Bug #931

FXRSTR: illegal FP MXCSR ffff002f didinit = 0

Added by eric.j.christeson about 6 years ago. Updated about 6 years ago.

Status:ClosedStart date:
Priority:NormalDue date:
Assignee:-% Done:

0%

Category:-
Target version:-

Description

Still no good. I deleted /usr/obj and updated to latest -HEAD this
morning, recompiled/installed both world and GENERIC kernel. Once
again, I took out the SIGFPE so I could run things. I booted single
user and mounted my fs. Both fsck and mount caused the error. Idle
in single-user the error doesn't occur. Other commands do too, but
some don't or sometimes do. 'ls' is one example. By itself, it does
not produce the error, but ls -l does. ls -R does not but ls -lR
does. dmesg by itself doesn't, but dmesg with an invalid option
(dmesg -v) does. Hopefully this is helpful.

Eric

History

#1 Updated by corecode about 6 years ago

What if you use kernel + world from a live cd? What if you only use the
kernel or only use the world from the live cd?

cheers
simon

#2 Updated by eric.j.christeson about 6 years ago

On Jan 25, 2008 3:12 PM, Simon 'corecode' Schubert
<> wrote:
> ejc wrote:
> > Still no good. I deleted /usr/obj and updated to latest -HEAD this
> > morning, recompiled/installed both world and GENERIC kernel.
>
> What if you use kernel + world from a live cd? What if you only use the
> kernel or only use the world from the live cd?

I have no problems with a kernel from live cd. That's how I fixed it
in the first place.
I booted from a live cd and copied the kernel to my hard drive. Then
I could reboot with that kernel and rebuild my world/kernel.
This would seem to indicate it's a kernel problem, not app/library, no?

eric

#3 Updated by corecode about 6 years ago

definitely.

are you *sure* you have fresh kernel sources? I couldn't explain else.

cheers
simon

#4 Updated by eric.j.christeson about 6 years ago

On Jan 25, 2008 5:33 PM, Simon 'corecode' Schubert
<> wrote:
>
> Simon 'corecode' Schubert <> added the comment:
>
> definitely.
>
> are you *sure* you have fresh kernel sources? I couldn't explain else.

I did a cvsup using the cvs-supfile to and empty directory, removed
/usr/src and /usr/obj/usr,
and did a cvs co from the new local cvs directory. The only change I
made to the code was
commenting out the FPE which would cause a panic. I'll put that back
in so I can debug, though
it wasn't very helpful last time. I don't see how that could bring in
any old stuff, unless the build
process is messed up.

Eric

#5 Updated by dillon about 6 years ago

:..
:commenting out the FPE which would cause a panic. I'll put that back
:in so I can debug, though
:it wasn't very helpful last time. I don't see how that could bring in
:any old stuff, unless the build
:process is messed up.
:
:Eric

Maybe you did something to your /etc/make.conf that is blowing up the
build. High bits of ffff can only happen when userland overwrites
the signal stack fp save area with a fnsave instruction, and only the
old threaded libc_r did that.

-Matt
Matthew Dillon
<>

#6 Updated by eric.j.christeson about 6 years ago

I resync'd my cvs repo and rebuilt world and kernel with the /etc/make.conf from
a recent snapshot image. Same problem. This morning I downloaded
2CSNAP-20080128-2330-Devel.iso Booting from it results in the same error. This
can't be a problem with my build env if a snapshot CD exhibits the error.

Eric

#7 Updated by dillon about 6 years ago

:I resync'd my cvs repo and rebuilt world and kernel with the /etc/make.conf from
:a recent snapshot image. Same problem. This morning I downloaded
:2CSNAP-20080128-2330-Devel.iso Booting from it results in the same error. This
:can't be a problem with my build env if a snapshot CD exhibits the error.
:
:Eric

Hmm. Maybe there's a bug with the OS related to machines without SSE
support. Could you post the CPU lines from your dmesg ? For example,

CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ (2009.79-MHz 686-class CPU)
Origin = "AuthenticAMD" Id = 0x20f32 Stepping = 2
Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT>
Features2=0x1<SSE3>
Hyperthreading: 2 logical CPUs
AMD Features=0xe0500000<<b20>,AMIE,<b29>,DSP,3DNow!>
AMD: Rerouting HyperTransport EXTINT/NMI to APIC

-Matt
Matthew Dillon
<>

#8 Updated by dillon about 6 years ago

Well well well. I do believe I see a bug in the code.

The kernel error message it is spouting it is not conditionalized
on the existance of SSE.

I also see a bug in the vkernel ... it isn't supported SSE extensions
like it should.

-Matt
Matthew Dillon
<>

#9 Updated by dillon about 6 years ago

Ok, I believe the problem has now been fixed on HEAD. It was a bug
in the kernel when running on machines without SSE support.

Can you get the latest HEAD or are you in a situation now where you
can't compile anything at all due to the bug?

-Matt
Matthew Dillon
<>

#10 Updated by eric.j.christeson about 6 years ago

Yes, I've got a couple of spare kernels on the box so I'll reboot and update.

Here's my CPU lines from dmesg FWIW:

CPU: AMD Athlon(tm) Processor (995.56-MHz 686-class CPU)
Origin = "AuthenticAMD" Id = 0x642 Stepping = 2
Features=0x183f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR>
AMD Features=0xc0440000<RSVD,AMIE,DSP,3DNow!>

Thanks,
Eric

#11 Updated by eric.j.christeson about 6 years ago

That fixed the problem. Thanks

Eric

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