i#1569 AArch64: Implement exchanging app's TLS.

Use the inline function write_thread_register on both ARM and AARCH64.

Review-URL: https://codereview.appspot.com/300510043

core/unix/os.c

@@ -2214,7 +2214,7 @@ os_swap_context(dcontext_t *dcontext, bool to_app, dr_state_flags_t flags)
 void
 os_swap_context_go_native(dcontext_t *dcontext, dr_state_flags_t flags)
 {
-#ifdef ARM
+#ifdef AARCHXX
     /* FIXME i#1582: remove this routine once os_should_swap_state()
      * is not disabled and we can actually call
      * os_swap_context_go_native() safely from multiple places.
@@ -5963,7 +5963,7 @@ os_switch_seg_to_context(dcontext_t *dcontext, reg_id_t seg, bool to_app)
         return false;
     }
     ASSERT(BOOLS_MATCH(to_app, os_using_app_state(dcontext)));
-#elif defined(ARM)
+#elif defined(AARCHXX)
     os_thread_data_t *ostd = (os_thread_data_t *)dcontext->os_field;
     ASSERT(INTERNAL_OPTION(private_loader));
     if (to_app) {
@@ -5987,7 +5987,7 @@ os_switch_seg_to_context(dcontext_t *dcontext, reg_id_t seg, bool to_app)
         *app_lib_tls_swap_slot = dr_tls_base;
         LOG(THREAD, LOG_LOADER, 2, "%s: switching to %s, setting coproc reg to 0x%x\n",
             __FUNCTION__, (to_app ? "app" : "dr"), os_tls->app_lib_tls_base);
-        res = dynamorio_syscall(SYS_set_tls, 1, os_tls->app_lib_tls_base) == 0;
+        res = write_thread_register(os_tls->app_lib_tls_base);
     } else {
         /* Restore the app's TLS slot that we used for storing DR's TLS base,
          * and put DR's TLS base back to privlib's TLS slot.
@@ -6006,7 +6006,7 @@ os_switch_seg_to_context(dcontext_t *dcontext, reg_id_t seg, bool to_app)
         LOG(THREAD, LOG_LOADER, 2, "%s: switching to %s, setting coproc reg to 0x%x\n",
             __FUNCTION__, (to_app ? "app" : "dr"),
             ostd->priv_lib_tls_base);
-        res = dynamorio_syscall(SYS_set_tls, 1, ostd->priv_lib_tls_base) == 0;
+        res = write_thread_register(ostd->priv_lib_tls_base);
     }
     LOG(THREAD, LOG_LOADER, 2,
         "%s %s: set_tls swap success=%d for thread "TIDFMT"\n",

core/unix/os_exports.h

@@ -368,8 +368,10 @@ get_clone_record_dstack(void *record);
 reg_t
 get_clone_record_stolen_value(void *record);
 
+# ifndef AARCH64
 uint /* dr_isa_mode_t but we have a header ordering problem */
 get_clone_record_isa_mode(void *record);
+# endif
 
 void
 set_thread_register_from_clone_record(void *record);

core/unix/signal.c

@@ -696,13 +696,8 @@ set_thread_register_from_clone_record(void *record)
      * thread did not setup TLS for the child, and we need clear the
      * thread register.
      */
-    if (((clone_record_t *)record)->app_lib_tls_base != NULL) {
-#ifdef AARCH64
-        write_thread_register(0);
-#else
-        dynamorio_syscall(SYS_set_tls, 1, NULL);
-#endif
-    }
+    if (((clone_record_t *)record)->app_lib_tls_base != NULL)
+        write_thread_register(NULL);
 }
 
 void

core/unix/tls.h

@@ -45,6 +45,9 @@
 #define _OS_TLS_H_ 1
 
 #include "os_private.h"  /* ASM_XAX */
+#if defined(ARM) && defined(LINUX)
+# include "include/syscall.h" /* SYS_set_tls */
+#endif
 
 /* We support 3 different methods of creating a segment (see os_tls_init()) */
 typedef enum {
@@ -161,11 +164,16 @@ read_thread_register(reg_id_t reg)
     return sel;
 }
 
-#ifdef AARCH64
-static inline void
+#ifdef AARCHXX
+static inline bool
 write_thread_register(void *val)
 {
+# ifdef AARCH64
     asm volatile("msr tpidr_el0, %0" : : "r"(val));
+    return true;
+# else
+    return (dynamorio_syscall(SYS_set_tls, 1, val) == 0);
+# endif
 }
 #endif
 

core/unix/tls_linux_aarchxx.c

@@ -69,12 +69,7 @@ tls_thread_init(os_local_state_t *os_tls, byte *segment)
     LOG(GLOBAL, LOG_THREADS, 2,
         "tls_thread_init: cur priv lib tls base is "PFX"\n",
         os_tls->os_seg_info.priv_lib_tls_base);
-#ifdef AARCH64
-    asm volatile("msr tpidr_el0, %0" : :
-                 "r"(os_tls->os_seg_info.priv_lib_tls_base));
-#else
-    dynamorio_syscall(SYS_set_tls, 1, os_tls->os_seg_info.priv_lib_tls_base);
-#endif
+    write_thread_register(os_tls->os_seg_info.priv_lib_tls_base);
     ASSERT(get_segment_base(TLS_REG_LIB) == os_tls->os_seg_info.priv_lib_tls_base);
     ASSERT(*get_dr_tls_base_addr() == NULL);
     *get_dr_tls_base_addr() = segment;