Update.cvs/libc-ud-970729

1997-07-28 23:35  Ulrich Drepper  <drepper@cygnus.com>

	* csu/gmon-start.c (__gmon_start__): Call __monstartup not
	monstartup.
	* gmon/gmon.c: Rename moncontrol to __moncontrol and monstartup
	to __monstartup.
	* gmon/sys/gmon.h: Fix prototypes.
	* gmon/sys/gmon_out.h: Pretty print.

	* gmon/bb_exit_func.c (__bb_exit_func): Use memcpy instead of bcopy.
	* gmon/gmon.c (__monstartup): Likewise.
	(write_hist): Remove dependency on 32 int.
	(_mcleanup): Don't call perror, use fprintf.

	* elf/dl-load.c: Fix handling of current directory in search path.

	* elf/Makefile (dl-routines): Add dl-profile.
	* elf/dl-profile.c: New file.
	* elf/dl-runtime.c (fixup): Add new parameter with address to store
	relocation result in to elf_machine_relplt.
	(profile_fixup): New function.
	* elf/do-rel.h (elf_dynamic_do_rel): Add new parameter with address
	to store relocation result in to elf_machine_relplt.
	* elf/dl-support.c: Define _dl_profile and _dl_profile_map.
	* elf/dynamic-link.h (ELF_DYNAMIC_RELOCATE): Add new parameter and
	call elf_machine_runtime_setup with extra argument.
	* elf/dl-reloc.c (_dl_relocate_object): Add new argument to
	ELF_DYNAMIC_RELOCATE.
	* elf/link.h: Add prototypes for new functions and variables.
	* elf/rtld.c: Parse LD_PROFILE and LD_PROFILE_OUTPUT environment
	variables and call _dl_start_profile if necessary.
	* include/sys/gmon_out.h: New file.
	* sysdeps/alpha/dl-machine.h (elf_machine_runtime_setup): Add
	new parameter to enable profiling.
	(elf_machine_rela): Add new parameter to specify place to store
	result in.
	* sysdeps/m68k/dl-machine.h: Likewise.
	* sysdeps/mips/dl-machine.h: Likewise.
	* sysdeps/mips/mips64/dl-machine.h: Likewise.
	* sysdeps/powerpc/dl-machine.h: Likewise.
	* sysdeps/sparc/dl-machine.h: Likewise.
	* sysdeps/sparc64/dl-machine.h: Likewise.
	* sysdeps/i386/dl-machine.h: Likewise.
	(elf_machine_runtime_setup): Setup got[2] to _dl_runtime_resolve if
	we do profiling.
	(ELF_MACHINE_RUNTIME_TRAMPOLINE): Add code for _dl_runtime_profile.

	* nis/nss_compat/compat-grp.c (internal_setgrent): Set FD_CLOEXEC
	for stream on input file.
	* nis/nss_compat/compat-pwd.c (internal_setpwent): Likewise.
	* nis/nss_compat/compat-spwd.c (internal_setspent): Likewise.
	* nss/nss_db/db-XXX.c (internal_setent): Likewise.
	* nss/nss_db/db-alias.c (internal_setent): Likewise.
	* nss/nss_db/db-netgrp.c (internal_setent): Likewise.
	* nss/nss_files/files-XXX.c (internal_setent): Likewise.
	* nss/nss_files/files-alias.c (internal_setent): Likewise.
	* nss/nss_files/files-netgrp.c (internal_setent): Likewise.

	* string/string.h: Pretty print.

	* sysdeps/i386/fpu/bits/mathinline.h: Major update by John Bowman.
	Add float and long double versions.

1997-07-27  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* elf/rtld.c (print_unresolved): Replace empty object name by main
	program name.

1997-07-27  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/generic/htons.c (htons): Renamed from __htons.

1997-07-27  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/m68k/bits/byteswap.h: New file.

1997-07-27 23:50  Philip Blundell  <Philip.Blundell@pobox.com>

	* inet/netinet/icmp6.h: Update for new drafts of POSIX.1g and IPv6
	advanced API.
	* inet/netinet/in.h: Likewise.
	* inet/netinet/ip6.h: Likewise.
	* sysdeps/unix/sysv/linux/bits/socket.h: Likewise.
	* posix/sys/types.h: Add socklen_t.

	* manual/socket.texi: Document some more IPv6 things.
	* manual/libc.texinfo: Likewise.

1997-07-26  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* libc.map: Define missing symbol.

1997-07-27 14:31  Thorsten Kukuk  <kukuk@vt.uni-paderborn.de>

	* nis/Makefile: Add nis_findserv.
	* nis/lckcache.c: Fix typo.
	* nis/nis_call.c: Fix problems with multihomed servers.
	* nis/nis_findserv.c: New file.
	* nis/nis_intern.h: Add more prototypes.
	* nis/nis_lookup.c (nis_lookup): Don't try the next server if network
	is unreachable.
	* nis/nis_table.c (nis_list): Likewise.
	* nis/nis_ping.c (nis_ping): Use MASTER_ONLY, don't call abort()
	in error case.
	* nis/nis_util.c (__nis_finddirectory): Give the right error code
	back.
	* nis/ypclnt.c: Make sure, that all sockets are closed.

10 files changed, 403 insertions, 16 deletions

diff --git a/elf/Makefile b/elf/Makefile
index e44711471b..904099cbeb 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -27,7 +27,8 @@ routines	= $(dl-routines) dl-open dl-close dl-symbol dl-support \
 # The core dynamic linking functions are in libc for the static and
 # profiled libraries.
 dl-routines	= $(addprefix dl-,load cache lookup object reloc deps \
-			          runtime error init fini debug misc)
+			          runtime error init fini debug misc \
+				  profile)
 # But they are absent from the shared libc, because that code is in ld.so.
 elide-routines.so = $(dl-routines) dl-support enbl-secure
 
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 1301e73996..f7c2c53f7e 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -193,7 +193,10 @@ fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
 			      "cannot create cache for search path");
 
 	  dirp->dirnamelen = len;
-	  dirp->dirstatus = unknown;
+	  /* We have to make sure all the relative directories are never
+	     ignored.  The current directory might change and all our
+	     saved information would be void.  */
+	  dirp->dirstatus = cp[0] != '/' ? existing : unknown;
 
 	  /* Add the name of the machine dependent directory if a machine
 	     is defined.  */
@@ -212,7 +215,7 @@ fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
 	      tmp[len + _dl_platformlen + 1] = '\0';
 
 	      dirp->dirname = tmp;
-	      dirp->machdirstatus = unknown;
+	      dirp->machdirstatus = dirp->dirstatus;
 
