From: Christophe Leroy christophe.leroy@csgroup.eu
[ Upstream commit 113ec9ccc8049c3772f0eab46b62c5d6654c09f7 ]
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.
This is not a performance critical path but this should be fixed for consistency.
Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/91b1d242525307ceceec7ef6e832bfbacdd4501b.162943647... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/entry_32.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index c72894ff9d61..09ef46e5690b 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -485,10 +485,10 @@ ret_from_fork: ret_from_kernel_thread: REST_NVGPRS(r1) bl schedule_tail - mtlr r14 + mtctr r14 mr r3,r15 PPC440EP_ERR42 - blrl + bctrl li r3,0 b ret_from_syscall