The hiddev driver currently lacks 32bit ioctl compatibility, so
if you're running with a 64bit kernel and 32bit userspace, it won't
work.
I'm pretty sure that the only thing missing is a compat_ioctl
implementation as all structs have fixed size fields.
With this change I can use revoco to configure my MX Revolution mouse.
Signed-off-by: Philip Langdale <[email protected]>
--- linux-2.6.23/drivers/hid/usbhid/hiddev.c 2007-10-09 13:31:38.000000000 -0700
+++ linux-phil/drivers/hid/usbhid/hiddev.c 2007-10-12 15:02:15.000000000 -0700
@@ -34,6 +34,7 @@
#include <linux/usb.h>
#include <linux/hid.h>
#include <linux/hiddev.h>
+#include <linux/compat.h>
#include "usbhid.h"
#ifdef CONFIG_USB_DYNAMIC_MINORS
@@ -738,6 +738,14 @@
return -EINVAL;
}
+#ifdef CONFIG_COMPAT
+static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ return hiddev_ioctl(inode, file, cmd, compat_ptr(arg));
+}
+#endif
+
static const struct file_operations hiddev_fops = {
.owner = THIS_MODULE,
.read = hiddev_read,
@@ -747,6 +754,9 @@
.release = hiddev_release,
.ioctl = hiddev_ioctl,
.fasync = hiddev_fasync,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = hiddev_compat_ioctl,
+#endif
};
static struct usb_class_driver hiddev_class = {
On Fri, Oct 12, 2007 at 04:51:00PM -0700, Philip Langdale wrote:
> The hiddev driver currently lacks 32bit ioctl compatibility, so
> if you're running with a 64bit kernel and 32bit userspace, it won't
> work.
>
> I'm pretty sure that the only thing missing is a compat_ioctl
> implementation as all structs have fixed size fields.
>
> +static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> + struct inode *inode = file->f_path.dentry->d_inode;
> + return hiddev_ioctl(inode, file, cmd, compat_ptr(arg));
> +}
Just how many instances of that sucker do we need? It's nothing but
struct inode *inode = file->f_path.dentry->d_inode;
return file->f_op->ioctl(inode, file, cmd, compat_ptr(arg));
Al Viro wrote:
>>
>> +static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>> +{
>> + struct inode *inode = file->f_path.dentry->d_inode;
>> + return hiddev_ioctl(inode, file, cmd, compat_ptr(arg));
>> +}
>
> Just how many instances of that sucker do we need? It's nothing but
>
> struct inode *inode = file->f_path.dentry->d_inode;
> return file->f_op->ioctl(inode, file, cmd, compat_ptr(arg));
>
So, I don't actually know what you're looking for, but of the 140 occasions
that .compat_ioctl is implemented in Linus' tree, I can't find another one
that actually uses this form. So, writing a shared implementation doesn't pick
off any low hanging fruit. Now, it's possible that some of the other implementations
could be reduced to this form - but for now, it seems the answer to your question
is 'one' in either case. :-)
--phil
Many drivers use only compatible ioctl numbers. In order to
avoid having to write a special compat_ioctl handler for each
of them or listing every ioctl number in fs/compat_ioctl.c,
let's introduce a generic handler that simply calls the
driver specific f_op->unlocked_ioctl() or f_op->ioctl() handler.
Signed-off-by: Arnd Bergman <[email protected]>
---
On Saturday 13 October 2007, Al Viro wrote:
> Just how many instances of that sucker do we need? It's nothing but
>
> struct inode *inode = file->f_path.dentry->d_inode;
> return file->f_op->ioctl(inode, file, cmd, compat_ptr(arg));
Is this what you had in mind? I've been meaning to do something like
it for some time, but had forgotten about it.
I guess we can kill a significant amount of COMPATIBLE_IOCTL
lines in fs/compat_ioctl.c with this.
Index: linux-2.6/fs/compat_ioctl.c
===================================================================
--- linux-2.6.orig/fs/compat_ioctl.c
+++ linux-2.6/fs/compat_ioctl.c
@@ -1877,6 +1877,30 @@ lp_timeout_trans(unsigned int fd, unsign
return sys_ioctl(fd, cmd, (unsigned long)tn);
}
+/*
+ * Helper function for device drivers that only have COMPATIBLE_IOCTL
+ * numbers. This can be used as f_op->compat_ioctl without any #ifdef
+ * and will simply call the native ioctl handler with the argument
+ * pointer.
+ * Don't use for drivers that interpret arg as an unsigned long instead
+ * of a pointer.
+ */
+long generic_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ int ret = -ENOTTY;
+ arg = (unsigned long)compat_ptr(arg);
+
+ if (file->f_op->unlocked_ioctl)
+ ret = file->f_op->unlocked_ioctl(file, cmd, arg);
+ else if (file->f_op->ioctl) {
+ lock_kernel();
+ ret = file->f_op->ioctl(file->f_dentry->d_inode, file, cmd, arg);
+ unlock_kernel();
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(generic_compat_ioctl);
typedef int (*ioctl_trans_handler_t)(unsigned int, unsigned int,
unsigned long, struct file *);
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h
+++ linux-2.6/include/linux/fs.h
@@ -1807,6 +1807,12 @@ extern void do_generic_mapping_read(stru
extern int generic_segment_checks(const struct iovec *iov,
unsigned long *nr_segs, size_t *count, int access_flags);
+#ifdef CONFIG_COMPAT
+extern long generic_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+#else
+#define generic_compat_ioctl (long (*)(struct file *, unsigned int, unsigned long))NULL
+#endif
+
/* fs/splice.c */
extern ssize_t generic_file_splice_read(struct file *, loff_t *,
struct pipe_inode_info *, size_t, unsigned int);
hiddev has both entries in fs/compat_ioctl.c and its own
compat_ioctl() handler. Remove both and use the new generic_compat_ioctl
helper instead.
