[PATCH v16 12/45] sg: ioctl handling

Douglas Gilbert
2021-02-20T02:03:43Z

Shorten sg_ioctl() by adding some helper functions. sg_ioctl()
is the main entry point for ioctls used on this driver's
devices.

Treat short copy to user space in sg_ctl_req_tbl() as -EFAULT
after report from test robot. This makes it consistent with
handling of all other copy_to_user/copy_from_user functions
in the driver.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
drivers/scsi/sg.c | 328 ++++++++++++++++++++++++++++------------------
1 file changed, 199 insertions(+), 129 deletions(-)

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 01e6961a9c0e..91467ce8db2e 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1019,6 +1019,56 @@ sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
}
}

+/*
+ * Handles ioctl(SG_IO) for blocking (sync) usage of v3 or v4 interface.
+ * Returns 0 on success else a negated errno.
+ */
+static int
+sg_ctl_sg_io(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
+ void __user *p)
+{
+ bool read_only = O_RDWR != (filp->f_flags & O_ACCMODE);
+ int res;
+ struct sg_request *srp;
+
+ res = sg_allow_if_err_recovery(sdp, false);
+ if (res)
+ return res;
+ res = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
+ true, &srp);
+ if (res < 0)
+ return res;
+ res = wait_event_interruptible
+ (sfp->read_wait, (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
+ if (SG_IS_DETACHING(sdp))
+ return -ENODEV;
+ spin_lock_irq(&sfp->rq_list_lock);
+ if (srp->done) {
+ srp->done = 2;
+ spin_unlock_irq(&sfp->rq_list_lock);
+ res = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
+ return (res < 0) ? res : 0;
+ }
+ srp->orphan = 1;
+ spin_unlock_irq(&sfp->rq_list_lock);
+ return res; /* -ERESTARTSYS because signal hit process */
+}
+
+static int
+sg_set_reserved_sz(struct sg_fd *sfp, int want_rsv_sz)
+{
+ if (want_rsv_sz != sfp->reserve.buflen) {
+ if (sfp->mmap_called ||
+ sfp->res_in_use) {
+ return -EBUSY;
+ }
+
+ sg_remove_scat(sfp, &sfp->reserve);
+ sg_build_reserve(sfp, want_rsv_sz);
+ }
+ return 0;
+}
+
#ifdef CONFIG_COMPAT
struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
char req_state;
@@ -1046,148 +1096,180 @@ static int put_compat_request_table(struct compat_sg_req_info __user *o,
}
#endif

+static int
+sg_ctl_req_tbl(struct sg_fd *sfp, void __user *p)
+{
+ int result;
+ unsigned long iflags;
+ sg_req_info_t *rinfo;
+
+ rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
+ GFP_KERNEL);
+ if (!rinfo)
+ return -ENOMEM;
+ spin_lock_irqsave(&sfp->rq_list_lock, iflags);
+ sg_fill_request_table(sfp, rinfo);
+ spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+#ifdef CONFIG_COMPAT
+ if (in_compat_syscall())
+ result = put_compat_request_table(p, rinfo);
+ else
+ result = copy_to_user(p, rinfo,
+ SZ_SG_REQ_INFO * SG_MAX_QUEUE);
+#else
+ result = copy_to_user(p, rinfo,
+ SZ_SG_REQ_INFO * SG_MAX_QUEUE);
+#endif
+ kfree(rinfo);
+ return result > 0 ? -EFAULT : result; /* treat short copy as error */
+}
+
+static int
+sg_ctl_scsi_id(struct scsi_device *sdev, struct sg_fd *sfp, void __user *p)
+{
+ struct sg_scsi_id ss_id;
+
+ SG_LOG(3, sfp, "%s: SG_GET_SCSI_ID\n", __func__);
+ ss_id.host_no = sdev->host->host_no;
+ ss_id.channel = sdev->channel;
+ ss_id.scsi_id = sdev->id;
+ ss_id.lun = sdev->lun;
+ ss_id.scsi_type = sdev->type;
+ ss_id.h_cmd_per_lun = sdev->host->cmd_per_lun;
+ ss_id.d_queue_depth = sdev->queue_depth;
+ ss_id.unused[0] = 0;
+ ss_id.unused[1] = 0;
+ if (copy_to_user(p, &ss_id, sizeof(struct sg_scsi_id)))
+ return -EFAULT;
+ return 0;
+}
+
static long
sg_ioctl_common(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
unsigned int cmd_in, void __user *p)
{
+ bool read_only = O_RDWR != (filp->f_flags & O_ACCMODE);
+ int val;
+ int result = 0;
int __user *ip = p;
- int result, val, read_only;
struct sg_request *srp;
+ struct scsi_device *sdev;
unsigned long iflags;
+ __maybe_unused const char *pmlp = ", pass to mid-level";

