Tue Jun 4 21:01:20 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu>

	* sysdeps/mach/hurd/getlogin_r.c: New file.

Wed Jun  5 02:11:30 1996  Ulrich Drepper  <drepper@cygnus.com>

	* io/Makefile (routines): Add ttyname_r.

	* resolv/res_debug.c, resolv/resolv.h: Update from bind-4.3.4-T4A.

	* sysdeps/libm-i387/e_asinl.S, sysdeps/libm-i387/e_atan2l.S,
	sysdeps/libm-i387/e_expl.S, sysdeps/libm-i387/e_fmodl.S,
	sysdeps/libm-i387/e_log10l.S, sysdeps/libm-i387/e_logl.S,
	sysdeps/libm-i387/e_remainderl.S, sysdeps/libm-i387/e_scalbl.S,
	sysdeps/libm-i387/e_sqrtl.S, sysdeps/libm-i387/s_atanl.S,
	sysdeps/libm-i387/s_cosl.S, sysdeps/libm-i387/s_ilogbl.S,
	sysdeps/libm-i387/s_log1pl.S, sysdeps/libm-i387/s_logbl.S,
	sysdeps/libm-i387/s_scalbnl.S, sysdeps/libm-i387/s_sinl.S,
	sysdeps/libm-i387/s_tanl.S: New files.  i387 assembler versions
	of `long double' math functions.

	* sysdeps/libm-ieee754/k_standard.c: Add handling for errors
	in long double functions.

	* sysdeps/libm-ieee754/s_ilogbl.c, sysdeps/libm-ieee754/s_logbl.c,
	sysdeps/libm-ieee754/s_modfl.c:  New files.  Generic versions
	of `long double' math functions.

	* sysdeps/libm-ieee754/s_isinf.c [NO_LONG_DOUBLE]: Add string
        alias for __isinfl.

	* sysdeps/libm-ieee754/w_acoshl.c, sysdeps/libm-ieee754/w_acosl.c,
	sysdeps/libm-ieee754/w_asinl.c, sysdeps/libm-ieee754/w_atan2l.c,
	sysdeps/libm-ieee754/w_atanhl.c, sysdeps/libm-ieee754/w_cabsl.c,
	sysdeps/libm-ieee754/w_coshl.c, sysdeps/libm-ieee754/w_dreml.c,
	sysdeps/libm-ieee754/w_expl.c, sysdeps/libm-ieee754/w_fmodl.c,
	sysdeps/libm-ieee754/w_gammal.c, sysdeps/libm-ieee754/w_gammal_r.c,
	sysdeps/libm-ieee754/w_hypotl.c, sysdeps/libm-ieee754/w_j0l.c,
	sysdeps/libm-ieee754/w_j1l.c, sysdeps/libm-ieee754/w_jnl.c,
	sysdeps/libm-ieee754/w_lgammal.c, sysdeps/libm-ieee754/w_lgammal_r.c,
	sysdeps/libm-ieee754/w_log10l.c, sysdeps/libm-ieee754/w_logl.c,
	sysdeps/libm-ieee754/w_powl.c, sysdeps/libm-ieee754/w_remainderl.c,
	sysdeps/libm-ieee754/w_scalbl.c, sysdeps/libm-ieee754/w_sinhl.c,
	sysdeps/libm-ieee754/w_sqrtl.c: New files.  Wrapper functions
	around long double function implementations.

	* sysdeps/posix/ttyname_r.c (ttyname_r): Use _D_EXACT_NAMLEN
	to determine length of directory entry name.

	* posix/Makefile (routines): Add getlogin_r.
	* posix/unistd.h: Add prototype for getlogin_r.
	* sysdeps/stub/getlogin_r.c: New file.  Reentrant version of
	getlogin function, specified in P1003.1c/D6.  Stub version.
	* sysdeps/unix/getlogin.c (getlogin): Use ttyname_r instead of
	ttyname.  This avoids saving and restoring the old content.
	Also use setutent_r, getutline_r and endutent_r instead of
	accing UTMP file directly.
	* sysdeps/unix/getlogin_r.c: New file.  Reentrant version of
	getlogin function, specified in P1003.1c/D6.

