diff --git a/arch/frv/include/asm/ptrace.h b/arch/frv/include/asm/ptrace.h
index a54b535c9e49..6bfad4cf1907 100644
--- a/arch/frv/include/asm/ptrace.h
+++ b/arch/frv/include/asm/ptrace.h
@@ -84,8 +84,6 @@ extern void show_regs(struct pt_regs *);
 #define task_pt_regs(task) ((task)->thread.frame0)
 
 #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__ */
diff --git a/arch/ia64/include/asm/ptrace.h b/arch/ia64/include/asm/ptrace.h
index 14055c636adf..7ae9c3f15a1c 100644
--- a/arch/ia64/include/asm/ptrace.h
+++ b/arch/ia64/include/asm/ptrace.h
@@ -319,11 +319,7 @@ static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 	ptrace_attach_sync_user_rbs(child)
 
   #define arch_has_single_step()  (1)
-  extern void user_enable_single_step(struct task_struct *);
-  extern void user_disable_single_step(struct task_struct *);
-
   #define arch_has_block_step()   (1)
-  extern void user_enable_block_step(struct task_struct *);
 
 #endif /* !__KERNEL__ */
 
diff --git a/arch/m68k/include/asm/ptrace.h b/arch/m68k/include/asm/ptrace.h
index 21605c736f69..6e6e3ac1d913 100644
--- a/arch/m68k/include/asm/ptrace.h
+++ b/arch/m68k/include/asm/ptrace.h
@@ -87,18 +87,10 @@ struct switch_stack {
 #define profile_pc(regs) instruction_pointer(regs)
 extern void show_regs(struct pt_regs *);
 
-/*
- * These are defined as per linux/ptrace.h.
- */
-struct task_struct;
-
 #define arch_has_single_step()	(1)
-extern void user_enable_single_step(struct task_struct *);
-extern void user_disable_single_step(struct task_struct *);
 
 #ifdef CONFIG_MMU
 #define arch_has_block_step()	(1)
-extern void user_enable_block_step(struct task_struct *);
 #endif
 
 #endif /* __KERNEL__ */
diff --git a/arch/mn10300/include/asm/ptrace.h b/arch/mn10300/include/asm/ptrace.h
index 1b0ba5e182b0..7c2e911052b6 100644
--- a/arch/mn10300/include/asm/ptrace.h
+++ b/arch/mn10300/include/asm/ptrace.h
@@ -99,8 +99,6 @@ struct task_struct;
 extern void show_regs(struct pt_regs *);
 
 #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  */
 
diff --git a/arch/parisc/include/asm/ptrace.h b/arch/parisc/include/asm/ptrace.h
index aead40b16dd8..7f09533da771 100644
--- a/arch/parisc/include/asm/ptrace.h
+++ b/arch/parisc/include/asm/ptrace.h
@@ -47,13 +47,8 @@ struct pt_regs {
 
 #define task_regs(task) ((struct pt_regs *) ((char *)(task) + TASK_REGS))
 
-struct task_struct;
 #define arch_has_single_step()	1
-void user_disable_single_step(struct task_struct *task);
-void user_enable_single_step(struct task_struct *task);
-
 #define arch_has_block_step()	1
-void user_enable_block_step(struct task_struct *task);
 
 /* XXX should we use iaoq[1] or iaoq[0] ? */
 #define user_mode(regs)			(((regs)->iaoq[0] & 3) ? 1 : 0)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index b45108126562..9e2d84c06b74 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -137,15 +137,8 @@ do {									      \
 } while (0)
 #endif /* __powerpc64__ */
 
-/*
- * These are defined as per linux/ptrace.h, which see.
- */
 #define arch_has_single_step()	(1)
 #define arch_has_block_step()	(!cpu_has_feature(CPU_FTR_601))
-extern void user_enable_single_step(struct task_struct *);
-extern void user_enable_block_step(struct task_struct *);
-extern void user_disable_single_step(struct task_struct *);
-
 #define ARCH_HAS_USER_SINGLE_STEP_INFO
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index dd2d913afcae..fef9b33cdd59 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -489,9 +489,6 @@ struct user_regs_struct
  * These are defined as per linux/ptrace.h, which see.
  */
 #define arch_has_single_step()	(1)
-struct task_struct;
-extern void user_enable_single_step(struct task_struct *);
-extern void user_disable_single_step(struct task_struct *);
 extern void show_regs(struct pt_regs * regs);
 
 #define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0)
diff --git a/arch/score/include/asm/ptrace.h b/arch/score/include/asm/ptrace.h
index d40e691f23e2..e89dc9b1ef49 100644
--- a/arch/score/include/asm/ptrace.h
+++ b/arch/score/include/asm/ptrace.h
@@ -90,8 +90,7 @@ extern int read_tsk_short(struct task_struct *, unsigned long,
 			 unsigned short *);
 
 #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 /* __KERNEL__ */
 
 #endif /* _ASM_SCORE_PTRACE_H */
diff --git a/arch/sh/include/asm/ptrace.h b/arch/sh/include/asm/ptrace.h
index e11b14ea2c43..2168fde25611 100644
--- a/arch/sh/include/asm/ptrace.h
+++ b/arch/sh/include/asm/ptrace.h
@@ -123,8 +123,6 @@ extern void show_regs(struct pt_regs *);
 struct task_struct;
 
 #define arch_has_single_step()	(1)
-extern void user_enable_single_step(struct task_struct *);
-extern void user_disable_single_step(struct task_struct *);
 
 struct perf_event;
 struct perf_sample_data;
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 20102808b191..69a686a7dff0 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -274,14 +274,7 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 		return 0;
 }
 
-/*
- * 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 *);
-
-extern void user_enable_block_step(struct task_struct *);
 #ifdef CONFIG_X86_DEBUGCTLMSR
 #define arch_has_block_step()	(1)
 #else
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index c5eab89da51e..e1fb60729979 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -264,6 +264,9 @@ static inline void user_enable_single_step(struct task_struct *task)
 static inline void user_disable_single_step(struct task_struct *task)
 {
 }
+#else
+extern void user_enable_single_step(struct task_struct *);
+extern void user_disable_single_step(struct task_struct *);
 #endif	/* arch_has_single_step */
 
 #ifndef arch_has_block_step
@@ -291,6 +294,8 @@ static inline void user_enable_block_step(struct task_struct *task)
 {
 	BUG();			/* This can never be called.  */
 }
+#else
+extern void user_enable_block_step(struct task_struct *);
 #endif	/* arch_has_block_step */
 
 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO