Update.

2004-02-20  Ulrich Drepper  <drepper@redhat.com>

	* dlfcn/dlsym.c: Get ld.so loading lock before the call into ld.so.
	* dlfcn/dlvsym.c: Likewise.
	* elf/dl-addr.c: Get loading lock while using _dl_loaded data.
	* elf/dl-fini.c: Likewise.
	Patch by Shunichi Sagawa <s-sagawa@jp.fujitsu.com>.

diff --git a/ChangeLog b/ChangeLog
index 1fe4098..2dcb477 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2004-02-20  Ulrich Drepper  <drepper@redhat.com>
+
+       * dlfcn/dlsym.c: Get ld.so loading lock before the call into ld.so.
+       * dlfcn/dlvsym.c: Likewise.
+       * elf/dl-addr.c: Get loading lock while using _dl_loaded data.
+       * elf/dl-fini.c: Likewise.
+       Patch by Shunichi Sagawa <s-sagawa@jp.fujitsu.com>.
+
 2004-02-20  Jakub Jelinek  <jakub@redhat.com>
 
        * sysdeps/sparc/sparc32/fpu/libm-test-ulps: Add ulps for the

diff --git a/dlfcn/dlsym.c b/dlfcn/dlsym.c
index ec071d9..76dda59 100644 (file)
--- a/dlfcn/dlsym.c
+++ b/dlfcn/dlsym.c
@@ -1,5 +1,5 @@
 /* Look up a symbol in a shared object loaded by `dlopen'.
-   Copyright (C) 1995, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1995-2000, 2004 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
@@ -20,6 +20,8 @@
 #include <dlfcn.h>
 #include <stddef.h>
 
+#include <ldsodefs.h>
+
 struct dlsym_args
 {
   /* The arguments to dlsym_doit.  */
@@ -48,5 +50,12 @@ dlsym (void *handle, const char *name)
   args.handle = handle;
   args.name = name;
 
-  return (_dlerror_run (dlsym_doit, &args) ? NULL : args.sym);
+  /* Protect against concurrent loads and unloads.  */
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+  void *result = (_dlerror_run (dlsym_doit, &args) ? NULL : args.sym);
+
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+
+  return result;
 }

diff --git a/dlfcn/dlvsym.c b/dlfcn/dlvsym.c
index 62415fe..2486845 100644 (file)
--- a/dlfcn/dlvsym.c
+++ b/dlfcn/dlvsym.c
@@ -1,5 +1,5 @@
 /* Look up a versioned symbol in a shared object loaded by `dlopen'.
-   Copyright (C) 1995, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1995-2000, 2004 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
@@ -20,6 +20,8 @@
 #include <dlfcn.h>
 #include <stddef.h>
 
+#include <ldsodefs.h>
+
 struct dlvsym_args
 {
   /* The arguments to dlvsym_doit.  */
@@ -51,6 +53,13 @@ __dlvsym (void *handle, const char *name, const char *version_str)
   args.who = RETURN_ADDRESS (0);
   args.version = version_str;
 
-  return (_dlerror_run (dlvsym_doit, &args) ? NULL : args.sym);
+  /* Protect against concurrent loads and unloads.  */
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+  void *result = (_dlerror_run (dlvsym_doit, &args) ? NULL : args.sym);
+
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+
+  return result;
 }
 weak_alias (__dlvsym, dlvsym)

diff --git a/elf/dl-addr.c b/elf/dl-addr.c
index 0b8328b..ae97398 100644 (file)
--- a/elf/dl-addr.c
+++ b/elf/dl-addr.c
@@ -1,5 +1,5 @@
 /* Locate the shared object symbol nearest a given address.
-   Copyright (C) 1996-2000,2001,2002,2003 Free Software Foundation, Inc.
+   Copyright (C) 1996-2003, 2004   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
@@ -33,6 +33,9 @@ _dl_addr (const void *address, Dl_info *info,
   const char *strtab;
   ElfW(Word) strtabsize;
 
+  /* Protect against concurrent loads and unloads.  */
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+
   /* Find the highest-addressed object that ADDRESS is not below.  */
   match = NULL;
   for (l = GL(dl_loaded); l; l = l->l_next)
@@ -56,62 +59,71 @@ _dl_addr (const void *address, Dl_info *info,
        break;
       }
 
