Messages in this thread | | | Date | Fri, 30 Jan 2004 23:24:15 +0800 | From | R Chan <> | Subject | Re: [CRYPTO]: Miscompiling sha256.c by gcc 3.2.3 and arch pentium3,4 |
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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 space. (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 right.
For the actual files please check bug #114610 in https://bugzilla.redhat.com. https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=114610 - the bug report includes sha256.c, tcrypt.c, and types.h necessary to demonstrate 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, >-dsp > >-----Original Message----- >From: linux-kernel-owner@vger.kernel.org >[mailto:linux-kernel-owner@vger.kernel.org]On Behalf Of James Morris >Sent: Friday, January 30, 2004 9:40 AM >To: R CHAN >Cc: linux-kernel@vger.kernel.org; David S. Miller >Subject: Re: [CRYPTO]: Miscompiling sha256.c by gcc 3.2.3 and arch >pentium3,4 > > >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 ><jmorris@redhat.com> > > >- >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html >Please read the FAQ at http://www.tux.org/lkml/ > > > > > >
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