SG_LOG(6, sfp, "%s: cmd=0x%x, O_NONBLOCK=%d\n", __func__, cmd_in,
!!(filp->f_flags & O_NONBLOCK));
- read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
+ if (unlikely(SG_IS_DETACHING(sdp)))
+ return -ENODEV;
+ sdev = sdp->device;

switch (cmd_in) {
case SG_IO:
- result = sg_allow_if_err_recovery(sdp, false);
- if (result)
- return result;
- result = sg_submit(sfp, filp, p, SZ_SG_IO_HDR, true, read_only,
- true, &srp);
- if (result < 0)
- return result;
- result = wait_event_interruptible(sfp->read_wait,
- (srp_done(sfp, srp) || SG_IS_DETACHING(sdp)));
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- spin_lock_irq(&sfp->rq_list_lock);
- if (srp->done) {
- srp->done = 2;
- spin_unlock_irq(&sfp->rq_list_lock);
- result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
- return (result < 0) ? result : 0;
- }
- srp->orphan = 1;
- spin_unlock_irq(&sfp->rq_list_lock);
- return result; /* -ERESTARTSYS because signal hit process */
- case SG_SET_TIMEOUT:
- result = get_user(val, ip);
- if (result)
- return result;
- if (val < 0)
- return -EIO;
- if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
- val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
- INT_MAX);
- sfp->timeout_user = val;
- sfp->timeout = mult_frac(val, HZ, USER_HZ);
-
- return 0;
- case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
- /* strange ..., for backward compatibility */
- return sfp->timeout_user;
- case SG_SET_FORCE_LOW_DMA:
- /*
- * N.B. This ioctl never worked properly, but failed to
- * return an error value. So returning '0' to keep compability
- * with legacy applications.
- */
- return 0;
- case SG_GET_LOW_DMA:
- return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
+ return sg_ctl_sg_io(filp, sdp, sfp, p);
case SG_GET_SCSI_ID:
- {
- sg_scsi_id_t v;
-
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- memset(&v, 0, sizeof(v));
- v.host_no = sdp->device->host->host_no;
- v.channel = sdp->device->channel;
- v.scsi_id = sdp->device->id;
- v.lun = sdp->device->lun;
- v.scsi_type = sdp->device->type;
- v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
- v.d_queue_depth = sdp->device->queue_depth;
- if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
- return -EFAULT;
- return 0;
- }
+ return sg_ctl_scsi_id(sdev, sfp, p);
case SG_SET_FORCE_PACK_ID:
+ SG_LOG(3, sfp, "%s: SG_SET_FORCE_PACK_ID\n", __func__);
result = get_user(val, ip);
if (result)
return result;
sfp->force_packid = val ? 1 : 0;
return 0;
case SG_GET_PACK_ID:
+ val = -1;
spin_lock_irqsave(&sfp->rq_list_lock, iflags);
list_for_each_entry(srp, &sfp->rq_list, entry) {
if ((1 == srp->done) && (!srp->sg_io_owned)) {
- spin_unlock_irqrestore(&sfp->rq_list_lock,
- iflags);
- return put_user(srp->header.pack_id, ip);
+ val = srp->header.pack_id;
+ break;
}
}
spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return put_user(-1, ip);
+ SG_LOG(3, sfp, "%s: SG_GET_PACK_ID=%d\n", __func__, val);
+ return put_user(val, ip);
case SG_GET_NUM_WAITING:
return put_user(atomic_read(&sfp->waiting), ip);
case SG_GET_SG_TABLESIZE:
+ SG_LOG(3, sfp, "%s: SG_GET_SG_TABLESIZE=%d\n", __func__,
+ sdp->max_sgat_sz);
return put_user(sdp->max_sgat_sz, ip);
case SG_SET_RESERVED_SIZE:
- result = get_user(val, ip);
