| From 4e6441b56402324283571d96bd9a55ef97b74b4d Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 13 Jan 2021 06:40:20 +0000 |
| Subject: powerpc/32s: Fix RTAS machine check with VMAP stack |
| |
| From: Christophe Leroy <christophe.leroy@csgroup.eu> |
| |
| [ Upstream commit 98bf2d3f4970179c702ef64db658e0553bc6ef3a ] |
| |
| When we have VMAP stack, exception prolog 1 sets r1, not r11. |
| |
| When it is not an RTAS machine check, don't trash r1 because it is |
| needed by prolog 1. |
| |
| Fixes: da7bb43ab9da ("powerpc/32: Fix vmap stack - Properly set r1 before activating MMU") |
| Fixes: d2e006036082 ("powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs") |
| Cc: stable@vger.kernel.org # v5.10+ |
| Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> |
| [mpe: Squash in fixup for RTAS machine check from Christophe] |
| Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
| Link: https://lore.kernel.org/r/bc77d61d1c18940e456a2dee464f1e2eda65a3f0.1608621048.git.christophe.leroy@csgroup.eu |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/powerpc/kernel/head_book3s_32.S | 9 +++++++++ |
| 1 file changed, 9 insertions(+) |
| |
| diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S |
| index a0dda2a1f2df0..d66da35f2e8d3 100644 |
| --- a/arch/powerpc/kernel/head_book3s_32.S |
| +++ b/arch/powerpc/kernel/head_book3s_32.S |
| @@ -262,10 +262,19 @@ __secondary_hold_acknowledge: |
| MachineCheck: |
| EXCEPTION_PROLOG_0 |
| #ifdef CONFIG_PPC_CHRP |
| +#ifdef CONFIG_VMAP_STACK |
| + mr r11, r1 |
| + mfspr r1, SPRN_SPRG_THREAD |
| + lwz r1, RTAS_SP(r1) |
| + cmpwi cr1, r1, 0 |
| + bne cr1, 7f |
| + mr r1, r11 |
| +#else |
| mfspr r11, SPRN_SPRG_THREAD |
| lwz r11, RTAS_SP(r11) |
| cmpwi cr1, r11, 0 |
| bne cr1, 7f |
| +#endif |
| #endif /* CONFIG_PPC_CHRP */ |
| EXCEPTION_PROLOG_1 for_rtas=1 |
| 7: EXCEPTION_PROLOG_2 |
| -- |
| 2.27.0 |
| |