 	      if (max_dirnamelen < dirp->machdirnamelen)
 		max_dirnamelen = dirp->machdirnamelen;
diff --git a/elf/dl-profile.c b/elf/dl-profile.c
new file mode 100644
index 0000000000..cc25b6105f
--- /dev/null
+++ b/elf/dl-profile.c
@@ -0,0 +1,267 @@
+/* Profiling of shared libraries.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   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 <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <link.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/gmon.h>
+#include <sys/gmon_out.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+/* The LD_PROFILE feature has to be implemented different to the
+   normal profiling using the gmon/ functions.  The problem is that an
+   arbitrary amount of processes simulataneously can be run using
+   profiling and all write the results in the same file.  To provide
+   this mechanism one could implement a complicated mechanism to merge
+   the content of two profiling runs or one could extend the file
+   format to allow more than one data set.  For the second solution we
+   would have the problem that the file can grow in size beyond any
+   limit and both solutions have the problem that the concurrency of
+   writing the results is a big problem.
+
+   Another much simpler method is to use mmap to map the same file in
+   all using programs and modify the data in the mmap'ed area and so
+   also automatically on the disk.  Using the MAP_SHARED option of
+   mmap(2) this can be done without big problems in more than one
+   file.
+
+   This approach is very different from the normal profiling.  We have
+   to use the profiling data in exactly the way they are expected to
+   be written to disk.  */
+
+extern char *_strerror_internal __P ((int, char *buf, size_t));
+
+extern int __profile_frequency __P ((void));
+
+
+static struct gmonparam param;
+
+/* We define a special type to address the elements of the arc table.
+   This is basically the `gmon_cg_arc_record' format but it includes
+   the room for the tag and it uses real types.  */
+struct here_cg_arc_record
+  {
+    char tag;
+    uintptr_t from_pc __attribute__ ((packed));
+    uintptr_t self_pc __attribute__ ((packed));
+    uint32_t count __attribute__ ((packed));
+  };
+
+static struct here_cg_arc_record *data;
+
+
+void
+_dl_start_profile (struct link_map *map, const char *output_dir)
+{
+  char *filename;
+  int fd;
+  struct stat st;
+  const ElfW(Phdr) *ph;
+  ElfW(Addr) mapstart = ~((ElfW(Addr)) 0);
+  ElfW(Addr) mapend = 0;
+  off_t expected_size;
+  struct gmon_hdr gmon_hdr;
+  struct gmon_hist_hdr hist_hdr;
+  struct gmon_hdr *addr;
+  char *hist;
+
+  /* Compute the size of the sections which contain program code.  */
+  for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph)
+    if (ph->p_type == PT_LOAD && (ph->p_flags & PF_X))
+      {
+	ElfW(Addr) start = (ph->p_vaddr & ~(_dl_pagesize - 1));
+	ElfW(Addr) end = ((ph->p_vaddr + ph->p_memsz + _dl_pagesize - 1)
+			  & ~(_dl_pagesize - 1));
+
+	if (start < mapstart)
+	  mapstart = start;
+	if (end > mapend)
+	  mapend = end;
+      }
+
+  /* Now we can compute the size of the profiling data.  This is done
+     with the same formulars as in `monstartup' (see gmon.c).  */
+  param.state = GMON_PROF_OFF;
+  param.lowpc = mapstart + map->l_addr;
+  param.highpc = mapend + map->l_addr;
+  param.textsize = mapend - mapstart;
+  param.kcountsize = param.textsize / HISTFRACTION;
+  param.hashfraction = HASHFRACTION;
+  param.log_hashfraction = -1;
+  if ((HASHFRACTION & (HASHFRACTION - 1)) == 0)
+    /* If HASHFRACTION is a power of two, mcount can use shifting
+       instead of integer division.  Precompute shift amount.  */
+    param.log_hashfraction = ffs (param.hashfraction
+				  * sizeof (*param.froms)) - 1;
+  param.fromssize = param.textsize / HASHFRACTION;
+  param.tolimit = param.textsize * ARCDENSITY / 100;
+  if (param.tolimit < MINARCS)
+    param.tolimit = MINARCS;
+  if (param.tolimit > MAXARCS)
+    param.tolimit = MAXARCS;
+  param.tossize = param.tolimit * sizeof (struct tostruct);
+
+  expected_size = (sizeof (struct gmon_hdr)
+		   + 1 + sizeof (struct gmon_hist_hdr)
+		   + ((1 + sizeof (struct gmon_cg_arc_record))
+		      * (param.fromssize / sizeof (*param.froms))));
+
+  /* Create the gmon_hdr we expect or write.  */
+  memset (&gmon_hdr, '\0', sizeof (struct gmon_hdr));
