2002-08-01 Roland McGrath <roland@redhat.com>
authorroland <roland>
Fri, 2 Aug 2002 03:30:17 +0000 (03:30 +0000)
committerroland <roland>
Fri, 2 Aug 2002 03:30:17 +0000 (03:30 +0000)
* sysdeps/i386/tls.h (TLS_DO_MODIFY_LDT): New macro, broken out of
TLS_INIT_TP.
(TLS_DO_SET_THREAD_AREA): New macro, uses thread_set_area syscall.
(TLS_SETUP_GS_SEGMENT): New macro, try one or the other or both.
(TLS_INIT_TP): Use that.

linuxthreads/sysdeps/i386/tls.h

index 24671db..b49543d 100644 (file)
@@ -77,16 +77,51 @@ typedef struct
 /* Install the dtv pointer.  The pointer passed is to the element with
    index -1 which contain the length.  */
 #  define INSTALL_DTV(descr, dtvp) \
-  ((tcbhead_t *) descr)->dtv = dtvp + 1
+  ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 
 /* Install new dtv for current thread.  */
 #  define INSTALL_NEW_DTV(dtv) \
   ({ struct _pthread_descr_struct *__descr;                                  \
-     THREAD_SETMEM (__descr, p_header.data.dtvp, dtv); })
+     THREAD_SETMEM (__descr, p_header.data.dtvp, (dtv)); })
 
 /* Return dtv of given thread descriptor.  */
 #  define GET_DTV(descr) \
-  (((tcbhead_t *) descr)->dtv)
+  (((tcbhead_t *) (descr))->dtv)
+
+#  define TLS_DO_MODIFY_LDT(descr, nr)                                       \
+({                                                                           \
+  struct modify_ldt_ldt_s ldt_entry =                                        \
+    { nr, (unsigned long int) (descr), sizeof (struct _pthread_descr_struct), \
+      1, 0, 0, 0, 0, 1, 0 };                                                 \
+  int result;                                                                \
+  asm ("pushl %%ebx\n\t"                                                     \
+       "movl $1, %%ebx\n\t"                                                  \
+       "int $0x80\n\t"                                                       \
+       "popl %%ebx"                                                          \
+       : "=a" (result)                                                       \
+       : "0" (__NR_modify_ldt), "d" (sizeof (ldt_entry)), "c" (&ldt_entry));  \
+  __builtin_expect (result, 0) != 0 ? -1 : nr * 8 + 7;                       \
+})
+
+#  define TLS_DO_SET_THREAD_AREA(descr) \
+ INLINE_SYSCALL (set_thread_area, 2, descr, 1);
+  if (__builtin_expect (__seg, 0) == -1)
+    /* Nothing else we can do.  */
+    asm ("hlt");
+  __seg;
+})
+
+#  ifdef __ASSUME_SET_THREAD_AREA_SYSCALL
+#   define TLS_SETUP_GS_SEGMENT(descr) \
+  INLINE_SYSCALL (set_thread_area, 2, descr, 1)
+#  elif defined __NR_set_thread_area
+#   define TLS_SETUP_GS_SEGMENT(descr) \
+  ({ int __seg = INLINE_SYSCALL (set_thread_area, 2, descr, 1); \
+     __seg == -1 ? TLS_DO_MODIFY_LDT (descr, 0) : __seg; })
+#  else
+#   define TLS_SETUP_GS_SEGMENT(descr) \
+  TLS_DO_MODIFY_LDT (descr, 0)
+#  endif
 
 /* Code to initially initialize the thread pointer.  This might need
    special attention since 'errno' is not yet available and if the
@@ -94,27 +129,18 @@ typedef struct
 #  define TLS_INIT_TP(descr) \
   do {                                                                       \
     void *_descr = (descr);                                                  \
-    struct modify_ldt_ldt_s ldt_entry =                                              \
-      { 0, (unsigned long int) _descr, 1048576, 1, 0, 0, 1, 0, 1, 0 };       \
-    int result;                                                                      \
     tcbhead_t *head = _descr;                                                \
+    int __gs;                                                                \
                                                                              \
     head->tcb = _descr;                                                              \
-    /* For now the thread descriptor isat the same address.  */                      \
+    /* For now the thread descriptor is at the same address.  */             \
     head->self = _descr;                                                     \
                                                                              \
-    asm ("pushl %%ebx\n\t"                                                   \
-        "movl $1, %%ebx\n\t"                                                 \
-        "int $0x80\n\t"                                                      \
-        "popl %%ebx"                                                         \
-        : "=a" (result)                                                      \
-        : "0" (__NR_modify_ldt), "d" (sizeof (ldt_entry)), "c" (&ldt_entry));\
-                                                                             \
-    if (__builtin_expect (result, 0) != 0)                                   \
+    __gs = TLS_SETUP_GS_SEGMENT (_descr);                                    \
+    if (__builtin_expect (__gs, 7) == -1)                                    \
       /* Nothing else we can do.  */                                         \
       asm ("hlt");                                                           \
-                                                                             \
-    asm ("movw %w0, %%gs" : : "q" (7));                                              \
+    asm ("movw %w0, %%gs" : : "q" (__gs));                                   \
   } while (0)