- if (result)
- return result;
- if (val < 0)
- return -EINVAL;
- val = min_t(int, val,
- max_sectors_bytes(sdp->device->request_queue));
mutex_lock(&sfp->f_mutex);
- if (val != sfp->reserve.buflen) {
- if (sfp->mmap_called ||
- sfp->res_in_use) {
- mutex_unlock(&sfp->f_mutex);
- return -EBUSY;
+ result = get_user(val, ip);
+ if (!result) {
+ if (val >= 0 && val <= (1024 * 1024 * 1024)) {
+ result = sg_set_reserved_sz(sfp, val);
+ } else {
+ SG_LOG(3, sfp, "%s: invalid size\n", __func__);
+ result = -EINVAL;
}
-
- sg_remove_scat(sfp, &sfp->reserve);
- sg_build_reserve(sfp, val);
}
mutex_unlock(&sfp->f_mutex);
- return 0;
+ return result;
case SG_GET_RESERVED_SIZE:
val = min_t(int, sfp->reserve.buflen,
- max_sectors_bytes(sdp->device->request_queue));
+ max_sectors_bytes(sdev->request_queue));
+ SG_LOG(3, sfp, "%s: SG_GET_RESERVED_SIZE=%d\n",
+ __func__, val);
return put_user(val, ip);
case SG_SET_COMMAND_Q:
+ SG_LOG(3, sfp, "%s: SG_SET_COMMAND_Q\n", __func__);
result = get_user(val, ip);
if (result)
return result;
sfp->cmd_q = val ? 1 : 0;
return 0;
case SG_GET_COMMAND_Q:
+ SG_LOG(3, sfp, "%s: SG_GET_COMMAND_Q\n", __func__);
return put_user((int) sfp->cmd_q, ip);
case SG_SET_KEEP_ORPHAN:
+ SG_LOG(3, sfp, "%s: SG_SET_KEEP_ORPHAN\n", __func__);
result = get_user(val, ip);
if (result)
return result;
sfp->keep_orphan = val;
return 0;
case SG_GET_KEEP_ORPHAN:
+ SG_LOG(3, sfp, "%s: SG_GET_KEEP_ORPHAN\n", __func__);
return put_user((int) sfp->keep_orphan, ip);
+ case SG_GET_VERSION_NUM:
+ SG_LOG(3, sfp, "%s: SG_GET_VERSION_NUM\n", __func__);
+ return put_user(sg_version_num, ip);
+ case SG_GET_REQUEST_TABLE:
+ return sg_ctl_req_tbl(sfp, p);
+ case SG_SCSI_RESET:
+ SG_LOG(3, sfp, "%s: SG_SCSI_RESET\n", __func__);
+ break;
+ case SG_SET_TIMEOUT:
+ SG_LOG(3, sfp, "%s: SG_SET_TIMEOUT\n", __func__);
+ result = get_user(val, ip);
+ if (result)
+ return result;
+ if (val < 0)
+ return -EIO;
+ if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
+ val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
+ INT_MAX);
+ sfp->timeout_user = val;
+ sfp->timeout = mult_frac(val, HZ, USER_HZ);
+ return 0;
+ case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
+ /* strange ..., for backward compatibility */
+ SG_LOG(3, sfp, "%s: SG_GET_TIMEOUT\n", __func__);
+ return sfp->timeout_user;
+ case SG_SET_FORCE_LOW_DMA:
+ /*
+ * N.B. This ioctl never worked properly, but failed to
+ * return an error value. So returning '0' to keep
+ * compatibility with legacy applications.
+ */
+ SG_LOG(3, sfp, "%s: SG_SET_FORCE_LOW_DMA\n", __func__);
+ return 0;
+ case SG_GET_LOW_DMA:
+ SG_LOG(3, sfp, "%s: SG_GET_LOW_DMA\n", __func__);
+ return put_user((int)sdev->host->unchecked_isa_dma, ip);
case SG_NEXT_CMD_LEN:
+ SG_LOG(3, sfp, "%s: SG_NEXT_CMD_LEN\n", __func__);
result = get_user(val, ip);
if (result)
return result;
@@ -1195,80 +1277,68 @@ sg_ioctl_common(struct file *filp, struct sg_device *sdp, struct sg_fd *sfp,
return -ENOMEM;
sfp->next_cmd_len = (val > 0) ? val : 0;
return 0;
- case SG_GET_VERSION_NUM:
- return put_user(sg_version_num, ip);
case SG_GET_ACCESS_COUNT:
+ SG_LOG(3, sfp, "%s: SG_GET_ACCESS_COUNT\n", __func__);
/* faked - we don't have a real access count anymore */
