Consolidate PTRACE_DETACH

Identical handlers of PTRACE_DETACH go into ptrace_request().
Not touching compat code.
Not touching archs that don't call ptrace_request.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.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 3eca7a5..0870523 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -386,6 +386,9 @@
 	case PTRACE_SETSIGINFO:
 		ret = ptrace_setsiginfo(child, (siginfo_t __user *) data);
 		break;
+	case PTRACE_DETACH:	 /* detach a process that was attached. */
+		ret = ptrace_detach(child, data);
+		break;
 	default:
 		break;
 	}