PROBLEM: __buggy_fxsr_alignment error 2.4.1 and 2.4.2

PROBLEM: __buggy_fxsr_alignment error 2.4.1 and 2.4.2

[Kurt V. Hindenburg]

asm-i386:
init/main.o(.text.init+0x63): undefined reference to `__buggy_fxsr_alignment'

I don't recall this error in 2.4.0, but it is present in 2.4.1 and was not
fixed in 2.4.2.

 >sh scripts/ver_linux 
-- Versions installed: (if some fields are empty or look
-- unusual then possibly you have very old versions)
Linux amdk7 2.4.1 #3 Sat Feb 3 18:50:44 EST 2001 i686 unknown
Kernel modules         2.4.1
Gnu C                  pgcc-2.95.2.1
Gnu Make               3.79.1
Binutils               2.10.1
Linux C Library        2.1.3
Dynamic linker         ldd: version 1.9.9
Procps                 2.0.7
Mount                  2.10q
Net-tools              1.57
Console-tools          0.2.3
Sh-utils               2.0
Modules Loaded         ppp_deflate bsd_comp ppp_async

Fix: Comment out line 217 in include/asm-i386/bugs.h
/*    __buggy_fxsr_alignment(); */

It compiles after this change.

Re: PROBLEM: __buggy_fxsr_alignment error 2.4.1 and 2.4.2

[Doug Ledford]

"Kurt V. Hindenburg" wrote:
> 
> asm-i386:
> init/main.o(.text.init+0x63): undefined reference to `__buggy_fxsr_alignment'
> 
> I don't recall this error in 2.4.0, but it is present in 2.4.1 and was not
> fixed in 2.4.2.
> 
>  >sh scripts/ver_linux
> -- Versions installed: (if some fields are empty or look
> -- unusual then possibly you have very old versions)
> Linux amdk7 2.4.1 #3 Sat Feb 3 18:50:44 EST 2001 i686 unknown
> Kernel modules         2.4.1
> Gnu C                  pgcc-2.95.2.1
> Gnu Make               3.79.1
> Binutils               2.10.1
> Linux C Library        2.1.3
> Dynamic linker         ldd: version 1.9.9
> Procps                 2.0.7
> Mount                  2.10q
> Net-tools              1.57
> Console-tools          0.2.3
> Sh-utils               2.0
> Modules Loaded         ppp_deflate bsd_comp ppp_async
> 
> Fix: Comment out line 217 in include/asm-i386/bugs.h
> /*    __buggy_fxsr_alignment(); */
> 
> It compiles after this change.

That "bug" is there for a reason.  Get a real compiler, then it will work OK. 
Compile that kernel with your compiler, your fix in place, and then try to run
it on a PIII or later CPU and it will Oops all over the place.  Run it on any
CPU that supports FXSAVE and it will likely blow chunks (all the Intel CPUs
will, but I don't know for sure about the AMD CPUs that support FXSAVE).

-- 

 Doug Ledford <dledford@redhat.com>  http://people.redhat.com/dledford
      Please check my web site for aic7xxx updates/answers before
                      e-mailing me about problems

Re: PROBLEM: __buggy_fxsr_alignment error 2.4.1 and 2.4.2

[J . A . Magallon]

On 02.23 Kurt V. Hindenburg wrote:
> asm-i386:
> init/main.o(.text.init+0x63): undefined reference to `__buggy_fxsr_alignment'
> 
> I don't recall this error in 2.4.0, but it is present in 2.4.1 and was not
> fixed in 2.4.2.
> 
>  >sh scripts/ver_linux 
> -- Versions installed: (if some fields are empty or look
> -- unusual then possibly you have very old versions)
> Linux amdk7 2.4.1 #3 Sat Feb 3 18:50:44 EST 2001 i686 unknown
> Kernel modules         2.4.1
> Gnu C                  pgcc-2.95.2.1

That is not a bug. That is there intentionally to catch broken compilers
like yours.

-- 
J.A. Magallon                                                      $> cd pub
mailto:jamagallon@able.es                                          $> more beer

Linux werewolf 2.4.2-ac1 #2 SMP Fri Feb 23 02:34:42 CET 2001 i686

Re: PROBLEM: __buggy_fxsr_alignment error 2.4.1 and 2.4.2

[Marc D. Williams]

In fa.linux.kernel, you wrote:
>asm-i386:
>init/main.o(.text.init+0x63): undefined reference to `__buggy_fxsr_alignment'
>
>I don't recall this error in 2.4.0, but it is present in 2.4.1 and was not
>fixed in 2.4.2.
>
>Gnu C                  pgcc-2.95.2.1
>
>Fix: Comment out line 217 in include/asm-i386/bugs.h
>/*    __buggy_fxsr_alignment(); */
>
>It compiles after this change.
>
[I'm not on the mailing list but do read it via usenet, can't post though]

As pointed out by Doug Ledford your kernel will surely oops when you
reboot. I have an Athlon and use AthlonGCC (pgcc-2.95.3 with patches).
I didn't want to go back to regular gcc but I fixed my problem anyway
and so far kernels from 2.4.1 to 2.4.2 run just fine.

The first fix was uncommenting in bugs.h as you did.
Not sure if it was proper but I did the whole section. :-)
I may retry it with just the last part commented out.

    	/* if (offsetof(struct task_struct, thread.i387.fxsave) & 15) {
                extern void __buggy_fxsr_alignment(void);
                __buggy_fxsr_alignment();
        } */
	
The problem is this fxsr thing. I found the following in 
arch/i386/kernel/setup.c (line 150):

static int disable_x86_fxsr __initdata = 0;

I changed the 0 to 1 (to disable x86_fxsr) and so far the kernels
have given me no problems.

Since apparently we're using buggy compilers no doubt this workaround
may be frowned upon. At least for me it works.

-- 
>>ANIME SENSHI<<

Marc D. Williams
marcdw@charter.net
http://www.oldskool.org/~tvdog/ -- DOS Internet & Tandy 1000
http://www.geocities.com/SiliconValley/Platform/8269/ -- Win3.x Makeover