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Date: Wed, 19 Nov 2014 14:43:40 -0800
From: Isaac Dunham <ibid.ag@...il.com>
To: musl@...ts.openwall.com
Subject: Re: webkitfltk segfaults in do_relocs

On Wed, Nov 19, 2014 at 03:56:35PM -0500, Rich Felker wrote:
> Got it. The line number in your original report seems to be off by a
> bit (it points to TLSDESC related cases) but I've found the offending
> relocation(s):
> 
> 0083deea  0000c402 R_386_PC32        00000000   exp
> 0083df03  00010a02 R_386_PC32        00000000   log
> 0083df1c  00030502 R_386_PC32        00000000   floor
> 0083df35  00024502 R_386_PC32        00000000   ceil
> 
> I have no idea why the linker is emitting these. It should have
> resolved them at ld time to PLT entries in the main program's PLT, but
> maybe since you're building as PIE (this is defautl on Alpine) that
> doesn't happen (this would be a linker bug, IMO). If it were going
> to do this (leave the relocations in the output), it should mark the
> program as DT_TEXTREL (having textrels), but this is probably
> suppressed for PIE because it's not supposed to happen.
> 
> My best guess as to what's triggering the problem is that there's some
> nasty asm or other hacks that are not PIE-compatible somewhere in the
> program. It's also possible that you're pulling in static libraries
> (which would not be PIE-compatible) due to not having the dynamic
> version of a needed library installed.

All external libs are available in shared format, except perhaps -lgcc
But the whole library is built in static form only, without -fPIC.
 
> Finding which .o or .a file these references to exp/log/floor/ceil are
> coming from would help narrow down the source of the problem.
> Alternatively you could try building as non-PIE.

A couple dozen bits of C++ that seem to call those by way of templates.
I need to read up on the PIE-related options.

Thanks,
Isaac Dunham

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