Re: [Qemu-devel] [PATCH] tcg: Merge GETPC and GETRA

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2016-07-26 at 06:12 +0530, Richard Henderson wrote:
> The return address argument to the softmmu template helpers was
> confused.  In the legacy case, we wanted to indicate that there
> is no return address, and so passed in NULL.  However, we then
> immediately subtracted GETPC_ADJ from NULL, resulting in a non-zero
> value, indicating the presence of an (invalid) return address.
> 
> Push the GETPC_ADJ subtraction down to the only point it's required:
> immediately before use within cpu_restore_state, after all NULL
> pointer
> checks have been completed.  This makes GETPC and GETRA identical.
> 
> Remove GETRA as the lesser used macro, replacing all uses with GETPC.
> 
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
> 
> Ben, this should fix the "-2" problem that you reported.  Of course,
> as also discussed in that thread, this won't fix the whole issue.

I haven't had a chance to review the details of the patch but I
verified that all my test OSes still boot with it applied ;-)

Cheers,
Ben.