powerpc: arch_has_single_step

This defines the new standard arch_has_single_step macro.  It makes the
existing set_single_step and clear_single_step entry points global, and
renames them to the new standard names user_enable_single_step and
user_disable_single_step, respectively.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/powerpc/kernel/ptrace.c

@@ -256,7 +256,7 @@ static int set_evrregs(struct task_struct *task, unsigned long *data)
 #endif /* CONFIG_SPE */
 
 
-static void set_single_step(struct task_struct *task)
+void user_enable_single_step(struct task_struct *task)
 {
 	struct pt_regs *regs = task->thread.regs;
 
@@ -271,7 +271,7 @@ static void set_single_step(struct task_struct *task)
 	set_tsk_thread_flag(task, TIF_SINGLESTEP);
 }
 
-static void clear_single_step(struct task_struct *task)
+void user_disable_single_step(struct task_struct *task)
 {
 	struct pt_regs *regs = task->thread.regs;
 
@@ -313,7 +313,7 @@ static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 void ptrace_disable(struct task_struct *child)
 {
 	/* make sure the single step bit is not set. */
-	clear_single_step(child);
+	user_disable_single_step(child);
 }
 
 /*
@@ -456,7 +456,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 		child->exit_code = data;
 		/* make sure the single step bit is not set. */
-		clear_single_step(child);
+		user_disable_single_step(child);
 		wake_up_process(child);
 		ret = 0;
 		break;
@@ -473,7 +473,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 			break;
 		child->exit_code = SIGKILL;
 		/* make sure the single step bit is not set. */
-		clear_single_step(child);
+		user_disable_single_step(child);
 		wake_up_process(child);
 		break;
 	}
@@ -483,7 +483,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		if (!valid_signal(data))
 			break;
 		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		set_single_step(child);
+		user_enable_single_step(child);
 		child->exit_code = data;
 		/* give it a chance to run. */
 		wake_up_process(child);

include/asm-powerpc/ptrace.h

@@ -119,6 +119,13 @@ do {									      \
 } while (0)
 #endif /* __powerpc64__ */
 
+/*
+ * These are defined as per linux/ptrace.h, which see.
+ */
+#define arch_has_single_step()	(1)
+extern void user_enable_single_step(struct task_struct *);
+extern void user_disable_single_step(struct task_struct *);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */