Re: video_usercopy() enforces change of VideoText IOCTLs since 2.6.8
From: Michael Geng
Date: Sun Oct 10 2004 - 03:58:23 EST
On Sat, Oct 09, 2004 at 02:18:45PM +0200, Gerd Knorr wrote:
> > I would prefer redefining them with respect
> > to the arguments passed to the IOCTLs.
>
> Thats possible as well.
>
> > Nevertheless there is one big disadvantage: The userspace programs
> > have to be recompiled because they of course have to use the same IOCTL
> > definitions.
>
> You can just keep the old ones and map them, so both old and new ones
> will work (and internally only the new ones are used).
> video_fix_command() does that for a number of v4l2 ioctls which
> initially got a _IO* define with wrong read/write bits. You can either
> just add the videotext ones there or translate them in the drivers right
> before calling video_usercopy().
That's a good idea. The patch below maps old IOCTLs to new ones in the
functions vtx_fix_command() in saa5246a.c and saa5249.c. The drivers now
internally use the new IOCTLs but old userspace programs will still work
without recompiling them.
For the new IOCTLs I need an identifying letter. According to
Documentation/ioctl-number.txt the letter 'q', seq# 0-0x1F is presently
allocated to the videotext drivers. I want to change this because
linux/serio.h also uses the letter 'q', seq# 0.
I now allocated 0x81 (the major number of /dev/vtx<n>), seq# 0-0x1F
to linux/videotext.h. I also added 'q', seq# 0-0x1F to linux/serio.h.
In the present ioctl-number.txt only a conflict is indicated but the
allocation for linux/serio.h is missing. I hope that's ok. Who else
must I ask for this change in Documentation/ioctl-number.txt?
In include/linux/videotext.h I additionally cleaned up some definitions
for a tuner because these definitions are not used any more anywhere in
the kernel.
Michael
----------------------
diff -u -N -r linux-2.6.8.1/Documentation/ioctl-number.txt linux/Documentation/ioctl-number.txt
--- linux-2.6.8.1/Documentation/ioctl-number.txt Sat Aug 14 12:56:22 2004
+++ linux/Documentation/ioctl-number.txt Sun Oct 10 08:34:44 2004
@@ -144,7 +144,7 @@
'p' 40-7F linux/nvram.h
'p' 80-9F user-space parport
<mailto:tim@xxxxxxxxxxxx>
-'q' 00-1F linux/videotext.h conflict!
+'q' 00-1F linux/serio.h
'q' 80-FF Internet PhoneJACK, Internet LineJACK
<http://www.quicknet.net>
'r' 00-1F linux/msdos_fs.h
@@ -162,6 +162,7 @@
'z' 40-7F CAN bus card
<mailto:oe@xxxxxxx>
0x80 00-1F linux/fb.h
+0x81 00-1F linux/videotext.h
0x89 00-06 asm-i386/sockios.h
0x89 0B-DF linux/sockios.h
0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range
diff -u -N -r linux-2.6.8.1/drivers/media/video/saa5246a.c linux/drivers/media/video/saa5246a.c
--- linux-2.6.8.1/drivers/media/video/saa5246a.c Sat Aug 14 12:55:22 2004
+++ linux/drivers/media/video/saa5246a.c Sun Oct 10 09:40:29 2004
@@ -682,6 +682,54 @@
}
/*
+ * Translates old vtx IOCTLs to new ones
+ *
+ * This keeps new kernel versions compatible with old userspace programs.
+ */
+static inline unsigned int vtx_fix_command(unsigned int cmd)
+{
+ switch (cmd) {
+ case VTXIOCGETINFO_OLD:
+ cmd = VTXIOCGETINFO;
+ break;
+ case VTXIOCCLRPAGE_OLD:
+ cmd = VTXIOCCLRPAGE;
+ break;
+ case VTXIOCCLRFOUND_OLD:
+ cmd = VTXIOCCLRFOUND;
+ break;
+ case VTXIOCPAGEREQ_OLD:
+ cmd = VTXIOCPAGEREQ;
+ break;
+ case VTXIOCGETSTAT_OLD:
+ cmd = VTXIOCGETSTAT;
+ break;
+ case VTXIOCGETPAGE_OLD:
+ cmd = VTXIOCGETPAGE;
+ break;
+ case VTXIOCSTOPDAU_OLD:
+ cmd = VTXIOCSTOPDAU;
+ break;
+ case VTXIOCPUTPAGE_OLD:
+ cmd = VTXIOCPUTPAGE;
+ break;
+ case VTXIOCSETDISP_OLD:
+ cmd = VTXIOCSETDISP;
+ break;
+ case VTXIOCPUTSTAT_OLD:
+ cmd = VTXIOCPUTSTAT;
