[PATCH V2 3/3] arch: ptrace: Cleanup ptrace_disable

[guoren at kernel.org]

From: Guo Ren <guoren at linux.alibaba.com>

Add a weak empty function in common and remove architectures' duplicated
ones.

Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
Signed-off-by: Guo Ren <guoren at kernel.org>
Reviewed-by: Oleg Nesterov <oleg at redhat.com>
---
 arch/arc/kernel/ptrace.c        |  4 ----
 arch/arm/kernel/ptrace.c        |  8 --------
 arch/microblaze/kernel/ptrace.c |  5 -----
 arch/nios2/kernel/ptrace.c      |  5 -----
 arch/riscv/kernel/ptrace.c      |  4 ----
 arch/sparc/kernel/ptrace_32.c   | 10 ----------
 arch/sparc/kernel/ptrace_64.c   | 10 ----------
 kernel/ptrace.c                 |  8 ++++++++
 8 files changed, 8 insertions(+), 46 deletions(-)

diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c
index da7542cea0d8..c227e145fede 100644
--- a/arch/arc/kernel/ptrace.c
+++ b/arch/arc/kernel/ptrace.c
@@ -317,10 +317,6 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 	return &user_arc_view;
 }
 
-void ptrace_disable(struct task_struct *child)
-{
-}
-
 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index bfe88c6e60d5..b85f5bdc56ef 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -186,14 +186,6 @@ put_user_reg(struct task_struct *task, int offset, long data)
 	return ret;
 }
 
-/*
- * Called by kernel/ptrace.c when detaching..
- */
-void ptrace_disable(struct task_struct *child)
-{
-	/* Nothing to do. */
-}
-
 /*
  * Handle hitting a breakpoint.
  */
diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
index 5234d0c1dcaa..72e3eece72aa 100644
--- a/arch/microblaze/kernel/ptrace.c
+++ b/arch/microblaze/kernel/ptrace.c
@@ -162,8 +162,3 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 		ptrace_report_syscall_exit(regs, step);
 }
-
-void ptrace_disable(struct task_struct *child)
-{
-	/* nothing to do */
-}
diff --git a/arch/nios2/kernel/ptrace.c b/arch/nios2/kernel/ptrace.c
index cd62f310778b..de5f4199c45f 100644
--- a/arch/nios2/kernel/ptrace.c
+++ b/arch/nios2/kernel/ptrace.c
@@ -117,11 +117,6 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 	return &nios2_user_view;
 }
 
-void ptrace_disable(struct task_struct *child)
-{
-
-}
-
 long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
 		 unsigned long data)
 {
diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index 44f4b1ca315d..19e4d8057e24 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -210,10 +210,6 @@ unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 		return 0;
 }
 
-void ptrace_disable(struct task_struct *child)
-{
-}
-
 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
diff --git a/arch/sparc/kernel/ptrace_32.c b/arch/sparc/kernel/ptrace_32.c
index e7db48acb838..f6df84e12739 100644
--- a/arch/sparc/kernel/ptrace_32.c
+++ b/arch/sparc/kernel/ptrace_32.c
@@ -29,16 +29,6 @@
 
 /* #define ALLOW_INIT_TRACING */
 
-/*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure single step bits etc are not set.
- */
-void ptrace_disable(struct task_struct *child)
-{
-	/* nothing to do */
-}
-
 enum sparc_regset {
 	REGSET_GENERAL,
 	REGSET_FP,
diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c
index 86a7eb5c27ba..b20a16ebe533 100644
--- a/arch/sparc/kernel/ptrace_64.c
+++ b/arch/sparc/kernel/ptrace_64.c
@@ -83,16 +83,6 @@ static const struct pt_regs_offset regoffset_table[] = {
 	REG_OFFSET_END,
 };
 
-/*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure single step bits etc are not set.
- */
-void ptrace_disable(struct task_struct *child)
-{
-	/* nothing to do */
-}
-
 /* To get the necessary page struct, access_process_vm() first calls
  * get_user_pages().  This has done a flush_dcache_page() on the
  * accessed page.  Then our caller (copy_{to,from}_user_page()) did
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 1893d909e45c..77299bb65d97 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -579,6 +579,14 @@ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
 	return dead;
 }
 
+__weak void ptrace_disable(struct task_struct *child)
+{
+	/*
+	 * Nothing to do.., some architectures would replace it with
+	 * their own function.
+	 */
+}
+
 static int ptrace_detach(struct task_struct *child, unsigned int data)
 {
 	if (!valid_signal(data))
-- 
2.36.1