linux-kernel - Re: [PATCH][RESEND] x86: Do not write to VGA memory space if CONFIG_VGA

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4BBA51F3.7070808@zytor.com>
Date:	Mon, 05 Apr 2010 14:11:15 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	guenter.roeck@...csson.com
CC:	linux-kernel@...r.kernel.org, penberg@...helsinki.fi,
	mingo@...hat.com, x86@...nel.org
Subject: Re: [PATCH][RESEND] x86: Do not write to VGA memory space if CONFIG_VGA_CONSOLE
 is undefined

On 04/05/2010 02:04 PM, Guenter Roeck wrote:
> 
> Would you accept a minimized patch like this ?
> 
>  /* Direct interface for emergencies */
> +#ifdef CONFIG_VGA_CONSOLE
>  static struct console *early_console = &early_vga_console;
> +#else
> +static struct console *early_console = &early_serial_console;
> +#endif
>  static int __initdata early_console_initialized;
> 
> This would prevent the problem while minimizing changes, and at the same
> time permit early messages to be written to the serial console.
> 

I'm unhappy about it, because *those early messages shouldn't exist in
the first place*.  It seems to be an indication that we're invoking
setup_early_printk() too late.  The whole playing around with max_xpos
and max_ypos instead of using boot_params.screen_info directly is
particularly bleacherous.

I would at least like to see if the improper invocation of
early_printk() can be avoided.

	-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/