fix rawctl compat ioctls breakage on amd64 and itanic
RAW_SETBIND and RAW_GETBIND 32bit versions are fscked in interesting ways.
1) fs/compat_ioctl.c has COMPATIBLE_IOCTL(RAW_SETBIND) followed by
HANDLE_IOCTL(RAW_SETBIND, raw_ioctl). The latter is ignored.
2) on amd64 (and itanic) the damn thing is broken - we have int + u64 + u64
and layouts on i386 and amd64 are _not_ the same. raw_ioctl() would
work there, but it's never called due to (1). As it is, i386 /sbin/raw
definitely doesn't work on amd64 boxen.
3) switching to raw_ioctl() as is would *not* work on e.g. sparc64 and ppc64,
which would be rather sad, seeing that normal userland there is 32bit.
The thing is, slapping __packed on the struct in question does not DTRT -
it eliminates *all* padding. The real solution is to use compat_u64.
4) of course, all that stuff has no business being outside of raw.c in the
first place - there should be ->compat_ioctl() for /dev/rawctl instead of
messing with compat_ioctl.c.
[akpm@linux-foundation.org: coding-style fixes]
[arnd@arndb.de: port to 2.6.36]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/char/raw.c b/drivers/char/raw.c
index b38942f..24b2b91 100644
--- a/drivers/char/raw.c
+++ b/drivers/char/raw.c
@@ -19,8 +19,8 @@
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/mutex.h>
-#include <linux/smp_lock.h>
#include <linux/gfp.h>
+#include <linux/compat.h>
#include <asm/uaccess.h>
@@ -55,7 +55,6 @@
return 0;
}
- lock_kernel();
mutex_lock(&raw_mutex);
/*
@@ -82,7 +81,6 @@
bdev->bd_inode->i_mapping;
filp->private_data = bdev;
mutex_unlock(&raw_mutex);
- unlock_kernel();
return 0;
out2:
@@ -91,7 +89,6 @@
blkdev_put(bdev, filp->f_mode);
out:
mutex_unlock(&raw_mutex);
- unlock_kernel();
return err;
}
@@ -125,20 +122,84 @@
raw_ioctl(struct file *filp, unsigned int command, unsigned long arg)
{
struct block_device *bdev = filp->private_data;
- int ret;
-
- lock_kernel();
- ret = blkdev_ioctl(bdev, 0, command, arg);
- unlock_kernel();
-
- return ret;
+ return blkdev_ioctl(bdev, 0, command, arg);
}
-static void bind_device(struct raw_config_request *rq)
+static int bind_set(int number, u64 major, u64 minor)
{
- device_destroy(raw_class, MKDEV(RAW_MAJOR, rq->raw_minor));
- device_create(raw_class, NULL, MKDEV(RAW_MAJOR, rq->raw_minor), NULL,
- "raw%d", rq->raw_minor);
+ dev_t dev = MKDEV(major, minor);
+ struct raw_device_data *rawdev;
+ int err = 0;
+
+ if (number <= 0 || number >= MAX_RAW_MINORS)
+ return -EINVAL;
+
+ if (MAJOR(dev) != major || MINOR(dev) != minor)
+ return -EINVAL;
+
+ rawdev = &raw_devices[number];
+
+ /*
+ * This is like making block devices, so demand the
+ * same capability
+ */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /*
+ * For now, we don't need to check that the underlying
+ * block device is present or not: we can do that when
+ * the raw device is opened. Just check that the
+ * major/minor numbers make sense.
