powerpc/ptrace: create ptrace_get_debugreg()

Create ptrace_get_debugreg() to handle PTRACE_GET_DEBUGREG and
reduce ifdef mess
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c1482c41a39cc216f4073a51070d8680f52d5054.1582848567.git.christophe.leroy@c-s.fr

arch/powerpc/kernel/ptrace/ptrace-adv.c

@@ -56,6 +56,15 @@ void user_disable_single_step(struct task_struct *task)
 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 }
 
+int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
+			unsigned long __user *datalp)
+{
+	/* We only support one DABR and no IABRS at the moment */
+	if (addr > 0)
+		return -EINVAL;
+	return put_user(child->thread.debug.dac1, datalp);
+}
+
 int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
 {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT

arch/powerpc/kernel/ptrace/ptrace-decl.h

@@ -176,6 +176,8 @@ int tm_cgpr32_set(struct task_struct *target, const struct user_regset *regset,
 extern const struct user_regset_view user_ppc_native_view;
 
 /* ptrace-(no)adv */
+int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
+			unsigned long __user *datalp);
 int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data);
 long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info);
 long ppc_del_hwdebug(struct task_struct *child, long data);

arch/powerpc/kernel/ptrace/ptrace-noadv.c

@@ -39,6 +39,19 @@ void user_disable_single_step(struct task_struct *task)
 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 }
 
+int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
+			unsigned long __user *datalp)
+{
+	unsigned long dabr_fake;
+
+	/* We only support one DABR and no IABRS at the moment */
+	if (addr > 0)
+		return -EINVAL;
+	dabr_fake = ((child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
+		     (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
+	return put_user(dabr_fake, datalp);
+}
+
 int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
 {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT

arch/powerpc/kernel/ptrace/ptrace.c

@@ -191,23 +191,9 @@ long arch_ptrace(struct task_struct *child, long request,
 		break;
 	}
 
-	case PTRACE_GET_DEBUGREG: {
-#ifndef CONFIG_PPC_ADV_DEBUG_REGS
-		unsigned long dabr_fake;
-#endif
-		ret = -EINVAL;
-		/* We only support one DABR and no IABRS at the moment */
-		if (addr > 0)
-			break;
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-		ret = put_user(child->thread.debug.dac1, datalp);
-#else
-		dabr_fake = ((child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
-			     (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
-		ret = put_user(dabr_fake, datalp);
-#endif
+	case PTRACE_GET_DEBUGREG:
+		ret = ptrace_get_debugreg(child, addr, datalp);
 		break;
-	}
 
 	case PTRACE_SET_DEBUGREG:
 		ret = ptrace_set_debugreg(child, addr, data);