linux-kernel - Re: [RFC] x86, mm: start mmap allocation for libs from low addresses

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:	Mon, 22 Aug 2011 13:17:47 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Vasiliy Kulikov <segoon@...nwall.com>
CC:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	kernel-hardening@...ts.openwall.com,
	Peter Zijlstra <peterz@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>, x86@...nel.org,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [RFC] x86, mm: start mmap allocation for libs from low addresses

On 08/22/2011 01:14 PM, Vasiliy Kulikov wrote:
> 
>> Code-wise:
>>
>> The code is horrific; it is full of open-coded magic numbers;
> 
> Agreed, the magic needs macro definition and comments.
> 
>> it also
>> puts a function called arch_get_unmapped_exec_area() in a generic file,
>> which could best be described as "WTF" -- the arch_ prefix we use
>> specifically to denote a per-architecture hook function.
> 
> Agreed.  But I'd want to leave it in mm/mmap.c as it's likely be used by
> other archs - the changes are bitness specific, not arch specific.  Is
> it OK if I do this?
> 
> #ifndef HAVE_ARCH_UNMAPPED_EXEC_AREA
> void *arch_get_unmapped_exec_area(...)
> {
>     ...
> }
> #endif
> 

Only if this is really an architecture-specific function overridden in
specific architectures.  I'm not so sure that applies here.
Furthermore, I'm not even all that sure what this function *does*.

	-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/