2000-11-02 19:21:37

by Ivo Zivkov

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Subject: Floating point emulation problem


Dear List,

I am running kernel 2.2.5-15. I am trying to calculate sin(0.9), and it crashes on a 386 board with no f/p hardware. The message I get is:

"Unable to handle kernel paging request at virtual address 7f3c0070......"

The interesting thing is sin(0.8) works fine. On a Pentium the program executes fine for all values.

I tried in 2 different 386 boards, and I get the same problem. The program was compiled on R.H.6.0, and "libm" was present on the 386. I even linked the program statically to eliminate any library dependencies.

This seems like a common problem, and easy to reproduce. Anybody had the same experience?

please reply to mailto:[email protected]

Regards,

Ivo





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2000-11-02 21:17:06

by Alan Cox

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Subject: Re: Floating point emulation problem

> I am running kernel 2.2.5-15. I am trying to calculate sin(0.9), and it crashes on a 386 board with no f/p hardware. The message I get is:
>
> "Unable to handle kernel paging request at virtual address 7f3c0070......"
>
> The interesting thing is sin(0.8) works fine. On a Pentium the program executes fine for all values.
>
> I tried in 2 different 386 boards, and I get the same problem. The program was compiled on R.H.6.0, and "libm" was present on the 386. I even linked the program statically to eliminate any library dependencies.
>
> This seems like a common problem, and easy to reproduce. Anybody had the same experience?

Either upgrade to a later 2.2 kernel or rebuild the kernel with gcc 2.7.2.3. Its
a bug in the FPU code when compiled with later compilers