_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct cdrom_info *info = ide_drv_g(bdev->bd_disk, cdrom_info); + int err; + + switch (cmd) { + case CDROMSETSPINDOWN: + return idecd_set_spindown(&info->devinfo, arg); + case CDROMGETSPINDOWN: + return idecd_get_spindown(&info->devinfo, arg); + default: + break; + } + + return cdrom_ioctl(&info->devinfo, bdev, mode, cmd, + (unsigned long)compat_ptr(arg)); +} + +static int idecd_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + int ret; + + mutex_lock(&ide_cd_mutex); + ret = idecd_locked_compat_ioctl(bdev, mode, cmd, arg); + mutex_unlock(&ide_cd_mutex); + + return ret; +} +#endif

static unsigned int idecd_check_events(struct gendisk *disk, unsigned int clearing) @@ -1732,6 +1765,9 @@ static const struct block_device_operations idecd_ops = { .open = idecd_open, .release = idecd_release, .ioctl = idecd_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = idecd_compat_ioctl, +#endif .check_events = idecd_check_events, .revalidate_disk = idecd_revalidate_disk }; diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 6033a886c42c..0fbb8fe6e521 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -628,13 +628,9 @@ static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsign goto put; }

- /* - * CDROM ioctls are handled in the block layer, but - * do the scsi blk ioctls here. - */ - ret = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp); - if (ret != -ENOTTY) - return ret; + ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, (unsigned long)argp); + if (ret != -ENOSYS) + goto put;

ret = scsi_compat_ioctl(sdev, cmd, argp);

Most of the HDIO ioctls are only used by the obsolete drivers/ide subsystem, these can be handled by changing ide_cmd_ioctl() to be aware of compat mode and doing the correct transformations in place and using it as both native and compat handlers for all drivers.

The SCSI drivers implementing the same commands are already doing this in the drivers, so the compat_blkdev_driver_ioctl() function is no longer needed now.

The BLKSECTSET and HDIO_GETGEO_BIG ioctls are not implemented in any driver any more and no longer need any conversion.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/compat_ioctl.c | 75 ---------------------------------- drivers/ide/ide-cd.c | 8 +++- drivers/ide/ide-disk.c | 3 ++ drivers/ide/ide-floppy_ioctl.c | 7 ++-- drivers/ide/ide-ioctls.c | 47 +++++++++++++-------- drivers/ide/ide-tape.c | 14 +++++++ 6 files changed, 57 insertions(+), 97 deletions(-)

diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index 7cb534d6e767..765aa5357655 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -77,24 +77,6 @@ static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev, return ret; }

-static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode, - unsigned int cmd, unsigned long arg) -{ - unsigned long __user *p; - int error; - - p = compat_alloc_user_space(sizeof(unsigned long)); - error = __blkdev_driver_ioctl(bdev, mode, - cmd, (unsigned long)p); - if (error == 0) { - unsigned int __user *uvp = compat_ptr(arg); - unsigned long v; - if (get_user(v, p) || put_user(v, uvp)) - error = -EFAULT; - } - return error; -} - struct compat_blkpg_ioctl_arg { compat_int_t op; compat_int_t flags; @@ -128,61 +110,6 @@ static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode, #define BLKBSZSET_32 _IOW(0x12, 113, int) #define BLKGETSIZE64_32 _IOR(0x12, 114, int)

