There are two code locations that implement the SG_IO ioctl: the old sg.c driver, and the generic scsi_ioctl helper that is in turn used by multiple drivers.
To eradicate the old compat_ioctl conversion handler for the SG_IO command, I implement a readable pair of put_sg_io_hdr() /get_sg_io_hdr() helper functions that can be used for both compat and native mode, and then I call this from both drivers.
For the iovec handling, there is already a compat_import_iovec() function that can simply be called in place of import_iovec().
To avoid having to pass the compat/native state through multiple indirections, I mark the SG_IO command itself as compatible in fs/compat_ioctl.c and use in_compat_syscall() to figure out where we are called from.
As a side-effect of this, the sg.c driver now also accepts the 32-bit sg_io_hdr format in compat mode using the read/write interface, not just ioctl. This should improve compatiblity with old 32-bit binaries, but it would break if any application intentionally passes the 64-bit data structure in compat mode here.
Steffen Maier helped debug an issue in an earlier version of this patch.
Cc: Steffen Maier maier@linux.ibm.com Cc: linux-scsi@vger.kernel.org Cc: Doug Gilbert dgilbert@interlog.com Cc: "James E.J. Bottomley" jejb@linux.ibm.com Cc: "Martin K. Petersen" martin.petersen@oracle.com Signed-off-by: Arnd Bergmann arnd@arndb.de --- block/scsi_ioctl.c | 132 ++++++++++++++++++++++++++++++++++-- drivers/scsi/sg.c | 19 +++--- fs/compat_ioctl.c | 148 +---------------------------------------- include/linux/blkdev.h | 2 + lib/iov_iter.c | 1 + 5 files changed, 143 insertions(+), 159 deletions(-)
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index f5e0ad65e86a..650bade5ea5a 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -2,6 +2,7 @@ /* * Copyright (C) 2001 Jens Axboe axboe@suse.de */ +#include <linux/compat.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/string.h> @@ -327,7 +328,14 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, struct iov_iter i; struct iovec *iov = NULL;
- ret = import_iovec(rq_data_dir(rq), +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + ret = compat_import_iovec(rq_data_dir(rq), + hdr->dxferp, hdr->iovec_count, + 0, &iov, &i); + else +#endif + ret = import_iovec(rq_data_dir(rq), hdr->dxferp, hdr->iovec_count, 0, &iov, &i); if (ret < 0) @@ -542,6 +550,122 @@ 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 + if (in_compat_syscall()) { + struct compat_sg_io_hdr hdr32 = { + .interface_id = hdr->interface_id, + .dxfer_direction = hdr->dxfer_direction, + .cmd_len = hdr->cmd_len, + .mx_sb_len = hdr->mx_sb_len, + .iovec_count = hdr->iovec_count, + .dxfer_len = hdr->dxfer_len, + .dxferp = (uintptr_t)hdr->dxferp, + .cmdp = (uintptr_t)hdr->cmdp, + .sbp = (uintptr_t)hdr->sbp, + .timeout = hdr->timeout, + .flags = hdr->flags, + .pack_id = hdr->pack_id, + .usr_ptr = (uintptr_t)hdr->usr_ptr, + .status = hdr->status, + .masked_status = hdr->masked_status, + .msg_status = hdr->msg_status, + .sb_len_wr = hdr->sb_len_wr, + .host_status = hdr->host_status, + .driver_status = hdr->driver_status, + .resid = hdr->resid, + .duration = hdr->duration, + .info = hdr->info, + }; + + if (copy_to_user(argp, &hdr32, sizeof(hdr32))) + return -EFAULT; + + return 0; + } +#endif + + if (copy_to_user(argp, hdr, sizeof(*hdr))) + return -EFAULT; + + return 0; +} +EXPORT_SYMBOL(put_sg_io_hdr); + +int get_sg_io_hdr(struct sg_io_hdr *hdr, const void __user *argp) +{ +#ifdef CONFIG_COMPAT + struct compat_sg_io_hdr hdr32; + + if (in_compat_syscall()) { + if (copy_from_user(&hdr32, argp, sizeof(hdr32))) + return -EFAULT; + + *hdr = (struct sg_io_hdr) { + .interface_id = hdr32.interface_id, + .dxfer_direction = hdr32.dxfer_direction, + .cmd_len = hdr32.cmd_len, + .mx_sb_len = hdr32.mx_sb_len, + .iovec_count = hdr32.iovec_count, + .dxfer_len = hdr32.dxfer_len, + .dxferp = compat_ptr(hdr32.dxferp), + .cmdp = compat_ptr(hdr32.cmdp), + .sbp = compat_ptr(hdr32.sbp), + .timeout = hdr32.timeout, + .flags = hdr32.flags, + .pack_id = hdr32.pack_id, + .usr_ptr = compat_ptr(hdr32.usr_ptr), + .status = hdr32.status, + .masked_status = hdr32.masked_status, + .msg_status = hdr32.msg_status, + .sb_len_wr = hdr32.sb_len_wr, + .host_status = hdr32.host_status, + .driver_status = hdr32.driver_status, + .resid = hdr32.resid, + .duration = hdr32.duration, + .info = hdr32.info, + }; + + return 0; + } +#endif + + if (copy_from_user(hdr, argp, sizeof(*hdr))) + return -EFAULT; + + return 0; +} +EXPORT_SYMBOL(get_sg_io_hdr); + int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode, unsigned int cmd, void __user *arg) { @@ -581,14 +705,14 @@ int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mod case SG_IO: { struct sg_io_hdr hdr;
- err = -EFAULT; - if (copy_from_user(&hdr, arg, sizeof(hdr))) + err = get_sg_io_hdr(&hdr, arg); + if (err) break; err = sg_io(q, bd_disk, &hdr, mode); if (err == -EFAULT) break;
- if (copy_to_user(arg, &hdr, sizeof(hdr))) + if (put_sg_io_hdr(&hdr, arg)) err = -EFAULT; break; } diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index cce757506383..8ae096af2667 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -447,8 +447,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) retval = -ENOMEM; goto free_old_hdr; } - retval =__copy_from_user - (new_hdr, buf, SZ_SG_IO_HDR); + retval = get_sg_io_hdr(new_hdr, buf); req_pack_id = new_hdr->pack_id; kfree(new_hdr); if (retval) { @@ -589,10 +588,7 @@ sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp) } if (hp->masked_status || hp->host_status || hp->driver_status) hp->info |= SG_INFO_CHECK; - if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) { - err = -EFAULT; - goto err_out; - } + err = put_sg_io_hdr(hp, buf); err_out: err2 = sg_finish_rem_req(srp); sg_remove_request(sfp, srp); @@ -735,7 +731,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, } srp->sg_io_owned = sg_io_owned; hp = &srp->header; - if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) { + if (get_sg_io_hdr(hp, buf)) { sg_remove_request(sfp, srp); return -EFAULT; } @@ -1797,7 +1793,14 @@ sg_start_req(Sg_request *srp, unsigned char *cmd) struct iovec *iov = NULL; struct iov_iter i;
- res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i); +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + res = compat_import_iovec(rw, hp->dxferp, iov_count, + 0, &iov, &i); + else +#endif + res = import_iovec(rw, hp->dxferp, iov_count, + 0, &iov, &i); if (res < 0) return res;
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index 10ba2d9e20bc..f279e77df256 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -64,151 +64,6 @@ static int do_ioctl(struct file *file, unsigned int cmd, unsigned long arg) }
#ifdef CONFIG_BLOCK -typedef struct sg_io_hdr32 { - 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 */ -} sg_io_hdr32_t; /* 64 bytes long (on sparc32) */ - -typedef struct sg_iovec32 { - compat_uint_t iov_base; - compat_uint_t iov_len; -} sg_iovec32_t; - -static int sg_build_iovec(sg_io_hdr_t __user *sgio, void __user *dxferp, u16 iovec_count) -{ - sg_iovec_t __user *iov = (sg_iovec_t __user *) (sgio + 1); - sg_iovec32_t __user *iov32 = dxferp; - int i; - - for (i = 0; i < iovec_count; i++) { - u32 base, len; - - if (get_user(base, &iov32[i].iov_base) || - get_user(len, &iov32[i].iov_len) || - put_user(compat_ptr(base), &iov[i].iov_base) || - put_user(len, &iov[i].iov_len)) - return -EFAULT; - } - - if (put_user(iov, &sgio->dxferp)) - return -EFAULT; - return 0; -} - -static int sg_ioctl_trans(struct file *file, unsigned int cmd, - sg_io_hdr32_t __user *sgio32) -{ - sg_io_hdr_t __user *sgio; - u16 iovec_count; - u32 data; - void __user *dxferp; - int err; - int interface_id; - - if (get_user(interface_id, &sgio32->interface_id)) - return -EFAULT; - if (interface_id != 'S') - return do_ioctl(file, cmd, (unsigned long)sgio32); - - if (get_user(iovec_count, &sgio32->iovec_count)) - return -EFAULT; - - { - void __user *top = compat_alloc_user_space(0); - void __user *new = compat_alloc_user_space(sizeof(sg_io_hdr_t) + - (iovec_count * sizeof(sg_iovec_t))); - if (new > top) - return -EINVAL; - - sgio = new; - } - - /* Ok, now construct. */ - if (copy_in_user(&sgio->interface_id, &sgio32->interface_id, - (2 * sizeof(int)) + - (2 * sizeof(unsigned char)) + - (1 * sizeof(unsigned short)) + - (1 * sizeof(unsigned int)))) - return -EFAULT; - - if (get_user(data, &sgio32->dxferp)) - return -EFAULT; - dxferp = compat_ptr(data); - if (iovec_count) { - if (sg_build_iovec(sgio, dxferp, iovec_count)) - return -EFAULT; - } else { - if (put_user(dxferp, &sgio->dxferp)) - return -EFAULT; - } - - { - unsigned char __user *cmdp; - unsigned char __user *sbp; - - if (get_user(data, &sgio32->cmdp)) - return -EFAULT; - cmdp = compat_ptr(data); - - if (get_user(data, &sgio32->sbp)) - return -EFAULT; - sbp = compat_ptr(data); - - if (put_user(cmdp, &sgio->cmdp) || - put_user(sbp, &sgio->sbp)) - return -EFAULT; - } - - if (copy_in_user(&sgio->timeout, &sgio32->timeout, - 3 * sizeof(int))) - return -EFAULT; - - if (get_user(data, &sgio32->usr_ptr)) - return -EFAULT; - if (put_user(compat_ptr(data), &sgio->usr_ptr)) - return -EFAULT; - - err = do_ioctl(file, cmd, (unsigned long) sgio); - - if (err >= 0) { - void __user *datap; - - if (copy_in_user(&sgio32->pack_id, &sgio->pack_id, - sizeof(int)) || - get_user(datap, &sgio->usr_ptr) || - put_user((u32)(unsigned long)datap, - &sgio32->usr_ptr) || - copy_in_user(&sgio32->status, &sgio->status, - (4 * sizeof(unsigned char)) + - (2 * sizeof(unsigned short)) + - (3 * sizeof(int)))) - err = -EFAULT; - } - - return err; -} - struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */ char req_state; char orphan; @@ -358,6 +213,7 @@ COMPATIBLE_IOCTL(SCSI_IOCTL_GET_PCI) #endif #ifdef CONFIG_BLOCK /* SG stuff */ +COMPATIBLE_IOCTL(SG_IO) COMPATIBLE_IOCTL(SG_SET_TIMEOUT) COMPATIBLE_IOCTL(SG_GET_TIMEOUT) COMPATIBLE_IOCTL(SG_EMULATED_HOST) @@ -435,8 +291,6 @@ static long do_ioctl_trans(unsigned int cmd, case PPPIOCSACTIVE32: return ppp_sock_fprog_ioctl_trans(file, cmd, argp); #ifdef CONFIG_BLOCK - case SG_IO: - return sg_ioctl_trans(file, cmd, argp); case SG_GET_REQUEST_TABLE: return sg_grt_trans(file, cmd, argp); #endif diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f3ea78b0c91c..2c8cd22b176b 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -870,6 +870,8 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t, unsigned int, void __user *); extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, struct scsi_ioctl_command __user *); +extern int get_sg_io_hdr(struct sg_io_hdr *hdr, const void __user *argp); +extern int put_sg_io_hdr(const struct sg_io_hdr *hdr, void __user *argp);
extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags); extern void blk_queue_exit(struct request_queue *q); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 639d5e7014c1..ffb52f2c0ef4 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1678,6 +1678,7 @@ ssize_t compat_import_iovec(int type, *iov = p == *iov ? NULL : p; return n; } +EXPORT_SYMBOL(compat_import_iovec); #endif
int import_single_range(int rw, void __user *buf, size_t len,