linux/drivers/scsi/scsi_ioctl.c
Linus Torvalds 96d4f267e4 Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00

293 lines
8.1 KiB
C

/*
* Changes:
* Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
* - get rid of some verify_areas and use __copy*user and __get/put_user
* for the ones that remain
*/
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/sg.h>
#include <scsi/scsi_dbg.h>
#include "scsi_logging.h"
#define NORMAL_RETRIES 5
#define IOCTL_NORMAL_TIMEOUT (10 * HZ)
#define MAX_BUF PAGE_SIZE
/**
* ioctl_probe -- return host identification
* @host: host to identify
* @buffer: userspace buffer for identification
*
* Return an identifying string at @buffer, if @buffer is non-NULL, filling
* to the length stored at * (int *) @buffer.
*/
static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
{
unsigned int len, slen;
const char *string;
if (buffer) {
if (get_user(len, (unsigned int __user *) buffer))
return -EFAULT;
if (host->hostt->info)
string = host->hostt->info(host);
else
string = host->hostt->name;
if (string) {
slen = strlen(string);
if (len > slen)
len = slen + 1;
if (copy_to_user(buffer, string, len))
return -EFAULT;
}
}
return 1;
}
/*
* The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
* The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES variables are used.
*
* dev is the SCSI device struct ptr, *(int *) arg is the length of the
* input data, if any, not including the command string & counts,
* *((int *)arg + 1) is the output buffer size in bytes.
*
* *(char *) ((int *) arg)[2] the actual command byte.
*
* Note that if more than MAX_BUF bytes are requested to be transferred,
* the ioctl will fail with error EINVAL.
*
* This size *does not* include the initial lengths that were passed.
*
* The SCSI command is read from the memory location immediately after the
* length words, and the input data is right after the command. The SCSI
* routines know the command size based on the opcode decode.
*
* The output area is then filled in starting from the command byte.
*/
static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
int timeout, int retries)
{
int result;
struct scsi_sense_hdr sshdr;
SCSI_LOG_IOCTL(1, sdev_printk(KERN_INFO, sdev,
"Trying ioctl with scsi command %d\n", *cmd));
result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
&sshdr, timeout, retries, NULL);
SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
"Ioctl returned 0x%x\n", result));
if (driver_byte(result) == DRIVER_SENSE &&
scsi_sense_valid(&sshdr)) {
switch (sshdr.sense_key) {
case ILLEGAL_REQUEST:
if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
sdev->lockable = 0;
else
sdev_printk(KERN_INFO, sdev,
"ioctl_internal_command: "
"ILLEGAL REQUEST "
"asc=0x%x ascq=0x%x\n",
sshdr.asc, sshdr.ascq);
break;
case NOT_READY: /* This happens if there is no disc in drive */
if (sdev->removable)
break;
/* FALLTHROUGH */
case UNIT_ATTENTION:
if (sdev->removable) {
sdev->changed = 1;
result = 0; /* This is no longer considered an error */
break;
}
/* FALLTHROUGH -- for non-removable media */
default:
sdev_printk(KERN_INFO, sdev,
"ioctl_internal_command return code = %x\n",
result);
scsi_print_sense_hdr(sdev, NULL, &sshdr);
break;
}
}
SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
"IOCTL Releasing command\n"));
return result;
}
int scsi_set_medium_removal(struct scsi_device *sdev, char state)
{
char scsi_cmd[MAX_COMMAND_SIZE];
int ret;
if (!sdev->removable || !sdev->lockable)
return 0;
scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
scsi_cmd[1] = 0;
scsi_cmd[2] = 0;
scsi_cmd[3] = 0;
scsi_cmd[4] = state;
scsi_cmd[5] = 0;
ret = ioctl_internal_command(sdev, scsi_cmd,
IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
if (ret == 0)
sdev->locked = (state == SCSI_REMOVAL_PREVENT);
return ret;
}
EXPORT_SYMBOL(scsi_set_medium_removal);
/*
* The scsi_ioctl_get_pci() function places into arg the value
* pci_dev::slot_name (8 characters) for the PCI device (if any).