+ break;
+ case VTXIOCCLRCACHE_OLD:
+ cmd = VTXIOCCLRCACHE;
+ break;
+ case VTXIOCSETVIRT_OLD:
+ cmd = VTXIOCSETVIRT;
+ break;
+ }
+ return cmd;
+}
+
+/*
* Handle the locking
*/
static int saa5246a_ioctl(struct inode *inode, struct file *file,
@@ -691,6 +739,7 @@
struct saa5246a_device *t = vd->priv;
int err;
+ cmd = vtx_fix_command(cmd);
down(&t->lock);
err = video_usercopy(inode, file, cmd, arg, do_saa5246a_ioctl);
up(&t->lock);
diff -u -N -r linux-2.6.8.1/drivers/media/video/saa5246a.h linux/drivers/media/video/saa5246a.h
--- linux-2.6.8.1/drivers/media/video/saa5246a.h Sat Aug 14 12:55:48 2004
+++ linux/drivers/media/video/saa5246a.h Sun Oct 10 08:34:13 2004
@@ -23,7 +23,7 @@
#define __SAA5246A_H__
#define MAJOR_VERSION 1 /* driver major version number */
-#define MINOR_VERSION 7 /* driver minor version number */
+#define MINOR_VERSION 8 /* driver minor version number */
#define IF_NAME "SAA5246A"
diff -u -N -r linux-2.6.8.1/drivers/media/video/saa5249.c linux/drivers/media/video/saa5249.c
--- linux-2.6.8.1/drivers/media/video/saa5249.c Sat Aug 14 12:55:48 2004
+++ linux/drivers/media/video/saa5249.c Sun Oct 10 09:40:33 2004
@@ -1,4 +1,7 @@
/*
+ * Modified in order to keep it compatible both with new and old videotext IOCTLs by
+ * Michael Geng <linux@xxxxxxxxxxxxxx>
+ *
* Cleaned up to use existing videodev interface and allow the idea
* of multiple teletext decoders on the video4linux iface. Changed i2c
* to cover addressing clashes on device busses. It's also rebuilt so
@@ -58,7 +61,7 @@
#include <asm/uaccess.h>
#define VTX_VER_MAJ 1
-#define VTX_VER_MIN 7
+#define VTX_VER_MIN 8
@@ -579,6 +582,54 @@
}
/*
+ * Translates old vtx IOCTLs to new ones
+ *
+ * This keeps new kernel versions compatible with old userspace programs.
+ */
+static inline unsigned int vtx_fix_command(unsigned int cmd)
+{
+ switch (cmd) {
+ case VTXIOCGETINFO_OLD:
+ cmd = VTXIOCGETINFO;
+ break;
+ case VTXIOCCLRPAGE_OLD:
+ cmd = VTXIOCCLRPAGE;
+ break;
+ case VTXIOCCLRFOUND_OLD:
+ cmd = VTXIOCCLRFOUND;
+ break;
+ case VTXIOCPAGEREQ_OLD:
+ cmd = VTXIOCPAGEREQ;
+ break;
+ case VTXIOCGETSTAT_OLD:
+ cmd = VTXIOCGETSTAT;
+ break;
+ case VTXIOCGETPAGE_OLD:
+ cmd = VTXIOCGETPAGE;
+ break;
+ case VTXIOCSTOPDAU_OLD:
+ cmd = VTXIOCSTOPDAU;
+ break;
+ case VTXIOCPUTPAGE_OLD:
+ cmd = VTXIOCPUTPAGE;
+ break;
+ case VTXIOCSETDISP_OLD:
+ cmd = VTXIOCSETDISP;
+ break;
+ case VTXIOCPUTSTAT_OLD:
+ cmd = VTXIOCPUTSTAT;
+ break;
+ case VTXIOCCLRCACHE_OLD:
+ cmd = VTXIOCCLRCACHE;
+ break;
+ case VTXIOCSETVIRT_OLD:
+ cmd = VTXIOCSETVIRT;
+ break;
+ }
+ return cmd;
+}
+
+/*
* Handle the locking
*/
@@ -589,6 +640,7 @@
struct saa5249_device *t=vd->priv;
int err;
+ cmd = vtx_fix_command(cmd);
down(&t->lock);
err = video_usercopy(inode,file,cmd,arg,do_saa5249_ioctl);
up(&t->lock);
diff -u -N -r linux-2.6.8.1/include/linux/videotext.h linux/include/linux/videotext.h
--- linux-2.6.8.1/include/linux/videotext.h Sat Aug 14 12:56:23 2004
+++ linux/include/linux/videotext.h Sun Oct 10 08:34:33 2004
@@ -1,7 +1,13 @@
#ifndef _VTX_H
#define _VTX_H
-/* $Id: videotext.h,v 1.1 1998/03/30 22:26:39 alan Exp $
+/*
+ * Teletext (=Videotext) hardware decoders using interface /dev/vtx
+ * Do not confuse with drivers using /dev/vbi which decode videotext by software
+ *
+ * Videotext IOCTLs changed in order to use _IO() macros defined in <linux/ioctl.h>,
+ * unused tuner IOCTLs cleaned up by
+ * Michael Geng <linux@xxxxxxxxxxxxxx>
*
* Copyright (c) 1994-97 Martin Buck <martin-2.buck@xxxxxxxxxxxxxxxxxx>
* Read COPYING for more information
@@ -12,19 +18,32 @@
/*
* Videotext ioctls
*/
-#define VTXIOCGETINFO 0x7101 /* get version of driver & capabilities of vtx-chipset */
