[lkml]   [2004]   [Jan]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [CRYPTO]: Miscompiling sha256.c by gcc 3.2.3 and arch pentium3,4
I've narrowed the problem - it seems to be a specific optimisation bug with
gcc-3.2.3-24 that comes with RedHat 3ES. The problem is not kernel
related (sorry!)
as the guts of the file exhibits the same problem when compiled in user
(All the non-sha256 test vectors in tcrypt.ko pass BTW.)

The older gcc32 that comes with Fedora Cora 1 and the gcc33 there get it

For the actual files please check bug #114610 in
- the bug report includes sha256.c, tcrypt.c, and types.h necessary to
the problem in user space.

Dave Paris wrote:

>Has this been demonstrated on *any* system/arch using GCC 3.2.3 (or other
>3.2 series) or is it limited in scope to the description below? Does it
>seem to do this with other implementations (other than sha256.c) or other
>kernels? Just trying to get an idea if this is a complier optimization bug
>or something much more limited in scope.
>My personal lab is currently being unboxed and I won't be able to run my own
>tests for another week or so. (apologies in advance)
>In any case, this is *extremely* serious from a number of angles.
>Kind Regards,
>-----Original Message-----
>[]On Behalf Of James Morris
>Sent: Friday, January 30, 2004 9:40 AM
>Cc:; David S. Miller
>Subject: Re: [CRYPTO]: Miscompiling sha256.c by gcc 3.2.3 and arch
>On Fri, 30 Jan 2004, R CHAN wrote:
>>2.6.2-rc2 sha256.c is miscompiled with gcc 3.2.3.
>>(User space is RedHat 3ES.)
>>Just an observation:
>>gcc 3.2.3 is miscompiling sha256.c when using
>>-O2 -march=pentium3
>>or pentium4.
>>gcc 3.3.x is ok, or the problem disappears
>>if I use arch=i686 or reduce the optimisation level to -O2.
>>Sympthoms are all the sha256 test vectors fail.
>>If I extract the guts of the file to compile in user space
>>the same problem occurs.
>Have you noticed if this happens for any of the other crypto algorithms?
>- James
>James Morris
>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>the body of a message to
>More majordomo info at
>Please read the FAQ at

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 14:00    [W:0.053 / U:0.332 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site