linux-kernel - Re: [PATCH v2 1/2] printk: Introduce FORCE

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: <ZyzbO5StIhsLv_EP@pathway.suse.cz>
Date: Thu, 7 Nov 2024 16:22:35 +0100
From: Petr Mladek <pmladek@...e.com>
To: Marcos Paulo de Souza <mpdesouza@...e.com>
Cc: Steven Rostedt <rostedt@...dmis.org>,
	John Ogness <john.ogness@...utronix.de>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jirislaby@...nel.org>, linux-kernel@...r.kernel.org,
	linux-serial@...r.kernel.org
Subject: Re: [PATCH v2 1/2] printk: Introduce FORCE_CON flag

On Tue 2024-11-05 16:45:08, Marcos Paulo de Souza wrote:
> Introduce FORCE_CON flag to printk. The new flag will make it possible to
> create a context where printk messages will never be suppressed.
> 
> This mechanism will be used in the next patch to create a force_con
> context on sysrq handling, removing an existing workaround on the
> loglevel global variable. The workaround existed to make sure that sysrq
> header messages were sent to all consoles, but this doesn't work with
> deferred messages because the loglevel might be restored to its original
> value before a console flushes the messages.
> 
> Signed-off-by: Marcos Paulo de Souza <mpdesouza@...e.com>

Looks good:

Reviewed-by: Petr Mladek <pmladek@...e.com>

Just a nit below.

> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -1319,11 +1319,11 @@ static void boot_delay_msec(int level)
>  {
>  	unsigned long long k;
>  	unsigned long timeout;
> +	bool suppress = !is_printk_force_console() &&
> +			suppress_message_printing(level);
>  
> -	if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING)
> -		|| suppress_message_printing(level)) {
> +	if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING) || suppress)
>  		return;

These spaghetti conditions are hard to follow. I would personally
prefer:

	if ((boot_delay == 0)
		return;

	if (system_state >= SYSTEM_RUNNING)
		return;

	if (suppress_message_printing(level) &&	!is_printk_force_console())
		return;

But I do not resist on it.


Best Regards,
Petr