Date: Sun, 14 Aug 2005 13:48:44 +0200 From: Roland Smith <rsmith@xs4all.nl> To: Miguel Mendez <flynn@energyhq.es.eu.org> Cc: freebsd-amd64@freebsd.org Subject: Re: 32bit Linux dri apps on FreeBSD/amd64? Message-ID: <20050814114844.GA58288@slackbox.xs4all.nl> In-Reply-To: <20050814113127.7d69af2b.flynn@energyhq.es.eu.org> References: <20050814113127.7d69af2b.flynn@energyhq.es.eu.org>
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On Sun, Aug 14, 2005 at 11:31:27AM +0200, Miguel Mendez wrote:
> I've installed said port and linux_dri, linux-base-8 and
> linux-XFree86-libs. When trying to run et it fails when
> opening /dev/dri/card0. Can anybody shed some light on what's going on?
<snip>
> 66553 et.x86 CALL open(0xffffc890,0x2,0)
> 66553 et.x86 NAMI "/compat/linux/dev/dri/card0"
> 66553 et.x86 NAMI "/dev/dri/card0"
> 66553 et.x86 RET open 8
> 66553 et.x86 CALL ioctl(0x8,0xc0086401 ,0xffffc990)
> 66553 et.x86 RET ioctl -1 errno -22 Unknown error: -22
> 66553 et.x86 CALL close(0x8)
> 66553 et.x86 RET close 0
It doesn't fail by opening the file, it's the ioctl call that
fails. Errno 22 is EINVAL (invalid argument).
The number of the ioctl can be broken down as follows (see
/usr/src/sys/sys/ioccom.h, /usr/src/sys/dev/drm/drm.h and
/usr/src/sys/dev/drm/drm_drv.h):
0xc0000000 =3D copy parameters in and out
0x00080000 =3D argument length <<16=20
0x00006400 =3D ioctl group <<8
0x00000001 =3D ioctl number 0x01 =3D DRM_IOCTL_GET_UNIQUE
The definition of getunique is:
int DRM(getunique)( DRM_IOCTL_ARGS )
{
DRM_DEVICE;
drm_unique_t u;
DRM_COPY_FROM_USER_IOCTL( u, (drm_unique_t *)data, sizeof(u) );
if (u.unique_len >=3D dev->unique_len) {
if (DRM_COPY_TO_USER(u.unique, dev->unique, dev->unique_len=
))
return DRM_ERR(EFAULT);
}
u.unique_len =3D dev->unique_len;
DRM_COPY_TO_USER_IOCTL( (drm_unique_t *)data, u, sizeof(u) );
return 0;
}
The DRM_IOCTL_ARGS are:=20
struct cdev *kdev, u_long cmd, caddr_t data, int flags,=20
DRM_STRUCTPROC *p, DRMFILE filp
As you can see below, DRM_COPY_FROM_USER_IOCTL can return EINVAL:
#define DRM_COPY_FROM_USER_IOCTL(kern, user, size) \
if ( IOCPARM_LEN(cmd) !=3D size) \
return EINVAL; \
kern =3D *user;
IOCPARM_LEN(cmd) is cmd>>16 & 0x1fff, which in this case gives 8 bytes.
And here is the error, I think. Because drm_unique_t is defined as:
typedef struct drm_unique {
size_t unique_len; /**< Length of unique */
char *unique; /**< Unique name for driver instantiation=
*/
} drm_unique_t;
On amd64, both size_t and char* are 8 bytes. So sizeof(drm_unique_t) is
16 bytes on amd64.
To fix this, the drm driver would have to know if ioctls were being made
by a 32-bit program, and adjust the parameter size tests accordingly. I
do not know if that is possible.
Roland
--=20
R.F.Smith (http://www.xs4all.nl/~rsmith/) Please send e-mail as plain text.
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