Update.

1998-03-06 17:04  Ulrich Drepper  <drepper@cygnus.com>

	* libc.map: Add _dl_debug_impcalls, _dl_debug_fd, _dl_sysdep_output,
	__libc_start_main.
	* csu/Makefile (routines): Add libc-start.
	* elf/dl-error.c: Remove declaration of _dl_argv.  Include <unitsd.h>.
	* elf/dl-lookup.c: Likewise.
	* elf/dl-version.c: Likewise.
	* sysdeps/i386/dl-machine.h: Likewise.
	* elf/link.h: Declare _dl_argv, _dl_debug_fd.
	Declare _dl_sysdep_output.  Make _dl_sysdep_fatal, _dl_sysdep_error and
	_dl_sysdep_message macros which use _dl_sysdep_output.
	* elf/dl-fini.c: Write out which destructor is called while debugging.
	* elf/dl-init.c: Likewise for constructor.
	* elf/dl-load.c: Use _dl_debug_message instead of _dl_sysdep_message.
	* elf/dl-misc.c: Remove _dl_sysdep_fatal, _dl_sysdep_error and
	_dl_sysdep_message.  Add _dl_sysdep_output.
	* elf/rtld.c: Recognize LD_DEBUG_OUTPUT.  Set _dl_debug_fd if
	this file can be opened.
	For LD_DEBUG=libs also set _dl_debug_impcalls.
	* sysdeps/generic/dl-cache.c: Include unistd.h.
	* sysdeps/generic/libc-start.c: New file.
	* sysdeps/i386/elf/start.S: Don't call main directly, call
	* sysdeps/unix/sysv/linux/libc-start.c: New file.
	__libc_start_main instead.

	* elf/Makefile ($(objpfx)ld.so): Add $(load-map-file) as dependency.

ChangeLog

@@ -1,3 +1,31 @@
+1998-03-06 17:04  Ulrich Drepper  <drepper@cygnus.com>
+
+	* libc.map: Add _dl_debug_impcalls, _dl_debug_fd, _dl_sysdep_output,
+	__libc_start_main.
+	* csu/Makefile (routines): Add libc-start.
+	* elf/dl-error.c: Remove declaration of _dl_argv.  Include <unitsd.h>.
+	* elf/dl-lookup.c: Likewise.
+	* elf/dl-version.c: Likewise.
+	* sysdeps/i386/dl-machine.h: Likewise.
+	* elf/link.h: Declare _dl_argv, _dl_debug_fd.
+	Declare _dl_sysdep_output.  Make _dl_sysdep_fatal, _dl_sysdep_error and
+	_dl_sysdep_message macros which use _dl_sysdep_output.
+	* elf/dl-fini.c: Write out which destructor is called while debugging.
+	* elf/dl-init.c: Likewise for constructor.
+	* elf/dl-load.c: Use _dl_debug_message instead of _dl_sysdep_message.
+	* elf/dl-misc.c: Remove _dl_sysdep_fatal, _dl_sysdep_error and
+	_dl_sysdep_message.  Add _dl_sysdep_output.
+	* elf/rtld.c: Recognize LD_DEBUG_OUTPUT.  Set _dl_debug_fd if
+	this file can be opened.
+	For LD_DEBUG=libs also set _dl_debug_impcalls.
+	* sysdeps/generic/dl-cache.c: Include unistd.h.
+	* sysdeps/generic/libc-start.c: New file.
+	* sysdeps/i386/elf/start.S: Don't call main directly, call
+	* sysdeps/unix/sysv/linux/libc-start.c: New file.
+	__libc_start_main instead.
+
+	* elf/Makefile ($(objpfx)ld.so): Add $(load-map-file) as dependency.
+
 1998-03-06  Ulrich Drepper  <drepper@cygnus.com>
 
 	* nss/nsswitch.c (__nss_nscd_not_available): Removed.