- val = (sdp->device ? 1 : 0);
+ val = (sdev ? 1 : 0);
return put_user(val, ip);
- case SG_GET_REQUEST_TABLE:
- {
- sg_req_info_t *rinfo;
-
- rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
- GFP_KERNEL);
- if (!rinfo)
- return -ENOMEM;
- spin_lock_irqsave(&sfp->rq_list_lock, iflags);
- sg_fill_request_table(sfp, rinfo);
- spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- #ifdef CONFIG_COMPAT
- if (in_compat_syscall())
- result = put_compat_request_table(p, rinfo);
- else
- #endif
- result = copy_to_user(p, rinfo,
- SZ_SG_REQ_INFO * SG_MAX_QUEUE);
- result = result ? -EFAULT : 0;
- kfree(rinfo);
- return result;
- }
case SG_EMULATED_HOST:
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- return put_user(sdp->device->host->hostt->emulated, ip);
+ SG_LOG(3, sfp, "%s: SG_EMULATED_HOST\n", __func__);
+ return put_user(sdev->host->hostt->emulated, ip);
case SCSI_IOCTL_SEND_COMMAND:
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
- return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_SEND_COMMAND\n", __func__);
+ return sg_scsi_ioctl(sdev->request_queue, NULL, filp->f_mode,
+ p);
case SG_SET_DEBUG:
+ SG_LOG(3, sfp, "%s: SG_SET_DEBUG\n", __func__);
result = get_user(val, ip);
if (result)
return result;
assign_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm, val);
return 0;
case BLKSECTGET:
- return put_user(max_sectors_bytes(sdp->device->request_queue),
- ip);
+ SG_LOG(3, sfp, "%s: BLKSECTGET\n", __func__);
+ return put_user(max_sectors_bytes(sdev->request_queue), ip);
case BLKTRACESETUP:
- return blk_trace_setup(sdp->device->request_queue,
+ SG_LOG(3, sfp, "%s: BLKTRACESETUP\n", __func__);
+ return blk_trace_setup(sdev->request_queue,
sdp->disk->disk_name,
MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
NULL, p);
case BLKTRACESTART:
- return blk_trace_startstop(sdp->device->request_queue, 1);
+ SG_LOG(3, sfp, "%s: BLKTRACESTART\n", __func__);
+ return blk_trace_startstop(sdev->request_queue, 1);
case BLKTRACESTOP:
- return blk_trace_startstop(sdp->device->request_queue, 0);
+ SG_LOG(3, sfp, "%s: BLKTRACESTOP\n", __func__);
+ return blk_trace_startstop(sdev->request_queue, 0);
case BLKTRACETEARDOWN:
- return blk_trace_remove(sdp->device->request_queue);
+ SG_LOG(3, sfp, "%s: BLKTRACETEARDOWN\n", __func__);
+ return blk_trace_remove(sdev->request_queue);
case SCSI_IOCTL_GET_IDLUN:
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_GET_IDLUN %s\n", __func__,
+ pmlp);
+ break;
case SCSI_IOCTL_GET_BUS_NUMBER:
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_GET_BUS_NUMBER%s\n",
+ __func__, pmlp);
+ break;
case SCSI_IOCTL_PROBE_HOST:
+ SG_LOG(3, sfp, "%s: SCSI_IOCTL_PROBE_HOST%s",
+ __func__, pmlp);
+ break;
case SG_GET_TRANSFORM:
- case SG_SCSI_RESET:
- if (SG_IS_DETACHING(sdp))
- return -ENODEV;
+ SG_LOG(3, sfp, "%s: SG_GET_TRANSFORM%s\n", __func__, pmlp);
break;
default:
+ SG_LOG(3, sfp, "%s: unrecognized ioctl [0x%x]%s\n",
+ __func__, cmd_in, pmlp);
if (read_only)
- return -EPERM; /* don't know so take safe approach */
+ return -EPERM; /* don't know, so take safer approach */
break;
}
-
result = sg_allow_if_err_recovery(sdp, filp->f_flags & O_NDELAY);
if (result)
return result;
-
return -ENOIOCTLCMD;
}

--
2.25.1