linux-kernel - Re: [PATCH] Uninline kcalloc()

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: <5480.1190620520@turing-police.cc.vt.edu>
Date:	Mon, 24 Sep 2007 03:55:20 -0400
From:	Valdis.Kletnieks@...edu
To:	Alexey Dobriyan <adobriyan@...il.com>
Cc:	akpm@...l.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Uninline kcalloc()

On Mon, 24 Sep 2007 11:44:35 +0400, Alexey Dobriyan said:
> On 9/24/07, Valdis.Kletnieks@...edu <Valdis.Kletnieks@...edu> wrote:
> > On Sun, 23 Sep 2007 00:03:49 +0400, Alexey Dobriyan said:
> >
> > > -static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
> > > -{
> > > -	if (n != 0 && size > ULONG_MAX / n)
> > > -		return NULL;
> > > -	return __kmalloc(n * size, flags | __GFP_ZERO);
> > > -}
> > > +void *kcalloc(size_t n, size_t size, gfp_t flags);
> >
> > NAK.
> >
> > This busticates some pretty subtle code in mm/slab.c that uses
> > uses __builtin_return_address() for debugging
> 
> Interesting. Here is output from kernel with patch applied and leak
> plugged into proc_dointvec() (I checked twice):
> 
>         $ grep kcalloc /proc/slab_allocators

Right.  That was the whole *point* of the patch to inline kcalloc - otherwise
you ended up with zillions of entries for kcalloc that didn't tell you where
they came from.

>         $ grep proc_dointvec /proc/slab_allocators
>         size-64: 19 proc_dointvec+0x48/0xa0

A lot more useful, no? ;)
<confoozled> I'm failing to see where proc_dointvec() ends up calling kcalloc?
So I'm not sure what that's

Content of type "application/pgp-signature" skipped