From: kettenis <kettenis@openbsd.org>
Date: Tue, 23 Aug 2016 06:46:17 +0000 (+0000)
Subject: Implement support for DT_INIT_ARRAY, DT_FINI_ARRAY and DT_PREINIT_ARRAY.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=86fa57a2792c6374b0849dd7b818a11e676e60ba;p=openbsd

Implement support for DT_INIT_ARRAY, DT_FINI_ARRAY and DT_PREINIT_ARRAY.
Don't skip DT_INIT and DT_FINI for the main executable.  This matches what
Linux and Solaris do.

ok guenther@
---

diff --git a/libexec/ld.so/loader.c b/libexec/ld.so/loader.c
index 6fcff3d62ac..b85db853f89 100644
--- a/libexec/ld.so/loader.c
+++ b/libexec/ld.so/loader.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: loader.c,v 1.165 2016/08/14 04:30:39 guenther Exp $ */
+/*	$OpenBSD: loader.c,v 1.166 2016/08/23 06:46:17 kettenis Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -53,6 +53,7 @@ void _dl_debug_state(void);
 void _dl_setup_env(const char *_argv0, char **_envp);
 void _dl_dtors(void);
 void _dl_fixup_user_env(void);
+void _dl_call_preinit(elf_object_t *);
 void _dl_call_init_recurse(elf_object_t *object, int initfirst);
 
 int  _dl_pagesz;
@@ -73,9 +74,31 @@ struct r_debug *_dl_debug_map;
 void _dl_dopreload(char *paths);
 
 /*
- * Run dtors for all objects that are eligible.
+ * Run dtors for a single object.
  */
+void
+_dl_run_dtors(elf_object_t *obj)
+{
+	if (obj->dyn.fini_array) {
+		int num = obj->dyn.fini_arraysz / sizeof(Elf_Addr);
+		int i;
+
+		DL_DEB(("doing finiarray obj %p @%p: [%s]\n",
+		    obj, obj->dyn.fini_array, obj->load_name));
+		for (i = num; i > 0; i--)
+			(*obj->dyn.fini_array[i-1])();
+	}
 
+	if (obj->dyn.fini) {
+		DL_DEB(("doing dtors obj %p @%p: [%s]\n",
+		    obj, obj->dyn.fini, obj->load_name));
+		(*obj->dyn.fini)();
+	}
+}
+
+/*
+ * Run dtors for all objects that are eligible.
+ */
 void
 _dl_run_all_dtors(void)
 {
@@ -91,10 +114,10 @@ _dl_run_all_dtors(void)
 
 	while (fini_complete == 0) {
 		fini_complete = 1;
-		for (node = _dl_objects->next;
+		for (node = _dl_objects;
 		    node != NULL;
 		    node = node->next) {
-			if ((node->dyn.fini) &&
+			if ((node->dyn.fini || node->dyn.fini_array) &&
 			    (OBJECT_REF_CNT(node) == 0) &&
 			    (node->status & STAT_INIT_DONE) &&
 			    ((node->status & STAT_FINI_DONE) == 0)) {
@@ -105,10 +128,10 @@ _dl_run_all_dtors(void)
 					node->status |= STAT_FINI_READY;
 			    }
 		}
-		for (node = _dl_objects->next;
+		for (node = _dl_objects;
 		    node != NULL;
 		    node = node->next ) {
-			if ((node->dyn.fini) &&
+			if ((node->dyn.fini || node->dyn.fini_array) &&
 			    (OBJECT_REF_CNT(node) == 0) &&
 			    (node->status & STAT_INIT_DONE) &&
 			    ((node->status & STAT_FINI_DONE) == 0) &&
@@ -120,18 +143,14 @@ _dl_run_all_dtors(void)
 		}
 
 
-		for (node = _dl_objects->next;
+		for (node = _dl_objects;
 		    node != NULL;
 		    node = node->next ) {
 			if (node->status & STAT_FINI_READY) {
-				DL_DEB(("doing dtors obj %p @%p: [%s]\n",
-				    node, node->dyn.fini,
-				    node->load_name));
-
 				fini_complete = 0;
 				node->status |= STAT_FINI_DONE;
 				node->status &= ~STAT_FINI_READY;
-				(*node->dyn.fini)();
+				_dl_run_dtors(node);
 			}
 		}
 
@@ -157,11 +176,6 @@ _dl_dtors(void)
 
 	DL_DEB(("doing dtors\n"));
 
-	/* main program runs its dtors itself
-	 * but we want to run dtors on all it's children);
-	 */
-	_dl_objects->status |= STAT_FINI_DONE;
-
 	_dl_objects->opencount--;
 	_dl_notify_unload_shlib(_dl_objects);
 
@@ -605,14 +619,10 @@ _dl_boot(const char **argv, char **envp, const long dyn_loff, long *dl_data)
 	_dl_debug_state();
 
 	/*
-	 * The first object is the executable itself,
-	 * it is responsible for running it's own ctors/dtors
-	 * thus do NOT run the ctors for the executable, all of
-	 * the shared libraries which follow.
 	 * Do not run init code if run from ldd.
 	 */
 	if (_dl_objects->next != NULL) {
-		_dl_objects->status |= STAT_INIT_DONE;
+		_dl_call_preinit(_dl_objects);
 		_dl_call_init(_dl_objects);
 	}
 
