[src/trunk]: src/libexec/ld.elf_so Use alloca(3) instead of local xmalloc for...

[roy <roy%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4e9683faf174
branches:  trunk
changeset: 753156:4e9683faf174
user:      roy <roy%NetBSD.org@localhost>
date:      Thu Mar 18 22:17:55 2010 +0000

description:
Use alloca(3) instead of local xmalloc for creating our DoneLists.
This allows threaded programs to use us a little better, PR lib/43005.
We need to disable SSP when using alloca.

diffstat:

 libexec/ld.elf_so/Makefile |   6 +++++-
 libexec/ld.elf_so/rtld.c   |   8 ++------
 libexec/ld.elf_so/rtld.h   |  13 +++++++------
 libexec/ld.elf_so/symbol.c |   6 ++----
 4 files changed, 16 insertions(+), 17 deletions(-)

diffs (114 lines):

diff -r 75e31281f24a -r 4e9683faf174 libexec/ld.elf_so/Makefile
--- a/libexec/ld.elf_so/Makefile        Thu Mar 18 22:11:48 2010 +0000
+++ b/libexec/ld.elf_so/Makefile        Thu Mar 18 22:17:55 2010 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: Makefile,v 1.93 2009/12/13 09:31:47 mrg Exp $
+#      $NetBSD: Makefile,v 1.94 2010/03/18 22:17:55 roy Exp $
 #
 # NOTE: when changing ld.so, ensure that ldd still compiles.
 #
@@ -16,6 +16,10 @@
 .include <bsd.init.mk>                 # for OBJECT_FMT definition
 .include <bsd.shlib.mk>                        # for SHLINKINSTALLDIR definition
 
+# We use alloca
+USE_FORT=      no
+USE_SSP=       no
+
 .if defined(LDELFSO_MACHINE_CPU) && !empty(LDELFSO_MACHINE_CPU) && \
     exists(${.CURDIR}/arch/${LDELFSO_MACHINE_CPU})
 ARCHSUBDIR=    ${LDELFSO_MACHINE_CPU}
diff -r 75e31281f24a -r 4e9683faf174 libexec/ld.elf_so/rtld.c
--- a/libexec/ld.elf_so/rtld.c  Thu Mar 18 22:11:48 2010 +0000
+++ b/libexec/ld.elf_so/rtld.c  Thu Mar 18 22:17:55 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld.c,v 1.129 2010/02/27 11:16:38 roy Exp $    */
+/*     $NetBSD: rtld.c,v 1.130 2010/03/18 22:17:55 roy Exp $    */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: rtld.c,v 1.129 2010/02/27 11:16:38 roy Exp $");
+__RCSID("$NetBSD: rtld.c,v 1.130 2010/03/18 22:17:55 roy Exp $");
 #endif /* not lint */
 
 #include <err.h>
@@ -822,8 +822,6 @@
        def = _rtld_symlook_list(name, hash, &_rtld_list_main, &obj, false,
            &donelist);
 
-       _rtld_donelist_clear(&donelist);
-
        if (def != NULL)
                return obj->relocbase + def->st_value;
        return(NULL);
@@ -919,10 +917,8 @@
                        _rtld_donelist_init(&depth);
                        def = _rtld_symlook_needed(name, hash, &fake, &defobj,
                            false, &donelist, &depth);
-                       _rtld_donelist_clear(&depth);
                }
 
-               _rtld_donelist_clear(&donelist);
                break;
        }
        
diff -r 75e31281f24a -r 4e9683faf174 libexec/ld.elf_so/rtld.h
--- a/libexec/ld.elf_so/rtld.h  Thu Mar 18 22:11:48 2010 +0000
+++ b/libexec/ld.elf_so/rtld.h  Thu Mar 18 22:17:55 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld.h,v 1.89 2010/02/27 11:16:38 roy Exp $     */
+/*     $NetBSD: rtld.h,v 1.90 2010/03/18 22:17:55 roy Exp $     */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -61,13 +61,14 @@
 
 /*
  * Fill in a DoneList with an allocation large enough to hold all of
- * the currently-loaded objects.
+ * the currently-loaded objects. Keep this in a macro since it calls
+ * alloca and we want that to occur within the scope of the caller.
  */
-#define _rtld_donelist_init(dlp)                                               \
-    ((dlp)->objs = xmalloc(_rtld_objcount * sizeof((dlp)->objs[0])),   \
-    (dlp)->num_alloc = _rtld_objcount,                                 \
+#define _rtld_donelist_init(dlp)                                       \
+    ((dlp)->num_alloc = _rtld_objcount,                                        \
+    (dlp)->objs = alloca((dlp)->num_alloc * sizeof((dlp)->objs[0])),   \
+    assert((dlp)->objs != NULL),                                       \
     (dlp)->num_used = 0)
-#define _rtld_donelist_clear(dlp)              xfree((dlp)->objs)
 
 #endif /* _RTLD_SOURCE */
 
diff -r 75e31281f24a -r 4e9683faf174 libexec/ld.elf_so/symbol.c
--- a/libexec/ld.elf_so/symbol.c        Thu Mar 18 22:11:48 2010 +0000
+++ b/libexec/ld.elf_so/symbol.c        Thu Mar 18 22:17:55 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: symbol.c,v 1.51 2010/02/27 11:16:38 roy Exp $   */
+/*     $NetBSD: symbol.c,v 1.52 2010/03/18 22:17:55 roy Exp $   */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: symbol.c,v 1.51 2010/02/27 11:16:38 roy Exp $");
+__RCSID("$NetBSD: symbol.c,v 1.52 2010/03/18 22:17:55 roy Exp $");
 #endif /* not lint */
 
 #include <err.h>
@@ -479,8 +479,6 @@
                }
        }
 
-       _rtld_donelist_clear(&donelist);
-
        if (def != NULL)
                *defobj_out = defobj;
        return def;