csu/Makefile

@@ -27,7 +27,7 @@
 
 subdir := csu
 
-routines = init-first
+routines = init-first libc-start
 csu-dummies = $(filter-out $(start-installed-name),crt1.o Mcrt1.o)
 extra-objs = start.o gmon-start.o \
 	     $(start-installed-name) g$(start-installed-name) \

elf/Makefile

@@ -109,7 +109,7 @@ $(rtld-ldscript): $(rtld-ldscript-in) $(rtld-parms)
 	    -e 's#@@rtld-base@@#$(rtld-base)#' $< >$@
 endif
 
-$(objpfx)ld.so: $(objpfx)librtld.os $(addprefix $(objpfx),$(rtld-ldscript))
+$(objpfx)ld.so: $(objpfx)librtld.os $(addprefix $(objpfx),$(rtld-ldscript)) $(load-map-file)
 	$(rtld-link) -Wl,-soname=$(rtld-installed-name)
 
 define rtld-link

elf/dl-error.c

@@ -1,5 +1,5 @@
 /* Error handling for runtime dynamic linker.
-   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -17,11 +17,11 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
-#include <stddef.h>
 #include <link.h>
 #include <setjmp.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 /* This is the internal function we use to generate the error string.  */
 extern char *_strerror_internal __P ((int, char *, size_t));
@@ -76,7 +76,6 @@ _dl_signal_error (int errcode,
   else
     {
       /* Lossage while resolving the program's own symbols is always fatal.  */
-      extern char **_dl_argv;	/* Set in rtld.c at startup.  */
       char buffer[1024];
       _dl_sysdep_fatal (_dl_argv[0] ?: "<program name unknown>",
 			": error in loading shared libraries: ",

elf/dl-fini.c

@@ -1,5 +1,5 @@
 /* Call the termination functions of loaded shared objects.
-   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -29,7 +29,15 @@ _dl_fini (void)
       {
 	if (l->l_info[DT_FINI] &&
 	    !(l->l_name[0] == '\0' && l->l_type == lt_executable))
+	  {
+	    /* When debugging print a message first.  */
+	    if (_dl_debug_impcalls)
+	      _dl_debug_message ("\n\tcalling fini: ",
+				 l->l_name[0] ? l->l_name : _dl_argv[0],
+				 "\n", NULL);
+
 	    (*(void (*) (void)) (l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr)) ();
+	  }
 	/* Make sure nothing happens if we are called twice.  */
 	l->l_init_called = 0;
       }

elf/dl-init.c

@@ -1,5 +1,5 @@
 /* Return the next shared object initializer function not yet run.
-   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -57,6 +57,13 @@ _dl_init_next (struct link_map *map)
 	{
 	  /* Run this object's initializer.  */
 	  l->l_init_running = 1;
+
+	  /* Print a debug message if wanted.  */
+	  if (_dl_debug_impcalls)
+	    _dl_debug_message ("\tcalling init: ",
+				l->l_name[0] ? l->l_name : _dl_argv[0],
+				"\n\n", NULL);
+
 	  return l->l_addr + l->l_info[DT_INIT]->d_un.d_ptr;
 	}
 

elf/dl-load.c

@@ -92,9 +92,6 @@ ELF_PREFERRED_ADDRESS_DATA;
 
 size_t _dl_pagesize;
 
-/* Arguments passed to the dynamic linker.  */
-extern char **_dl_argv;
-
 extern const char *_dl_platform;
 extern size_t _dl_platformlen;
 
@@ -879,7 +876,7 @@ open_path (const char *name, size_t namelen, int preloaded,
 
           /* Print name we try if this is wanted.  */
 	  if (_dl_debug_libs)
-	    _dl_sysdep_message ("\t  trying file=", buf, "\n", NULL);
+	    _dl_debug_message ("\t  trying file=", buf, "\n", NULL);
 
 	  fd = __open (buf, O_RDONLY);
 	  if (this_dir->machdirstatus == unknown)
@@ -934,7 +931,7 @@ open_path (const char *name, size_t namelen, int preloaded,
 
