m32r: convert to generic sys_ptrace

Convert m32r to the generic sys_ptrace.  The conversion requires an
architecture hook after ptrace_attach which this patch adds.  The hook
will also be needed for a conersion of ia64 to the generic ptrace code.

Thanks to Hirokazu Takata for fixing a bug in the first version of this
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 0870523..a73ebd3 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -453,6 +453,10 @@
 	return child;
 }
 
+#ifndef arch_ptrace_attach
+#define arch_ptrace_attach(child)	do { } while (0)
+#endif
+
 #ifndef __ARCH_SYS_PTRACE
 asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
 {
@@ -476,6 +480,12 @@
 
 	if (request == PTRACE_ATTACH) {
 		ret = ptrace_attach(child);
+		/*
+		 * Some architectures need to do book-keeping after
+		 * a ptrace attach.
+		 */
+		if (!ret)
+			arch_ptrace_attach(child);
 		goto out_put_task_struct;
 	}