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authorUlrich Drepper <drepper@redhat.com>2004-02-21 01:06:02 +0000
committerUlrich Drepper <drepper@redhat.com>2004-02-21 01:06:02 +0000
commita461b14777bc56a19d3252d7fa5b47ee598757a0 (patch)
treecd4ec84558ed8db4b6a0af36d57f56328ee686ce /elf
parent5990e1fe120708a10ae8ab0caf4a284b5d6b10f8 (diff)
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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>.
Diffstat (limited to 'elf')
-rw-r--r--elf/dl-addr.c122
-rw-r--r--elf/dl-fini.c16
2 files changed, 76 insertions, 62 deletions
diff --git a/elf/dl-addr.c b/elf/dl-addr.c
index 0b8328b..ae97398 100644
--- 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
--- 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");