-static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode, - unsigned cmd, unsigned long arg) -{ - switch (cmd) { - case HDIO_GET_UNMASKINTR: - case HDIO_GET_MULTCOUNT: - case HDIO_GET_KEEPSETTINGS: - case HDIO_GET_32BIT: - case HDIO_GET_NOWERR: - case HDIO_GET_DMA: - case HDIO_GET_NICE: - case HDIO_GET_WCACHE: - case HDIO_GET_ACOUSTIC: - case HDIO_GET_ADDRESS: - case HDIO_GET_BUSSTATE: - return compat_hdio_ioctl(bdev, mode, cmd, arg); - - /* - * No handler required for the ones below, we just need to - * convert arg to a 64 bit pointer. - */ - case BLKSECTSET: - /* - * 0x03 -- HD/IDE ioctl's used by hdparm and friends. - * Some need translations, these do not. - */ - case HDIO_GET_IDENTITY: - case HDIO_DRIVE_TASK: - case HDIO_DRIVE_CMD: - /* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */ - case 0x330: - arg = (unsigned long)compat_ptr(arg); - /* These intepret arg as an unsigned long, not as a pointer, - * so we must not do compat_ptr() conversion. */ - case HDIO_SET_MULTCOUNT: - case HDIO_SET_UNMASKINTR: - case HDIO_SET_KEEPSETTINGS: - case HDIO_SET_32BIT: - case HDIO_SET_NOWERR: - case HDIO_SET_DMA: - case HDIO_SET_PIO_MODE: - case HDIO_SET_NICE: - case HDIO_SET_WCACHE: - case HDIO_SET_ACOUSTIC: - case HDIO_SET_BUSSTATE: - case HDIO_SET_ADDRESS: - break; - default: - /* unknown ioctl number */ - return -ENOIOCTLCMD; - } - - return __blkdev_driver_ioctl(bdev, mode, cmd, arg); -} - /* Most of the generic ioctls are handled in the normal fallback path. This assumes the blkdev's low level compat_ioctl always returns ENOIOCTLCMD for unknown ioctls. */ @@ -293,8 +220,6 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) default: if (disk->fops->compat_ioctl) ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg); - if (ret == -ENOIOCTLCMD) - ret = compat_blkdev_driver_ioctl(bdev, mode, cmd, arg); return ret; } } diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 2de6e8ace957..521564da8707 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -1727,8 +1727,12 @@ static int idecd_locked_compat_ioctl(struct block_device *bdev, fmode_t mode, break; }

- return cdrom_ioctl(&info->devinfo, bdev, mode, cmd, - (unsigned long)compat_ptr(arg)); + err = generic_ide_ioctl(info->drive, bdev, cmd, arg); + if (err == -EINVAL) + err = cdrom_ioctl(&info->devinfo, bdev, mode, cmd, + (unsigned long)compat_ptr(arg)); + + return err; }

static int idecd_compat_ioctl(struct block_device *bdev, fmode_t mode, diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c index 197912af5c2f..27f1098e4bcd 100644 --- a/drivers/ide/ide-disk.c +++ b/drivers/ide/ide-disk.c @@ -794,4 +794,7 @@ const struct ide_disk_ops ide_ata_disk_ops = { .set_doorlock = ide_disk_set_doorlock, .do_request = ide_do_rw_disk, .ioctl = ide_disk_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = ide_disk_ioctl, +#endif }; diff --git a/drivers/ide/ide-floppy_ioctl.c b/drivers/ide/ide-floppy_ioctl.c index 4fd70f804d6f..39a790ac6cc3 100644 --- a/drivers/ide/ide-floppy_ioctl.c +++ b/drivers/ide/ide-floppy_ioctl.c @@ -329,10 +329,9 @@ int ide_floppy_compat_ioctl(ide_drive_t *drive, struct block_device *bdev, if (cmd != CDROM_SEND_PACKET && cmd != SCSI_IOCTL_SEND_COMMAND) err = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);

- /* - * there is no generic_ide_compat_ioctl(), that is handled - * through compat_blkdev_ioctl(). - */ + if (err == -ENOTTY) + err = generic_ide_ioctl(drive, bdev, cmd, arg); + out: mutex_unlock(&ide_floppy_ioctl_mutex); return err; diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c index d48c17003874..d97da46fdd79 100644 --- a/drivers/ide/ide-ioctls.c +++ b/drivers/ide/ide-ioctls.c @@ -3,11 +3,21 @@ * IDE ioctls handling. */

+#include <linux/compat.h> #include <linux/export.h> #include <linux/hdreg.h> #include <linux/ide.h> #include <linux/slab.h>

