Re: [PATCH] powerpc/32: indirect function call use bctrl rather than blrl in ret_from_kernel_thread

On Fri, Aug 20, 2021 at 12:18:45PM -0500, Segher Boessenkool wrote:

On Fri, Aug 20, 2021 at 10:15:11PM +1000, Michael Ellerman wrote:

quoted

Christophe Leroy [off-list ref] writes:

quoted

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.

7450 and later, that is.  Will I ever get that right, sigh.


Segher