+  memcpy (&gmon_hdr.cookie[0], GMON_MAGIC, sizeof (gmon_hdr.cookie));
+  *(int32_t *) gmon_hdr.version = GMON_VERSION;
+
+  /* Create the hist_hdr we expect or write.  */
+  *(char **) hist_hdr.low_pc = (char *) mapstart;
+  *(char **) hist_hdr.high_pc = (char *) mapend;
+  *(int32_t *) hist_hdr.hist_size = param.kcountsize / sizeof (HISTCOUNTER);
+  *(int32_t *) hist_hdr.prof_rate = __profile_frequency ();
+  strncpy (hist_hdr.dimen, "seconds", sizeof (hist_hdr.dimen));
+  hist_hdr.dimen_abbrev = 's';
+
+  /* First determine the output name.  We write in the directory
+     OUTPUT_DIR and the name is composed from the shared objects
+     soname (or the file name) and the ending ".profile".  */
+  filename = (char *) alloca (strlen (output_dir) + 1 + strlen (_dl_profile)
+			      + sizeof ".profile");
+  __stpcpy (__stpcpy (__stpcpy (__stpcpy (filename, output_dir), "/"),
+		      _dl_profile),
+	    ".profile");
+
+  fd = __open (filename, O_RDWR | O_CREAT, 0666);
+  if (fd == -1)
+    /* We cannot write the profiling data so don't do anthing.  */
+    return;
+
+  if (fstat (fd, &st) < 0 || !S_ISREG (st.st_mode))
+    {
+      /* Not stat'able or not a regular file => don't use it.  */
+      close (fd);
+      return;
+    }
+
+  /* Test the size.  If it does not match what we expect from the size
+     values in the map MAP we don't use it and warn the user.  */
+  if (st.st_size == 0)
+    {
+      /* We have to create the file.  */
+      char buf[_dl_pagesize];
+
+      memset (buf, '\0', _dl_pagesize);
+
+      if (__lseek (fd, expected_size & ~(_dl_pagesize - 1), SEEK_SET) == -1)
+	{
+	  char buf[400];
+	  int errnum;
+	cannot_create:
+	  errnum = errno;
+	  __close (fd);
+	  fprintf (stderr, "%s: cannot create file: %s\n", filename,
+		   _strerror_internal (errnum, buf, sizeof buf));
+	  return;
+	}
+
+      if (TEMP_FAILURE_RETRY (__write (fd, buf, (expected_size
+						 & (_dl_pagesize - 1)))) < 0)
+	goto cannot_create;
+    }
+  else if (st.st_size != expected_size)
+    {
+      __close (fd);
+    wrong_format:
+      fprintf (stderr, "%s: file is no correct profile data file for `%s'\n",
+	       filename, _dl_profile);
+      return;
+    }
+
+  addr = (void *) __mmap (NULL, expected_size, PROT_READ|PROT_WRITE,
+			  MAP_SHARED|MAP_FILE, fd, 0);
+  if (addr == (void *) -1)
+    {
+      char buf[400];
+      int errnum = errno;
+      __close (fd);
+      fprintf (stderr, "%s: cannot map file: %s\n", filename,
+	       _strerror_internal (errnum, buf, sizeof buf));
+      return;
+    }
+
+  /* We don't need the file desriptor anymore.  */
+  __close (fd);
+
+  /* Pointer to data after the header.  */
+  hist = (char *) (addr + 1);
+
+  /* Compute pointer to array of the arc information.  */
+  data = (struct here_cg_arc_record *) (hist + 1
+					+ sizeof (struct gmon_hist_hdr));
+
+  if (st.st_size == 0)
+    {
+      /* Create the signature.  */
+      size_t cnt;
+
+      memcpy (addr, &gmon_hdr, sizeof (struct gmon_hdr));
+
+      *hist = GMON_TAG_TIME_HIST;
+      memcpy (hist + 1, &hist_hdr, sizeof (struct gmon_hist_hdr));
+
+      for (cnt = 0; cnt < param.fromssize / sizeof (*param.froms); ++cnt)
+	data[cnt].tag = GMON_TAG_CG_ARC;
+    }
+  else
+    {
+      /* Test the signature in the file.  */
+      if (memcmp (addr, &gmon_hdr, sizeof (struct gmon_hdr)) != 0
+	  || *hist != GMON_TAG_TIME_HIST
+	  || memcmp (hist + 1, &hist_hdr, sizeof (struct gmon_hist_hdr)) != 0)
+	goto wrong_format;
+    }
+
+  /* Turn on profiling.  */
+  param.state = GMON_PROF_ON;
+}
+
+
+void
+_dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
+{
+  if (param.state != GMON_PROF_ON)
+    return;
+  param.state = GMON_PROF_BUSY;
+
+  /* Compute relative addresses.  The shared object can be loaded at
+     any address.  The value of frompc could be anything.  We cannot
+     restrict it in any way, just set to a fixed value (0) in case it
+     is outside the allowed range.  These calls show up as calls from
+     <external> in the gprof output.  */
+  frompc -= param.lowpc;
+  if (frompc >= param.textsize)
+    frompc = 0;
+  selfpc -= param.lowpc;
+
+  param.state = GMON_PROF_ON;
+}
diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c
index 5b22a506da..4f6eff8835 100644
--- a/elf/dl-reloc.c
+++ b/elf/dl-reloc.c
@@ -24,6 +24,7 @@
 #include <errno.h>
 #include "dynamic-link.h"
 
