drivers/tty/vt/vt.c | 24 ++++++ drivers/tty/vt/vt_ioctl.c | 11 +++ drivers/video/console/newport_con.c | 21 +++++- drivers/video/console/sticon.c | 25 ++++++- drivers/video/console/vgacon.c | 21 +++++- drivers/video/fbdev/core/fbcon.c | 16 ++++ include/linux/console.h | 3 + include/linux/vt_kern.h | 1 + include/uapi/linux/kd.h | 109 ++++++++++++++++------------ 9 files changed, 176 insertions(+), 55 deletions(-)
We now have KD_FONT_OP_SET_TALL, but in fact such large fonts cannot be loaded. No console driver supports tall fonts. Unfortunately, userspace cannot distinguish the lack of support in the driver from errors in the font itself. In all cases, EINVAL will be returned. This patchset adds a separate ioctl to obtain the font parameters supported by the console driver. v4: * Rebased on v6.9-rc1 and conflicts have been fixed. * Do not copy KDFONTINFO data from the userspace. * Header include/uapi/linux/kd.h uses _IOC macros to define ioctls. v3: * Added the use of the in_range macro. * Squashed the commits that add ioctl to console divers. v2: * Instead of the KDFONTOP extension, a new ioctl has been added to obtain font information. Alexey Gladkov (3): VT: Use macros to define ioctls VT: Add KDFONTINFO ioctl VT: Allow to get max font width and height drivers/tty/vt/vt.c | 24 ++++++ drivers/tty/vt/vt_ioctl.c | 11 +++ drivers/video/console/newport_con.c | 21 +++++- drivers/video/console/sticon.c | 25 ++++++- drivers/video/console/vgacon.c | 21 +++++- drivers/video/fbdev/core/fbcon.c | 16 ++++ include/linux/console.h | 3 + include/linux/vt_kern.h | 1 + include/uapi/linux/kd.h | 109 ++++++++++++++++------------ 9 files changed, 176 insertions(+), 55 deletions(-) -- 2.44.0
We now have KD_FONT_OP_SET_TALL, but in fact such large fonts cannot be loaded. No console driver supports tall fonts. Unfortunately, userspace cannot distinguish the lack of support in the driver from errors in the font itself. In all cases, EINVAL will be returned. This patchset adds a separate ioctl to obtain the font parameters supported by the console driver. v5: * Use data types that are compatible with the uapi structure. * Use _IOR to define a new ioctl as required for new ioctls. v4: * Rebased on v6.9-rc1 and conflicts have been fixed. * Do not copy KDFONTINFO data from the userspace. * Header include/uapi/linux/kd.h uses _IOC macros to define ioctls. v3: * Added the use of the in_range macro. * Squashed the commits that add ioctl to console divers. v2: * Instead of the KDFONTOP extension, a new ioctl has been added to obtain font information. Alexey Gladkov (3): VT: Use macros to define ioctls VT: Add KDFONTINFO ioctl VT: Allow to get max font width and height drivers/tty/vt/vt.c | 24 ++++++ drivers/tty/vt/vt_ioctl.c | 13 ++++ drivers/video/console/newport_con.c | 21 +++++- drivers/video/console/sticon.c | 25 ++++++- drivers/video/console/vgacon.c | 21 +++++- drivers/video/fbdev/core/fbcon.c | 16 ++++ include/linux/console.h | 3 + include/linux/vt_kern.h | 1 + include/uapi/linux/kd.h | 110 ++++++++++++++++------------ 9 files changed, 180 insertions(+), 54 deletions(-) -- 2.44.0
All other headers use _IOC() macros to describe ioctls for a long time
now. This header is stuck in the last century.
Simply use the _IO() macro. No other changes.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
---
include/uapi/linux/kd.h | 96 +++++++++++++++++++++--------------------
1 file changed, 49 insertions(+), 47 deletions(-)
diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
index 6b384065c013..8ddb2219a84b 100644
--- a/include/uapi/linux/kd.h
+++ b/include/uapi/linux/kd.h
@@ -5,60 +5,61 @@
#include <linux/compiler.h>
/* 0x4B is 'K', to avoid collision with termios and vt */
+#define KD_IOCTL_BASE 'K'
-#define GIO_FONT 0x4B60 /* gets font in expanded form */
-#define PIO_FONT 0x4B61 /* use font in expanded form */
+#define GIO_FONT _IO(KD_IOCTL_BASE, 0x60) /* gets font in expanded form */
+#define PIO_FONT _IO(KD_IOCTL_BASE, 0x61) /* use font in expanded form */
-#define GIO_FONTX 0x4B6B /* get font using struct consolefontdesc */
-#define PIO_FONTX 0x4B6C /* set font using struct consolefontdesc */
+#define GIO_FONTX _IO(KD_IOCTL_BASE, 0x6B) /* get font using struct consolefontdesc */
+#define PIO_FONTX _IO(KD_IOCTL_BASE, 0x6C) /* set font using struct consolefontdesc */
struct consolefontdesc {
unsigned short charcount; /* characters in font (256 or 512) */
unsigned short charheight; /* scan lines per character (1-32) */
char __user *chardata; /* font data in expanded form */
};
-#define PIO_FONTRESET 0x4B6D /* reset to default font */
+#define PIO_FONTRESET _IO(KD_IOCTL_BASE, 0x6D) /* reset to default font */
-#define GIO_CMAP 0x4B70 /* gets colour palette on VGA+ */
-#define PIO_CMAP 0x4B71 /* sets colour palette on VGA+ */
+#define GIO_CMAP _IO(KD_IOCTL_BASE, 0x70) /* gets colour palette on VGA+ */
+#define PIO_CMAP _IO(KD_IOCTL_BASE, 0x71) /* sets colour palette on VGA+ */
-#define KIOCSOUND 0x4B2F /* start sound generation (0 for off) */
-#define KDMKTONE 0x4B30 /* generate tone */
+#define KIOCSOUND _IO(KD_IOCTL_BASE, 0x2F) /* start sound generation (0 for off) */
+#define KDMKTONE _IO(KD_IOCTL_BASE, 0x30) /* generate tone */
-#define KDGETLED 0x4B31 /* return current led state */
-#define KDSETLED 0x4B32 /* set led state [lights, not flags] */
+#define KDGETLED _IO(KD_IOCTL_BASE, 0x31) /* return current led state */
+#define KDSETLED _IO(KD_IOCTL_BASE, 0x32) /* set led state [lights, not flags] */
#define LED_SCR 0x01 /* scroll lock led */
#define LED_NUM 0x02 /* num lock led */
#define LED_CAP 0x04 /* caps lock led */
-#define KDGKBTYPE 0x4B33 /* get keyboard type */
+#define KDGKBTYPE _IO(KD_IOCTL_BASE, 0x33) /* get keyboard type */
#define KB_84 0x01
#define KB_101 0x02 /* this is what we always answer */
#define KB_OTHER 0x03
-#define KDADDIO 0x4B34 /* add i/o port as valid */
-#define KDDELIO 0x4B35 /* del i/o port as valid */
-#define KDENABIO 0x4B36 /* enable i/o to video board */
-#define KDDISABIO 0x4B37 /* disable i/o to video board */
+#define KDADDIO _IO(KD_IOCTL_BASE, 0x34) /* add i/o port as valid */
+#define KDDELIO _IO(KD_IOCTL_BASE, 0x35) /* del i/o port as valid */
+#define KDENABIO _IO(KD_IOCTL_BASE, 0x36) /* enable i/o to video board */
+#define KDDISABIO _IO(KD_IOCTL_BASE, 0x37) /* disable i/o to video board */
-#define KDSETMODE 0x4B3A /* set text/graphics mode */
+#define KDSETMODE _IO(KD_IOCTL_BASE, 0x3A) /* set text/graphics mode */
#define KD_TEXT 0x00
#define KD_GRAPHICS 0x01
#define KD_TEXT0 0x02 /* obsolete */
#define KD_TEXT1 0x03 /* obsolete */
-#define KDGETMODE 0x4B3B /* get current mode */
+#define KDGETMODE _IO(KD_IOCTL_BASE, 0x3B) /* get current mode */
-#define KDMAPDISP 0x4B3C /* map display into address space */
-#define KDUNMAPDISP 0x4B3D /* unmap display from address space */
+#define KDMAPDISP _IO(KD_IOCTL_BASE, 0x3C) /* map display into address space */
+#define KDUNMAPDISP _IO(KD_IOCTL_BASE, 0x3D) /* unmap display from address space */
typedef char scrnmap_t;
#define E_TABSZ 256
-#define GIO_SCRNMAP 0x4B40 /* get screen mapping from kernel */
