linux-kernel - Re: upcoming kerneloops.org item: get_page_from

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:	Wed, 24 Jun 2009 09:46:22 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Arjan van de Ven <arjan@...radead.org>
Cc:	linux-kernel@...r.kernel.org, torvalds@...ux-foundation.org
Subject: Re: upcoming kerneloops.org item: get_page_from_freelist

On Wed, 24 Jun 2009 08:07:53 -0700 Arjan van de Ven <arjan@...radead.org> wrote:

> Hi,
> 
> a new item is coming up fast in the kerneloops.org stats, and it's new
> in 2.6.31-rc;
> 
> http://www.kerneloops.org/searchweek.php?search=get_page_from_freelist
> 
> it's this warning in mm/page_alloc.c:
> 
>                         * __GFP_NOFAIL is not to be used in new code.
>                          *
>                          * All __GFP_NOFAIL callers should be fixed so that they
>                          * properly detect and handle allocation failures.
>                          *
>                          * We most definitely don't want callers attempting to
>                          * allocate greater than single-page units with
>                          * __GFP_NOFAIL.
>                          */
>                         WARN_ON_ONCE(order > 0);
>   
> 
> typical backtraces look like
> 
> get_page_from_freelist
> __alloc_pages_nodemask
> alloc_pages_current
> alloc_slab_page
> new_slab
> __slab_alloc
> kmem_cache_alloc_notrace
> start_this_handle
> jbd2_journal_start
> 
> and
> 
> get_page_from_freelist
> __alloc_pages_nodemask
> alloc_pages_current
> alloc_slab_page
> new_slab
> __slab_alloc
> kmem_cache_alloc_notrace
> start_this_handle
> journal_start
> ext3_journal_start_sb
> ext3_journal_start
> ext3_dirty_inode
> 
> but there are some other ones as well at the url above.
> 
> 
> git blame shows that 
> 
> commit dab48dab37d2770824420d1e01730a107fade1aa
> Author: Andrew Morton <akpm@...ux-foundation.org>
> Date:   Tue Jun 16 15:32:37 2009 -0700
> 
> introduced this WARN_ON.....

Well yes.  Using GFP_NOFAIL on a higher-order allocation is bad.  This
patch is there to find, name, shame, blame and hopefully fix callers.

A fix for cxgb3 is in the works.  slub's design is a big problem.

But we'll probably have to revert it for 2.6.31 :(
--
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/