Module Name: src
Committed By: riastradh
Date: Sun Mar 30 16:17:05 UTC 2025
Modified Files:
src/lib/libc: Makefile
src/lib/libc/gen: ctype_guard.h
Log Message:
ctype(3): Actually conditionalize guard page on shared libc.
Apparently we build the libc .o files with -fPIC too (I guess this is
so that libc.a works in position-independent executables? but why
don't they just use libc_pic.a?), so use a purpose-built cpp macro
_CTYPE_DYNAMIC for this instead of using __PIC__.
Now this shows the right symbol sizes:
$ readelf -s ctype_.pico | grep _C_ctype_tab_guarded_
3: 0000000000000000 4610 OBJECT LOCAL DEFAULT 11 _C_ctype_tab_guarded_
$ readelf -s ctype_.po | grep _C_ctype_tab_guarded_
3: 0000000000000000 514 OBJECT LOCAL DEFAULT 7 _C_ctype_tab_guarded_
$ readelf -s ctype_.o | grep _C_ctype_tab_guarded_
3: 0000000000000000 514 OBJECT LOCAL DEFAULT 7 _C_ctype_tab_guarded_
PR lib/58208: ctype(3) provides poor runtime feedback of abuse
To generate a diff of this commit:
cvs rdiff -u -r1.174 -r1.175 src/lib/libc/Makefile
cvs rdiff -u -r1.4 -r1.5 src/lib/libc/gen/ctype_guard.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/Makefile
diff -u src/lib/libc/Makefile:1.174 src/lib/libc/Makefile:1.175
--- src/lib/libc/Makefile:1.174 Mon May 29 18:25:52 2023
+++ src/lib/libc/Makefile Sun Mar 30 16:17:04 2025
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.174 2023/05/29 18:25:52 lukem Exp $
+# $NetBSD: Makefile,v 1.175 2025/03/30 16:17:04 riastradh Exp $
# @(#)Makefile 8.2 (Berkeley) 2/3/94
#
# All library objects contain sccsid strings by default; they may be
@@ -157,6 +157,10 @@ FILESDIR= /var/db
# dlopen() from within statically linked binaries.
CSHLIBFLAGS+= -D_I18N_DYNAMIC
+# Tell ctype(3) that this is a dynamic libc, so if appropriate it
+# should allocate a guard page.
+CSHLIBFLAGS+= -D_CTYPE_DYNAMIC
+
.include <bsd.lib.mk>
# force the dynamic linker to initialize libc first
Index: src/lib/libc/gen/ctype_guard.h
diff -u src/lib/libc/gen/ctype_guard.h:1.4 src/lib/libc/gen/ctype_guard.h:1.5
--- src/lib/libc/gen/ctype_guard.h:1.4 Sun Mar 30 15:38:38 2025
+++ src/lib/libc/gen/ctype_guard.h Sun Mar 30 16:17:05 2025
@@ -1,4 +1,4 @@
-/* $NetBSD: ctype_guard.h,v 1.4 2025/03/30 15:38:38 riastradh Exp $ */
+/* $NetBSD: ctype_guard.h,v 1.5 2025/03/30 16:17:05 riastradh Exp $ */
/*-
* Copyright (c) 2025 The NetBSD Foundation, Inc.
@@ -96,7 +96,7 @@
#if defined(__CHAR_UNSIGNED__) /* disable if char is unsigned */
# define _CTYPE_GUARD_PAGE 0
-#elif defined(__PIC__) /* enable in shared libc */
+#elif defined(_CTYPE_DYNAMIC) /* enable in shared libc */
# define _CTYPE_GUARD_PAGE 1
#else /* static libc -- let's aim for space-efficiency for now */
# define _CTYPE_GUARD_PAGE 0
