From: Segher Boessenkool <segher@kernel.crashing.org>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc/32: indirect function call use bctrl rather than blrl in ret_from_kernel_thread
Date: Fri, 20 Aug 2021 12:18:45 -0500 [thread overview]
Message-ID: <20210820171845.GS1583@gate.crashing.org> (raw)
In-Reply-To: <871r6oe2i8.fsf@mpe.ellerman.id.au>
On Fri, Aug 20, 2021 at 10:15:11PM +1000, Michael Ellerman wrote:
> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> > Copied from commit 89bbe4c798bc ("powerpc/64: indirect function call
> > use bctrl rather than blrl in ret_from_kernel_thread")
> >
> > blrl is not recommended to use as an indirect function call, as it may
> > corrupt the link stack predictor.
>
> Do we know if any 32-bit CPUs have a link stack predictor or similar?
74xx do.
Segher
next prev parent reply other threads:[~2021-08-20 17:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 5:16 [PATCH] powerpc/32: indirect function call use bctrl rather than blrl in ret_from_kernel_thread Christophe Leroy
2021-08-20 12:15 ` Michael Ellerman
2021-08-20 17:18 ` Segher Boessenkool [this message]
2021-08-20 18:12 ` Segher Boessenkool
2021-08-27 13:15 ` Michael Ellerman
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