[PATCH 4.1 64/95] arm64: Fix compat register mappings

From: Greg Kroah-Hartman
Date: Mon Dec 07 2015 - 09:49:46 EST


4.1-stable review patch. If anyone has any objections, please let me know.

------------------

From: Robin Murphy <robin.murphy@xxxxxxx>

commit 5accd17d0eb523350c9ef754d655e379c9bb93b3 upstream.

For reasons not entirely apparent, but now enshrined in history, the
architectural mapping of AArch32 banked registers to AArch64 registers
actually orders SP_<mode> and LR_<mode> backwards compared to the
intuitive r13/r14 order, for all modes except FIQ.

Fix the compat_<reg>_<mode> macros accordingly, in the hope of avoiding
subtle bugs with KVM and AArch32 guests.

Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm64/include/asm/ptrace.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -83,14 +83,14 @@
#define compat_sp regs[13]
#define compat_lr regs[14]
#define compat_sp_hyp regs[15]
-#define compat_sp_irq regs[16]
-#define compat_lr_irq regs[17]
-#define compat_sp_svc regs[18]
-#define compat_lr_svc regs[19]
-#define compat_sp_abt regs[20]
-#define compat_lr_abt regs[21]
-#define compat_sp_und regs[22]
-#define compat_lr_und regs[23]
+#define compat_lr_irq regs[16]
+#define compat_sp_irq regs[17]
+#define compat_lr_svc regs[18]
+#define compat_sp_svc regs[19]
+#define compat_lr_abt regs[20]
+#define compat_sp_abt regs[21]
+#define compat_lr_und regs[22]
+#define compat_sp_und regs[23]
#define compat_r8_fiq regs[24]
#define compat_r9_fiq regs[25]
#define compat_r10_fiq regs[26]


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