-#define PIO_SCRNMAP 0x4B41 /* put screen mapping table in kernel */
-#define GIO_UNISCRNMAP 0x4B69 /* get full Unicode screen mapping */
-#define PIO_UNISCRNMAP 0x4B6A /* set full Unicode screen mapping */
+#define GIO_SCRNMAP _IO(KD_IOCTL_BASE, 0x40) /* get screen mapping from kernel */
+#define PIO_SCRNMAP _IO(KD_IOCTL_BASE, 0x41) /* put screen mapping table in kernel */
+#define GIO_UNISCRNMAP _IO(KD_IOCTL_BASE, 0x69) /* get full Unicode screen mapping */
+#define PIO_UNISCRNMAP _IO(KD_IOCTL_BASE, 0x6A) /* set full Unicode screen mapping */
-#define GIO_UNIMAP 0x4B66 /* get unicode-to-font mapping from kernel */
+#define GIO_UNIMAP _IO(KD_IOCTL_BASE, 0x66) /* get unicode-to-font mapping from kernel */
struct unipair {
unsigned short unicode;
unsigned short fontpos;
@@ -67,8 +68,8 @@ struct unimapdesc {
unsigned short entry_ct;
struct unipair __user *entries;
};
-#define PIO_UNIMAP 0x4B67 /* put unicode-to-font mapping in kernel */
-#define PIO_UNIMAPCLR 0x4B68 /* clear table, possibly advise hash algorithm */
+#define PIO_UNIMAP _IO(KD_IOCTL_BASE, 0x67) /* put unicode-to-font mapping in kernel */
+#define PIO_UNIMAPCLR _IO(KD_IOCTL_BASE, 0x68) /* clear table, possibly advise hash algorithm */
struct unimapinit {
unsigned short advised_hashsize; /* 0 if no opinion */
unsigned short advised_hashstep; /* 0 if no opinion */
@@ -83,19 +84,19 @@ struct unimapinit {
#define K_MEDIUMRAW 0x02
#define K_UNICODE 0x03
#define K_OFF 0x04
-#define KDGKBMODE 0x4B44 /* gets current keyboard mode */
-#define KDSKBMODE 0x4B45 /* sets current keyboard mode */
+#define KDGKBMODE _IO(KD_IOCTL_BASE, 0x44) /* gets current keyboard mode */
+#define KDSKBMODE _IO(KD_IOCTL_BASE, 0x45) /* sets current keyboard mode */
#define K_METABIT 0x03
#define K_ESCPREFIX 0x04
-#define KDGKBMETA 0x4B62 /* gets meta key handling mode */
-#define KDSKBMETA 0x4B63 /* sets meta key handling mode */
+#define KDGKBMETA _IO(KD_IOCTL_BASE, 0x62) /* gets meta key handling mode */
+#define KDSKBMETA _IO(KD_IOCTL_BASE, 0x63) /* sets meta key handling mode */
#define K_SCROLLLOCK 0x01
#define K_NUMLOCK 0x02
#define K_CAPSLOCK 0x04
-#define KDGKBLED 0x4B64 /* get led flags (not lights) */
-#define KDSKBLED 0x4B65 /* set led flags (not lights) */
+#define KDGKBLED _IO(KD_IOCTL_BASE, 0x64) /* get led flags (not lights) */
+#define KDSKBLED _IO(KD_IOCTL_BASE, 0x65) /* set led flags (not lights) */
struct kbentry {
unsigned char kb_table;
@@ -107,15 +108,15 @@ struct kbentry {
#define K_ALTTAB 0x02
#define K_ALTSHIFTTAB 0x03
-#define KDGKBENT 0x4B46 /* gets one entry in translation table */
-#define KDSKBENT 0x4B47 /* sets one entry in translation table */
+#define KDGKBENT _IO(KD_IOCTL_BASE, 0x46) /* gets one entry in translation table */
+#define KDSKBENT _IO(KD_IOCTL_BASE, 0x47) /* sets one entry in translation table */
struct kbsentry {
unsigned char kb_func;
unsigned char kb_string[512];
};
-#define KDGKBSENT 0x4B48 /* gets one function key string entry */
-#define KDSKBSENT 0x4B49 /* sets one function key string entry */
+#define KDGKBSENT _IO(KD_IOCTL_BASE, 0x48) /* gets one function key string entry */
+#define KDSKBSENT _IO(KD_IOCTL_BASE, 0x49) /* sets one function key string entry */
struct kbdiacr {
unsigned char diacr, base, result;
@@ -124,8 +125,8 @@ struct kbdiacrs {
unsigned int kb_cnt; /* number of entries in following array */
struct kbdiacr kbdiacr[256]; /* MAX_DIACR from keyboard.h */
};
-#define KDGKBDIACR 0x4B4A /* read kernel accent table */
-#define KDSKBDIACR 0x4B4B /* write kernel accent table */
+#define KDGKBDIACR _IO(KD_IOCTL_BASE, 0x4A) /* read kernel accent table */
+#define KDSKBDIACR _IO(KD_IOCTL_BASE, 0x4B) /* write kernel accent table */
struct kbdiacruc {
unsigned int diacr, base, result;
@@ -134,16 +135,16 @@ struct kbdiacrsuc {
unsigned int kb_cnt; /* number of entries in following array */
struct kbdiacruc kbdiacruc[256]; /* MAX_DIACR from keyboard.h */
};
-#define KDGKBDIACRUC 0x4BFA /* read kernel accent table - UCS */
-#define KDSKBDIACRUC 0x4BFB /* write kernel accent table - UCS */
+#define KDGKBDIACRUC _IO(KD_IOCTL_BASE, 0xFA) /* read kernel accent table - UCS */
+#define KDSKBDIACRUC _IO(KD_IOCTL_BASE, 0xFB) /* write kernel accent table - UCS */
struct kbkeycode {
unsigned int scancode, keycode;
};
-#define KDGETKEYCODE 0x4B4C /* read kernel keycode table entry */
-#define KDSETKEYCODE 0x4B4D /* write kernel keycode table entry */
+#define KDGETKEYCODE _IO(KD_IOCTL_BASE, 0x4C) /* read kernel keycode table entry */
+#define KDSETKEYCODE _IO(KD_IOCTL_BASE, 0x4D) /* write kernel keycode table entry */
-#define KDSIGACCEPT 0x4B4E /* accept kbd generated signals */
+#define KDSIGACCEPT _IO(KD_IOCTL_BASE, 0x4E) /* accept kbd generated signals */
struct kbd_repeat {
int delay; /* in msec; <= 0: don't change */
@@ -151,10 +152,11 @@ struct kbd_repeat {
/* earlier this field was misnamed "rate" */
};
-#define KDKBDREP 0x4B52 /* set keyboard delay/repeat rate;
- * actually used values are returned */
+#define KDKBDREP _IO(KD_IOCTL_BASE, 0x52) /* set keyboard delay/repeat rate;
+ * actually used values are returned
+ */
-#define KDFONTOP 0x4B72 /* font operations */
+#define KDFONTOP _IO(KD_IOCTL_BASE, 0x72) /* font operations */
struct console_font_op {
unsigned int op; /* operation code KD_FONT_OP_* */
--
2.44.0On Wed, Apr 17, 2024 at 07:37:35PM +0200, Alexey Gladkov wrote: > All other headers use _IOC() macros to describe ioctls for a long time > now. This header is stuck in the last century. > > Simply use the _IO() macro. No other changes. > > Signed-off-by: Alexey Gladkov <legion@kernel.org> > --- > include/uapi/linux/kd.h | 96 +++++++++++++++++++++-------------------- > 1 file changed, 49 insertions(+), 47 deletions(-) This is a nice cleanup, thanks for doing it, I'll just take this one change now if you don't object. thanks, greg k-h
On 18. 04. 24, 8:18, Greg Kroah-Hartman wrote: > On Wed, Apr 17, 2024 at 07:37:35PM +0200, Alexey Gladkov wrote: >> All other headers use _IOC() macros to describe ioctls for a long time >> now. This header is stuck in the last century. >> >> Simply use the _IO() macro. No other changes. >> >> Signed-off-by: Alexey Gladkov <legion@kernel.org> >> --- >> include/uapi/linux/kd.h | 96 +++++++++++++++++++++-------------------- >> 1 file changed, 49 insertions(+), 47 deletions(-) > > This is a nice cleanup, thanks for doing it, I'll just take this one > change now if you don't object. Unfortunately, _IOC_NONE is 1 on some archs as noted by Arnd, and this commit changed the kd ioctl values in there which broke stuff as noted by Al. We either: * use _IOC(0, X, Y) in here, instead of _IO(X, Y), or * define KDIOC(X) as _IOC(0, KD_IOCTL_BASE, X), or * revert the commit which landed to -rc1 already. thanks, -- js
On Wed, May 29, 2024 at 09:29:23AM +0200, Jiri Slaby wrote:
> On 18. 04. 24, 8:18, Greg Kroah-Hartman wrote:
> > On Wed, Apr 17, 2024 at 07:37:35PM +0200, Alexey Gladkov wrote:
> > > All other headers use _IOC() macros to describe ioctls for a long time
> > > now. This header is stuck in the last century.
