[PATCH v10 3/5] powerpc/vdso: Save and restore TOC pointer on PPC64

From: Christophe Leroy
Date: Wed Aug 05 2020 - 03:09:32 EST


On PPC64, the TOC pointer needs to be saved and restored.

Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
v9: New.

I'm not sure this is really needed, I can't see the VDSO C code doing
anything with r2, at least on ppc64_defconfig.

So I let you decide whether you take it or not.
---
arch/powerpc/include/asm/vdso/gettimeofday.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/powerpc/include/asm/vdso/gettimeofday.h b/arch/powerpc/include/asm/vdso/gettimeofday.h
index e2c462796a22..8ed4329c9fb8 100644
--- a/arch/powerpc/include/asm/vdso/gettimeofday.h
+++ b/arch/powerpc/include/asm/vdso/gettimeofday.h
@@ -19,10 +19,16 @@
.cfi_register lr, r0
PPC_STLU r1, -STACK_FRAME_OVERHEAD(r1)
PPC_STL r0, STACK_FRAME_OVERHEAD + PPC_LR_STKOFF(r1)
+#ifdef CONFIG_PPC64
+ PPC_STL r2, STACK_FRAME_OVERHEAD + STK_GOT(r1)
+#endif
get_datapage r5, r0
addi r5, r5, VDSO_DATA_OFFSET
bl \funct
PPC_LL r0, STACK_FRAME_OVERHEAD + PPC_LR_STKOFF(r1)
+#ifdef CONFIG_PPC64
+ PPC_LL r2, STACK_FRAME_OVERHEAD + STK_GOT(r1)
+#endif
cmpwi r3, 0
mtlr r0
.cfi_restore lr
@@ -42,10 +48,16 @@
.cfi_register lr, r0
PPC_STLU r1, -STACK_FRAME_OVERHEAD(r1)
PPC_STL r0, STACK_FRAME_OVERHEAD + PPC_LR_STKOFF(r1)
+#ifdef CONFIG_PPC64
+ PPC_STL r2, STACK_FRAME_OVERHEAD + STK_GOT(r1)
+#endif
get_datapage r4, r0
addi r4, r4, VDSO_DATA_OFFSET
bl \funct
PPC_LL r0, STACK_FRAME_OVERHEAD + PPC_LR_STKOFF(r1)
+#ifdef CONFIG_PPC64
+ PPC_LL r2, STACK_FRAME_OVERHEAD + STK_GOT(r1)
+#endif
crclr so
mtlr r0
.cfi_restore lr
--
2.25.0