ARM cleanups

3 files changed, 34 insertions, 25 deletions

diff --git a/sysdeps/linux-gnu/arm/regs.c b/sysdeps/linux-gnu/arm/regs.c
index bd86370..e9e825e 100644
--- a/sysdeps/linux-gnu/arm/regs.c
+++ b/sysdeps/linux-gnu/arm/regs.c
@@ -39,9 +39,6 @@
 # define PTRACE_POKEUSER PTRACE_POKEUSR
 #endif
 
-#define off_pc ((void *)60)
-#define off_sp ((void *)52)
-
 int
 arm_get_register(struct process *proc, enum arm_register reg, uint32_t *lp)
 {
@@ -54,6 +51,13 @@ arm_get_register(struct process *proc, enum arm_register reg, uint32_t *lp)
 }
 
 int
+arm_set_register(struct process *proc, enum arm_register reg, uint32_t lp)
+{
+	return ptrace(PTRACE_PEEKUSER, proc->pid,
+		      (void *)(reg * 4L), (void *)lp);
+}
+
+int
 arm_get_register_offpc(struct process *proc, enum arm_register reg,
 		       uint32_t *lp)
 {
@@ -116,36 +120,38 @@ arm_get_shifted_register(struct process *proc, uint32_t inst, int carry,
 	return 0;
 }
 
-arch_addr_t
-get_instruction_pointer(struct process *proc)
+static arch_addr_t
+get_register_nocheck(struct process *proc, enum arm_register r)
 {
 	uint32_t reg;
-	if (arm_get_register(proc, ARM_REG_PC, &reg) < 0)
+	if (arm_get_register(proc, r, &reg) < 0)
 		/* XXX double cast. */
 		return (arch_addr_t)-1;
 	/* XXX double cast.  */
 	return (arch_addr_t)(uintptr_t)reg;
 }
 
+arch_addr_t
+get_instruction_pointer(struct process *proc)
+{
+	return get_register_nocheck(proc, ARM_REG_PC);
+}
+
 void
-set_instruction_pointer(struct process *proc, void *addr)
+set_instruction_pointer(struct process *proc, arch_addr_t addr)
 {
-	ptrace(PTRACE_POKEUSER, proc->pid, off_pc, addr);
+	/* XXX double cast.  */
+	arm_set_register(proc, ARM_REG_PC, (uint32_t)addr);
 }
 
 void *
 get_stack_pointer(struct process *proc)
 {
-	return (void *)ptrace(PTRACE_PEEKUSER, proc->pid, off_sp, 0);
+	return get_register_nocheck(proc, ARM_REG_SP);
 }
 
 arch_addr_t
 get_return_addr(struct process *proc, arch_addr_t stack_pointer)
 {
-	uint32_t reg;
-	if (arm_get_register(proc, ARM_REG_LR, &reg) < 0)
-		/* XXX double cast. */
-		return (arch_addr_t)-1;
-	/* XXX double cast.  */
-	return (arch_addr_t)(uintptr_t)reg;
+	return get_register_nocheck(proc, ARM_REG_LR);
 }
diff --git a/sysdeps/linux-gnu/arm/regs.h b/sysdeps/linux-gnu/arm/regs.h
index 1566f92..f9a5a86 100644
--- a/sysdeps/linux-gnu/arm/regs.h
+++ b/sysdeps/linux-gnu/arm/regs.h
@@ -25,6 +25,8 @@
 	((long) (BITS(obj,st,fn) | ((long) BIT(obj,fn) * ~ SUBMASK(fn - st))))
 
 enum arm_register {
+	ARM_REG_R7 = 7,
+	ARM_REG_IP = 12,
 	ARM_REG_SP = 13,
 	ARM_REG_LR = 14,
 	ARM_REG_PC = 15,
diff --git a/sysdeps/linux-gnu/arm/trace.c b/sysdeps/linux-gnu/arm/trace.c
index a4d82ac..5e51e91 100644
--- a/sysdeps/linux-gnu/arm/trace.c
+++ b/sysdeps/linux-gnu/arm/trace.c
@@ -35,6 +35,7 @@
 #include "output.h"
 #include "ptrace.h"
 #include "regs.h"
+#include "type.h"
 
 #if (!defined(PTRACE_PEEKUSER) && defined(PTRACE_PEEKUSR))
 # define PTRACE_PEEKUSER PTRACE_PEEKUSR
@@ -44,12 +45,6 @@
 # define PTRACE_POKEUSER PTRACE_POKEUSR
 #endif
 
-#define off_r0 ((void *)0)
-#define off_r7 ((void *)28)
-#define off_ip ((void *)48)
-#define off_pc ((void *)60)
-#define off_cpsr ((void *)64)
-
 void
 get_arch_dep(struct process *proc)
 {
@@ -71,18 +66,24 @@ syscall_p(struct process *proc, int status, int *sysnum)
 {
 	if (WIFSTOPPED(status)
 	    && WSTOPSIG(status) == (SIGTRAP | proc->tracesysgood)) {
-		/* get the user's pc (plus 8) */
-		unsigned pc = ptrace(PTRACE_PEEKUSER, proc->pid, off_pc, 0);
+		uint32_t pc, ip;
+		if (arm_get_register(proc, ARM_REG_PC, &pc) < 0
+		    || arm_get_register(proc, ARM_REG_IP, &ip) < 0)
+			return -1;
+
 		pc = pc - 4;
+
 		/* fetch the SWI instruction */
 		unsigned insn = ptrace(PTRACE_PEEKTEXT, proc->pid,
 				       (void *)pc, 0);
-		int ip = ptrace(PTRACE_PEEKUSER, proc->pid, off_ip, 0);
 
 		if (insn == 0xef000000 || insn == 0x0f000000
 		    || (insn & 0xffff0000) == 0xdf000000) {
 			/* EABI syscall */
-			*sysnum = ptrace(PTRACE_PEEKUSER, proc->pid, off_r7, 0);
+			uint32_t r7;
+			if (arm_get_register(proc, ARM_REG_R7, &r7) < 0)
+				return -1;
+			*sysnum = r7;
 		} else if ((insn & 0xfff00000) == 0xef900000) {
 			/* old ABI syscall */
 			*sysnum = insn & 0xfffff;