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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Tue, 26 Jul 2016 22:28:57 +1000
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Subject: Re: [Qemu-devel] [PATCH] tcg: Merge GETPC and GETRA
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To: Richard Henderson <rth@twiddle.net>, qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, leon.alrae@imgtec.com

On Tue, 2016-07-26 at 06:12 +0530, Richard Henderson wrote:
> The return address argument to the softmmu template helpers was
> confused.=C2=A0=C2=A0In the legacy case, we wanted to indicate that the=
re
> is no return address, and so passed in NULL.=C2=A0=C2=A0However, we the=
n
> immediately subtracted GETPC_ADJ from NULL, resulting in a non-zero
> value, indicating the presence of an (invalid) return address.
>=20
> 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.=C2=A0=C2=A0This makes GETPC and GETRA ident=
ical.
>=20
> Remove GETRA as the lesser used macro, replacing all uses with GETPC.
>=20
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>=20
> Ben, this should fix the "-2" problem that you reported.=C2=A0=C2=A0Of =
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.