Signed-off-by: Arnd Bergmann <[email protected]>
Index: linux-2.6/drivers/hid/hidraw.c
===================================================================
--- linux-2.6.orig/drivers/hid/hidraw.c
+++ linux-2.6/drivers/hid/hidraw.c
@@ -268,6 +268,7 @@ static const struct file_operations hidr
.open = hidraw_open,
.release = hidraw_release,
.ioctl = hidraw_ioctl,
+ .compat_ioctl = generic_compat_ioctl,
};
void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
Index: linux-2.6/drivers/hid/usbhid/hiddev.c
===================================================================
--- linux-2.6.orig/drivers/hid/usbhid/hiddev.c
+++ linux-2.6/drivers/hid/usbhid/hiddev.c
@@ -739,14 +739,6 @@ inval:
return -EINVAL;
}
-#ifdef CONFIG_COMPAT
-static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
- struct inode *inode = file->f_path.dentry->d_inode;
- return hiddev_ioctl(inode, file, cmd, compat_ptr(arg));
-}
-#endif
-
static const struct file_operations hiddev_fops = {
.owner = THIS_MODULE,
.read = hiddev_read,
@@ -756,9 +748,7 @@ static const struct file_operations hidd
.release = hiddev_release,
.ioctl = hiddev_ioctl,
.fasync = hiddev_fasync,
-#ifdef CONFIG_COMPAT
- .compat_ioctl = hiddev_compat_ioctl,
-#endif
+ .compat_ioctl = generic_compat_ioctl,
};
static struct usb_class_driver hiddev_class = {
Index: linux-2.6/fs/compat_ioctl.c
===================================================================
--- linux-2.6.orig/fs/compat_ioctl.c
+++ linux-2.6/fs/compat_ioctl.c
@@ -102,8 +102,6 @@
#include <linux/filter.h>
#include <linux/pktcdvd.h>
-#include <linux/hiddev.h>
-
#include <linux/dvb/audio.h>
#include <linux/dvb/dmx.h>
#include <linux/dvb/frontend.h>
@@ -2575,23 +2573,6 @@ COMPATIBLE_IOCTL(SIOCSIWPOWER)
COMPATIBLE_IOCTL(SIOCGIWPOWER)
COMPATIBLE_IOCTL(SIOCSIWAUTH)
COMPATIBLE_IOCTL(SIOCGIWAUTH)
-/* hiddev */
-COMPATIBLE_IOCTL(HIDIOCGVERSION)
-COMPATIBLE_IOCTL(HIDIOCAPPLICATION)
-COMPATIBLE_IOCTL(HIDIOCGDEVINFO)
-COMPATIBLE_IOCTL(HIDIOCGSTRING)
-COMPATIBLE_IOCTL(HIDIOCINITREPORT)
-COMPATIBLE_IOCTL(HIDIOCGREPORT)
-COMPATIBLE_IOCTL(HIDIOCSREPORT)
-COMPATIBLE_IOCTL(HIDIOCGREPORTINFO)
-COMPATIBLE_IOCTL(HIDIOCGFIELDINFO)
-COMPATIBLE_IOCTL(HIDIOCGUSAGE)
-COMPATIBLE_IOCTL(HIDIOCSUSAGE)
-COMPATIBLE_IOCTL(HIDIOCGUCODE)
-COMPATIBLE_IOCTL(HIDIOCGFLAG)
-COMPATIBLE_IOCTL(HIDIOCSFLAG)
-COMPATIBLE_IOCTL(HIDIOCGCOLLECTIONINDEX)
-COMPATIBLE_IOCTL(HIDIOCGCOLLECTIONINFO)
/* dvb */
COMPATIBLE_IOCTL(AUDIO_STOP)
COMPATIBLE_IOCTL(AUDIO_PLAY)
On Sat, Oct 20, 2007 at 05:50:57PM +0200, Arnd Bergmann wrote:
> Many drivers use only compatible ioctl numbers. In order to
> avoid having to write a special compat_ioctl handler for each
> of them or listing every ioctl number in fs/compat_ioctl.c,
> let's introduce a generic handler that simply calls the
> driver specific f_op->unlocked_ioctl() or f_op->ioctl() handler.
At least for the unlocked_ioctl case this is not nessecary because
the driver an simply set both the unlocked_ioctl and compat_ioctl
handlers to the same function. For the drivers not using unlocked_ioctl
yet a function like this makes sense in theory, but I'd prefer to
just switch them to ->unlocked_ioctl.
On Saturday 20 October 2007, Christoph Hellwig wrote:
> At least for the unlocked_ioctl case this is not nessecary because
> the driver an simply set both the unlocked_ioctl and compat_ioctl
> handlers to the same function. ?For the drivers not using unlocked_ioctl
> yet a function like this makes sense in theory, but I'd prefer to
> just switch them to ->unlocked_ioctl.
>
There is still the problem with s390 compat_ptr() conversion, a driver
using the same handler for both may interpret a pointer with the high
bit set as out of range.
Arnd <><