 	  /* Print name we try if this is wanted.  */
 	  if (_dl_debug_libs)
-	    _dl_sysdep_message ("\t  trying file=", buf, "\n", NULL);
+	    _dl_debug_message ("\t  trying file=", buf, "\n", NULL);
 
 	  fd = __open (buf, O_RDONLY);
 	  if (this_dir->dirstatus == unknown)
@@ -1053,7 +1050,7 @@ _dl_map_object (struct link_map *loader, const char *name, int preloaded,
       size_t namelen = strlen (name) + 1;
 
       if (_dl_debug_libs)
-	_dl_sysdep_message ("\tfind library=", name, "; searching\n", NULL);
+	_dl_debug_message ("\tfind library=", name, "; searching\n", NULL);
 
       fd = -1;
 
@@ -1117,7 +1114,7 @@ _dl_map_object (struct link_map *loader, const char *name, int preloaded,
 
       /* Add another newline when we a tracing the library loading.  */
       if (_dl_debug_libs)
-        _dl_sysdep_message ("\n", NULL);
+        _dl_debug_message ("\n", NULL);
     }
   else
     {

elf/dl-lookup.c

@@ -280,7 +280,6 @@ _dl_lookup_versioned_symbol (const char *undef_name, const ElfW(Sym) **ref,
 			     const struct r_found_version *version,
 			     int reloc_type)
 {
-  extern char **_dl_argv;
   const unsigned long int hash = _dl_elf_hash (undef_name);
   struct sym_val current_value = { 0, NULL };
   struct link_map **scope;

elf/dl-misc.c

@@ -74,8 +74,12 @@ _dl_sysdep_read_whole_file (const char *file, size_t *sizep, int prot)
 }
 
 
+/* Descriptor to write debug messages to.  */
+int _dl_debug_fd;
+
+
 void
-_dl_sysdep_fatal (const char *msg, ...)
+_dl_sysdep_output (int fd, const char *msg, ...)
 {
   va_list ap;
 
@@ -83,41 +87,7 @@ _dl_sysdep_fatal (const char *msg, ...)
   do
     {
       size_t len = strlen (msg);
-      __write (STDERR_FILENO, msg, len);
+      __write (fd, msg, len);
-      msg = va_arg (ap, const char *);
-    } while (msg);
-  va_end (ap);
-
-  _exit (127);
-}
-
-
-void
-_dl_sysdep_error (const char *msg, ...)
-{
-  va_list ap;
-
-  va_start (ap, msg);
-  do
-    {
-      size_t len = strlen (msg);
-      __write (STDERR_FILENO, msg, len);
-      msg = va_arg (ap, const char *);
-    } while (msg);
-  va_end (ap);
-}
-
-
-void
-_dl_sysdep_message (const char *msg, ...)
-{
-  va_list ap;
-
-  va_start (ap, msg);
-  do
-    {
-      size_t len = strlen (msg);
-      __write (STDOUT_FILENO, msg, len);
       msg = va_arg (ap, const char *);
     } while (msg);
   va_end (ap);

elf/dl-version.c

@@ -1,5 +1,5 @@
 /* Handle symbol and library versioning.
-   Copyright (C) 1997 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -28,9 +28,6 @@
 #include <stdio-common/_itoa.h>
 
 
-/* Set in rtld.c at startup.  */
-extern char **_dl_argv;
-
 #define VERSTAG(tag)	(DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (tag))
 
 

elf/link.h

@@ -231,6 +231,9 @@ typedef void (*receiver_fct) (int, const char *, const char *);
    user interface to run-time dynamic linking.  */
 
 
+/* Parameters passed to te dynamic linker.  */
+extern char **_dl_argv;
+
 /* Cached value of `getpagesize ()'.  */
 extern size_t _dl_pagesize;
 
@@ -244,26 +247,48 @@ extern struct link_map *_dl_profile_map;
 
 /* If nonzero the appropriate debug information if printed.  */
 extern int _dl_debug_libs;
+extern int _dl_debug_impcalls;
+
+/* File deccriptor to write debug messages to.  */
+extern int _dl_debug_fd;
 
 /* OS-dependent function to open the zero-fill device.  */
 extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
 
