Tsan (#109)

x86_64: tsan clean

4 files changed, 17 insertions, 9 deletions

diff --git a/include/libunwind_i.h b/include/libunwind_i.h
index 36cf7a14..e0f45401 100644
--- a/include/libunwind_i.h
+++ b/include/libunwind_i.h
@@ -140,6 +140,7 @@ cmpxchg_ptr (void *addr, void *old, void *new)
 }
 # define fetch_and_add1(_ptr)           AO_fetch_and_add1(_ptr)
 # define fetch_and_add(_ptr, value)     AO_fetch_and_add(_ptr, value)
+# define atomic_read(ptr) (AO_load(ptr))
    /* GCC 3.2.0 on HP-UX crashes on cmpxchg_ptr() */
 #  if !(defined(__hpux) && __GNUC__ == 3 && __GNUC_MINOR__ == 2)
 #   define HAVE_CMPXCHG
@@ -164,10 +165,14 @@ cmpxchg_ptr (void *addr, void *old, void *new)
 }
 # define fetch_and_add1(_ptr)           __sync_fetch_and_add(_ptr, 1)
 # define fetch_and_add(_ptr, value)     __sync_fetch_and_add(_ptr, value)
+# define atomic_read(ptr) (__atomic_load_n(ptr,__ATOMIC_RELAXED))
 # define HAVE_CMPXCHG
 # define HAVE_FETCH_AND_ADD
 #endif
+
+#ifndef atomic_read
 #define atomic_read(ptr)        (*(ptr))
+#endif
 
 #define UNWI_OBJ(fn)      UNW_PASTE(UNW_PREFIX,UNW_PASTE(I,fn))
 #define UNWI_ARCH_OBJ(fn) UNW_PASTE(UNW_PASTE(UNW_PASTE(_UI,UNW_TARGET),_), fn)
diff --git a/src/x86_64/Gglobal.c b/src/x86_64/Gglobal.c
index 8d1fbb4b..d0560582 100644
--- a/src/x86_64/Gglobal.c
+++ b/src/x86_64/Gglobal.c
@@ -30,7 +30,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 #include "dwarf_i.h"
 
 HIDDEN define_lock (x86_64_lock);
-HIDDEN int tdep_init_done;
+HIDDEN sig_atomic_t tdep_init_done;
 
 /* See comments for svr4_dbx_register_map[] in gcc/config/i386/i386.c.  */
 
@@ -77,15 +77,17 @@ HIDDEN void
 tdep_init (void)
 {
   intrmask_t saved_mask;
+  intrmask_t full_mask;
+  sigfillset (&full_mask);
 
-  sigfillset (&unwi_full_mask);
-
-  lock_acquire (&x86_64_lock, saved_mask);
+  SIGPROCMASK (SIG_SETMASK, &full_mask, &saved_mask);
+  mutex_lock (&x86_64_lock);
   {
-    if (tdep_init_done)
+    if (atomic_read(&tdep_init_done))
       /* another thread else beat us to it... */
       goto out;
 
+    sigfillset (&unwi_full_mask);
     mi_init ();
 
     dwarf_init ();
@@ -95,8 +97,9 @@ tdep_init (void)
 #ifndef UNW_REMOTE_ONLY
     x86_64_local_addr_space_init ();
 #endif
-    tdep_init_done = 1; /* signal that we're initialized... */
+    fetch_and_add1(&tdep_init_done); /* signal that we're initialized... */
   }
  out:
-  lock_release (&x86_64_lock, saved_mask);
+  mutex_unlock(&x86_64_lock);
+  SIGPROCMASK (SIG_SETMASK, &saved_mask, NULL);
 }
diff --git a/src/x86_64/Ginit_local.c b/src/x86_64/Ginit_local.c
index 5eaead0f..12a9e3e4 100644
--- a/src/x86_64/Ginit_local.c
+++ b/src/x86_64/Ginit_local.c
@@ -43,7 +43,7 @@ unw_init_local_common (unw_cursor_t *cursor, ucontext_t *uc, unsigned use_prev_i
 {
   struct cursor *c = (struct cursor *) cursor;
 
-  if (unlikely (!tdep_init_done))
+  if (unlikely (!atomic_read(&tdep_init_done)))
     tdep_init ();
 
   Debug (1, "(cursor=%p)\n", c);
diff --git a/src/x86_64/Ginit_remote.c b/src/x86_64/Ginit_remote.c
index efd61d64..f411b233 100644
--- a/src/x86_64/Ginit_remote.c
+++ b/src/x86_64/Ginit_remote.c
@@ -36,7 +36,7 @@ unw_init_remote (unw_cursor_t *cursor, unw_addr_space_t as, void *as_arg)
 #else /* !UNW_LOCAL_ONLY */
   struct cursor *c = (struct cursor *) cursor;
 
-  if (!tdep_init_done)
+  if (!atomic_read(&tdep_init_done))
     tdep_init ();
 
   Debug (1, "(cursor=%p)\n", c);