> > >
> > > Simply use the _IO() macro. No other changes.
> > >
> > > Signed-off-by: Alexey Gladkov <legion@kernel.org>
> > > ---
> > > include/uapi/linux/kd.h | 96 +++++++++++++++++++++--------------------
> > > 1 file changed, 49 insertions(+), 47 deletions(-)
> >
> > This is a nice cleanup, thanks for doing it, I'll just take this one
> > change now if you don't object.
>
> Unfortunately, _IOC_NONE is 1 on some archs as noted by Arnd, and this
> commit changed the kd ioctl values in there which broke stuff as noted by
> Al.
>
> We either:
> * use _IOC(0, X, Y) in here, instead of _IO(X, Y), or
> * define KDIOC(X) as _IOC(0, KD_IOCTL_BASE, X), or
> * revert the commit which landed to -rc1 already.
Revert, IMO. If nothing else, _IO... macros are there to
* document the copyin/copyout direction
* make sure that argument size mismatches between the kernel
and userland get caught
Turning 16bit hex constants into that won't serve any purpose other
than preventing such patches in the future; adding a comment would
deal with that just fine.
BTW, the original odd choice for _IOC_NONE appears to have been motivated
by avoiding conflicts with legacy ioctl numbers: in CSRG repo there's
this:
commit 02cbc6a653b48bb4ec6052cbe6b3979530011c46
Author: Sam Leffler <sam@ucbvax.Berkeley.EDU>
Date: Mon Aug 2 02:22:17 1982 -0800
new ioctl's
...
+/*
+ * Ioctl's have the command encoded in the lower word,
+ * and the size of any in or out parameters in the upper
+ * word. The high 2 bits of the upper word are used
+ * to encode the in/out status of the parameter; for now
+ * we restrict parameters to at most 128 bytes.
+ */
+#define IOCPARM_MASK 0x7f /* parameters must be < 128 bytes */
+#define IOC_VOID 0x20000000 /* no parameters */
+#define IOC_OUT 0x40000000 /* copy out parameters */
+#define IOC_IN 0x80000000 /* copy in parameters */
+#define IOC_INOUT (IOC_IN|IOC_OUT)
+/* the 0x20000000 is so we can distinguish new ioctl's from old */
+#define _IO(x,y) (IOC_VOID|('x'<<8)|y)
+#define _IOR(x,y,t) (IOC_OUT|((sizeof(t)&IOCPARM_MASK)<<16)|('x'<<8)|y)
+#define _IOW(x,y,t) (IOC_IN|((sizeof(t)&IOCPARM_MASK)<<16)|('x'<<8)|y)
+/* this should be _IORW, but stdio got there first */
+#define _IOWR(x,y,t) (IOC_INOUT|((sizeof(t)&IOCPARM_MASK)<<16)|('x'<<8)|y)
FWIW, the upper limit on parameter size went up from 128 bytes to 8Kb in
commit 856ed9ecd2795280feed42baf3889ac7c7f9a26d
Author: Mike Karels <karels@ucbvax.Berkeley.EDU>
Date: Thu Feb 19 22:16:28 1987 -0800
larger ioctl's (for disklabels)
Wonder what got us (in sparc port?) to lift it from 8Kb to 16Kb...
In our historical tree that has happened in
commit 1c29224f169362b671a4bef4cd864464ef810d42
Author: Pete Zaitcev <zaitcev@redhat.com>
Date: Sun Mar 2 08:45:12 2003 -0800
[SPARC32/64]: Expand ioctl size field in backwards-compatible way.
No explanations there...
On Wed, May 29, 2024, at 09:29, Jiri Slaby wrote:
> On 18. 04. 24, 8:18, Greg Kroah-Hartman wrote:
>>
>> This is a nice cleanup, thanks for doing it, I'll just take this one
>> change now if you don't object.
>
> Unfortunately, _IOC_NONE is 1 on some archs as noted by Arnd, and this
> commit changed the kd ioctl values in there which broke stuff as noted
> by Al.
>
> We either:
> * use _IOC(0, X, Y) in here, instead of _IO(X, Y), or
> * define KDIOC(X) as _IOC(0, KD_IOCTL_BASE, X), or
> * revert the commit which landed to -rc1 already.
I would prefer a simple revert, as the other options may
end up more confusing. Another option might be a new
global macro, if we then go an convert all plain ioctl
command numbers to that.
Arnd
Each driver has its own restrictions on font size. There is currently no
way to understand what the requirements are. The new ioctl allows
userspace to get the minimum and maximum font size values.
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
---
drivers/tty/vt/vt.c | 24 ++++++++++++++++++++++++
drivers/tty/vt/vt_ioctl.c | 13 +++++++++++++
include/linux/console.h | 3 +++
include/linux/vt_kern.h | 1 +
include/uapi/linux/kd.h | 14 ++++++++++++++
5 files changed, 55 insertions(+)
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 9b5b98dfc8b4..e8db0e9ea674 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -4851,6 +4851,30 @@ int con_font_op(struct vc_data *vc, struct console_font_op *op)
return -ENOSYS;
}
+int con_font_info(struct vc_data *vc, struct console_font_info *info)
+{
+ int rc;
+
+ info->min_height = 0;
+ info->max_height = max_font_height;
+
+ info->min_width = 0;
+ info->max_width = max_font_width;
+
+ info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
+
+ console_lock();
+ if (vc->vc_mode != KD_TEXT)
+ rc = -EINVAL;
+ else if (vc->vc_sw->con_font_info)
+ rc = vc->vc_sw->con_font_info(vc, info);
+ else
+ rc = -ENOSYS;
+ console_unlock();
+
+ return rc;
+}
+
/*
* Interface exported to selection and vcs.
*/
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
index 4b91072f3a4e..9a2f8081f650 100644
--- a/drivers/tty/vt/vt_ioctl.c
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -479,6 +479,19 @@ static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
break;
}
+ case KDFONTINFO: {
+ struct console_font_info fnt_info;
+
+ memset(&fnt_info, 0, sizeof(fnt_info));
+
+ ret = con_font_info(vc, &fnt_info);
+ if (ret)
+ return ret;
+ if (copy_to_user(up, &fnt_info, sizeof(fnt_info)))
+ return -EFAULT;
+ break;
+ }
+
default:
return -ENOIOCTLCMD;
}
diff --git a/include/linux/console.h b/include/linux/console.h
index 31a8f5b85f5d..4b798322aa01 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -21,6 +21,7 @@
#include <linux/vesa.h>
struct vc_data;
+struct console_font_info;
struct console_font_op;
struct console_font;
struct module;
@@ -102,6 +103,8 @@ struct consw {
bool (*con_switch)(struct vc_data *vc);
bool (*con_blank)(struct vc_data *vc, enum vesa_blank_mode blank,
bool mode_switch);
+ int (*con_font_info)(struct vc_data *vc,
+ struct console_font_info *info);
int (*con_font_set)(struct vc_data *vc,
const struct console_font *font,
unsigned int vpitch, unsigned int flags);
diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
index d008c3d0a9bb..383b3a4f6113 100644
--- a/include/linux/vt_kern.h
+++ b/include/linux/vt_kern.h
@@ -33,6 +33,7 @@ void do_blank_screen(int entering_gfx);
void do_unblank_screen(int leaving_gfx);
void poke_blanked_console(void);
int con_font_op(struct vc_data *vc, struct console_font_op *op);
+int con_font_info(struct vc_data *vc, struct console_font_info *info);
int con_set_cmap(unsigned char __user *cmap);
int con_get_cmap(unsigned char __user *cmap);
void scrollback(struct vc_data *vc);
diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
index 8ddb2219a84b..68b715ad4d5c 100644
--- a/include/uapi/linux/kd.h
+++ b/include/uapi/linux/kd.h
@@ -185,6 +185,20 @@ struct console_font {
#define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
+/* font information */
+
+#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
+#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
+
+struct console_font_info {
+ __u32 flags; /* KD_FONT_INFO_FLAG_* */
+ __u32 min_width, min_height; /* minimal font size */
+ __u32 max_width, max_height; /* maximum font size */
+ __u32 reserved[5]; /* This field is reserved for future use. Must be 0. */
+};
+
+#define KDFONTINFO _IOR(KD_IOCTL_BASE, 0x73, struct console_font_info)
+
/* note: 0x4B00-0x4B4E all have had a value at some time;
don't reuse for the time being */
/* note: 0x4B60-0x4B6D, 0x4B70-0x4B72 used above */
--
2.44.0On Wed, Apr 17, 2024 at 07:37:36PM +0200, Alexey Gladkov wrote:
> Each driver has its own restrictions on font size. There is currently no
> way to understand what the requirements are. The new ioctl allows
> userspace to get the minimum and maximum font size values.
