Re: dwarf_next_cfi returns -1

[Mark Wielaard <mark at klomp dot org>]

On Wed, Jun 27, 2018 at 11:01:25PM +0000, Sasha Da Rocha Pinheiro wrote:
> This is a binary that infinite loops with dwarf_next_cfi -1 because the offset is not updated.
> https://rice.box.com/s/yzul9oavplq1qdx12ozjpgssawea36xy
> 
> A fix was done by saving the previous *next_off and comparing with the current, after getting -1 in the return value.

That is probably the best way to handle that.

Looking at the file I see it has (multiple) zero terminators, that
dwarf_next_cfi seems to not handle. Strangely these aren't described
in the Dwarf spec, but they are mentioned in the LSB exception frames
spec: https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html#EHFRAME

Totally untested patch attached. If you could test it that would be
wonderful. I'll write a proper testcase tomorrow.

Thanks,

Mark

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