linux-kernel - Re: [PATCH V2] mips: kernel: fix detect_memory

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]

Date: Tue, 25 Jun 2024 09:46:34 +0200
From: Thomas Bogendoerfer <tsbogend@...ha.franken.de>
To: Shiji Yang <yangshiji66@...look.com>
Cc: linux-mips@...r.kernel.org, Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Javier Martinez Canillas <javierm@...hat.com>,
	Khalid Aziz <khalid@...ehiking.org>, Baoquan He <bhe@...hat.com>,
	Jiaxun Yang <jiaxun.yang@...goat.com>,
	Serge Semin <fancer.lancer@...il.com>, linux-kernel@...r.kernel.org,
	Mieczyslaw Nalewaj <namiltd@...oo.com>
Subject: Re: [PATCH V2] mips: kernel: fix detect_memory_region() function

On Tue, Jun 25, 2024 at 09:44:44AM +0800, Shiji Yang wrote:
>  	for (size = sz_min; size < sz_max; size <<= 1) {
> -		if (!memcmp(dm, dm + size, sizeof(detect_magic)))
> -			break;
> +		__raw_writel(MIPS_MEM_TEST_PATTERN, dm);
> +		if (__raw_readl(dm) == __raw_readl(dm + size)) {
> +			__raw_writel(~MIPS_MEM_TEST_PATTERN, dm);
> +			if (__raw_readl(dm) == __raw_readl(dm + size))
> +				break;
> +		}

you are testing memory, so just use pointers. __raw_readl and __raw_writel
are for io regions (which should be ioremppaed before usage).

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]