Re: [PATCH] x86 page fault handler not interrupt safe

Jesper Juhl (juhl@eisenstein.dk)
Tue, 08 May 2001 00:52:32 +0200


Linus Torvalds wrote:

>
> In particular, does anybody have a buggy Pentium to test with the F0 0F
> lock-up bug? It _should_ be caught with the error-code test (it's a
> protection fault, not a non-present fault and thus the F0 0F case never
> enters the vmalloc path), but it's been several years since the thing..
>
> If anybody has such a beast, please try this kernel patch _and_ running
> the F0 0F bug-producing program (search for it on the 'net - it must be
> out there somewhere) to verify that the code still correctly handles that
> case.
>

I have a Thinkpad with a buggy pentium (see cat /proc/cpuinfo below) and
I tried running the F00F test program available from
http://lwn.net/2001/0329/a/ltp-f00f.php3 first on a 2.2.17 kernel that
I've been running for ages without problems I got this output:

Testing for proper f00f instruction handling.
SIGILL received from f00f instruction. Good.

Then I tried 2.4.4 with your patch applied and got the same output (and
no lockup), so according to that test program your patch does not break
the F00F handling code. :-)

If you want me to test other patches, just let me know and I'll be happy
to do so!

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 5
model : 8
model name : Mobile Pentium MMX
stepping : 1
cpu MHz : 232.111
fdiv_bug : no
hlt_bug : no
sep_bug : no
f00f_bug : yes
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr mce cx8 mmx
bogomips : 463.67

Best regards,
Jesper Juhl - juhl@eisenstein.dk

-
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/