+
 void
 _dl_relocate_object (struct link_map *l, struct link_map *scope[], int lazy)
 {
@@ -65,7 +66,7 @@ _dl_relocate_object (struct link_map *l, struct link_map *scope[], int lazy)
 			  l->l_name, (flags)))
 
 #include "dynamic-link.h"
-    ELF_DYNAMIC_RELOCATE (l, lazy);
+    ELF_DYNAMIC_RELOCATE (l, lazy, 1);
   }
 
   /* Mark the object so we know this work has been done.  */
diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c
index 7a44ea4ce3..1b34026d38 100644
--- a/elf/dl-runtime.c
+++ b/elf/dl-runtime.c
@@ -137,17 +137,18 @@ fixup (
     /* Perform the specified relocation.  */
     if (l->l_info[VERSYMIDX (DT_VERSYM)])
       {
-	const ElfW(Half) * version =
+	const ElfW(Half) *version =
 	  (const ElfW(Half) *) (l->l_addr +
 				l->l_info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr);
 	ElfW(Half) ndx = version[ELFW(R_SYM) (reloc->r_info)];
 
 	elf_machine_relplt (l, reloc, &symtab[ELFW(R_SYM) (reloc->r_info)],
-			    &l->l_versions[ndx]);
+			    &l->l_versions[ndx],
+			    (void *) (l->l_addr + reloc->r_offset));
       }
     else
       elf_machine_relplt (l, reloc, &symtab[ELFW(R_SYM) (reloc->r_info)],
-			  NULL);
+			  NULL, (void *) (l->l_addr + reloc->r_offset));
   }
 
