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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-05 15:40:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-05 15:40:12 -0800
commit07d106d0a33d6063d2061305903deb02489eba20 (patch)
tree6f257f877a9c2e653ca0515253e930fa6606239a
parent805a6af8dba5dfdd35ec35dc52ec0122400b2610 (diff)
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vfs: fix up ENOIOCTLCMD error handling
We're doing some odd things there, which already messes up various users (see the net/socket.c code that this removes), and it was going to add yet more crud to the block layer because of the incorrect error code translation. ENOIOCTLCMD is not an error return that should be returned to user mode from the "ioctl()" system call, but it should *not* be translated as EINVAL ("Invalid argument"). It should be translated as ENOTTY ("Inappropriate ioctl for device"). That EINVAL confusion has apparently so permeated some code that the block layer actually checks for it, which is sad. We continue to do so for now, but add a big comment about how wrong that is, and we should remove it entirely eventually. In the meantime, this tries to keep the changes localized to just the EINVAL -> ENOTTY fix, and removing code that makes it harder to do the right thing. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--block/ioctl.c26
-rw-r--r--fs/compat_ioctl.c38
-rw-r--r--fs/ioctl.c2
-rw-r--r--net/socket.c16
4 files changed, 26 insertions, 56 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
index ca939fc1030..d510c2a4eff 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -180,6 +180,26 @@ int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
/*
+ * Is it an unrecognized ioctl? The correct returns are either
+ * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
+ * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
+ * code before returning.
+ *
+ * Confused drivers sometimes return EINVAL, which is wrong. It
+ * means "I understood the ioctl command, but the parameters to
+ * it were wrong".
+ *
+ * We should aim to just fix the broken drivers, the EINVAL case
+ * should go away.
+ */
+static inline int is_unrecognized_ioctl(int ret)
+{
+ return ret == -EINVAL ||
+ ret == -ENOTTY ||
+ ret == -ENOIOCTLCMD;
+}
+
+/*
* always keep this in sync with compat_blkdev_ioctl()
*/
int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
@@ -196,8 +216,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
return -EACCES;
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
- /* -EINVAL to handle old uncorrected drivers */
- if (ret != -EINVAL && ret != -ENOTTY)
+ if (!is_unrecognized_ioctl(ret))
return ret;
fsync_bdev(bdev);
@@ -206,8 +225,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
case BLKROSET:
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
- /* -EINVAL to handle old uncorrected drivers */
- if (ret != -EINVAL && ret != -ENOTTY)
+ if (!is_unrecognized_ioctl(ret))
return ret;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 51352de88ef..a10e428b32b 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -1506,35 +1506,6 @@ static long do_ioctl_trans(int fd, unsigned int cmd,
return -ENOIOCTLCMD;
}
-static void compat_ioctl_error(struct file *filp, unsigned int fd,
- unsigned int cmd, unsigned long arg)
-{
- char buf[10];
- char *fn = "?";
- char *path;
-
- /* find the name of the device. */
- path = (char *)__get_free_page(GFP_KERNEL);
- if (path) {
- fn = d_path(&filp->f_path, path, PAGE_SIZE);
- if (IS_ERR(fn))
- fn = "?";
- }
-
- sprintf(buf,"'%c'", (cmd>>_IOC_TYPESHIFT) & _IOC_TYPEMASK);
- if (!isprint(buf[1]))
- sprintf(buf, "%02x", buf[1]);
- compat_printk("ioctl32(%s:%d): Unknown cmd fd(%d) "
- "cmd(%08x){t:%s;sz:%u} arg(%08x) on %s\n",
- current->comm, current->pid,
- (int)fd, (unsigned int)cmd, buf,
- (cmd >> _IOC_SIZESHIFT) & _IOC_SIZEMASK,
- (unsigned int)arg, fn);
-
- if (path)
- free_page((unsigned long)path);
-}
-
static int compat_ioctl_check_table(unsigned int xcmd)
{
int i;
@@ -1621,13 +1592,8 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
goto found_handler;
error = do_ioctl_trans(fd, cmd, arg, filp);
- if (error == -ENOIOCTLCMD) {
- static int count;
-
- if (++count <= 50)
- compat_ioctl_error(filp, fd, cmd, arg);
- error = -EINVAL;
- }
+ if (error == -ENOIOCTLCMD)
+ error = -ENOTTY;
goto out_fput;
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 1d9b9fcb2db..066836e8184 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -42,7 +42,7 @@ static long vfs_ioctl(struct file *filp, unsigned int cmd,
error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
if (error == -ENOIOCTLCMD)
- error = -EINVAL;
+ error = -ENOTTY;
out:
return error;
}
diff --git a/net/socket.c b/net/socket.c
index 2877647f347..a0053750e37 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2883,7 +2883,7 @@ static int bond_ioctl(struct net *net, unsigned int cmd,
return dev_ioctl(net, cmd, uifr);
default:
- return -EINVAL;
+ return -ENOIOCTLCMD;
}
}
@@ -3210,20 +3210,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
return sock_do_ioctl(net, sock, cmd, arg);
}
- /* Prevent warning from compat_sys_ioctl, these always
- * result in -EINVAL in the native case anyway. */
- switch (cmd) {
- case SIOCRTMSG:
- case SIOCGIFCOUNT:
- case SIOCSRARP:
- case SIOCGRARP:
- case SIOCDRARP:
- case SIOCSIFLINK:
- case SIOCGIFSLAVE:
- case SIOCSIFSLAVE:
- return -EINVAL;
- }
-
return -ENOIOCTLCMD;
}