Is there any userspace code that uses this yet that we can point to
here?
I know tty ioctls are woefully undocumented, but could there be some
documentation here?
>
> Acked-by: Helge Deller <deller@gmx.de>
> Signed-off-by: Alexey Gladkov <legion@kernel.org>
> ---
> drivers/tty/vt/vt.c | 24 ++++++++++++++++++++++++
> drivers/tty/vt/vt_ioctl.c | 13 +++++++++++++
> include/linux/console.h | 3 +++
> include/linux/vt_kern.h | 1 +
> include/uapi/linux/kd.h | 14 ++++++++++++++
> 5 files changed, 55 insertions(+)
>
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index 9b5b98dfc8b4..e8db0e9ea674 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -4851,6 +4851,30 @@ int con_font_op(struct vc_data *vc, struct console_font_op *op)
> return -ENOSYS;
> }
>
> +int con_font_info(struct vc_data *vc, struct console_font_info *info)
> +{
> + int rc;
> +
> + info->min_height = 0;
> + info->max_height = max_font_height;
> +
> + info->min_width = 0;
> + info->max_width = max_font_width;
> +
> + info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
> +
> + console_lock();
> + if (vc->vc_mode != KD_TEXT)
> + rc = -EINVAL;
> + else if (vc->vc_sw->con_font_info)
> + rc = vc->vc_sw->con_font_info(vc, info);
> + else
> + rc = -ENOSYS;
> + console_unlock();
> +
> + return rc;
> +}
> +
> /*
> * Interface exported to selection and vcs.
> */
> diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
> index 4b91072f3a4e..9a2f8081f650 100644
> --- a/drivers/tty/vt/vt_ioctl.c
> +++ b/drivers/tty/vt/vt_ioctl.c
> @@ -479,6 +479,19 @@ static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
> break;
> }
>
> + case KDFONTINFO: {
> + struct console_font_info fnt_info;
> +
> + memset(&fnt_info, 0, sizeof(fnt_info));
> +
> + ret = con_font_info(vc, &fnt_info);
Shouldn't con_font_info() memset it first? No need to do it in the
caller.
> + if (ret)
> + return ret;
> + if (copy_to_user(up, &fnt_info, sizeof(fnt_info)))
> + return -EFAULT;
> + break;
> + }
> +
> default:
> return -ENOIOCTLCMD;
> }
> diff --git a/include/linux/console.h b/include/linux/console.h
> index 31a8f5b85f5d..4b798322aa01 100644
> --- a/include/linux/console.h
> +++ b/include/linux/console.h
> @@ -21,6 +21,7 @@
> #include <linux/vesa.h>
>
> struct vc_data;
> +struct console_font_info;
> struct console_font_op;
> struct console_font;
> struct module;
> @@ -102,6 +103,8 @@ struct consw {
> bool (*con_switch)(struct vc_data *vc);
> bool (*con_blank)(struct vc_data *vc, enum vesa_blank_mode blank,
> bool mode_switch);
> + int (*con_font_info)(struct vc_data *vc,
> + struct console_font_info *info);
To make the names more obvious, how about:
con_font_info_get()?
> int (*con_font_set)(struct vc_data *vc,
> const struct console_font *font,
> unsigned int vpitch, unsigned int flags);
> diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
> index d008c3d0a9bb..383b3a4f6113 100644
> --- a/include/linux/vt_kern.h
> +++ b/include/linux/vt_kern.h
> @@ -33,6 +33,7 @@ void do_blank_screen(int entering_gfx);
> void do_unblank_screen(int leaving_gfx);
> void poke_blanked_console(void);
> int con_font_op(struct vc_data *vc, struct console_font_op *op);
> +int con_font_info(struct vc_data *vc, struct console_font_info *info);
> int con_set_cmap(unsigned char __user *cmap);
> int con_get_cmap(unsigned char __user *cmap);
> void scrollback(struct vc_data *vc);
> diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
> index 8ddb2219a84b..68b715ad4d5c 100644
> --- a/include/uapi/linux/kd.h
> +++ b/include/uapi/linux/kd.h
> @@ -185,6 +185,20 @@ struct console_font {
>
> #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
>
> +/* font information */
> +
> +#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
> +#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
I don't understand why bit 0 and bit 1 have those comments after them.
That's confusing (i.e. bit 0 is NOT 256...)
> +
> +struct console_font_info {
> + __u32 flags; /* KD_FONT_INFO_FLAG_* */
Why are there flags if you are only setting these 2 values? What are
the flags for?
If this is going to be a "multiplexed" type of structure, then make it a
union? Or maybe we are totally over thinking this whole thing.
All you want is the min/max font size of the console, right? So perhaps
the whole structure is just:
> + __u32 min_width, min_height; /* minimal font size */
> + __u32 max_width, max_height; /* maximum font size */
Those 4 variables? Why have anything else here at all? For any new
thing you wish to discover, have it be a new ioctl?
> + __u32 reserved[5]; /* This field is reserved for future use. Must be 0. */
I understand the "must be 0" but this is a read-only structure, so
saying "it will be set to 0" might be better?" Or something like that?
> +};
> +
> +#define KDFONTINFO _IOR(KD_IOCTL_BASE, 0x73, struct console_font_info)
As mentioned above how about KDFONTINFOGET?
thanks,
greg k-h
On Thu, Apr 18, 2024 at 08:18:33AM +0200, Greg Kroah-Hartman wrote:
> On Wed, Apr 17, 2024 at 07:37:36PM +0200, Alexey Gladkov wrote:
> > Each driver has its own restrictions on font size. There is currently no
> > way to understand what the requirements are. The new ioctl allows
> > userspace to get the minimum and maximum font size values.
>
> Is there any userspace code that uses this yet that we can point to
> here?
Yes. I have a code that uses this. It waits for this ioctl to appear in
the kernel.
https://git.kernel.org/pub/scm/linux/kernel/git/legion/kbd.git/commit/?h=kdfontinfo-v1&id=e2ad0117ca8e46cedd8668934db7b04e9054d5d7
> I know tty ioctls are woefully undocumented, but could there be some
> documentation here?
Yes, this is a big problem for this interface. The ioctl_console(2)
describes PIO_FONT/PIO_FONTX, which is no longer supported, but does not
describe KDFONTOP at all, which is exactly used by userspace.
My TODO has a task to fix this.
But I would suggest creating documentation in the kernel because life
shows that man-page is far behind what is implemented.