+/* OS-dependent function to write a message on the specified
+   descriptor FD.  All arguments are `const char *'; args until a null
+   pointer are concatenated to form the message to print.  */
+extern void _dl_sysdep_output (int fd, const char *string, ...);
+
+/* OS-dependent function to write a debug message on the specified
+   descriptor for this.  All arguments are `const char *'; args until
+   a null pointer are concatenated to form the message to print.  */
+#define _dl_debug_message(string, args...) \
+  _dl_sysdep_output (_dl_debug_fd, string, ##args)
+
 /* OS-dependent function to write a message on the standard output.
    All arguments are `const char *'; args until a null pointer
    are concatenated to form the message to print.  */
-extern void _dl_sysdep_message (const char *string, ...);
+#define _dl_sysdep_message(string, args...) \
+  _dl_sysdep_output (STDOUT_FILENO, string, ##args)
 
 /* OS-dependent function to write a message on the standard error.
    All arguments are `const char *'; args until a null pointer
    are concatenated to form the message to print.  */
-extern void _dl_sysdep_error (const char *string, ...);
+#define _dl_sysdep_error(string, args...) \
+  _dl_sysdep_output (STDERR_FILENO, string, ##args)
 
 /* OS-dependent function to give a fatal error message and exit
    when the dynamic linker fails before the program is fully linked.
    All arguments are `const char *'; args until a null pointer
    are concatenated to form the message to print.  */
-extern void _dl_sysdep_fatal (const char *string, ...)
+#define _dl_sysdep_fatal(string, args...) \
-     __attribute__ ((__noreturn__));
+  do									      \
+    {									      \
+      _dl_sysdep_output (STDERR_FILENO, string, ##args);		      \
+      _exit (127);							      \
+    }									      \
+  while (1)
 
 /* Nonzero if the program should be "secure" (i.e. it's setuid or somesuch).
    This tells the dynamic linker to ignore environment variables.  */

elf/rtld.c

@@ -17,6 +17,7 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
+#include <fcntl.h>
 #include <link.h>
 #include <stddef.h>
 #include <stdlib.h>
@@ -74,6 +75,7 @@ const char *_dl_profile;
 const char *_dl_profile_output;
 struct link_map *_dl_profile_map;
 int _dl_debug_libs;
+int _dl_debug_impcalls;
 
 /* Set nonzero during loading and initialization of executable and
    libraries, cleared before the executable's entry point runs.  This
@@ -907,6 +909,9 @@ print_missing_version (int errcode __attribute__ ((unused)),
 		    objname, ": ", errstring, "\n", NULL);
 }
 
+/* Nonzero if any of the debugging options is enabled.  */
+static int any_debug;
+
 /* Process the string given as the parameter which explains which debugging
    options are enabled.  */
 static void
@@ -924,6 +929,8 @@ process_dl_debug (char *dl_debug)
 	      && (issep (dl_debug[4]) || dl_debug[4] == '\0'))
 	    {
 	      _dl_debug_libs = 1;
+	      _dl_debug_impcalls = 1;
+	      any_debug = 1;
 	      dl_debug += 4;
 	    }
 	  else if (strncmp (dl_debug, "help", 4) == 0
@@ -956,6 +963,7 @@ process_envvars (enum mode *modep, int *lazyp)
   char *envline;
   enum mode mode = normal;
   int bind_now = 0;
+  char *debug_output = NULL;
 
   /* This is the default place for profiling data file.  */
   _dl_profile_output = "/var/tmp";
@@ -984,6 +992,16 @@ process_envvars (enum mode *modep, int *lazyp)
       if (result < 0)
 	continue;
 
+      /* Where to place the profiling data file.  */
+      result = strncmp (&envline[3], "DEBUG_OUTPUT=", 13);
+      if (result == 0)
+	{
+	  debug_output = &envline[16];
+	  continue;
+	}
+      if (result < 0)
+	continue;
+
       /* Which shared object shall be profiled.  */
       result = strncmp (&envline[3], "PROFILE=", 8);
       if (result == 0)
@@ -1038,6 +1056,18 @@ process_envvars (enum mode *modep, int *lazyp)
 	}
     }
 