@@ -689,6 +699,20 @@ _dl_rtld(elf_object_t *object)
 	return (fails);
 }
 
+void
+_dl_call_preinit(elf_object_t *object)
+{
+	if (object->dyn.preinit_array) {
+		int num = object->dyn.preinit_arraysz / sizeof(Elf_Addr);
+		int i;
+
+		DL_DEB(("doing preinitarray obj %p @%p: [%s]\n",
+		    object, object->dyn.preinit_array, object->load_name));
+		for (i = 0; i < num; i++)
+			(*object->dyn.preinit_array[i])();
+	}
+}
+
 void
 _dl_call_init(elf_object_t *object)
 {
@@ -723,6 +747,16 @@ _dl_call_init_recurse(elf_object_t *object, int initfirst)
 		(*object->dyn.init)();
 	}
 
+	if (object->dyn.init_array) {
+		int num = object->dyn.init_arraysz / sizeof(Elf_Addr);
+		int i;
+
+		DL_DEB(("doing initarray obj %p @%p: [%s]\n",
+		    object, object->dyn.init_array, object->load_name));
+		for (i = 0; i < num; i++)
+			(*object->dyn.init_array[i])();
+	}
+
 	object->status |= STAT_INIT_DONE;
 }
 
diff --git a/libexec/ld.so/resolve.c b/libexec/ld.so/resolve.c
index dc384c7bed0..02d96833cb2 100644
--- a/libexec/ld.so/resolve.c
+++ b/libexec/ld.so/resolve.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: resolve.c,v 1.74 2016/08/08 21:59:20 guenther Exp $ */
+/*	$OpenBSD: resolve.c,v 1.75 2016/08/23 06:46:17 kettenis Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -246,6 +246,7 @@ _dl_finalize_object(const char *objname, Elf_Dyn *dynp, Elf_Phdr *phdrp,
     int phdrc, const int objtype, const long lbase, const long obase)
 {
 	elf_object_t *object;
+
 #if 0
 	_dl_printf("objname [%s], dynp %p, objtype %x lbase %lx, obase %lx\n",
 	    objname, dynp, objtype, lbase, obase);
@@ -322,6 +323,12 @@ _dl_finalize_object(const char *objname, Elf_Dyn *dynp, Elf_Phdr *phdrp,
 		object->Dyn.info[DT_FINI] += obase;
 	if (object->Dyn.info[DT_JMPREL])
 		object->Dyn.info[DT_JMPREL] += obase;
+	if (object->Dyn.info[DT_INIT_ARRAY])
+		object->Dyn.info[DT_INIT_ARRAY] += obase;
+	if (object->Dyn.info[DT_FINI_ARRAY])
+		object->Dyn.info[DT_FINI_ARRAY] += obase;
+	if (object->Dyn.info[DT_PREINIT_ARRAY])
+		object->Dyn.info[DT_PREINIT_ARRAY] += obase;
 
 	if (object->Dyn.info[DT_HASH] != 0) {
 		Elf_Word *hashtab = (Elf_Word *)object->Dyn.info[DT_HASH];
diff --git a/libexec/ld.so/resolve.h b/libexec/ld.so/resolve.h
index df0469c9fc0..24dbef66133 100644
--- a/libexec/ld.so/resolve.h
+++ b/libexec/ld.so/resolve.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: resolve.h,v 1.79 2016/08/08 21:59:20 guenther Exp $ */
+/*	$OpenBSD: resolve.h,v 1.80 2016/08/23 06:46:17 kettenis Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -81,13 +81,23 @@ struct elf_object {
 			const char	*soname;
 			const char	*rpath;
 			Elf_Addr	symbolic;
-			Elf_Rel	*rel;
+			Elf_Rel		*rel;
 			Elf_Addr	relsz;
 			Elf_Addr	relent;
 			Elf_Addr	pltrel;
 			Elf_Addr	debug;
 			Elf_Addr	textrel;
 			Elf_Addr	jmprel;
+			Elf_Addr	bind_now;
+			void		(**init_array)(void);
+			void		(**fini_array)(void);
+			Elf_Addr	init_arraysz;
+			Elf_Addr	fini_arraysz;
+			const char	*runpath;
+			Elf_Addr	flags;
+			Elf_Addr	encoding;
+			void		(**preinit_array)(void);
+			Elf_Addr	preinit_arraysz;
 		} u;
 	} Dyn;
 #define dyn Dyn.u
diff --git a/sys/sys/exec_elf.h b/sys/sys/exec_elf.h
index f1c5d48dc16..f3186e6db6e 100644
--- a/sys/sys/exec_elf.h
+++ b/sys/sys/exec_elf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: exec_elf.h,v 1.59 2016/07/14 06:03:46 guenther Exp $	*/
+/*	$OpenBSD: exec_elf.h,v 1.60 2016/08/23 06:46:17 kettenis Exp $	*/
 /*
  * Copyright (c) 1995, 1996 Erik Theisen.  All rights reserved.
  *
@@ -526,7 +526,7 @@ typedef struct {
 #define DF_1_CONLFAT	0x00002000
 
 /* ld.so: number of low tags that are used saved internally (0 .. DT_NUM-1) */
-#define DT_NUM		(DT_JMPREL+1)
+#define DT_NUM		(DT_PREINIT_ARRAYSZ+1)
 
 /* Standard ELF hashing function */
 unsigned int elf_hash(const unsigned char *name);