> >
> > Acked-by: Helge Deller <deller@gmx.de>
> > Signed-off-by: Alexey Gladkov <legion@kernel.org>
> > ---
> > drivers/tty/vt/vt.c | 24 ++++++++++++++++++++++++
> > drivers/tty/vt/vt_ioctl.c | 13 +++++++++++++
> > include/linux/console.h | 3 +++
> > include/linux/vt_kern.h | 1 +
> > include/uapi/linux/kd.h | 14 ++++++++++++++
> > 5 files changed, 55 insertions(+)
> >
> > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> > index 9b5b98dfc8b4..e8db0e9ea674 100644
> > --- a/drivers/tty/vt/vt.c
> > +++ b/drivers/tty/vt/vt.c
> > @@ -4851,6 +4851,30 @@ int con_font_op(struct vc_data *vc, struct console_font_op *op)
> > return -ENOSYS;
> > }
> >
> > +int con_font_info(struct vc_data *vc, struct console_font_info *info)
> > +{
> > + int rc;
> > +
> > + info->min_height = 0;
> > + info->max_height = max_font_height;
> > +
> > + info->min_width = 0;
> > + info->max_width = max_font_width;
> > +
> > + info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
> > +
> > + console_lock();
> > + if (vc->vc_mode != KD_TEXT)
> > + rc = -EINVAL;
> > + else if (vc->vc_sw->con_font_info)
> > + rc = vc->vc_sw->con_font_info(vc, info);
> > + else
> > + rc = -ENOSYS;
> > + console_unlock();
> > +
> > + return rc;
> > +}
> > +
> > /*
> > * Interface exported to selection and vcs.
> > */
> > diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
> > index 4b91072f3a4e..9a2f8081f650 100644
> > --- a/drivers/tty/vt/vt_ioctl.c
> > +++ b/drivers/tty/vt/vt_ioctl.c
> > @@ -479,6 +479,19 @@ static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
> > break;
> > }
> >
> > + case KDFONTINFO: {
> > + struct console_font_info fnt_info;
> > +
> > + memset(&fnt_info, 0, sizeof(fnt_info));
> > +
> > + ret = con_font_info(vc, &fnt_info);
>
> Shouldn't con_font_info() memset it first? No need to do it in the
> caller.
>
> > + if (ret)
> > + return ret;
> > + if (copy_to_user(up, &fnt_info, sizeof(fnt_info)))
> > + return -EFAULT;
> > + break;
> > + }
> > +
> > default:
> > return -ENOIOCTLCMD;
> > }
> > diff --git a/include/linux/console.h b/include/linux/console.h
> > index 31a8f5b85f5d..4b798322aa01 100644
> > --- a/include/linux/console.h
> > +++ b/include/linux/console.h
> > @@ -21,6 +21,7 @@
> > #include <linux/vesa.h>
> >
> > struct vc_data;
> > +struct console_font_info;
> > struct console_font_op;
> > struct console_font;
> > struct module;
> > @@ -102,6 +103,8 @@ struct consw {
> > bool (*con_switch)(struct vc_data *vc);
> > bool (*con_blank)(struct vc_data *vc, enum vesa_blank_mode blank,
> > bool mode_switch);
> > + int (*con_font_info)(struct vc_data *vc,
> > + struct console_font_info *info);
>
> To make the names more obvious, how about:
> con_font_info_get()?
>
> > int (*con_font_set)(struct vc_data *vc,
> > const struct console_font *font,
> > unsigned int vpitch, unsigned int flags);
> > diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
> > index d008c3d0a9bb..383b3a4f6113 100644
> > --- a/include/linux/vt_kern.h
> > +++ b/include/linux/vt_kern.h
> > @@ -33,6 +33,7 @@ void do_blank_screen(int entering_gfx);
> > void do_unblank_screen(int leaving_gfx);
> > void poke_blanked_console(void);
> > int con_font_op(struct vc_data *vc, struct console_font_op *op);
> > +int con_font_info(struct vc_data *vc, struct console_font_info *info);
> > int con_set_cmap(unsigned char __user *cmap);
> > int con_get_cmap(unsigned char __user *cmap);
> > void scrollback(struct vc_data *vc);
> > diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
> > index 8ddb2219a84b..68b715ad4d5c 100644
> > --- a/include/uapi/linux/kd.h
> > +++ b/include/uapi/linux/kd.h
> > @@ -185,6 +185,20 @@ struct console_font {
> >
> > #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
> >
> > +/* font information */
> > +
> > +#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
> > +#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
>
> I don't understand why bit 0 and bit 1 have those comments after them.
> That's confusing (i.e. bit 0 is NOT 256...)
>
> > +
> > +struct console_font_info {
> > + __u32 flags; /* KD_FONT_INFO_FLAG_* */
>
> Why are there flags if you are only setting these 2 values? What are
> the flags for?
>
> If this is going to be a "multiplexed" type of structure, then make it a
> union? Or maybe we are totally over thinking this whole thing.
>
> All you want is the min/max font size of the console, right? So perhaps
> the whole structure is just:
>
> > + __u32 min_width, min_height; /* minimal font size */
> > + __u32 max_width, max_height; /* maximum font size */
>
> Those 4 variables? Why have anything else here at all? For any new
> thing you wish to discover, have it be a new ioctl?
>
> > + __u32 reserved[5]; /* This field is reserved for future use. Must be 0. */
>
> I understand the "must be 0" but this is a read-only structure, so
> saying "it will be set to 0" might be better?" Or something like that?
>
> > +};
> > +
> > +#define KDFONTINFO _IOR(KD_IOCTL_BASE, 0x73, struct console_font_info)
>
> As mentioned above how about KDFONTINFOGET?
>
> thanks,
>
> greg k-h
>
--
Rgrds, legion
On 4/17/24 19:37, Alexey Gladkov wrote:
> Each driver has its own restrictions on font size. There is currently no
> way to understand what the requirements are. The new ioctl allows
> userspace to get the minimum and maximum font size values.
>
> Acked-by: Helge Deller <deller@gmx.de>
> Signed-off-by: Alexey Gladkov <legion@kernel.org>
> ---
> drivers/tty/vt/vt.c | 24 ++++++++++++++++++++++++
> drivers/tty/vt/vt_ioctl.c | 13 +++++++++++++
> include/linux/console.h | 3 +++
> include/linux/vt_kern.h | 1 +
> include/uapi/linux/kd.h | 14 ++++++++++++++
> 5 files changed, 55 insertions(+)
>
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index 9b5b98dfc8b4..e8db0e9ea674 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -4851,6 +4851,30 @@ int con_font_op(struct vc_data *vc, struct console_font_op *op)
> return -ENOSYS;
> }
>
> +int con_font_info(struct vc_data *vc, struct console_font_info *info)
> +{
> + int rc;
> +
> + info->min_height = 0;
> + info->max_height = max_font_height;
> +
> + info->min_width = 0;
> + info->max_width = max_font_width;
> +
> + info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
> +
> + console_lock();
> + if (vc->vc_mode != KD_TEXT)
> + rc = -EINVAL;
> + else if (vc->vc_sw->con_font_info)
> + rc = vc->vc_sw->con_font_info(vc, info);
> + else
> + rc = -ENOSYS;
> + console_unlock();
> +
> + return rc;
> +}
> +
> /*
> * Interface exported to selection and vcs.
> */
> diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
> index 4b91072f3a4e..9a2f8081f650 100644
> --- a/drivers/tty/vt/vt_ioctl.c
> +++ b/drivers/tty/vt/vt_ioctl.c
> @@ -479,6 +479,19 @@ static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
> break;
> }
>
> + case KDFONTINFO: {
> + struct console_font_info fnt_info;
> +
> + memset(&fnt_info, 0, sizeof(fnt_info));
> +
> + ret = con_font_info(vc, &fnt_info);
> + if (ret)
> + return ret;
> + if (copy_to_user(up, &fnt_info, sizeof(fnt_info)))
> + return -EFAULT;
> + break;
> + }
> +
> default:
> return -ENOIOCTLCMD;
> }
> diff --git a/include/linux/console.h b/include/linux/console.h
> index 31a8f5b85f5d..4b798322aa01 100644
> --- a/include/linux/console.h
> +++ b/include/linux/console.h
> @@ -21,6 +21,7 @@
> #include <linux/vesa.h>
>
> struct vc_data;
> +struct console_font_info;
> struct console_font_op;
> struct console_font;
> struct module;
> @@ -102,6 +103,8 @@ struct consw {
> bool (*con_switch)(struct vc_data *vc);
> bool (*con_blank)(struct vc_data *vc, enum vesa_blank_mode blank,
> bool mode_switch);
> + int (*con_font_info)(struct vc_data *vc,
> + struct console_font_info *info);
> int (*con_font_set)(struct vc_data *vc,
> const struct console_font *font,
> unsigned int vpitch, unsigned int flags);
> diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
> index d008c3d0a9bb..383b3a4f6113 100644
> --- a/include/linux/vt_kern.h
> +++ b/include/linux/vt_kern.h
> @@ -33,6 +33,7 @@ void do_blank_screen(int entering_gfx);
> void do_unblank_screen(int leaving_gfx);
> void poke_blanked_console(void);
> int con_font_op(struct vc_data *vc, struct console_font_op *op);
> +int con_font_info(struct vc_data *vc, struct console_font_info *info);
> int con_set_cmap(unsigned char __user *cmap);
> int con_get_cmap(unsigned char __user *cmap);
> void scrollback(struct vc_data *vc);
> diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
> index 8ddb2219a84b..68b715ad4d5c 100644
> --- a/include/uapi/linux/kd.h
> +++ b/include/uapi/linux/kd.h
> @@ -185,6 +185,20 @@ struct console_font {
>
> #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
>
> +/* font information */
> +
> +#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
> +#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
Do we really need those bits?