-#define VTXIOCCLRPAGE 0x7102 /* clear page-buffer */
-#define VTXIOCCLRFOUND 0x7103 /* clear bits indicating that page was found */
-#define VTXIOCPAGEREQ 0x7104 /* search for page */
-#define VTXIOCGETSTAT 0x7105 /* get status of page-buffer */
-#define VTXIOCGETPAGE 0x7106 /* get contents of page-buffer */
-#define VTXIOCSTOPDAU 0x7107 /* stop data acquisition unit */
-#define VTXIOCPUTPAGE 0x7108 /* display page on TV-screen */
-#define VTXIOCSETDISP 0x7109 /* set TV-mode */
-#define VTXIOCPUTSTAT 0x710a /* set status of TV-output-buffer */
-#define VTXIOCCLRCACHE 0x710b /* clear cache on VTX-interface (if avail.) */
-#define VTXIOCSETVIRT 0x710c /* turn on virtual mode (this disables TV-display) */
-
+#define VTXIOCGETINFO _IOR (0x81, 1, vtx_info_t)
+#define VTXIOCCLRPAGE _IOW (0x81, 2, vtx_pagereq_t)
+#define VTXIOCCLRFOUND _IOW (0x81, 3, vtx_pagereq_t)
+#define VTXIOCPAGEREQ _IOW (0x81, 4, vtx_pagereq_t)
+#define VTXIOCGETSTAT _IOW (0x81, 5, vtx_pagereq_t)
+#define VTXIOCGETPAGE _IOW (0x81, 6, vtx_pagereq_t)
+#define VTXIOCSTOPDAU _IOW (0x81, 7, vtx_pagereq_t)
+#define VTXIOCPUTPAGE _IO (0x81, 8)
+#define VTXIOCSETDISP _IO (0x81, 9)
+#define VTXIOCPUTSTAT _IO (0x81, 10)
+#define VTXIOCCLRCACHE _IO (0x81, 11)
+#define VTXIOCSETVIRT _IOW (0x81, 12, long)
+
+/* for compatibility, will go away some day */
+#define VTXIOCGETINFO_OLD 0x7101 /* get version of driver & capabilities of vtx-chipset */
+#define VTXIOCCLRPAGE_OLD 0x7102 /* clear page-buffer */
+#define VTXIOCCLRFOUND_OLD 0x7103 /* clear bits indicating that page was found */
+#define VTXIOCPAGEREQ_OLD 0x7104 /* search for page */
+#define VTXIOCGETSTAT_OLD 0x7105 /* get status of page-buffer */
+#define VTXIOCGETPAGE_OLD 0x7106 /* get contents of page-buffer */
+#define VTXIOCSTOPDAU_OLD 0x7107 /* stop data acquisition unit */
+#define VTXIOCPUTPAGE_OLD 0x7108 /* display page on TV-screen */
+#define VTXIOCSETDISP_OLD 0x7109 /* set TV-mode */
+#define VTXIOCPUTSTAT_OLD 0x710a /* set status of TV-output-buffer */
+#define VTXIOCCLRCACHE_OLD 0x710b /* clear cache on VTX-interface (if avail.) */
+#define VTXIOCSETVIRT_OLD 0x710c /* turn on virtual mode (this disables TV-display) */
/*
* Definitions for VTXIOCGETINFO
@@ -102,43 +121,5 @@
unsigned hamming : 1; /* hamming-error occurred */
}
vtx_pageinfo_t;
-
-
-/*
- * Definitions for VTXIOCSETDISP
- */
-
-typedef enum {
- DISPOFF, DISPNORM, DISPTRANS, DISPINS, INTERLACE_OFFSET
-} vtxdisp_t;
-
-
-
-/*
- * Tuner ioctls
- */
-#define TUNIOCGETINFO 0x7201 /* get version of driver & capabilities of tuner */
-#define TUNIOCRESET 0x7202 /* reset tuner */
-#define TUNIOCSETFREQ 0x7203 /* set tuning frequency (unit: kHz) */
-#define TUNIOCGETFREQ 0x7204 /* get tuning frequency (unit: kHz) */
-#define TUNIOCSETCHAN 0x7205 /* set tuning channel */
-#define TUNIOCGETCHAN 0x7206 /* get tuning channel */
-
-
-typedef struct
-{
- int version_major, version_minor; /* version of driver; if version_major changes, driver */
- /* is not backward compatible!!! CHECK THIS!!! */
- unsigned freq : 1; /* tuner can be set to given frequency */
- unsigned chan : 1; /* tuner stores several channels */
- unsigned scan : 1; /* tuner supports scanning */
- unsigned autoscan : 1; /* tuner supports scanning with automatic stop */
- unsigned afc : 1; /* tuner supports AFC */
- unsigned dummy1, dummy2, dummy3, dummy4, dummy5, dummy6, dummy7, dummy8, dummy9, dummy10,
- dummy11 : 1;
- int dummy12, dummy13, dummy14, dummy15, dummy16, dummy17, dummy18, dummy19;
-} tuner_info_t;
-
-
#endif /* _VTX_H */
-
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