Tue Jun  4 20:10:09 1996  J.T. Conklin  <jtc@cygnus.com>

	* sysdeps/libm-i387/s_finitef.S: Fix mask for exponent.

	* elf/dl-lookup.c (_dl_lookup_symbol): Grok magical undefined symbols
	_GNU_libc_dl_{open,close,symbol} and resolve them to dl functions.

	* elf/rtld.c (rtld_map): Renamed to _dl_rtld_map, made global.
	* elf/link.h: Declare _dl_rtld_map.

	* elf/dl-lookup.c (_dl_symbol_value): New function.
	* elf/link.h: Declare it.

	stdio-common/vfscanf.c: Prepare for reentrant libio.
	Used in reentrant libio.

1 files changed, 45 insertions, 5 deletions

diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c
index 26357c2484..b2e9bff984 100644
--- a/elf/dl-lookup.c
+++ b/elf/dl-lookup.c
@@ -110,11 +110,39 @@ _dl_lookup_symbol (const char *undef_name, const Elf32_Sym **ref,
 
   if (weak_value.s == NULL && ELF32_ST_BIND ((*ref)->st_info) != STB_WEAK)
     {
-      const char msg[] = "undefined symbol: ";
-      char buf[sizeof msg + strlen (undef_name)];
-      memcpy (buf, msg, sizeof msg - 1);
-      memcpy (&buf[sizeof msg - 1], undef_name, sizeof buf - sizeof msg + 1);
-      _dl_signal_error (0, reference_name, buf);
+      /* The symbol was not defined by any object in scope.  To allow
+	 access to dynamic linker functionality without using -ldl and
+	 thereby brining the dynamic linker's symbols into scope, we
+	 recognize a few magical symbol names and resolve them to the
+	 addresses of functions inside the dynamic linker.  */
+
+      struct magic
+	{
+	  unsigned long int hash;
+	  const char *name;
+	  Elf32_Addr value;
+	};
+      static struct magic magic[] =
+	{
+	  { 0xd6a2a5e, "_GNU_libc_dl_open", (Elf32_Addr) &_dl_open },
+	  { 0x69ef845, "_GNU_libc_dl_close", (Elf32_Addr) &_dl_close },
+	  { 0xae4d63c, "_GNU_libc_dl_symbol", (Elf32_Addr) &_dl_symbol_value },
+	  { 0, NULL, 0 }
+	};
+      struct magic *m;
+
+      for (m = magic; m->hash; ++m)
+	if (hash == m->hash && !strcmp (name, m->name))
+	  return m->value;
+
+      {
+	const char msg[] = "undefined symbol: ";
+	char buf[sizeof msg + strlen (undef_name)];
+	memcpy (buf, msg, sizeof msg - 1);
+	memcpy (&buf[sizeof msg - 1], undef_name,
+		sizeof buf - sizeof msg + 1);
+	_dl_signal_error (0, reference_name, buf);
+      }
     }
 
   *ref = weak_value.s;
@@ -135,3 +163,15 @@ _dl_setup_hash (struct link_map *map)
   hash += map->l_nbuckets;
   map->l_chain = hash;
 }
+
+/* Look up symbol NAME in MAP's scope and return its run-time address.  */
+
+Elf32_Addr
+_dl_symbol_value (struct link_map *map, const char *name)
+{
+  Elf32_Addr loadbase;
+  const Elf32_Sym *ref = NULL;
+  struct link_map *scope[2] = { map, NULL };
+  loadbase = _dl_lookup_symbol (name, &ref, scope, map->l_name, 0, 0);
+  return loadbase + ref->st_value;
+}