You set a default min/max font size in con_font_info() above,
and all drivers can override those values.
So, there are always min/max sizes available.
> +struct console_font_info {
> + __u32 flags; /* KD_FONT_INFO_FLAG_* */
One space too much in front of "flags" ?
> + __u32 min_width, min_height; /* minimal font size */
> + __u32 max_width, max_height; /* maximum font size */
> + __u32 reserved[5]; /* This field is reserved for future use. Must be 0. */
> +};
> +
> +#define KDFONTINFO _IOR(KD_IOCTL_BASE, 0x73, struct console_font_info)
> +
> /* note: 0x4B00-0x4B4E all have had a value at some time;
> don't reuse for the time being */
> /* note: 0x4B60-0x4B6D, 0x4B70-0x4B72 used above */
On Wed, Apr 17, 2024 at 09:31:53PM +0200, Helge Deller wrote:
> On 4/17/24 19:37, Alexey Gladkov wrote:
> > Each driver has its own restrictions on font size. There is currently no
> > way to understand what the requirements are. The new ioctl allows
> > userspace to get the minimum and maximum font size values.
> >
> > Acked-by: Helge Deller <deller@gmx.de>
> > Signed-off-by: Alexey Gladkov <legion@kernel.org>
> > ---
> > drivers/tty/vt/vt.c | 24 ++++++++++++++++++++++++
> > drivers/tty/vt/vt_ioctl.c | 13 +++++++++++++
> > include/linux/console.h | 3 +++
> > include/linux/vt_kern.h | 1 +
> > include/uapi/linux/kd.h | 14 ++++++++++++++
> > 5 files changed, 55 insertions(+)
> >
> > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> > index 9b5b98dfc8b4..e8db0e9ea674 100644
> > --- a/drivers/tty/vt/vt.c
> > +++ b/drivers/tty/vt/vt.c
> > @@ -4851,6 +4851,30 @@ int con_font_op(struct vc_data *vc, struct console_font_op *op)
> > return -ENOSYS;
> > }
> >
> > +int con_font_info(struct vc_data *vc, struct console_font_info *info)
> > +{
> > + int rc;
> > +
> > + info->min_height = 0;
> > + info->max_height = max_font_height;
> > +
> > + info->min_width = 0;
> > + info->max_width = max_font_width;
> > +
> > + info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
> > +
> > + console_lock();
> > + if (vc->vc_mode != KD_TEXT)
> > + rc = -EINVAL;
> > + else if (vc->vc_sw->con_font_info)
> > + rc = vc->vc_sw->con_font_info(vc, info);
> > + else
> > + rc = -ENOSYS;
> > + console_unlock();
> > +
> > + return rc;
> > +}
> > +
> > /*
> > * Interface exported to selection and vcs.
> > */
> > diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
> > index 4b91072f3a4e..9a2f8081f650 100644
> > --- a/drivers/tty/vt/vt_ioctl.c
> > +++ b/drivers/tty/vt/vt_ioctl.c
> > @@ -479,6 +479,19 @@ static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
> > break;
> > }
> >
> > + case KDFONTINFO: {
> > + struct console_font_info fnt_info;
> > +
> > + memset(&fnt_info, 0, sizeof(fnt_info));
> > +
> > + ret = con_font_info(vc, &fnt_info);
> > + if (ret)
> > + return ret;
> > + if (copy_to_user(up, &fnt_info, sizeof(fnt_info)))
> > + return -EFAULT;
> > + break;
> > + }
> > +
> > default:
> > return -ENOIOCTLCMD;
> > }
> > diff --git a/include/linux/console.h b/include/linux/console.h
> > index 31a8f5b85f5d..4b798322aa01 100644
> > --- a/include/linux/console.h
> > +++ b/include/linux/console.h
> > @@ -21,6 +21,7 @@
> > #include <linux/vesa.h>
> >
> > struct vc_data;
> > +struct console_font_info;
> > struct console_font_op;
> > struct console_font;
> > struct module;
> > @@ -102,6 +103,8 @@ struct consw {
> > bool (*con_switch)(struct vc_data *vc);
> > bool (*con_blank)(struct vc_data *vc, enum vesa_blank_mode blank,
> > bool mode_switch);
> > + int (*con_font_info)(struct vc_data *vc,
> > + struct console_font_info *info);
> > int (*con_font_set)(struct vc_data *vc,
> > const struct console_font *font,
> > unsigned int vpitch, unsigned int flags);
> > diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
> > index d008c3d0a9bb..383b3a4f6113 100644
> > --- a/include/linux/vt_kern.h
> > +++ b/include/linux/vt_kern.h
> > @@ -33,6 +33,7 @@ void do_blank_screen(int entering_gfx);
> > void do_unblank_screen(int leaving_gfx);
> > void poke_blanked_console(void);
> > int con_font_op(struct vc_data *vc, struct console_font_op *op);
> > +int con_font_info(struct vc_data *vc, struct console_font_info *info);
> > int con_set_cmap(unsigned char __user *cmap);
> > int con_get_cmap(unsigned char __user *cmap);
> > void scrollback(struct vc_data *vc);
> > diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
> > index 8ddb2219a84b..68b715ad4d5c 100644
> > --- a/include/uapi/linux/kd.h
> > +++ b/include/uapi/linux/kd.h
> > @@ -185,6 +185,20 @@ struct console_font {
> >
> > #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
> >
> > +/* font information */
> > +
> > +#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
> > +#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
>
> Do we really need those bits?
> You set a default min/max font size in con_font_info() above,
> and all drivers can override those values.
> So, there are always min/max sizes available.
These bits are not about the minimum and maximum glyph size, but about the
number of glyphs in the font.
Maybe this is an overkill, but sticon has this check:
if ((w < 6) || (h < 6) || (w > 32) || (h > 32) || (vpitch != 32)
|| (op->charcount != 256 && op->charcount != 512))
[ to be honest, I don’t know why this driver doesn’t accept a glyph of
width 4 ]
I thought it would be worth fixing the maximum number of requirements in
the drivers since I started adding a new ioctl.
> > +struct console_font_info {
> > + __u32 flags; /* KD_FONT_INFO_FLAG_* */
>
> One space too much in front of "flags" ?
No problem. I will fix.
>
> > + __u32 min_width, min_height; /* minimal font size */
> > + __u32 max_width, max_height; /* maximum font size */
> > + __u32 reserved[5]; /* This field is reserved for future use. Must be 0. */
> > +};
> > +
> > +#define KDFONTINFO _IOR(KD_IOCTL_BASE, 0x73, struct console_font_info)
> > +
> > /* note: 0x4B00-0x4B4E all have had a value at some time;
> > don't reuse for the time being */
> > /* note: 0x4B60-0x4B6D, 0x4B70-0x4B72 used above */
>
--
Rgrds, legion
On 4/18/24 12:45, Alexey Gladkov wrote:
> On Wed, Apr 17, 2024 at 09:31:53PM +0200, Helge Deller wrote:
>> On 4/17/24 19:37, Alexey Gladkov wrote:
>>> Each driver has its own restrictions on font size. There is currently no
>>> way to understand what the requirements are. The new ioctl allows
>>> userspace to get the minimum and maximum font size values.