   *_dl_global_scope_end = NULL;
@@ -161,6 +162,70 @@ fixup (
 }
 
 
+#ifndef PROF
+static ElfW(Addr)
+profile_fixup (
+#ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
+       ELF_MACHINE_RUNTIME_FIXUP_ARGS,
+#endif
+       struct link_map *l, ElfW(Word) reloc_offset, ElfW(Addr) retaddr)
+{
+  void (*mcount_fct) (ElfW(Addr), ElfW(Addr)) = _dl_mcount;
+  const ElfW(Sym) *const symtab
+    = (const ElfW(Sym) *) (l->l_addr + l->l_info[DT_SYMTAB]->d_un.d_ptr);
+  const char *strtab =
+    (const char *) (l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr);
+
+  const PLTREL *const reloc
+    = (const void *) (l->l_addr + l->l_info[DT_JMPREL]->d_un.d_ptr +
+		      reloc_offset);
+  ElfW(Addr) result;
+
+  /* Set up the scope to find symbols referenced by this object.  */
+  struct link_map **scope = _dl_object_relocation_scope (l);
+
+  {
+    /* This macro is used as a callback from the elf_machine_relplt code.  */
+#define RESOLVE(ref, version, flags) \
+  ((version) != NULL && (version)->hash != 0				      \
+   ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, (ref), scope,     \
+				  l->l_name, (version), (flags))	      \
+   : _dl_lookup_symbol (strtab + (*ref)->st_name, (ref), scope,		      \
+			l->l_name, (flags)))
+#include "dynamic-link.h"
+
+    /* Perform the specified relocation.  */
+    if (l->l_info[VERSYMIDX (DT_VERSYM)])
+      {
+	const ElfW(Half) *version =
+	  (const ElfW(Half) *) (l->l_addr +
+				l->l_info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr);
+	ElfW(Half) ndx = version[ELFW(R_SYM) (reloc->r_info)];
+
+	elf_machine_relplt (l, reloc, &symtab[ELFW(R_SYM) (reloc->r_info)],
+			    &l->l_versions[ndx], (void *) &result);
+      }
+    else
+      elf_machine_relplt (l, reloc, &symtab[ELFW(R_SYM) (reloc->r_info)],
+			  NULL, (void *) &result);
+  }
+
+  *_dl_global_scope_end = NULL;
+
+  /* Return the address that was written by the relocation.  */
+#ifdef ELF_FIXUP_RETURNS_ADDRESS
+  (*mcount_fct) (retaddr, result);
+
+  return &result;	/* XXX This cannot work.  What to do??? --drepper */
+#else
+  (*mcount_fct) (retaddr, result);
+
+  return result;
+#endif
+}
+#endif
+
+
 /* This macro is defined in dl-machine.h to define the entry point called
    by the PLT.  The `fixup' function above does the real work, but a little
    more twiddling is needed to get the stack right and jump to the address
diff --git a/elf/dl-support.c b/elf/dl-support.c
index 3333bf10fb..41997ccafb 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -42,6 +42,10 @@ int _dl_verbose;
 /* Structure to store information about search paths.  */
 struct r_search_path *_dl_search_paths;
 
+/* We never do profiling.  */
+const char *_dl_profile;
+struct link_map *_dl_profile_map;
+
 
 static void non_dynamic_init (void) __attribute__ ((unused));
 
diff --git a/elf/do-rel.h b/elf/do-rel.h
index 766e62c219..7f4b1259a2 100644
--- a/elf/do-rel.h
+++ b/elf/do-rel.h
@@ -63,12 +63,14 @@ elf_dynamic_do_rel (struct link_map *map,
 	    {
 	      ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)];
 	      elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)],
-			       &map->l_versions[ndx]);
+			       &map->l_versions[ndx],
+			       (void *) (map->l_addr + r->r_offset));
 	    }
 	}
       else
 	for (; r < end; ++r)
-	  elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL);
+	  elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL,
+			   (void *) (map->l_addr + r->r_offset));
     }
 }
 
diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h
index 3377ee7ff6..4a946f8ad8 100644
--- a/elf/dynamic-link.h
+++ b/elf/dynamic-link.h
@@ -102,11 +102,14 @@ elf_get_dynamic_info (ElfW(Dyn) *dyn,
 
 /* This can't just be an inline function because GCC is too dumb
    to inline functions containing inlines themselves.  */
-#define ELF_DYNAMIC_RELOCATE(map, lazy)				\
-  do {								\
-    int edr_lazy = elf_machine_runtime_setup((map), (lazy));	\
-    ELF_DYNAMIC_DO_REL ((map), edr_lazy);			\
-    ELF_DYNAMIC_DO_RELA ((map), edr_lazy);			\
+#define ELF_DYNAMIC_RELOCATE(map, lazy, consider_profile) \
+  do {									      \
+    int profile = (consider_profile && _dl_profile != NULL		      \
+		   && _dl_name_match_p (_dl_profile, (map)));		      \
+    int edr_lazy = elf_machine_runtime_setup ((map), (lazy) || profile,	      \
+					      profile);			      \
+    ELF_DYNAMIC_DO_REL ((map), edr_lazy);				      \
+    ELF_DYNAMIC_DO_RELA ((map), edr_lazy);				      \
   } while (0)
 
