From: miod <miod@openbsd.org>
Date: Tue, 19 May 2015 20:39:12 +0000 (+0000)
Subject: Extend the libsa loadfile(9) granularity to tell apart randomness from the rest
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=cd230c960d89f0a893a1ea79bd9667802ad9a5bb;p=openbsd

Extend the libsa loadfile(9) granularity to tell apart randomness from the rest
of the kernel, and extend the array filled by loadfile to report the location
of the randomness area.

This doesn't introduce any change for bootblocks (save for a slightly larger
stack usage due to the larger array), for the new {LOAD,COUNT}_RANDOM bits
are included in the {LOAD,COUNT}_ALL masks everything uses or computes from.
---

diff --git a/sys/lib/libsa/loadfile.h b/sys/lib/libsa/loadfile.h
index 2c05e5a2a21..8cac6af5349 100644
--- a/sys/lib/libsa/loadfile.h
+++ b/sys/lib/libsa/loadfile.h
@@ -1,5 +1,5 @@
 /*	$NetBSD: loadfile.h,v 1.1 1999/04/28 09:08:50 christos Exp $	 */
-/*	$OpenBSD: loadfile.h,v 1.3 2008/06/26 05:42:20 ray Exp $	 */
+/*	$OpenBSD: loadfile.h,v 1.4 2015/05/19 20:39:12 miod Exp $	 */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -38,7 +38,9 @@
 #define	MARK_NSYM	2
 #define MARK_SYM	3
 #define	MARK_END	4
-#define	MARK_MAX	5
+#define	MARK_RANDOM	5
+#define	MARK_ERANDOM	6
+#define	MARK_MAX	7
 
 /*
  * Bit flags for sections to load
@@ -49,7 +51,8 @@
 #define	LOAD_BSS	0x0008
 #define	LOAD_SYM	0x0010
 #define	LOAD_HDR	0x0020
-#define LOAD_ALL	0x003f
+#define	LOAD_RANDOM	0x0040
+#define LOAD_ALL	0x007f
 
 #define	COUNT_TEXT	0x0100
 #define	COUNT_TEXTA	0x0200
@@ -57,7 +60,8 @@
 #define	COUNT_BSS	0x0800
 #define	COUNT_SYM	0x1000
 #define	COUNT_HDR	0x2000
-#define COUNT_ALL	0x3f00
+#define	COUNT_RANDOM	0x4000
+#define COUNT_ALL	0x7f00
 
 int loadfile(const char *, u_long *, int);
 
diff --git a/sys/lib/libsa/loadfile_elf.c b/sys/lib/libsa/loadfile_elf.c
index 083a286d5b0..432f977e712 100644
--- a/sys/lib/libsa/loadfile_elf.c
+++ b/sys/lib/libsa/loadfile_elf.c
@@ -1,5 +1,5 @@
 /* $NetBSD: loadfile.c,v 1.10 2000/12/03 02:53:04 tsutsui Exp $ */
-/* $OpenBSD: loadfile_elf.c,v 1.10 2014/10/26 10:33:48 miod Exp $ */
+/* $OpenBSD: loadfile_elf.c,v 1.11 2015/05/19 20:39:12 miod Exp $ */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -99,7 +99,7 @@ ELFNAME(exec)(int fd, Elf_Ehdr *elf, u_long *marks, int flags)
 			int m;
 
 			/* Fill segment if asked for. */
-			if (flags & LOAD_DATA) {
+			if (flags & LOAD_RANDOM) {
 				for (pos = 0; pos < phdr[i].p_filesz;
 				    pos += m) {
 					m = MIN(phdr[i].p_filesz - pos,
@@ -108,6 +108,11 @@ ELFNAME(exec)(int fd, Elf_Ehdr *elf, u_long *marks, int flags)
 					    m);
 				}
 			}
+			if (flags & (LOAD_RANDOM | COUNT_RANDOM)) {
+				marks[MARK_RANDOM] = LOADADDR(phdr[i].p_paddr);
+				marks[MARK_ERANDOM] =
+				    marks[MARK_RANDOM] + phdr[i].p_filesz;
+			}
 			continue;
 		}