>>>
>>> Acked-by: Helge Deller <deller@gmx.de>
>>> Signed-off-by: Alexey Gladkov <legion@kernel.org>
>>> ---
>>> drivers/tty/vt/vt.c | 24 ++++++++++++++++++++++++
>>> drivers/tty/vt/vt_ioctl.c | 13 +++++++++++++
>>> include/linux/console.h | 3 +++
>>> include/linux/vt_kern.h | 1 +
>>> include/uapi/linux/kd.h | 14 ++++++++++++++
>>> 5 files changed, 55 insertions(+)
>>>
>>> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
>>> index 9b5b98dfc8b4..e8db0e9ea674 100644
>>> --- a/drivers/tty/vt/vt.c
>>> +++ b/drivers/tty/vt/vt.c
>>> @@ -4851,6 +4851,30 @@ int con_font_op(struct vc_data *vc, struct console_font_op *op)
>>> return -ENOSYS;
>>> }
>>>
>>> +int con_font_info(struct vc_data *vc, struct console_font_info *info)
>>> +{
>>> + int rc;
>>> +
>>> + info->min_height = 0;
>>> + info->max_height = max_font_height;
>>> +
>>> + info->min_width = 0;
>>> + info->max_width = max_font_width;
>>> +
>>> + info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
>>> +
>>> + console_lock();
>>> + if (vc->vc_mode != KD_TEXT)
>>> + rc = -EINVAL;
>>> + else if (vc->vc_sw->con_font_info)
>>> + rc = vc->vc_sw->con_font_info(vc, info);
>>> + else
>>> + rc = -ENOSYS;
>>> + console_unlock();
>>> +
>>> + return rc;
>>> +}
>>> +
>>> /*
>>> * Interface exported to selection and vcs.
>>> */
>>> diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
>>> index 4b91072f3a4e..9a2f8081f650 100644
>>> --- a/drivers/tty/vt/vt_ioctl.c
>>> +++ b/drivers/tty/vt/vt_ioctl.c
>>> @@ -479,6 +479,19 @@ static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
>>> break;
>>> }
>>>
>>> + case KDFONTINFO: {
>>> + struct console_font_info fnt_info;
>>> +
>>> + memset(&fnt_info, 0, sizeof(fnt_info));
>>> +
>>> + ret = con_font_info(vc, &fnt_info);
>>> + if (ret)
>>> + return ret;
>>> + if (copy_to_user(up, &fnt_info, sizeof(fnt_info)))
>>> + return -EFAULT;
>>> + break;
>>> + }
>>> +
>>> default:
>>> return -ENOIOCTLCMD;
>>> }
>>> diff --git a/include/linux/console.h b/include/linux/console.h
>>> index 31a8f5b85f5d..4b798322aa01 100644
>>> --- a/include/linux/console.h
>>> +++ b/include/linux/console.h
>>> @@ -21,6 +21,7 @@
>>> #include <linux/vesa.h>
>>>
>>> struct vc_data;
>>> +struct console_font_info;
>>> struct console_font_op;
>>> struct console_font;
>>> struct module;
>>> @@ -102,6 +103,8 @@ struct consw {
>>> bool (*con_switch)(struct vc_data *vc);
>>> bool (*con_blank)(struct vc_data *vc, enum vesa_blank_mode blank,
>>> bool mode_switch);
>>> + int (*con_font_info)(struct vc_data *vc,
>>> + struct console_font_info *info);
>>> int (*con_font_set)(struct vc_data *vc,
>>> const struct console_font *font,
>>> unsigned int vpitch, unsigned int flags);
>>> diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
>>> index d008c3d0a9bb..383b3a4f6113 100644
>>> --- a/include/linux/vt_kern.h
>>> +++ b/include/linux/vt_kern.h
>>> @@ -33,6 +33,7 @@ void do_blank_screen(int entering_gfx);
>>> void do_unblank_screen(int leaving_gfx);
>>> void poke_blanked_console(void);
>>> int con_font_op(struct vc_data *vc, struct console_font_op *op);
>>> +int con_font_info(struct vc_data *vc, struct console_font_info *info);
>>> int con_set_cmap(unsigned char __user *cmap);
>>> int con_get_cmap(unsigned char __user *cmap);
>>> void scrollback(struct vc_data *vc);
>>> diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
>>> index 8ddb2219a84b..68b715ad4d5c 100644
>>> --- a/include/uapi/linux/kd.h
>>> +++ b/include/uapi/linux/kd.h
>>> @@ -185,6 +185,20 @@ struct console_font {
>>>
>>> #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
>>>
>>> +/* font information */
>>> +
>>> +#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
>>> +#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
>>
>> Do we really need those bits?
>> You set a default min/max font size in con_font_info() above,
>> and all drivers can override those values.
>> So, there are always min/max sizes available.
>
> These bits are not about the minimum and maximum glyph size, but about the
> number of glyphs in the font.
>
> Maybe this is an overkill, but sticon has this check:
>
> if ((w < 6) || (h < 6) || (w > 32) || (h > 32) || (vpitch != 32)
> || (op->charcount != 256 && op->charcount != 512))
>
> [ to be honest, I don’t know why this driver doesn’t accept a glyph of
> width 4 ]
I think there was no technical limitation when I added that.
It's just that the font would be so small...
> I thought it would be worth fixing the maximum number of requirements in
> the drivers since I started adding a new ioctl.
Ok.
Helge
On Thu, Apr 25, 2024 at 12:33:28PM +0200, Helge Deller wrote:
> >>> diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
> >>> index 8ddb2219a84b..68b715ad4d5c 100644
> >>> --- a/include/uapi/linux/kd.h
> >>> +++ b/include/uapi/linux/kd.h
> >>> @@ -185,6 +185,20 @@ struct console_font {
> >>>
> >>> #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
> >>>
> >>> +/* font information */
> >>> +
> >>> +#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
> >>> +#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
> >>
> >> Do we really need those bits?
> >> You set a default min/max font size in con_font_info() above,
> >> and all drivers can override those values.
> >> So, there are always min/max sizes available.
> >
> > These bits are not about the minimum and maximum glyph size, but about the
> > number of glyphs in the font.
> >
> > Maybe this is an overkill, but sticon has this check:
> >
> > if ((w < 6) || (h < 6) || (w > 32) || (h > 32) || (vpitch != 32)
> > || (op->charcount != 256 && op->charcount != 512))
> >
> > [ to be honest, I don’t know why this driver doesn’t accept a glyph of
> > width 4 ]
>
> I think there was no technical limitation when I added that.
> It's just that the font would be so small...
If so, then I can remove min_height/min_width from the ioctl structure.
And most likely the flags can also be left empty since at the moment all
drivers support 512.
> > I thought it would be worth fixing the maximum number of requirements in
> > the drivers since I started adding a new ioctl.
>
> Ok.
>
> Helge
>
--
Rgrds, legion
On 4/25/24 13:06, Alexey Gladkov wrote:
> On Thu, Apr 25, 2024 at 12:33:28PM +0200, Helge Deller wrote:
>>>>> diff --git a/include/uapi/linux/kd.h b/include/uapi/linux/kd.h
>>>>> index 8ddb2219a84b..68b715ad4d5c 100644
>>>>> --- a/include/uapi/linux/kd.h
>>>>> +++ b/include/uapi/linux/kd.h
>>>>> @@ -185,6 +185,20 @@ struct console_font {
>>>>>
>>>>> #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
>>>>>
>>>>> +/* font information */
>>>>> +
>>>>> +#define KD_FONT_INFO_FLAG_LOW_SIZE _BITUL(0) /* 256 */
>>>>> +#define KD_FONT_INFO_FLAG_HIGH_SIZE _BITUL(1) /* 512 */
>>>>
>>>> Do we really need those bits?
>>>> You set a default min/max font size in con_font_info() above,
>>>> and all drivers can override those values.
>>>> So, there are always min/max sizes available.
>>>
>>> These bits are not about the minimum and maximum glyph size, but about the
>>> number of glyphs in the font.
>>>
>>> Maybe this is an overkill, but sticon has this check:
>>>
>>> if ((w < 6) || (h < 6) || (w > 32) || (h > 32) || (vpitch != 32)
>>> || (op->charcount != 256 && op->charcount != 512))
>>>
>>> [ to be honest, I don’t know why this driver doesn’t accept a glyph of
>>> width 4 ]
>>
>> I think there was no technical limitation when I added that.
>> It's just that the font would be so small...
>
> If so, then I can remove min_height/min_width from the ioctl structure.
> And most likely the flags can also be left empty since at the moment all
> drivers support 512.
Yes, I think that's ok.
Helge
The Console drivers has more restrictive font size limits than vt_ioctl.
This leads to errors that are difficult to handle. If a font whose size
is not supported is used, an EINVAL error will be returned, which is
also returned in case of errors in the font itself. At the moment there
is no way to understand what font sizes the current console driver
supports.
To solve this problem, we need to transfer information about the
supported font to userspace from the console driver.
