Re: [PATCH] powerpc/32s: Fix RTAS machine check with VMAP stack

2020-12-23 Thread Michael Ellerman 
Christophe Leroy  writes:
> Le 22/12/2020 à 08:11, Christophe Leroy a écrit :
>> When we have VMAP stack, exception prolog 1 sets r1, not r11.
>
> But exception prolog 1 uses r1 to setup r1 when machine check happens in 
> kernel.
> So r1 must be restored when the branch is not taken. See subsequent patch I 
> just sent out.

OK. This is still on the tip of fixes, so I'll rewind it to drop this
commit, and then apply this and the fixup as one patch next week.

cheers

Re: [PATCH] powerpc/32s: Fix RTAS machine check with VMAP stack

2020-12-22 Thread Christophe Leroy 




Le 22/12/2020 à 08:11, Christophe Leroy a écrit :

When we have VMAP stack, exception prolog 1 sets r1, not r11.


But exception prolog 1 uses r1 to setup r1 when machine check happens in kernel.
So r1 must be restored when the branch is not taken. See subsequent patch I 
just sent out.

Christophe



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: sta...@vger.kernel.org
Signed-off-by: Christophe Leroy 
---
  arch/powerpc/kernel/head_book3s_32.S | 7 +++
  1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kernel/head_book3s_32.S 
b/arch/powerpc/kernel/head_book3s_32.S
index 349bf3f0c3af..fbc48a500846 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -260,9 +260,16 @@ __secondary_hold_acknowledge:
  MachineCheck:
EXCEPTION_PROLOG_0
  #ifdef CONFIG_PPC_CHRP
+#ifdef CONFIG_VMAP_STACK
+   mtspr   SPRN_SPRG_SCRATCH2,r1
+   mfspr   r1, SPRN_SPRG_THREAD
+   lwz r1, RTAS_SP(r1)
+   cmpwi   cr1, r1, 0
+#else
mfspr   r11, SPRN_SPRG_THREAD
lwz r11, RTAS_SP(r11)
cmpwi   cr1, r11, 0
+#endif
bne cr1, 7f
  #endif /* CONFIG_PPC_CHRP */
EXCEPTION_PROLOG_1 for_rtas=1

[PATCH] powerpc/32s: Fix RTAS machine check with VMAP stack - again

2020-12-22 Thread Christophe Leroy 
When it is not a RTAS machine check, don't trash r1
because it is needed by prolog 1.

Fixes: 9c7422b92cb2 ("powerpc/32s: Fix RTAS machine check with VMAP stack")
Cc: sta...@vger.kernel.org
Signed-off-by: Christophe Leroy 
---
Sorry Michael for this last minute fix of the fix.

 arch/powerpc/kernel/head_book3s_32.S | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_book3s_32.S 
b/arch/powerpc/kernel/head_book3s_32.S
index fbc48a500846..858fbc8b19f3 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -265,12 +265,14 @@ MachineCheck:
mfspr   r1, SPRN_SPRG_THREAD
lwz r1, RTAS_SP(r1)
cmpwi   cr1, r1, 0
+   bne cr1, 7f
+   mfspr   r1, SPRN_SPRG_SCRATCH2
 #else
mfspr   r11, SPRN_SPRG_THREAD
lwz r11, RTAS_SP(r11)
cmpwi   cr1, r11, 0
-#endif
bne cr1, 7f
+#endif
 #endif /* CONFIG_PPC_CHRP */
EXCEPTION_PROLOG_1 for_rtas=1
 7: EXCEPTION_PROLOG_2
-- 
2.25.0

Re: [PATCH] powerpc/32s: Fix RTAS machine check with VMAP stack

2020-12-22 Thread Michael Ellerman 
On Tue, 22 Dec 2020 07:11:18 + (UTC), Christophe Leroy wrote:
> When we have VMAP stack, exception prolog 1 sets r1, not r11.

Applied to powerpc/fixes.

[1/1] powerpc/32s: Fix RTAS machine check with VMAP stack
  https://git.kernel.org/powerpc/c/9c7422b92cb27369653c371ad9c44a502e5eea8f

cheers

[PATCH] powerpc/32s: Fix RTAS machine check with VMAP stack

2020-12-21 Thread Christophe Leroy 
When we have VMAP stack, exception prolog 1 sets r1, not r11.

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: sta...@vger.kernel.org
Signed-off-by: Christophe Leroy 
---
 arch/powerpc/kernel/head_book3s_32.S | 7 +++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kernel/head_book3s_32.S 
b/arch/powerpc/kernel/head_book3s_32.S
index 349bf3f0c3af..fbc48a500846 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -260,9 +260,16 @@ __secondary_hold_acknowledge:
 MachineCheck:
EXCEPTION_PROLOG_0
 #ifdef CONFIG_PPC_CHRP
+#ifdef CONFIG_VMAP_STACK
+   mtspr   SPRN_SPRG_SCRATCH2,r1
+   mfspr   r1, SPRN_SPRG_THREAD
+   lwz r1, RTAS_SP(r1)
+   cmpwi   cr1, r1, 0
+#else
mfspr   r11, SPRN_SPRG_THREAD
lwz r11, RTAS_SP(r11)
cmpwi   cr1, r11, 0
+#endif
bne cr1, 7f
 #endif /* CONFIG_PPC_CHRP */
EXCEPTION_PROLOG_1 for_rtas=1
-- 
2.25.0