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compat_ioctl: move SG_GET_REQUEST_TABLE handling

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SG_GET_REQUEST_TABLE is now the last ioctl command that needs a conversion
handler. This is only used in a single file, so the implementation should
be there.

I'm trying to simplify it in the process, to get rid of
the compat_alloc_user_space() and extra copy, by adding a
put_compat_request_table() function instead, which copies the data in
the right format to user space.

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>
This commit is contained in:
Arnd Bergmann 2018-08-24 14:53:13 +02:00
parent 8f5d9f2ce3
commit fd6c3d5acc
2 changed files with 36 additions and 61 deletions
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40
drivers/scsi/sg.c
View File

@ -889,6 +889,33 @@ sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
}
}
#ifdef CONFIG_COMPAT
struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
char req_state;
char orphan;
char sg_io_owned;
char problem;
int pack_id;
compat_uptr_t usr_ptr;
unsigned int duration;
int unused;
};
static int put_compat_request_table(struct compat_sg_req_info __user *o,
struct sg_req_info *rinfo)
{
int i;
for (i = 0; i < SG_MAX_QUEUE; i++) {
if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
put_user(rinfo[i].duration, &o[i].duration) ||
put_user(rinfo[i].unused, &o[i].unused))
return -EFAULT;
}
return 0;
}
#endif
static long
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
@ -1069,9 +1096,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
val = (sdp->device ? 1 : 0);
return put_user(val, ip);
case SG_GET_REQUEST_TABLE:
if (!access_ok(p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
return -EFAULT;
else {
{
sg_req_info_t *rinfo;
rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
@ -1081,8 +1106,13 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
read_lock_irqsave(&sfp->rq_list_lock, iflags);
sg_fill_request_table(sfp, rinfo);
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
result = __copy_to_user(p, rinfo,
SZ_SG_REQ_INFO * SG_MAX_QUEUE);
#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;

57
fs/compat_ioctl.c
View File

@ -52,53 +52,6 @@
#include <linux/sort.h>
#ifdef CONFIG_BLOCK
static int do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int err;
err = security_file_ioctl(file, cmd, arg);
if (err)
return err;
return vfs_ioctl(file, cmd, arg);
}
struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
char req_state;
char orphan;
char sg_io_owned;
char problem;
int pack_id;
compat_uptr_t usr_ptr;
unsigned int duration;
int unused;
};
static int sg_grt_trans(struct file *file,
unsigned int cmd, struct compat_sg_req_info __user *o)
{
int err, i;
sg_req_info_t __user *r;
r = compat_alloc_user_space(sizeof(sg_req_info_t)*SG_MAX_QUEUE);
err = do_ioctl(file, cmd, (unsigned long)r);
if (err < 0)
return err;
for (i = 0; i < SG_MAX_QUEUE; i++) {
void __user *ptr;
int d;
if (copy_in_user(o + i, r + i, offsetof(sg_req_info_t, usr_ptr)) ||
get_user(ptr, &r[i].usr_ptr) ||
get_user(d, &r[i].duration) ||
put_user((u32)(unsigned long)(ptr), &o[i].usr_ptr) ||
put_user(d, &o[i].duration))
return -EFAULT;
}
return err;
}
#endif /* CONFIG_BLOCK */
/*
* simple reversible transform to make our table more evenly
* distributed after sorting.
@ -121,6 +74,7 @@ COMPATIBLE_IOCTL(SCSI_IOCTL_GET_PCI)
#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)
@ -156,15 +110,6 @@ COMPATIBLE_IOCTL(SG_GET_KEEP_ORPHAN)
static long do_ioctl_trans(unsigned int cmd,
unsigned long arg, struct file *file)
{
#ifdef CONFIG_BLOCK
void __user *argp = compat_ptr(arg);
switch (cmd) {
case SG_GET_REQUEST_TABLE:
return sg_grt_trans(file, cmd, argp);
}
#endif
return -ENOIOCTLCMD;
}