Bug#651934: How to debug seed FTBFS on sparc?

[Jurij Smakov]

On Sun, Feb 26, 2012 at 02:19:59AM +0000, peter green wrote:
> Found 651934 3.0.0-2
> Thanks
> 
> Thanks jurij for your help.
> >'disassemble' command may be used to look up the assembler code
> >around the instruction which caused the crash:
> Some further notes on the dissasemble command I ran into while
> trying to use it.
> 
> 1: it seems you have to explicitly select a range unless you want a
> whole function
> 2: if you have debug symbols installed you have to use "info frame"
> to get the address of the program counter
> 3: the addresses were different on my system, i'm not sure whether
> this was because my system was slightly out of date at the time or
> because of address randomisation.
> >Figuring out why this happens is the tricky part :-).
> mmm, the webkit (webkit is the source package for libjavascriptcore)
> build log has a huge number of cast alignment warnings :( worse the
> file in which the error occoured is generated at webkit build time
> and is therefore not available in the webkit source package. I don't
> have the resources to build webkit on sparc in a reasonable time.
> 
> Since testing an unstable have different versions of both seed and
> webkit. I decided the next thing to try was to build both testing's
> version of seed and unstable's versions of seed in both testing and
> unstable to try and narrow down which package caused the regression.
> However all four combinations failed with a bus error so it seems
> this regression happened before the version of webkit that is now in
> testing.
> 
> I'm now marking this bug as affecting the version in testing as well.
> 
> Webkit maintainers: Is any form of testsuite for libjavascriptcore
> run at webkit build time? I didn't spot anything on a quick look at
> the log but the log is massive so it's possible I missed it.

I poked around the webkit source a bit and found that there is a 
WTF_CPU_NEEDS_ALIGNED_ACCESS macro, which is conditionally set to 1 
only for ARM, MIPS and SH4 CPUs. I'm currently trying to build webkit 
with attached patch to see whether this improves things.

Best regards,
-- 
Jurij Smakov                                           jurij at wooyd.org
Key: http://www.wooyd.org/pgpkey/                      KeyID: C99E03CC
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