* Returns: 0 on success
* -ENXIO if there isn't a PCI device pointer
* (could be because the SCSI driver hasn't been
* updated yet, or because it isn't a SCSI
* device)
* any copy_to_user() error on failure there
*/
static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
{
struct device *dev = scsi_get_device(sdev->host);
const char *name;
if (!dev)
return -ENXIO;
name = dev_name(dev);
/* compatibility with old ioctl which only returned
* 20 characters */
return copy_to_user(arg, name, min(strlen(name), (size_t)20))
? -EFAULT: 0;
}
/**
* scsi_ioctl - Dispatch ioctl to scsi device
* @sdev: scsi device receiving ioctl
* @cmd: which ioctl is it
* @arg: data associated with ioctl
*
* Description: The scsi_ioctl() function differs from most ioctls in that it
* does not take a major/minor number as the dev field. Rather, it takes
* a pointer to a &struct scsi_device.
*/
int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
{
char scsi_cmd[MAX_COMMAND_SIZE];
struct scsi_sense_hdr sense_hdr;
/* Check for deprecated ioctls ... all the ioctls which don't
* follow the new unique numbering scheme are deprecated */
switch (cmd) {
case SCSI_IOCTL_SEND_COMMAND:
case SCSI_IOCTL_TEST_UNIT_READY:
case SCSI_IOCTL_BENCHMARK_COMMAND:
case SCSI_IOCTL_SYNC:
case SCSI_IOCTL_START_UNIT:
case SCSI_IOCTL_STOP_UNIT:
printk(KERN_WARNING "program %s is using a deprecated SCSI "
"ioctl, please convert it to SG_IO\n", current->comm);
break;
default:
break;
}
switch (cmd) {
case SCSI_IOCTL_GET_IDLUN:
if (!access_ok(arg, sizeof(struct scsi_idlun)))
return -EFAULT;
__put_user((sdev->id & 0xff)
+ ((sdev->lun & 0xff) << 8)
+ ((sdev->channel & 0xff) << 16)
+ ((sdev->host->host_no & 0xff) << 24),
&((struct scsi_idlun __user *)arg)->dev_id);
__put_user(sdev->host->unique_id,
&((struct scsi_idlun __user *)arg)->host_unique_id);
return 0;
case SCSI_IOCTL_GET_BUS_NUMBER:
return put_user(sdev->host->host_no, (int __user *)arg);
case SCSI_IOCTL_PROBE_HOST:
return ioctl_probe(sdev->host, arg);
case SCSI_IOCTL_SEND_COMMAND:
if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
return -EACCES;
return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
case SCSI_IOCTL_DOORLOCK:
return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
case SCSI_IOCTL_DOORUNLOCK:
return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
case SCSI_IOCTL_TEST_UNIT_READY:
return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
NORMAL_RETRIES, &sense_hdr);
case SCSI_IOCTL_START_UNIT:
scsi_cmd[0] = START_STOP;
scsi_cmd[1] = 0;
scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
scsi_cmd[4] = 1;
return ioctl_internal_command(sdev, scsi_cmd,
START_STOP_TIMEOUT, NORMAL_RETRIES);
case SCSI_IOCTL_STOP_UNIT:
scsi_cmd[0] = START_STOP;
scsi_cmd[1] = 0;
scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
scsi_cmd[4] = 0;
return ioctl_internal_command(sdev, scsi_cmd,
START_STOP_TIMEOUT, NORMAL_RETRIES);
case SCSI_IOCTL_GET_PCI:
return scsi_ioctl_get_pci(sdev, arg);
case SG_SCSI_RESET:
return scsi_ioctl_reset(sdev, arg);
default:
if (sdev->host->hostt->ioctl)
return sdev->host->hostt->ioctl(sdev, cmd, arg);
}
return -EINVAL;
}
EXPORT_SYMBOL(scsi_ioctl);
/*
* We can process a reset even when a device isn't fully operable.
*/
int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
bool ndelay)
{
if (cmd == SG_SCSI_RESET && ndelay) {
if (scsi_host_in_recovery(sdev->host))
return -EAGAIN;
} else {
if (!scsi_block_when_processing_errors(sdev))
return -ENODEV;
}
return 0;
}
EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);