From 73d7a97914f23397b012e851f6a1fe4061923a82 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sat, 30 Jan 2021 23:08:20 +1000 Subject: [PATCH] powerpc/32: transfer can avoid saving r4/r5 over trace call Now that handlers get all registers from pt_regs, r4 and r5 are no longer live here and may be clobbered. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210130130852.2952424-11-npiggin@gmail.com --- arch/powerpc/kernel/entry_32.S | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 238eacfda7b0..d6ea3f2d6cc0 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -276,8 +276,7 @@ reenable_mmu: * We save a bunch of GPRs, * r3 can be different from GPR3(r1) at this point, r9 and r11 * contains the old MSR and handler address respectively, - * r4 & r5 can contain page fault arguments that need to be passed - * along as well. r0, r6-r8, r12, CCR, CTR, XER etc... are left + * r0, r4-r8, r12, CCR, CTR, XER etc... are left * clobbered as they aren't useful past this point. */ @@ -285,15 +284,11 @@ reenable_mmu: stw r9,8(r1) stw r11,12(r1) stw r3,16(r1) - stw r4,20(r1) - stw r5,24(r1) /* If we are disabling interrupts (normal case), simply log it with * lockdep */ 1: bl trace_hardirqs_off - lwz r5,24(r1) - lwz r4,20(r1) lwz r3,16(r1) lwz r11,12(r1) lwz r9,8(r1) -- 2.39.2