From: Jiri Slaby <jirislaby@kernel.org>
To: Alexey Gladkov <legion@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
kbd@lists.linux.dev, linux-api@vger.kernel.org,
linux-fbdev@vger.kernel.org, linux-serial@vger.kernel.org,
Helge Deller <deller@gmx.de>
Subject: Re: [RESEND PATCH v3 1/2] VT: Add KDFONTINFO ioctl
Date: Tue, 2 Apr 2024 13:02:20 +0200 [thread overview]
Message-ID: <74ca50e0-61b1-4d4c-85dd-a5d920548c04@kernel.org> (raw)
In-Reply-To: <ed056326540f04b72c97a276fbcc316e1b2f6371.1712053848.git.legion@kernel.org>
Hi,
On 02. 04. 24, 12:32, 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 minmum and maximum font size values.
minimum
> 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 | 2 ++
> include/linux/vt_kern.h | 1 +
> include/uapi/linux/kd.h | 13 ++++++++++++-
> 5 files changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index 156efda7c80d..8c2a3d98b5ec 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -4680,6 +4680,30 @@ 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 = -EINVAL;
This initialization appears to be unneeded.
> +
> + 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 8c685b501404..b3b4e4b69366 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;
> +
> + if (copy_from_user(&fnt_info, up, sizeof(fnt_info)))
> + return -EFAULT;
Who uses the copied values?
> + ret = con_font_info(vc, &fnt_info);
> + if (ret)
> + return ret;
> + if (copy_to_user(up, &fnt_info, sizeof(fnt_info)))
We should do the preferred sizeof(*up) here...
> + return -EFAULT;
> + break;
> + }
> +
> default:
> return -ENOIOCTLCMD;
> }
...
> --- a/include/uapi/linux/kd.h
> +++ b/include/uapi/linux/kd.h
> @@ -183,8 +183,19 @@ struct console_font {
>
> #define KD_FONT_FLAG_DONT_RECALC 1 /* Don't recalculate hw charcell size [compat] */
>
> +#define KDFONTINFO 0x4B73 /* font information */
Why not properly define the number using IOC() et al.? K (that 0x4b) is
even reserved for kd.h.
> +#define KD_FONT_INFO_FLAG_LOW_SIZE (1U << 0) /* 256 */
> +#define KD_FONT_INFO_FLAG_HIGH_SIZE (1U << 1) /* 512 */
_BITUL()
> +struct console_font_info {
> + unsigned int min_width, min_height; /* minimal font size */
> + unsigned int max_width, max_height; /* maximum font size */
> + unsigned int flags; /* KD_FONT_INFO_FLAG_* */
This does not look like a well-defined™ and extendable uapi structure.
While it won't change anything here, still use fixed-length __u32.
And you should perhaps add some reserved fields. Do not repeat the same
mistakes as your predecessors with the current kd uapi.
> +};
thanks,
--
js
suse labs
next prev parent reply other threads:[~2024-04-02 11:02 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1708960303.git.legion@kernel.org>
2024-03-12 14:23 ` [PATCH v3 0/2] VT: Add ability to get font requirements legion
2024-03-12 14:23 ` [PATCH v3 1/2] VT: Add KDFONTINFO ioctl legion
2024-03-15 9:15 ` Helge Deller
2024-03-12 14:23 ` [PATCH v3 2/2] VT: Allow to get max font width and height legion
2024-03-13 17:40 ` Oleg Bulatov
2024-04-02 11:09 ` Jiri Slaby
2024-03-15 9:16 ` Helge Deller
2024-04-02 10:32 ` [RESEND PATCH v3 0/2] VT: Add ability to get font requirements Alexey Gladkov
2024-04-02 10:32 ` [RESEND PATCH v3 1/2] VT: Add KDFONTINFO ioctl Alexey Gladkov
2024-04-02 11:02 ` Jiri Slaby [this message]
2024-04-02 13:19 ` Alexey Gladkov
2024-04-03 5:27 ` Jiri Slaby
2024-04-10 16:29 ` Alexey Gladkov
2024-04-10 17:11 ` Greg Kroah-Hartman
2024-04-02 17:50 ` [PATCH v4 0/3] VT: Add ability to get font requirements Alexey Gladkov
2024-04-02 17:50 ` [PATCH v4 1/3] VT: Use macros to define ioctls Alexey Gladkov
2024-04-02 17:50 ` [PATCH v4 2/3] VT: Add KDFONTINFO ioctl Alexey Gladkov
2024-04-03 4:55 ` Greg Kroah-Hartman
2024-04-03 5:05 ` Jiri Slaby
2024-04-10 16:36 ` Alexey Gladkov
2024-04-11 3:53 ` Jiri Slaby
2024-04-02 17:50 ` [PATCH v4 3/3] VT: Allow to get max font width and height Alexey Gladkov
2024-04-17 17:37 ` [PATCH v5 0/3] VT: Add ability to get font requirements Alexey Gladkov
2024-04-17 17:37 ` [PATCH v5 1/3] VT: Use macros to define ioctls Alexey Gladkov
2024-04-18 6:18 ` Greg Kroah-Hartman
2024-05-29 7:29 ` Jiri Slaby
2024-05-29 7:44 ` Arnd Bergmann
2024-05-29 8:44 ` Al Viro
2024-04-17 17:37 ` [PATCH v5 2/3] VT: Add KDFONTINFO ioctl Alexey Gladkov
2024-04-17 19:31 ` Helge Deller
2024-04-18 10:45 ` Alexey Gladkov
2024-04-25 10:33 ` Helge Deller
2024-04-25 11:06 ` Alexey Gladkov
2024-04-25 11:35 ` Helge Deller
2024-04-18 6:18 ` Greg Kroah-Hartman
2024-04-18 10:27 ` Alexey Gladkov
2024-04-17 17:37 ` [PATCH v5 3/3] VT: Allow to get max font width and height Alexey Gladkov
2024-04-02 10:32 ` [RESEND PATCH v3 2/2] " Alexey Gladkov
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