PTRACE_POKEDATA consolidation

Identical implementations of PTRACE_POKEDATA go into generic_ptrace_pokedata()
function.

AFAICS, fix bug on xtensa where successful PTRACE_POKEDATA will nevertheless
return EPERM.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/m32r/kernel/ptrace.c b/arch/m32r/kernel/ptrace.c
index 01a1c9a..57a92ef 100644
--- a/arch/m32r/kernel/ptrace.c
+++ b/arch/m32r/kernel/ptrace.c
@@ -619,15 +619,9 @@
 	 */
 	case PTRACE_POKETEXT:
 	case PTRACE_POKEDATA:
-		ret = access_process_vm(child, addr, &data, sizeof(data), 1);
-		if (ret == sizeof(data)) {
-			ret = 0;
-			if (request == PTRACE_POKETEXT) {
-				invalidate_cache();
-			}
-		} else {
-			ret = -EIO;
-		}
+		ret = generic_ptrace_pokedata(child, addr, data);
+		if (ret == 0 && request == PTRACE_POKETEXT)
+			invalidate_cache();
 		break;
 
 	/*