+static int put_user_long(long val, unsigned long arg) +{ +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + return put_user(val, (compat_long_t __user *)compat_ptr(arg)); +#endif + return put_user(val, (long __user *)arg); +} + static const struct ide_ioctl_devset ide_ioctl_settings[] = { { HDIO_GET_32BIT, HDIO_SET_32BIT, &ide_devset_io_32bit }, { HDIO_GET_KEEPSETTINGS, HDIO_SET_KEEPSETTINGS, &ide_devset_keepsettings }, @@ -37,7 +47,7 @@ int ide_setting_ioctl(ide_drive_t *drive, struct block_device *bdev, mutex_lock(&ide_setting_mtx); err = ds->get(drive); mutex_unlock(&ide_setting_mtx); - return err >= 0 ? put_user(err, (long __user *)arg) : err; + return err >= 0 ? put_user_long(err, arg) : err;

set_val: if (bdev != bdev->bd_contains) @@ -56,7 +66,7 @@ int ide_setting_ioctl(ide_drive_t *drive, struct block_device *bdev, EXPORT_SYMBOL_GPL(ide_setting_ioctl);

static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd, - unsigned long arg) + void __user *argp) { u16 *id = NULL; int size = (cmd == HDIO_GET_IDENTITY) ? (ATA_ID_WORDS * 2) : 142; @@ -77,7 +87,7 @@ static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd, memcpy(id, drive->id, size); ata_id_to_hd_driveid(id);

- if (copy_to_user((void __user *)arg, id, size)) + if (copy_to_user(argp, id, size)) rc = -EFAULT;

kfree(id); @@ -87,10 +97,10 @@ static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd,

static int ide_get_nice_ioctl(ide_drive_t *drive, unsigned long arg) { - return put_user((!!(drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) + return put_user_long((!!(drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) << IDE_NICE_DSC_OVERLAP) | (!!(drive->dev_flags & IDE_DFLAG_NICE1) - << IDE_NICE_1), (long __user *)arg); + << IDE_NICE_1), arg); }

static int ide_set_nice_ioctl(ide_drive_t *drive, unsigned long arg) @@ -115,7 +125,7 @@ static int ide_set_nice_ioctl(ide_drive_t *drive, unsigned long arg) return 0; }

-static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg) +static int ide_cmd_ioctl(ide_drive_t *drive, void __user *argp) { u8 *buf = NULL; int bufsize = 0, err = 0; @@ -123,7 +133,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg) struct ide_cmd cmd; struct ide_taskfile *tf = &cmd.tf;

- if (NULL == (void *) arg) { + if (NULL == argp) { struct request *rq;

rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0); @@ -135,7 +145,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg) return err; }

- if (copy_from_user(args, (void __user *)arg, 4)) + if (copy_from_user(args, argp, 4)) return -EFAULT;

memset(&cmd, 0, sizeof(cmd)); @@ -181,19 +191,18 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg) args[1] = tf->error; args[2] = tf->nsect; abort: - if (copy_to_user((void __user *)arg, &args, 4)) + if (copy_to_user(argp, &args, 4)) err = -EFAULT; if (buf) { - if (copy_to_user((void __user *)(arg + 4), buf, bufsize)) + if (copy_to_user((argp + 4), buf, bufsize)) err = -EFAULT; kfree(buf); } return err; }

-static int ide_task_ioctl(ide_drive_t *drive, unsigned long arg) +static int ide_task_ioctl(ide_drive_t *drive, void __user *p) { - void __user *p = (void __user *)arg; int err = 0; u8 args[7]; struct ide_cmd cmd; @@ -237,6 +246,12 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev, unsigned int cmd, unsigned long arg) { int err; + void __user *argp = (void __user *)arg; + +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + argp = compat_ptr(arg); +#endif