 #endif
diff --git a/elf/link.h b/elf/link.h
index e0fccd0fca..38a7c88d9a 100644
--- a/elf/link.h
+++ b/elf/link.h
@@ -225,6 +225,11 @@ extern size_t _dl_pagesize;
 /* File descriptor referring to the zero-fill device.  */
 extern int _dl_zerofd;
 
+/* Name of the shared object to be profiled (if any).  */
+extern const char *_dl_profile;
+/* Map of shared object to be profiled.  */
+extern struct link_map *_dl_profile_map;
+
 /* OS-dependent function to open the zero-fill device.  */
 extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
 
@@ -430,8 +435,14 @@ extern void _dl_debug_state (void);
 extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase);
 
 /* Initialize the basic data structure for the search paths.  */
-void _dl_init_paths (void);
+extern void _dl_init_paths (void);
+
+/* Gather the information needed to install the profiling tables and start
+   the timers.  */
+extern void _dl_start_profile (struct link_map *map, const char *output_dir);
 
+/* The actual functions used to keep book on the calls.  */
+extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
 
 __END_DECLS
 
diff --git a/elf/rtld.c b/elf/rtld.c
index 7189ca6b2b..726463c882 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -61,6 +61,9 @@ int _dl_verbose;
 const char *_dl_platform;
 size_t _dl_platformlen;
 struct r_search_path *_dl_search_paths;
+const char *_dl_profile;
+const char *_dl_profile_output;
+struct link_map *_dl_profile_map;
 
 /* Set nonzero during loading and initialization of executable and
    libraries, cleared before the executable's entry point runs.  This
@@ -109,7 +112,7 @@ _dl_start (void *arg)
   /* Relocate ourselves so we can do normal function calls and
      data access using the global offset table.  */
 
-  ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0);
+  ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
 
   /* Now life is sane; we can call functions and access global data.
      Set up to use the operating system facilities, and find out from
@@ -269,6 +272,26 @@ dl_main (const ElfW(Phdr) *phdr,
   else
     lazy = !__libc_enable_secure && *(getenv ("LD_BIND_NOW") ?: "") == '\0';
 
+  /* See whether we want to use profiling.  */
+  _dl_profile = getenv ("LD_PROFILE");
+  if (_dl_profile != NULL)
+    if (_dl_profile[0] == '\0')
+      /* An empty string is of not much help.  Disable profiling.  */
+      _dl_profile = NULL;
+    else
+      {
+	/* OK, we have the name of a shared object we want to
+	   profile.  It's up to the user to provide a good name, it
+	   must match the file name or soname of one of the loaded
+	   objects.  Now let's see where we are supposed to place the
+	   result.  */
+	_dl_profile_output = getenv ("LD_PROFILE_OUTPUT");
+
+	if (_dl_profile_output == NULL || _dl_profile_output[0] == '\0')
+	  /* This is the default place.  */
+	  _dl_profile_output = "/var/tmp";
+      }
+
   /* Set up a flag which tells we are just starting.  */
   _dl_starting_up = 1;
 
@@ -814,6 +837,11 @@ of this helper program; chances are you did not intend to run this program.\n",
     _dl_debug_state ();
   }
 
+  /* Now enable profiling if needed.  */
+  if (_dl_profile_map != NULL)
+    /* We must prepare the profiling.  */
+    _dl_start_profile (_dl_profile_map, _dl_profile_output);
+
   /* Once we return, _dl_sysdep_start will invoke
      the DT_INIT functions and then *USER_ENTRY.  */
 }
@@ -824,6 +852,8 @@ static void
 print_unresolved (int errcode __attribute__ ((unused)), const char *objname,
 		  const char *errstring)
 {
+  if (objname[0] == '\0')
+    objname = _dl_argv[0] ?: "<main program>";
   _dl_sysdep_error (errstring, "	(", objname, ")\n", NULL);
 }