Subject: Seemingly random SIGILL in SMP
To: port-macppc mailing-list <port-macppc@netbsd.org>
From: Michael Lorenz <macallan@netbsd.org>
List: port-macppc
Date: 10/05/2007 11:06:29
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Hello,

in both -current and 4.0 I occasionally see processes dies with  
SIGILL, apparently at random. Looking at the core files revealed that  
the faulting instruction was always part of a PLT table, apparently  
they're not always flushed out after writing them. I can't reliably  
trigger the fault but building something non-trivial ( like a  
userland ) usually runs into it at some point.
So,
- - does anyone else see this?
- - if so, in SMP or in UP as well? I've never seen this with an  
uniprocessor kernel.

I changed the powerpc-specific part of ld.elf_so to flush the cache  
in a more consistent way and since then I haven't seen any SIGILL and  
my G4's been building stuff from pkgsrc all night.

If you see those SIGILL on a recent -current please try my patched  
ld.elf_so ( just dump it into /libexec, you might have to use install  
instead of cp though ) and see if they go away. The binary is here:
ftp://ftp.netbsd.org/pub/NetBSD/misc/macallan/macppc/ld.elf_so
built from yesterday's sources.

If that indeed fixes the SIGILL problem it needs to go into 4.0 fast.

have fun
Michael
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