err = ide_setting_ioctl(drive, bdev, cmd, arg, ide_ioctl_settings); if (err != -EOPNOTSUPP) @@ -247,7 +262,7 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev, case HDIO_GET_IDENTITY: if (bdev != bdev->bd_contains) return -EINVAL; - return ide_get_identity_ioctl(drive, cmd, arg); + return ide_get_identity_ioctl(drive, cmd, argp); case HDIO_GET_NICE: return ide_get_nice_ioctl(drive, arg); case HDIO_SET_NICE: @@ -265,11 +280,11 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev, case HDIO_DRIVE_CMD: if (!capable(CAP_SYS_RAWIO)) return -EACCES; - return ide_cmd_ioctl(drive, arg); + return ide_cmd_ioctl(drive, argp); case HDIO_DRIVE_TASK: if (!capable(CAP_SYS_RAWIO)) return -EACCES; - return ide_task_ioctl(drive, arg); + return ide_task_ioctl(drive, argp); case HDIO_DRIVE_RESET: if (!capable(CAP_SYS_ADMIN)) return -EACCES; @@ -277,7 +292,7 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev, case HDIO_GET_BUSSTATE: if (!capable(CAP_SYS_ADMIN)) return -EACCES; - if (put_user(BUSSTATE_ON, (long __user *)arg)) + if (put_user_long(BUSSTATE_ON, arg)) return -EFAULT; return 0; case HDIO_SET_BUSSTATE: diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c index 3e7482695f77..4c2a95a2f0b6 100644 --- a/drivers/ide/ide-tape.c +++ b/drivers/ide/ide-tape.c @@ -1945,11 +1945,25 @@ static int idetape_ioctl(struct block_device *bdev, fmode_t mode, return err; }

+#ifdef CONFIG_COMPAT +static int idetape_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + if (cmd == 0x0340 || cmd == 0x350) + arg = (unsigned long)compat_ptr(arg); + + return idetape_ioctl(bdev, mode, cmd, arg); +} +#endif + static const struct block_device_operations idetape_block_ops = { .owner = THIS_MODULE, .open = idetape_open, .release = idetape_release, .ioctl = idetape_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = idetape_compat_ioctl, +#endif };

static int ide_tape_probe(ide_drive_t *drive)

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.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/ioctl.c | 74 ++++++++++++++++++++++++++------------------------- 1 file changed, 38 insertions(+), 36 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c index f8c4e2649335..d6911a1149f5 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -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)

Documentation/process/botching-up-ioctls.rst was orignally written as a blog post for DRM driver writers, so it it misses some points while going into a lot of detail on others.

Try to provide a replacement that addresses typical issues across a wider range of subsystems, and follows the style of the core-api documentation better.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- Documentation/core-api/index.rst | 1 + Documentation/core-api/ioctl.rst | 250 +++++++++++++++++++++++++++++++ 2 files changed, 251 insertions(+) create mode 100644 Documentation/core-api/ioctl.rst

diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst index ab0eae1c153a..3f28b2f668be 100644 --- a/Documentation/core-api/index.rst +++ b/Documentation/core-api/index.rst @@ -39,6 +39,7 @@ Core utilities ../RCU/index gcc-plugins symbol-namespaces + ioctl

