linux-kernel - Re: [RFC] Sectionized printk data

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: <Pine.LNX.4.64.0802100116560.6917@fbirervta.pbzchgretzou.qr>
Date:	Sun, 10 Feb 2008 01:18:18 +0100 (CET)
From:	Jan Engelhardt <jengelh@...putergmbh.de>
To:	Arnaldo Carvalho de Melo <acme@...hat.com>
cc:	Sam Ravnborg <sam@...nborg.org>,
	Johannes Weiner <hannes@...urebad.de>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [RFC] Sectionized printk data


On Feb 9 2008 21:54, Arnaldo Carvalho de Melo wrote:
>> To drop strings that are only shown once anyway, such as:
>> 
>> static int __init ebtables_init(void)
>> {
>>         int ret;
>> 
>>         mutex_lock(&ebt_mutex);
>>         list_add(&ebt_standard_target.list, &ebt_targets);
>>         mutex_unlock(&ebt_mutex);
>>         if ((ret = nf_register_sockopt(&ebt_sockopts)) < 0)
>>                 return ret;
>> 
>> ->      printk(KERN_INFO "Ebtables v2.0 registered\n");
>>         return 0;
>> }
>> 
>> >If you say "saving memory" then please let us know with specific examples
>> >in what area these savings will really pay off.
>
>[...]
>With a tool like this the advantage is that no source code has to be
>changed, strings in __init functions are automagically moved to
>.init.data, the disadvantage is that not all strings can be moved to
>.init.data as there were (are?) subsystems that keep pointers to the
>string passed and another tool would be involved in the build process.

There is one corner case to consider:


	static char abc[] = "foo";

	int __init init_module(void)
	{
		printk(abc);
	}

I am not sure if gcc/ld is smart enough to figure out that abc is
only ever used from within an __init function and that it could hence
be moved to __initdata.
--
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/