From 5353bfc3b42e775870f8a456a8504a69ce8a1450 Mon Sep 17 00:00:00 2001
From: John Polstra <jdp@FreeBSD.org>
Date: Wed, 21 Apr 1999 04:06:57 +0000
Subject: [PATCH] After relocating the main program, but before calling any of
 the _init() functions, initialize the global variables "__progname" and
 "environ".  This makes it possible for the _init() functions to call things
 like getenv() and err().

---
 libexec/rtld-elf/rtld.c | 40 +++++++++++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 7196575ddda..5ac7fcdebef 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -22,7 +22,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *      $Id: rtld.c,v 1.20 1999/04/09 00:28:31 jdp Exp $
+ *      $Id: rtld.c,v 1.21 1999/04/09 06:42:00 jdp Exp $
  */
 
 /*
@@ -76,6 +76,7 @@ typedef void (*func_ptr_type)();
 /*
  * Function declarations.
  */
+static const char *basename(const char *);
 static void call_fini_functions(Obj_Entry *);
 static void call_init_functions(Obj_Entry *);
 static void die(void);
@@ -95,16 +96,13 @@ static Obj_Entry *obj_from_addr(const void *);
 static int relocate_objects(Obj_Entry *, bool);
 static void rtld_exit(void);
 static char *search_library_path(const char *, const char *);
+static void set_program_var(const char *, const void *);
 static void unref_object_dag(Obj_Entry *);
 static void trace_loaded_objects(Obj_Entry *obj);
 
 void r_debug_state(void);
 void xprintf(const char *, ...);
 
-#ifdef DEBUG
-static const char *basename(const char *);
-#endif
-
 /*
  * Data declarations.
  */
@@ -296,6 +294,10 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
     if (do_copy_relocations(obj_main) == -1)
 	die();
 
+    dbg("initializing key program variables");
+    set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
+    set_program_var("environ", env);
+
     dbg("calling _init functions");
     call_init_functions(obj_main->next);
 
@@ -355,14 +357,12 @@ _rtld_error(const char *fmt, ...)
     va_end(ap);
 }
 
-#ifdef DEBUG
 static const char *
 basename(const char *name)
 {
     const char *p = strrchr(name, '/');
     return p != NULL ? p + 1 : name;
 }
-#endif
 
 static void
 call_fini_functions(Obj_Entry *first)
@@ -1365,6 +1365,32 @@ r_debug_state(void)
 {
 }
 
+/*
+ * Set a pointer variable in the main program to the given value.  This
+ * is used to set key variables such as "environ" before any of the
+ * init functions are called.
+ */
+static void
+set_program_var(const char *name, const void *value)
+{
+    const Obj_Entry *obj;
+    unsigned long hash;
+
+    hash = elf_hash(name);
+    for (obj = obj_main;  obj != NULL;  obj = obj->next) {
+	const Elf_Sym *def;
+
+	if ((def = symlook_obj(name, hash, obj, false)) != NULL) {
+	    const void **addr;
+
+	    addr = (const void **)(obj->relocbase + def->st_value);
+	    dbg("\"%s\": *%p <-- %p", name, addr, value);
+	    *addr = value;
+	    break;
+	}
+    }
+}
+
 /*
  * Search the symbol table of a single shared object for a symbol of
  * the given name.  Returns a pointer to the symbol, or NULL if no