[POWERPC] Use user_regset accessors for GPRs

This implements user_regset-style accessors for the powerpc general
registers.  In the future these functions will be the only place that
needs to understand the user_regset layout (core dump format) and how
it maps to the internal representation of user thread state.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/ptrace.c

@@ -119,6 +119,97 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
 	return -EIO;
 }
 
+static int gpr_get(struct task_struct *target, const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   void *kbuf, void __user *ubuf)
+{
+	int ret;
+
+	if (target->thread.regs == NULL)
+		return -EIO;
+
+	CHECK_FULL_REGS(target->thread.regs);
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  target->thread.regs,
+				  0, offsetof(struct pt_regs, msr));
+	if (!ret) {
+		unsigned long msr = get_user_msr(target);
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
+					  offsetof(struct pt_regs, msr),
+					  offsetof(struct pt_regs, msr) +
+					  sizeof(msr));
+	}
+
+	BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
+		     offsetof(struct pt_regs, msr) + sizeof(long));
+
+	if (!ret)
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+					  &target->thread.regs->orig_gpr3,
+					  offsetof(struct pt_regs, orig_gpr3),
+					  sizeof(struct pt_regs));
+	if (!ret)
+		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					       sizeof(struct pt_regs), -1);
+
+	return ret;
+}
+
+static int gpr_set(struct task_struct *target, const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   const void *kbuf, const void __user *ubuf)
+{
+	unsigned long reg;
+	int ret;
+
+	if (target->thread.regs == NULL)
+		return -EIO;
+
+	CHECK_FULL_REGS(target->thread.regs);
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 target->thread.regs,
+				 0, PT_MSR * sizeof(reg));
+
+	if (!ret && count > 0) {
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
+					 PT_MSR * sizeof(reg),
+					 (PT_MSR + 1) * sizeof(reg));
+		if (!ret)
+			ret = set_user_msr(target, reg);
+	}
+
+	BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
+		     offsetof(struct pt_regs, msr) + sizeof(long));
+
+	if (!ret)
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+					 &target->thread.regs->orig_gpr3,
+					 PT_ORIG_R3 * sizeof(reg),
+					 (PT_MAX_PUT_REG + 1) * sizeof(reg));
+
+	if (PT_MAX_PUT_REG + 1 < PT_TRAP && !ret)
+		ret = user_regset_copyin_ignore(
+			&pos, &count, &kbuf, &ubuf,
+			(PT_MAX_PUT_REG + 1) * sizeof(reg),
+			PT_TRAP * sizeof(reg));
+
+	if (!ret && count > 0) {
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
+					 PT_TRAP * sizeof(reg),
+					 (PT_TRAP + 1) * sizeof(reg));
+		if (!ret)
+			ret = set_user_trap(target, reg);
+	}
+
+	if (!ret)
+		ret = user_regset_copyin_ignore(
+			&pos, &count, &kbuf, &ubuf,
+			(PT_TRAP + 1) * sizeof(reg), -1);
+
+	return ret;
+}
 
 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 		   unsigned int pos, unsigned int count,