[PATCH 5.10 001/103] powerpc/32s: Fix RTAS machine check with VMAP stack
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-01-15 12:49:29
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: Christophe Leroy <redacted>
[ 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 <redacted>
[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 (local)
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