+  /* If we have to run the dynamic linker in debugging mode and the
+     LD_DEBUG_OUTPUT environment variable is given, we write the debug
+     messages to this file.  */
+  if (any_debug && debug_output != NULL)
+    {
+      _dl_debug_fd = __open (debug_output, O_WRONLY | O_APPEND | O_CREAT,
+			     0666);
+      if (_dl_debug_fd == -1)
+	/* We use standard output if opening the file failed.  */
+	_dl_debug_fd = STDOUT_FILENO;
+    }
+
   /* LAZY is determined by the environment variable LD_WARN and
      LD_BIND_NOW if we trace the binary.  */
   if (mode == trace)

libc.map

@@ -11,7 +11,7 @@ GLIBC_2.0 {
     __collate_element_strings; __collate_symbol_classes;
     __collate_symbol_hash; __collate_symbol_strings;
     _obstack;
-    __progname_full; __progname;
+    __progname_full; __progname; _dl_debug_impcalls; _dl_debug_fd;
 
     _IO_list_all; _IO_stderr_; _IO_stdin_; _IO_stdout_;
 
@@ -21,7 +21,7 @@ GLIBC_2.0 {
     .div; .mul; .rem; .udiv; .umul; .urem;
 
     # helper functions
-    __errno_location; __libc_init_first; __h_errno_location;
+    __errno_location; __libc_init_first; __h_errno_location; __libc_start_main;
 
     # functions with special/multiple interfaces
     __sigsetjmp; _setjmp; __sigaddset; __sigdelset; __sigismember;
@@ -98,7 +98,7 @@ GLIBC_2.0 {
     __vsscanf; __vfscanf; __vsnprintf;
     _rpc_dtablesize; _null_auth; _seterr_reply;
     __res_randomid;  __getpid;
-    __strcasecmp; __write; _strerror_internal;
+    __strcasecmp; __write; _strerror_internal; _dl_sysdep_output;
 
     # Exception handling support functions from libgcc
     __register_frame; __register_frame_table; __deregister_frame;

sysdeps/generic/dl-cache.c

@@ -18,7 +18,7 @@
    Boston, MA 02111-1307, USA.  */
 
 #include <link.h>
-#include <stddef.h>
+#include <unistd.h>
 #include <sys/mman.h>
 
 /* System-dependent function to read a file's whole contents

sysdeps/generic/libc-start.c

@@ -0,0 +1,24 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+int
+__libc_start_main (int (*main) (int, char **, char **), int argc,
+		   char **argv, char **envp)
+{
+  return (*main) (argc, argv, envp);
+}

sysdeps/i386/dl-machine.h

@@ -1,5 +1,5 @@
 /* Machine-dependent ELF dynamic relocation inline functions.  i386 version.
-   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -302,8 +302,6 @@ elf_machine_plt_value (struct link_map *map, const Elf32_Rel *reloc,
 
 #ifdef RESOLVE
 
-extern char **_dl_argv;
-
 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
    MAP is the object containing the reloc.  */
 

sysdeps/i386/elf/start.S

@@ -1,5 +1,5 @@
 /* Startup code compliant to the ELF i386 ABI.
-   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -88,9 +88,11 @@ _start:
 	call atexit
 	popl %eax
 
-	/* Call the user's main function, and exit with its value.  */
+	/* Call the user's main function, and exit with its value.
-	call main
+	   But let the libc call main.    */
+	movl $main, %eax
 	pushl %eax
+	call __libc_start_main
 	call exit
 	hlt			/* Crash if somehow `exit' does return.  */
 

sysdeps/unix/sysv/linux/libc-start.c

@@ -0,0 +1,31 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <link.h>
+
+int
+__libc_start_main (int (*main) (int, char **, char **), int argc,
+		   char **argv, char **envp)
+{
+#ifdef PIC
+  if (_dl_debug_impcalls)
+    _dl_debug_message ("\ttransferring control: ", argv[0], "\n\n", NULL);
+#endif
+
+  return (*main) (argc, argv, envp);
+}