-  if (match == NULL)
-    return 0;
-
-  /* Now we know what object the address lies in.  */
-  info->dli_fname = match->l_name;
-  info->dli_fbase = (void *) match->l_map_start;
-
-  /* If this is the main program the information is incomplete.  */
-  if (__builtin_expect (l->l_name[0], 'a') == '\0'
-      && l->l_type == lt_executable)
-    info->dli_fname = _dl_argv[0];
-
-  symtab = (const void *) D_PTR (match, l_info[DT_SYMTAB]);
-  strtab = (const void *) D_PTR (match, l_info[DT_STRTAB]);
-
-  strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
-
-  if (match->l_info[DT_HASH] != NULL)
-    symtabend = symtab + ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1];
-  else
-    /* There is no direct way to determine the number of symbols in the
-       dynamic symbol table and no hash table is present.  The ELF
-       binary is ill-formed but what shall we do?  Use the beginning of
-       the string table which generally follows the symbol table.  */
-    symtabend = (const ElfW(Sym) *) strtab;
-
-  /* We assume that the string table follows the symbol table, because
-     there is no way in ELF to know the size of the dynamic symbol table!!  */
-  for (matchsym = NULL; (void *) symtab < (void *) symtabend; ++symtab)
-    if (addr >= match->l_addr + symtab->st_value
-       && ((symtab->st_size == 0 && addr == match->l_addr + symtab->st_value)
-           || addr < match->l_addr + symtab->st_value + symtab->st_size)
-       && symtab->st_name < strtabsize
-       && (matchsym == NULL || matchsym->st_value < symtab->st_value)
-       && (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
-           || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK))
-      matchsym = (ElfW(Sym) *) symtab;
-
-  if (mapp)
-    *mapp = match;
-  if (symbolp)
-    *symbolp = matchsym;
-
-  if (matchsym)
-    {
-      /* We found a symbol close by.  Fill in its name and exact address.  */
-      info->dli_sname = strtab + matchsym->st_name;
-      info->dli_saddr = (void *) (match->l_addr + matchsym->st_value);
-    }
-  else
+  int result = 0;
+  if (match != NULL)
     {
-      /* No symbol matches.  We return only the containing object.  */
-      info->dli_sname = NULL;
-      info->dli_saddr = NULL;
+      /* Now we know what object the address lies in.  */
+      info->dli_fname = match->l_name;
+      info->dli_fbase = (void *) match->l_map_start;
+
+      /* If this is the main program the information is incomplete.  */
+      if (__builtin_expect (l->l_name[0], 'a') == '\0'
+         && l->l_type == lt_executable)
+       info->dli_fname = _dl_argv[0];
+
+      symtab = (const void *) D_PTR (match, l_info[DT_SYMTAB]);
+      strtab = (const void *) D_PTR (match, l_info[DT_STRTAB]);
+
+      strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
+
+      if (match->l_info[DT_HASH] != NULL)
+       symtabend = (symtab
+                    + ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]);
+      else
+       /* There is no direct way to determine the number of symbols in the
+          dynamic symbol table and no hash table is present.  The ELF
+          binary is ill-formed but what shall we do?  Use the beginning of
+          the string table which generally follows the symbol table.  */
+       symtabend = (const ElfW(Sym) *) strtab;
+
+      /* We assume that the string table follows the symbol table,
+        because there is no way in ELF to know the size of the
+        dynamic symbol table!!  */
+      for (matchsym = NULL; (void *) symtab < (void *) symtabend; ++symtab)
+       if (addr >= match->l_addr + symtab->st_value
+           && ((symtab->st_size == 0
+                && addr == match->l_addr + symtab->st_value)
+               || addr < match->l_addr + symtab->st_value + symtab->st_size)
+           && symtab->st_name < strtabsize
+           && (matchsym == NULL || matchsym->st_value < symtab->st_value)
+           && (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
+               || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK))
+         matchsym = (ElfW(Sym) *) symtab;
+
+      if (mapp)
+       *mapp = match;
+      if (symbolp)
+       *symbolp = matchsym;
+
+      if (matchsym)
+       {
+         /* We found a symbol close by.  Fill in its name and exact
+            address.  */
+         info->dli_sname = strtab + matchsym->st_name;
+         info->dli_saddr = (void *) (match->l_addr + matchsym->st_value);
+       }
+      else
+       {
+         /* No symbol matches.  We return only the containing object.  */
+         info->dli_sname = NULL;
+         info->dli_saddr = NULL;
+       }
+
+      result = 1;
     }
 
-  return 1;
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+
+  return result;
 }
 libc_hidden_def (_dl_addr)

diff --git a/elf/dl-fini.c b/elf/dl-fini.c
index 4620273..7115efb 100644 (file)
--- a/elf/dl-fini.c
+++ b/elf/dl-fini.c
@@ -1,5 +1,5 @@
 /* Call the termination functions of loaded shared objects.
-   Copyright (C) 1995,96,98,99,2000,2001,2002 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,1998-2002,2004 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
@@ -46,6 +46,9 @@ _dl_fini (void)
   struct link_map *l;
   struct link_map **maps;
 
+  /* Protect against concurrent loads and unloads.  */
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+
   /* XXX Could it be (in static binaries) that there is no object loaded?  */
   assert (GL(dl_nloaded) > 0);
 
@@ -71,7 +74,7 @@ _dl_fini (void)
       unsigned int j;
       unsigned int k;
 
-      /* Find the place in the `maps' array.  */
+      /* Find the place in the 'maps' array.  */
       for (j = 1; maps[j] != l; ++j)
        ;
 
@@ -79,9 +82,7 @@ _dl_fini (void)
         move the found object (if necessary) in front.  */
       for (k = j + 1; k < GL(dl_nloaded); ++k)
        {
-         struct link_map **runp;
-
-         runp = maps[k]->l_initfini;
+         struct link_map **runp = maps[k]->l_initfini;
          if (runp != NULL)
            {
              while (*runp != NULL)
@@ -120,13 +121,12 @@ _dl_fini (void)
 
                      break;
                    }
-
                }
            }
        }
     }
 
-  /* `maps' now contains the objects in the right order.  Now call the
+  /* 'maps' now contains the objects in the right order.  Now call the
      destructors.  We have to process this array from the front.  */
   for (i = 0; i < GL(dl_nloaded); ++i)
     {
@@ -172,6 +172,8 @@ _dl_fini (void)
       --l->l_opencount;
     }
 
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+
   if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_STATISTICS, 0))
     {
       INTUSE(_dl_debug_printf) ("\nruntime linker statistics:\n");