linux-kernel - Re: [PATCH v4 5/8] vmcore: copy ELF note segments in the 2nd kernel per page vmcore objects

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, 29 Apr 2013 15:36:12 -0400
From:	Vivek Goyal <vgoyal@...hat.com>
To:	HATAYAMA Daisuke <d.hatayama@...fujitsu.com>
Cc:	ebiederm@...ssion.com, akpm@...ux-foundation.org, cpw@....com,
	kumagai-atsushi@....nes.nec.co.jp, lisa.mitchell@...com,
	kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
	zhangyanfei@...fujitsu.com, jingbai.ma@...com
Subject: Re: [PATCH v4 5/8] vmcore: copy ELF note segments in the 2nd kernel
 per page vmcore objects

On Sat, Apr 13, 2013 at 09:21:33AM +0900, HATAYAMA Daisuke wrote:

[..]
> ELF notes are per-cpu, so total size of ELF note segments increases
> according to the number of CPUs. The current maximum number of CPUs on
> x86_64 is 5192, and there's already system with 4192 CPUs in SGI,
> where total size amounts to 1MB. This can be larger in the neare
> futrue or possibly even now on another architecture. Thus, to avoid
> the case where memory allocation for large block fails, we allocate
> vmcore objects per pages.

IIRC, eric had suggested using vmalloc() and remap_vmalloc_range(). What's
wrong with that? That should keep your vc_list relatively smaller.

Thanks
Vivek
--
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/