arm64: expand register mapping between AArch32 and AArch64

The general purpose registers in AArch32 are mapped in an
architecturally defined manner into the AArch64 registers.

It allows the AArch32 registers of an application or a virtual
machine to be inspected by the OS or an hypervisor.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 19 insertions, 2 deletions

diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index b04d3404f0d1..de68a5aa60c3 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -44,10 +44,27 @@
 
 /* sizeof(struct user) for AArch32 */
 #define COMPAT_USER_SZ  296
-/* AArch32 uses x13 as the stack pointer... */
+
+/* Architecturally defined mapping between AArch32 and AArch64 registers */
+#define compat_usr(x)   regs[(x)]
 #define compat_sp       regs[13]
-/* ... and x14 as the link register. */
 #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_r8_fiq   regs[24]
+#define compat_r9_fiq   regs[25]
+#define compat_r10_fiq  regs[26]
+#define compat_r11_fiq  regs[27]
+#define compat_r12_fiq  regs[28]
+#define compat_sp_fiq   regs[29]
+#define compat_lr_fiq   regs[30]
 
 /*
  * This struct defines the way the registers are stored on the stack during an