+ */
+
+ if (MAJOR(dev) == 0 && dev != 0)
+ return -EINVAL;
+
+ mutex_lock(&raw_mutex);
+ if (rawdev->inuse) {
+ mutex_unlock(&raw_mutex);
+ return -EBUSY;
+ }
+ if (rawdev->binding) {
+ bdput(rawdev->binding);
+ module_put(THIS_MODULE);
+ }
+ if (!dev) {
+ /* unbind */
+ rawdev->binding = NULL;
+ device_destroy(raw_class, MKDEV(RAW_MAJOR, number));
+ } else {
+ rawdev->binding = bdget(dev);
+ if (rawdev->binding == NULL) {
+ err = -ENOMEM;
+ } else {
+ dev_t raw = MKDEV(RAW_MAJOR, number);
+ __module_get(THIS_MODULE);
+ device_destroy(raw_class, raw);
+ device_create(raw_class, NULL, raw, NULL,
+ "raw%d", number);
+ }
+ }
+ mutex_unlock(&raw_mutex);
+ return err;
+}
+
+static int bind_get(int number, dev_t *dev)
+{
+ struct raw_device_data *rawdev;
+ struct block_device *bdev;
+
+ if (number <= 0 || number >= MAX_RAW_MINORS)
+ return -EINVAL;
+
+ rawdev = &raw_devices[number];
+
+ mutex_lock(&raw_mutex);
+ bdev = rawdev->binding;
+ *dev = bdev ? bdev->bd_dev : 0;
+ mutex_unlock(&raw_mutex);
+ return 0;
}
/*
@@ -149,106 +210,79 @@
unsigned long arg)
{
struct raw_config_request rq;
- struct raw_device_data *rawdev;
- int err = 0;
+ dev_t dev;
+ int err;
- lock_kernel();
switch (command) {
case RAW_SETBIND:
+ if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
+ return -EFAULT;
+
+ return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
+
case RAW_GETBIND:
+ if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
+ return -EFAULT;
- /* First, find out which raw minor we want */
+ err = bind_get(rq.raw_minor, &dev);
+ if (err)
+ return err;
- if (copy_from_user(&rq, (void __user *) arg, sizeof(rq))) {
- err = -EFAULT;
- goto out;
- }
+ rq.block_major = MAJOR(dev);
+ rq.block_minor = MINOR(dev);
- if (rq.raw_minor <= 0 || rq.raw_minor >= MAX_RAW_MINORS) {
- err = -EINVAL;
- goto out;
- }
- rawdev = &raw_devices[rq.raw_minor];
+ if (copy_to_user((void __user *)arg, &rq, sizeof(rq)))
+ return -EFAULT;
- if (command == RAW_SETBIND) {
- dev_t dev;
-
- /*
- * This is like making block devices, so demand the
- * same capability
- */
- if (!capable(CAP_SYS_ADMIN)) {
- err = -EPERM;
- goto out;
- }
-
- /*
- * For now, we don't need to check that the underlying
- * block device is present or not: we can do that when
- * the raw device is opened. Just check that the
- * major/minor numbers make sense.
- */
-
- dev = MKDEV(rq.block_major, rq.block_minor);
- if ((rq.block_major == 0 && rq.block_minor != 0) ||
- MAJOR(dev) != rq.block_major ||
- MINOR(dev) != rq.block_minor) {
- err = -EINVAL;
- goto out;
- }
-
- mutex_lock(&raw_mutex);
- if (rawdev->inuse) {
- mutex_unlock(&raw_mutex);
- err = -EBUSY;
- goto out;
- }
- if (rawdev->binding) {
- bdput(rawdev->binding);
- module_put(THIS_MODULE);
- }
- if (rq.block_major == 0 && rq.block_minor == 0) {
- /* unbind */
- rawdev->binding = NULL;
- device_destroy(raw_class,
- MKDEV(RAW_MAJOR, rq.raw_minor));
- } else {
- rawdev->binding = bdget(dev);
- if (rawdev->binding == NULL)
- err = -ENOMEM;
- else {
- __module_get(THIS_MODULE);
- bind_device(&rq);
- }
- }
- mutex_unlock(&raw_mutex);
- } else {
- struct block_device *bdev;
-
- mutex_lock(&raw_mutex);
- bdev = rawdev->binding;
- if (bdev) {
- rq.block_major = MAJOR(bdev->bd_dev);
- rq.block_minor = MINOR(bdev->bd_dev);
- } else {
- rq.block_major = rq.block_minor = 0;
- }
- mutex_unlock(&raw_mutex);
- if (copy_to_user((void __user *)arg, &rq, sizeof(rq))) {
- err = -EFAULT;
- goto out;
- }
- }
- break;
- default:
- err = -EINVAL;
- break;
+ return 0;
}
-out:
- unlock_kernel();
- return err;
+
+ return -EINVAL;
}
+#ifdef CONFIG_COMPAT
+struct raw32_config_request {
+ compat_int_t raw_minor;
+ compat_u64 block_major;
+ compat_u64 block_minor;
+};
+
+static long raw_ctl_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct raw32_config_request __user *user_req = compat_ptr(arg);
+ struct raw32_config_request rq;
+ dev_t dev;
+ int err = 0;
+
+ switch (cmd) {
+ case RAW_SETBIND:
+ if (copy_from_user(&rq, user_req, sizeof(rq)))
+ return -EFAULT;
+
+ return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
+
+ case RAW_GETBIND:
+ if (copy_from_user(&rq, user_req, sizeof(rq)))
+ return -EFAULT;
+
+ err = bind_get(rq.raw_minor, &dev);
+ if (err)
+ return err;
+
+ rq.block_major = MAJOR(dev);
+ rq.block_minor = MINOR(dev);
+
+ if (copy_to_user(user_req, &rq, sizeof(rq)))
+ return -EFAULT;
+
+ return 0;
+ }
+
+ return -EINVAL;
+}
+#endif
+
static const struct file_operations raw_fops = {
.read = do_sync_read,
.aio_read = generic_file_aio_read,
@@ -263,6 +297,9 @@
static const struct file_operations raw_ctl_fops = {
.unlocked_ioctl = raw_ctl_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = raw_ctl_compat_ioctl,
+#endif
.open = raw_open,
.owner = THIS_MODULE,
};