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authorUlrich Drepper <drepper@redhat.com>2006-10-10 00:51:29 +0000
committerUlrich Drepper <drepper@redhat.com>2006-10-10 00:51:29 +0000
commit1100f84983f22e570a5081cbe79b0ef8fe4952d7 (patch)
tree3472df1372abf7816fb10f02573ba114c5b5a003 /elf/dl-sym.c
parent7484f797e4d4f9c174d4391f59d208e83027b285 (diff)
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Jakub Jelinek <jakub@redhat.com>
Implement reference counting of scope records. * elf/dl-close.c (_dl_close): Remove all scopes from removed objects from the list in objects which remain. Always allocate new scope record. * elf/dl-open.c (dl_open_worker): When growing array for scopes, don't resize, allocate a new one. * elf/dl-runtime.c: Update reference counters before using a scope array. * elf/dl-sym.c: Likewise. * elf/dl-libc.c: Adjust for l_scope name change. * elf/dl-load.c: Likewise. * elf/dl-object.c: Likewise. * elf/rtld.c: Likewise. * include/link.h: Inlcude <rtld-lowlevel.h>. Define struct r_scoperec. Replace r_scope with pointer to r_scoperec structure. Add l_scoperec_lock. * sysdeps/generic/ldsodefs.h: Include <rtld-lowlevel.h>. * sysdeps/generic/rtld-lowlevel.h: New file. * include/atomic.h: Rename atomic_and to atomic_and_val and atomic_or to atomic_or_val. Define new macros atomic_and and atomic_or which do not return values. * sysdeps/x86_64/bits/atomic.h: Define atomic_and and atomic_or. Various cleanups. * sysdeps/i386/i486/bits/atomic.h: Likewise.
Diffstat (limited to 'elf/dl-sym.c')
-rw-r--r--elf/dl-sym.c85
1 files changed, 81 insertions, 4 deletions
diff --git a/elf/dl-sym.c b/elf/dl-sym.c
index d2b0ec0..1c66310 100644
--- a/elf/dl-sym.c
+++ b/elf/dl-sym.c
@@ -17,6 +17,7 @@
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
+#include <assert.h>
#include <stddef.h>
#include <setjmp.h>
#include <libintl.h>
@@ -58,6 +59,30 @@ _dl_tls_symaddr (struct link_map *map, const ElfW(Sym) *ref)
#endif
+struct call_dl_lookup_args
+{
+ /* Arguments to do_dlsym. */
+ struct link_map *map;
+ const char *name;
+ struct r_scope_elem **scope;
+ struct r_found_version *vers;
+ int flags;
+
+ /* Return values of do_dlsym. */
+ lookup_t loadbase;
+ const ElfW(Sym) **refp;
+};
+
+static void
+call_dl_lookup (void *ptr)
+{
+ struct call_dl_lookup_args *args = (struct call_dl_lookup_args *) ptr;
+ args->map = GLRO(dl_lookup_symbol_x) (args->name, args->map, args->refp,
+ args->scope, args->vers, 0,
+ args->flags, NULL);
+}
+
+
static void *
internal_function
do_sym (void *handle, const char *name, void *who,
@@ -84,10 +109,62 @@ do_sym (void *handle, const char *name, void *who,
}
if (handle == RTLD_DEFAULT)
- /* Search the global scope. */
- result = GLRO(dl_lookup_symbol_x) (name, match, &ref, match->l_scope,
- vers, 0, flags|DL_LOOKUP_ADD_DEPENDENCY,
- NULL);
+ {
+ /* Search the global scope. We have the simple case where
+ we look up in the scope of an object which was part of
+ the initial binary. And then the more complex part
+ where the object is dynamically loaded and the scope
+ array can change. */
+ if (match->l_type != lt_loaded)
+ result = GLRO(dl_lookup_symbol_x) (name, match, &ref,
+ match->l_scoperec->scope, vers, 0,
+ flags | DL_LOOKUP_ADD_DEPENDENCY,
+ NULL);
+ else
+ {
+ __rtld_mrlock_lock (match->l_scoperec_lock);
+ struct r_scoperec *scoperec = match->l_scoperec;
+ atomic_increment (&scoperec->nusers);
+ __rtld_mrlock_unlock (match->l_scoperec_lock);
+
+ struct call_dl_lookup_args args;
+ args.name = name;
+ args.map = match;
+ args.scope = scoperec->scope;
+ args.vers = vers;
+ args.flags = flags | DL_LOOKUP_ADD_DEPENDENCY;
+ args.refp = &ref;
+
+ const char *objname;
+ const char *errstring = NULL;
+ bool malloced;
+ int err = GLRO(dl_catch_error) (&objname, &errstring, &malloced,
+ call_dl_lookup, &args);
+
+ if (atomic_decrement_val (&scoperec->nusers) == 0
+ && __builtin_expect (scoperec->remove_after_use, 0))
+ {
+ if (scoperec->notify)
+ __rtld_notify (scoperec->nusers);
+ else
+ free (scoperec);
+ }
+
+ if (__builtin_expect (errstring != NULL, 0))
+ {
+ /* The lookup was unsuccessful. Rethrow the error. */
+ char *errstring_dup = strdupa (errstring);
+ char *objname_dup = strdupa (objname);
+ if (malloced)
+ free ((char *) errstring);
+
+ GLRO(dl_signal_error) (err, objname_dup, NULL, errstring_dup);
+ /* NOTREACHED */
+ }
+
+ result = args.map;
+ }
+ }
else if (handle == RTLD_NEXT)
{
if (__builtin_expect (match == GL(dl_ns)[LM_ID_BASE]._ns_loaded, 0))