Interfaces for kernel debugging diff --git a/Documentation/core-api/ioctl.rst b/Documentation/core-api/ioctl.rst new file mode 100644 index 000000000000..cb2c86ae63e7 --- /dev/null +++ b/Documentation/core-api/ioctl.rst @@ -0,0 +1,250 @@ +====================== +ioctl based interfaces +====================== + +:c:func:`ioctl` is the most common way for applications to interface +with device drivers. It is flexible and easily extended by adding new +commands and can be passed through character devices, block devices as +well as sockets and other special file descriptors. + +However, it is also very easy to get ioctl command definitions wrong, +and hard to fix them later without breaking existing applications, +so this documentation tries to help developers get it right. + +Command number definitions +========================== + +The command number, or request number, is the second argument passed to +the ioctl system call. While this can be any 32-bit number that uniquely +identifies an action for a particular driver, there are a number of +conventions around defining them. + +``include/uapi/asm-generic/ioctl.h`` provides four macros for defining +ioctl commands that follow modern conventions: ``_IOC``, ``_IOR``, +``_IOW``, and ``_IORW``. These should be used for all new commands, +with the correct parameters: + +_IO/_IOR/_IOW/_IOWR + The macro name determines whether the argument is used for passing + data into kernel (_IOW), from the kernel (_IOR), both (_IOWR) or is + not a pointer (_IOC). It is possible but not recommended to pass an + integer value instead of a pointer with _IOC. + +type + An 8-bit number, often a character literal, specific to a subsystem + or driver, and listed in :doc:`../ioctl/ioctl-number` + +nr + An 8-bit number identifying the specific command, unique for a give + value of 'type' + +size + The name of the data type pointed to by the argument, the command + number encodes the ``sizeof(size)`` value in a 13-bit or 14-bit integer, + leading to a limit of 8191 bytes for the maximum size of the argument. + Note: do not pass sizeof(type) type into _IOR/IOW, as that will lead + to encoding sizeof(sizeof(type)), i.e. sizeof(size_t). + + +Interface versions +================== + +Some subsystems use version numbers in data structures to overload +commands with different interpretations of the argument. + +This is generally a bad idea, since changes to existing commands tend +to break existing applications. + +A better approach is to add a new ioctl command with a new number. The +old command still needs to be implemented in the kernel for compatibility, +but this can be a wrapper around the new implementation. + +Return code +=========== + +ioctl commands can return negative error codes as documented in errno(3), +these get turned into errno values in user space. On success, the return +code should be zero. It is also possible but not recommended to return +a positive 'long' value. + +When the ioctl callback is called with an unknown command number, the +handler returns either -ENOTTY or -ENOIOCTLCMD, which also results in +-ENOTTY being returned from the system call. Some subsystems return +-ENOSYS or -EINVAL here for historic reasons, but this is wrong. + +Prior to Linux-5.5, compat_ioctl handlers were required to return +-ENOIOCTLCMD in order to use the fallback conversion into native +commands. As all subsystems are now responsible for handling compat +mode themselves, this is no longer needed, but it may be important to +consider when backporting bug fixes to older kernels. + +Timestamps +========== + +Traditionally, timestamps and timeout values are passed as ``struct +timespec`` or ``struct timeval``, but these are problematic because of +incompatible definitions of these structures in user space after the +move to 64-bit time_t. + +The __kernel_timespec type can be used instead to be embedded in other +data structures when separate second/nanosecond values are desired, +or passed to user space directly. This is still not ideal though, +as the structure matches neither the kernel's timespec64 nor the user +space timespec exactly. The get_timespec64() and put_timespec64() helper +functions canbe used to ensure that the layout remains compatible with +user space and the padding is treated correctly. + +As it is cheap to convert seconds to nanoseconds, but the opposite +requires an expensive 64-bit division, a simple __u64 nanosecond value +can be simpler and more efficient. + +Timeout values and timestamps should ideally use CLOCK_MONOTONIC time, +as returned by ``ktime_get_ns()`` or ``ktime_get_ts64()``. Unlike +CLOCK_REALTIME, this makes the timestamps immune from jumping backwards +or forwards due to leap second adjustments and clock_settime() calls. + +``ktime_get_real_ns()`` can be used for CLOCK_REALTIME timestamps that +may be required for timestamps that need to be persistent across a reboot +or between multiple machines. + +32-bit compat mode +================== + +In order to support 32-bit user space running on a 64-bit machine, each +subsystem or driver that implements an ioctl callback handler must also +implement the corresponding compat_ioctl handler. + +As long as all the rules for data structures are followed, this is as +easy as setting the .compat_ioctl pointer to a helper function such as +``compat_ptr_ioctl()`` or ``blkdev_compat_ptr_ioctl``. + +compat_ptr() +------------ + +On the s/390 architecture, 31-bit user space has ambiguous representations +for data pointers, with the upper bit being ignored. When running such +a process in compat mode, the ``compat_ptr()`` helper must be used to +clear the upper bit of a compat_uptr_t and turn it into a valid 64-bit +pointer. On other architectures, this macro only performs a cast to a +``void __user *`` pointer. + +In an compat_ioctl() callback, the last argument is an unsigned long, +which can be interpreted as either a pointer or a scalar depending on +the command. If it is a scalar, then compat_ptr() must not be used, to +ensure that the 64-bit kernel behaves the same way as a 32-bit kernel +for arguments with the upper bit set. + +The compat_ptr_ioctl() helper can be used in place of a custom +compat_ioctl file operation for drivers that only take arguments that +are pointers to compatible data structures. + +Structure layout +---------------- + +Compatible data structures have the same layout on all architectures, +avoiding all problematic members: + +* ``long`` and ``unsigned long`` are the size of a register, so + they can be either 32 bit or 64 bit wide and cannot be used in portable + data structures. Fixed-length replacements are ``__s32``, ``__u32``, + ``__s64`` and ``__u64``. + +* Pointers have the same problem, in addition to requiring the + use of ``compat_ptr()``. The best workaround is to use ``__u64`` + in place of pointers, which requires a cast to ``uintptr_t`` in user + space, and the use of ``u64_to_user_ptr()`` in the kernel to convert + it back into a user pointer. + +* On the x86-32 (i386) architecture, the alignment of 64-bit variables + is only 32 bit, but they are naturally aligned on most other + architectures including x86-64. This means a structure like + + :: + + struct foo { + __u32 a; + __u64 b; + __u32 c; + }; + + has four bytes of padding between a and b on x86-64, plus another four + bytes of padding at the end, but no padding on i386, and it needs a + compat_ioctl conversion handler to translate between the two formats. + + To avoid this problem, all structures should have their members + naturally aligned, or explicit reserved fields added in place of the + implicit padding. + +* On ARM OABI user space, 16-bit member variables have 32-bit + alignment, making them incompatible with modern EABI kernels. + Conversely, on the m68k architecture, all struct members have at most + 16-bit alignment. These rarely cause problems as neither ARM-OABI nor + m68k are supported by any compat mode, but for consistency, it is best + to completely avoid 16-bit member variables. + + +* Bitfields and enums generally work as one would expect them to, + but some properties of them are implementation-defined, so it is better + to avoid them completely in ioctl interfaces. + +* ``char`` members can be either signed or unsigned, depending on + the architecture, so the __u8 and __s8 types should be used for 8-bit + integer values, though char arrays are clearer for fixed-length strings. + +Information leaks +================= + +Uninitialized data must not be copied back to user space, as this can +cause an information leak, which can be used to defeat kernel address +space layout randomization (KASLR), helping in an attack. + +As explained for the compat mode, it is best to not avoid any padding in +data structures, but if there is already padding in existing structures, +the kernel driver must be careful to zero out the padding using +``memset()`` or similar before copying it to user space. + +Subsystem abstractions +====================== + +While some device drivers implement their own ioctl function, most +subsystems implement the same command for multiple drivers. Ideally the +subsystem has an .ioctl() handler that copies the arguments from and +to user space, passing them into subsystem specific callback functions +through normal kernel pointers. + +This helps in various ways: + +* Applications written for one driver are more likely to work for + another one in the same subsystem if there are no subtle differences + in the user space ABI. + +* The complexity of user space access and data structure layout at done + in one place, reducing the potential for implementation bugs. + +* It is more likely to be reviewed by experienced developers + that can spot problems in the interface when the ioctl is shared + between multiple drivers than when it is only used in a single driver. + +Alternatives to ioctl +===================== + +There are many cases in which ioctl is not the best solution for a +problem. Alternatives include + +* System calls are a better choice for a system-wide feature that + is not tied to a physical device or constrained by the file system + permissions of a character device node + +* netlink is the preferred way of configuring any network related + objects through sockets. + +* debugfs is used for ad-hoc interfaces for debugging functionality + that does not need to be exposed as a stable interface to applications. + +* sysfs is a good way to expose the state of an in-kernel object + that is not tied to a file descriptor. + +* configfs can be used for more complex configuration than sysfs + +* A custom file system can provide extra flexibility with a simple + user interface but add a lot of complexity in the implementation.