Re: [Fwd: Fix arm_addr_bits_remove: 26-bit Thumb doesn't exist]

[Nick Clifton <nickc@cambridge.redhat.com>]

Hi Fernando, Hi Ben,

> From: Ben Harris <bjh21@netbsd.org>
> 
> I haven't actually encountered this bug in reality yet, but it looks
> to me as if arm_addr_bits_remove() is bogus.  Specifically, it has a
> case for Thumb state in a 26-bit mode.  According to the ARM ARM
> (2nd Edition, section A8.1), no processor will support both 26-bit
> mode and thumb state at all, let alone at the same time.  I suspect
> this might be a noticeable problem when debugging SVC mode code,
> since then R15 will have its bottom bit set, which arm_pc_is_thumb()
> is likely to interpret as meaning the CPU is in Thumb state.
> 
> ChangeLog entry:
> 
> 2001-10-20  Ben Harris  <bjh21@netbsd.org>
> 
> 	* arm-tdep.c (arm_addr_bits_remove): Don't believe in 26-bit
> 	Thumb.

This looks like a reasonable patch to me.  I do not have the authority
to approve it, but I would certainly recommend it to the GDB
maintainers.

Cheers
        Nick