Patch "arm64: Fix compat register mappings" has been added to the 4.2-stable tree

This is a note to let you know that I've just added the patch titled

arm64: Fix compat register mappings

to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arm64-fix-compat-register-mappings.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Robin Murphy <[email protected]>
Date: Thu, 22 Oct 2015 15:41:52 +0100
Subject: arm64: Fix compat register mappings

From: Robin Murphy <[email protected]>

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.

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

@@ -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]

Patches currently in stable-queue which might be from [email protected] are

queue-4.2/arm64-fix-compat-register-mappings.patch