2020-02-14 08:40:29

by Christophe Leroy

Subject: [PATCH RESEND with Fixes: tag] powerpc/chrp: Fix enter_rtas() with CONFIG_VMAP_STACK

With CONFIG_VMAP_STACK, data MMU has to be enabled
to read data on the stack.

Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/entry_32.S | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0713daa651d9..bc056d906b51 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1354,12 +1354,17 @@ _GLOBAL(enter_rtas)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
RFI
-1: tophys(r9,r1)
+1: tophys_novmstack r9, r1
+#ifdef CONFIG_VMAP_STACK
+ li r0, MSR_KERNEL & ~MSR_IR /* can take DTLB miss */
+ mtmsr r0
+ isync
+#endif
lwz r8,INT_FRAME_SIZE+4(r9) /* get return address */
lwz r9,8(r9) /* original msr value */
addi r1,r1,INT_FRAME_SIZE
li r0,0
- tophys(r7, r2)
+ tophys_novmstack r7, r2
stw r0, THREAD + RTAS_SP(r7)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
--
2.25.0

2020-02-19 12:41:43

by Michael Ellerman

Subject: Re: [PATCH RESEND with Fixes: tag] powerpc/chrp: Fix enter_rtas() with CONFIG_VMAP_STACK

On Fri, 2020-02-14 at 08:39:50 UTC, Christophe Leroy wrote:
> With CONFIG_VMAP_STACK, data MMU has to be enabled
> to read data on the stack.
>
> Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
> Signed-off-by: Christophe Leroy <[email protected]>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/5a528eb67908bcf493f3583cb4726fbd8e129605

cheers