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author | Al Viro <viro@ZenIV.linux.org.uk> | 2009-08-25 00:42:56 +0200 |
---|---|---|
committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-19 11:29:54 +0200 |
commit | c4a047272566b44b44222369d50a307c708c4f74 (patch) | |
tree | 05f3883b35741afb8afec90c61891f8a1b2c8da9 /drivers/char/raw.c | |
parent | uml: kill big kernel lock (diff) | |
download | linux-c4a047272566b44b44222369d50a307c708c4f74.tar.xz linux-c4a047272566b44b44222369d50a307c708c4f74.zip |
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>
Diffstat (limited to 'drivers/char/raw.c')
-rw-r--r-- | drivers/char/raw.c | 243 |
1 files changed, 140 insertions, 103 deletions
diff --git a/drivers/char/raw.c b/drivers/char/raw.c index b38942f6bf31..24b2b9160aa6 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 @@ static int raw_open(struct inode *inode, struct file *filp) return 0; } - lock_kernel(); mutex_lock(&raw_mutex); /* @@ -82,7 +81,6 @@ static int raw_open(struct inode *inode, struct file *filp) bdev->bd_inode->i_mapping; filp->private_data = bdev; mutex_unlock(&raw_mutex); - unlock_kernel(); return 0; out2: @@ -91,7 +89,6 @@ out1: blkdev_put(bdev, filp->f_mode); out: mutex_unlock(&raw_mutex); - unlock_kernel(); return err; } @@ -125,20 +122,84 @@ static long raw_ioctl(struct file *filp, unsigned int command, unsigned long arg) { struct block_device *bdev = filp->private_data; - int ret; + return blkdev_ioctl(bdev, 0, command, arg); +} + +static int bind_set(int number, u64 major, u64 minor) +{ + dev_t dev = MKDEV(major, minor); + struct raw_device_data *rawdev; + int err = 0; - lock_kernel(); - ret = blkdev_ioctl(bdev, 0, command, arg); - unlock_kernel(); + if (number <= 0 || number >= MAX_RAW_MINORS) + return -EINVAL; - return ret; + 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 void bind_device(struct raw_config_request *rq) +static int bind_get(int number, dev_t *dev) { - 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); + 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; } /* @@ -149,105 +210,78 @@ static long raw_ctl_ioctl(struct file *filp, unsigned int command, 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 (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; + if (copy_to_user((void __user *)arg, &rq, sizeof(rq))) + return -EFAULT; + + 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, @@ -263,6 +297,9 @@ static const struct file_operations raw_fops = { 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, }; |