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
---
drivers/video/console/newport_con.c | 21 +++++++++++++++++----
drivers/video/console/sticon.c | 25 +++++++++++++++++++++++--
drivers/video/console/vgacon.c | 21 ++++++++++++++++++++-
drivers/video/fbdev/core/fbcon.c | 16 ++++++++++++++++
4 files changed, 76 insertions(+), 7 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index a51cfc1d560e..6167f45326ac 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -33,6 +33,9 @@
#define NEWPORT_LEN 0x10000
+#define NEWPORT_MAX_FONT_WIDTH 8
+#define NEWPORT_MAX_FONT_HEIGHT 16
+
#define FONT_DATA ((unsigned char *)font_vga_8x16.data)
static unsigned char *font_data[MAX_NR_CONSOLES];
@@ -328,8 +331,8 @@ static void newport_init(struct vc_data *vc, bool init)
{
int cols, rows;
- cols = newport_xsize / 8;
- rows = newport_ysize / 16;
+ cols = newport_xsize / NEWPORT_MAX_FONT_WIDTH;
+ rows = newport_ysize / NEWPORT_MAX_FONT_HEIGHT;
vc->vc_can_do_color = 1;
if (init) {
vc->vc_cols = cols;
@@ -507,8 +510,8 @@ static int newport_set_font(int unit, const struct console_font *op,
/* ladis: when I grow up, there will be a day... and more sizes will
* be supported ;-) */
- if ((w != 8) || (h != 16) || (vpitch != 32)
- || (op->charcount != 256 && op->charcount != 512))
+ if ((w != NEWPORT_MAX_FONT_WIDTH) || (h != NEWPORT_MAX_FONT_HEIGHT) ||
+ (vpitch != 32) || (op->charcount != 256 && op->charcount != 512))
return -EINVAL;
if (!(new_data = kmalloc(FONT_EXTRA_WORDS * sizeof(int) + size,
@@ -570,6 +573,15 @@ static int newport_font_default(struct vc_data *vc, struct console_font *op,
return newport_set_def_font(vc->vc_num, op);
}
+static int newport_font_info(struct vc_data *vc, struct console_font_info *info)
+{
+ info->min_width = info->max_width = NEWPORT_MAX_FONT_WIDTH;
+ info->min_height = info->max_height = NEWPORT_MAX_FONT_HEIGHT;
+ info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
+
+ return 0;
+}
+
static int newport_font_set(struct vc_data *vc, const struct console_font *font,
unsigned int vpitch, unsigned int flags)
{
@@ -689,6 +701,7 @@ const struct consw newport_con = {
.con_scroll = newport_scroll,
.con_switch = newport_switch,
.con_blank = newport_blank,
+ .con_font_info = newport_font_info,
.con_font_set = newport_font_set,
.con_font_default = newport_font_default,
.con_save_screen = newport_save_screen
diff --git a/drivers/video/console/sticon.c b/drivers/video/console/sticon.c
index 4c7b4959a1aa..490e6b266a31 100644
--- a/drivers/video/console/sticon.c
+++ b/drivers/video/console/sticon.c
@@ -56,6 +56,11 @@
#define BLANK 0
static int vga_is_gfx;
+#define STICON_MIN_FONT_WIDTH 6
+#define STICON_MIN_FONT_HEIGHT 6
+#define STICON_MAX_FONT_WIDTH 32
+#define STICON_MAX_FONT_HEIGHT 32
+
#define STI_DEF_FONT sticon_sti->font
/* borrowed from fbcon.c */
@@ -166,8 +171,10 @@ static int sticon_set_font(struct vc_data *vc, const struct console_font *op,
struct sti_cooked_font *cooked_font;
unsigned char *data = op->data, *p;
- if ((w < 6) || (h < 6) || (w > 32) || (h > 32) || (vpitch != 32)
- || (op->charcount != 256 && op->charcount != 512))
+ if (!in_range(w, STICON_MIN_FONT_WIDTH, STICON_MAX_FONT_WIDTH) ||
+ !in_range(h, STICON_MIN_FONT_HEIGHT, STICON_MAX_FONT_HEIGHT) ||
+ (vpitch != 32) ||
+ (op->charcount != 256 && op->charcount != 512))
return -EINVAL;
pitch = ALIGN(w, 8) / 8;
bpc = pitch * h;
@@ -260,6 +267,19 @@ static int sticon_font_set(struct vc_data *vc, const struct console_font *font,
return sticon_set_font(vc, font, vpitch);
}
+static int sticon_font_info(struct vc_data *vc, struct console_font_info *info)
+{
+ info->min_width = STICON_MIN_FONT_WIDTH;
+ info->min_height = STICON_MIN_FONT_HEIGHT;
+
+ info->max_width = STICON_MAX_FONT_WIDTH;
+ info->max_height = STICON_MAX_FONT_HEIGHT;
+
+ info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
+
+ return 0;
+}
+
static void sticon_init(struct vc_data *c, bool init)
{
struct sti_struct *sti = sticon_sti;
@@ -356,6 +376,7 @@ static const struct consw sti_con = {
.con_scroll = sticon_scroll,
.con_switch = sticon_switch,
.con_blank = sticon_blank,
+ .con_font_info = sticon_font_info,
.con_font_set = sticon_font_set,
.con_font_default = sticon_font_default,
.con_build_attr = sticon_build_attr,
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 7597f04b0dc7..b5465e555fdc 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -61,6 +61,10 @@ static struct vgastate vgastate;
#define BLANK 0x0020
#define VGA_FONTWIDTH 8 /* VGA does not support fontwidths != 8 */
+
+#define VGACON_MAX_FONT_WIDTH VGA_FONTWIDTH
+#define VGACON_MAX_FONT_HEIGHT 32
+
/*
* Interface used by the world
*/
@@ -1039,6 +1043,19 @@ static int vgacon_adjust_height(struct vc_data *vc, unsigned fontheight)
return 0;
}
+static int vgacon_font_info(struct vc_data *vc, struct console_font_info *info)
+{
+ info->min_width = VGACON_MAX_FONT_WIDTH;
+ info->min_height = 0;
+
+ info->max_width = VGACON_MAX_FONT_WIDTH;
+ info->max_height = VGACON_MAX_FONT_HEIGHT;
+
+ info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
+
+ return 0;
+}
+
static int vgacon_font_set(struct vc_data *c, const struct console_font *font,
unsigned int vpitch, unsigned int flags)
{
@@ -1048,7 +1065,8 @@ static int vgacon_font_set(struct vc_data *c, const struct console_font *font,
if (vga_video_type < VIDEO_TYPE_EGAM)
return -EINVAL;
- if (font->width != VGA_FONTWIDTH || font->height > 32 || vpitch != 32 ||
+ if (font->width != VGACON_MAX_FONT_WIDTH ||
+ font->height > VGACON_MAX_FONT_HEIGHT || vpitch != 32 ||
(charcount != 256 && charcount != 512))
return -EINVAL;
@@ -1201,6 +1219,7 @@ const struct consw vga_con = {
.con_scroll = vgacon_scroll,
.con_switch = vgacon_switch,
.con_blank = vgacon_blank,
+ .con_font_info = vgacon_font_info,
.con_font_set = vgacon_font_set,
.con_font_get = vgacon_font_get,
.con_resize = vgacon_resize,
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index fcabc668e9fb..b54031da49fd 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2452,6 +2452,21 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
return ret;
}
+
+static int fbcon_font_info(struct vc_data *vc, struct console_font_info *info)
+{
+ info->min_width = 0;
+ info->min_height = 0;
+
+ info->max_width = FB_MAX_BLIT_WIDTH;
+ info->max_height = FB_MAX_BLIT_HEIGHT;
+
+ info->flags = KD_FONT_INFO_FLAG_LOW_SIZE | KD_FONT_INFO_FLAG_HIGH_SIZE;
+
+ return 0;
+}
+
+
/*
* User asked to set font; we are guaranteed that charcount does not exceed 512
* but lets not assume that, since charcount of 512 is small for unicode support.
@@ -3127,6 +3142,7 @@ static const struct consw fb_con = {
.con_scroll = fbcon_scroll,
.con_switch = fbcon_switch,
.con_blank = fbcon_blank,
+ .con_font_info = fbcon_font_info,
.con_font_set = fbcon_set_font,
.con_font_get = fbcon_get_font,
.con_font_default = fbcon_set_def_font,
--
2.44.0© 2016 - 2026 Red Hat, Inc.