Module Name: src
Committed By: kamil
Date: Fri Apr 27 16:50:57 UTC 2018
Modified Files:
src/sys/kern: sys_ptrace_common.c
Log Message:
Correct XXX comment in the ptrace(2) kernel code
Explain I and D read/write operations and its history, removing dummy XXX
comments.
Sponsored by <The NetBSD Foundation>
To generate a diff of this commit:
cvs rdiff -u -r1.36 -r1.37 src/sys/kern/sys_ptrace_common.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/sys_ptrace_common.c
diff -u src/sys/kern/sys_ptrace_common.c:1.36 src/sys/kern/sys_ptrace_common.c:1.37
--- src/sys/kern/sys_ptrace_common.c:1.36 Sun Apr 8 14:46:32 2018
+++ src/sys/kern/sys_ptrace_common.c Fri Apr 27 16:50:56 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_ptrace_common.c,v 1.36 2018/04/08 14:46:32 kamil Exp $ */
+/* $NetBSD: sys_ptrace_common.c,v 1.37 2018/04/27 16:50:56 kamil Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -118,7 +118,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_ptrace_common.c,v 1.36 2018/04/08 14:46:32 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_ptrace_common.c,v 1.37 2018/04/27 16:50:56 kamil Exp $");
#ifdef _KERNEL_OPT
#include "opt_ptrace.h"
@@ -1020,12 +1020,21 @@ do_ptrace(struct ptrace_methods *ptm, st
t->p_opptr = t->p_pptr;
break;
- case PT_WRITE_I: /* XXX no separate I and D spaces */
+ /*
+ * The I and D separate address space has been inherited from PDP-11.
+ * The 16-bit UNIX started with a single address space per program,
+ * but was extended to two 16-bit (2 x 64kb) address spaces.
+ *
+ * We no longer maintain this feature in maintained architectures, but
+ * we keep the API for backward compatiblity. Currently the I and D
+ * operations are exactly the same and not distinguished in debuggers.
+ */
+ case PT_WRITE_I:
case PT_WRITE_D:
write = 1;
tmp = data;
/* FALLTHROUGH */
- case PT_READ_I: /* XXX no separate I and D spaces */
+ case PT_READ_I:
case PT_READ_D:
piod.piod_addr = &tmp;
piod.piod_len = sizeof(tmp);
