nptl: Move stack list variables into _rtld_global

Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT,
formerly __wait_lookup_done) can be implemented directly in ld.so,
eliminating the unprotected GL (dl_wait_lookup_done) function
pointer.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

4 files changed, 23 insertions, 6 deletions

diff --git a/elf/Makefile b/elf/Makefile
index f10cc59..2015383 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -34,7 +34,8 @@ dl-routines	= $(addprefix dl-,load lookup object reloc deps \
 				  version profile tls origin scope \
 				  execstack open close trampoline \
 				  exception sort-maps lookup-direct \
-				  call-libc-early-init write)
+				  call-libc-early-init write \
+				  thread_gscope_wait)
 ifeq (yes,$(use-ldconfig))
 dl-routines += dl-cache
 endif
@@ -54,7 +55,8 @@ endif
 all-dl-routines = $(dl-routines) $(sysdep-dl-routines)
 # But they are absent from the shared libc, because that code is in ld.so.
 elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-origin \
-		    dl-sysdep dl-exception dl-reloc-static-pie
+		    dl-sysdep dl-exception dl-reloc-static-pie \
+		    thread_gscope_wait
 
 # ld.so uses those routines, plus some special stuff for being the program
 # interpreter and operating independent of libc.
diff --git a/elf/dl-support.c b/elf/dl-support.c
index afbc94d..15e6d78 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -183,10 +183,11 @@ ElfW(Word) _dl_stack_flags = DEFAULT_STACK_PERMS;
 int (*_dl_make_stack_executable_hook) (void **) = _dl_make_stack_executable;
 
 
-/* Function in libpthread to wait for termination of lookups.  */
-void (*_dl_wait_lookup_done) (void);
-
-#if !THREAD_GSCOPE_IN_TCB
+#if THREAD_GSCOPE_IN_TCB
+list_t _dl_stack_used;
+list_t _dl_stack_user;
+int _dl_stack_cache_lock;
+#else
 int _dl_thread_gscope_count;
 #endif
 struct dl_scope_free_list *_dl_scope_free_list;
diff --git a/elf/dl-thread_gscope_wait.c b/elf/dl-thread_gscope_wait.c
new file mode 100644
index 0000000..28e1494
--- /dev/null
+++ b/elf/dl-thread_gscope_wait.c
@@ -0,0 +1,2 @@
+/* By default, the dynamic linker does not use an out-of-line
+   __thread_gscope_wait function.  */
diff --git a/elf/rtld.c b/elf/rtld.c
index 5d117d0..c4ffc8d 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -48,6 +48,7 @@
 #include <array_length.h>
 #include <libc-early-init.h>
 #include <dl-main.h>
+#include <list.h>
 
 #include <assert.h>
 
@@ -799,6 +800,9 @@ cannot allocate TLS data structures for initial thread\n");
   const char *lossage = TLS_INIT_TP (tcbp);
   if (__glibc_unlikely (lossage != NULL))
     _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
+#if THREAD_GSCOPE_IN_TCB
+  list_add (&THREAD_SELF->list, &GL (dl_stack_user));
+#endif
   tls_init_tp_called = true;
 
   return tcbp;
@@ -1139,6 +1143,11 @@ dl_main (const ElfW(Phdr) *phdr,
   GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
 #endif
 
+#if THREAD_GSCOPE_IN_TCB
+  INIT_LIST_HEAD (&GL (dl_stack_used));
+  INIT_LIST_HEAD (&GL (dl_stack_user));
+#endif
+
   /* The explicit initialization here is cheaper than processing the reloc
      in the _rtld_local definition's initializer.  */
   GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
@@ -2383,6 +2392,9 @@ dl_main (const ElfW(Phdr) *phdr,
       if (__glibc_unlikely (lossage != NULL))
 	_dl_fatal_printf ("cannot set up thread-local storage: %s\n",
 			  lossage);
+#if THREAD_GSCOPE_IN_TCB
+      list_add (&THREAD_SELF->list, &GL (dl_stack_user));
+#endif
     }
 
   /* Make sure no new search directories have been added.  */