Re: [RESEND PATCH v3 1/2] VT: Add KDFONTINFO ioctl

From: Jiri Slaby
Date: Wed Apr 03 2024 - 01:28:09 EST


On 02. 04. 24, 15:19, Alexey Gladkov wrote:
--- a/include/uapi/linux/kd.h
+++ b/include/uapi/linux/kd.h
..
+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.

I thought about it, but I thought it would be overengineering.

It would not. UAPI structs are set in stone once released.

And in this case, it's likely you would want to know more info about fonts in the future.

Can you suggest how best to do this?

Given you have flags in there already (to state that the structure contains more), just add an array of u32 reserved[] space. 3 or 5, I would say (to align the struct to 64bit).

thanks,
--
js
suse labs