1 files changed, 83 insertions, 14 deletions

diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index 3ec5bb032b..379f22e972 100644
--- a/sysdeps/mach/hurd/i386/tls.h
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -53,6 +53,10 @@ typedef struct
   void *__private_tm[4];
   /* GCC split stack support.  */
   void *__private_ss;
+
+  /* Keep this field last */
+  mach_port_t reply_port;	/* This thread's reply port.  */
+  struct hurd_sigstate *_hurd_sigstate;
 } tcbhead_t;
 #endif
 
@@ -72,6 +76,8 @@ typedef struct
 #  define __i386_set_gdt(thr, sel, desc) ((void) (thr), (void) (sel), (void) (desc), MIG_BAD_ID)
 # endif
 
+#define __i386_selector_is_ldt(sel) (!!((sel) & 4))
+
 # include <errno.h>
 # include <assert.h>
 
@@ -88,41 +94,57 @@ typedef struct
       | (((unsigned int) (tcb)) & 0xff000000) /* base 24..31 */		      \
     }
 
+# define HURD_DESC_TLS(desc)						      \
+  ({									      \
+   (tcbhead_t *) (   (desc->low_word >> 16)				      \
+                  | ((desc->high_word & 0xff) << 16)			      \
+                  |  (desc->high_word & 0xff000000)			      \
+     );})
+
+#define __LIBC_NO_TLS()							      \
+  ({ unsigned short ds, gs;						      \
+     asm ("movw %%ds,%w0; movw %%gs,%w1" : "=q" (ds), "=q" (gs));	      \
+     ds == gs; })
 
 static inline const char * __attribute__ ((unused))
 _hurd_tls_init (tcbhead_t *tcb)
 {
   HURD_TLS_DESC_DECL (desc, tcb);
+  thread_t self = __mach_thread_self ();
+  const char *msg = NULL;
 
   /* This field is used by TLS accesses to get our "thread pointer"
      from the TLS point of view.  */
   tcb->tcb = tcb;
 
-  /* Cache our thread port.  */
-  tcb->self = __mach_thread_self ();
-
   /* Get the first available selector.  */
   int sel = -1;
-  error_t err = __i386_set_gdt (tcb->self, &sel, desc);
+  kern_return_t err = __i386_set_gdt (tcb->self, &sel, desc);
   if (err == MIG_BAD_ID)
     {
       /* Old kernel, use a per-thread LDT.  */
       sel = 0x27;
-      err = __i386_set_ldt (tcb->self, sel, &desc, 1);
+      err = __i386_set_ldt (self, sel, &desc, 1);
       assert_perror (err);
       if (err)
-	return "i386_set_ldt failed";
+      {
+	msg = "i386_set_ldt failed";
+	goto out;
+      }
     }
   else if (err)
     {
       assert_perror (err); /* Separate from above with different line #. */
-      return "i386_set_gdt failed";
+      msg = "i386_set_gdt failed";
+      goto out;
     }
 
   /* Now install the new selector.  */
   asm volatile ("mov %w0, %%gs" :: "q" (sel));
 
-  return 0;
+out:
+  __mach_port_deallocate (__mach_task_self (), self);
+  return msg;
 }
 
 /* Code to initially initialize the thread pointer.  This might need
@@ -138,6 +160,20 @@ _hurd_tls_init (tcbhead_t *tcb)
 	      : "i" (offsetof (tcbhead_t, tcb)));			      \
      __tcb;})
 
+/* Return the TCB address of a thread given its state.  */
+# define THREAD_TCB(thread, thread_state)				      \
+  ({ int __sel = (thread_state)->basic.gs;				      \
+     struct descriptor __desc, *___desc = &__desc;			      \
+     unsigned int __count = 1;						      \
+     kern_return_t __err;						      \
+     if (__builtin_expect (__sel, 0x48) & 4) /* LDT selector */		      \
+       __err = __i386_get_ldt ((thread), __sel, 1, &___desc, &__count);	      \
+     else								      \
+       __err = __i386_get_gdt ((thread), __sel, &__desc);		      \
+     assert_perror (__err);						      \
+     assert (__count == 1);						      \
+     HURD_DESC_TLS(___desc);})
+
 /* Install new dtv for current thread.  */
 # define INSTALL_NEW_DTV(dtvp)						      \
   ({ asm volatile ("movl %0,%%gs:%P1"					      \
@@ -151,9 +187,40 @@ _hurd_tls_init (tcbhead_t *tcb)
 
 # include <mach/machine/thread_status.h>
 
-/* Set up TLS in the new thread of a fork child, copying from our own.  */
-static inline error_t __attribute__ ((unused))
-_hurd_tls_fork (thread_t child, struct i386_thread_state *state)
+/* Set up TLS in the new thread of a fork child, copying from the original.  */
+static inline kern_return_t __attribute__ ((unused))
+_hurd_tls_fork (thread_t child, thread_t orig, struct i386_thread_state *state)
+{
+  /* Fetch the selector set by _hurd_tls_init.  */
+  int sel;
+  asm ("mov %%gs, %w0" : "=q" (sel) : "0" (0));
+  if (sel == state->ds)		/* _hurd_tls_init was never called.  */
+    return 0;
+
+  struct descriptor desc, *_desc = &desc;
+  kern_return_t err;
+  unsigned int count = 1;
+
+  if (__glibc_unlikely (__i386_selector_is_ldt(sel)))
+    err = __i386_get_ldt (orig, sel, 1, &_desc, &count);
+  else
+    err = __i386_get_gdt (orig, sel, &desc);
+
+  assert_perror (err);
+  if (err)
+    return err;
+
+  if (__glibc_unlikely (__i386_selector_is_ldt(sel)))
+    err = __i386_set_ldt (child, sel, &desc, 1);
+  else
+    err = __i386_set_gdt (child, &sel, desc);
+
+  state->gs = sel;
+  return err;
+}
+
+static inline kern_return_t __attribute__ ((unused))
+_hurd_tls_new (thread_t child, struct i386_thread_state *state, tcbhead_t *tcb)
 {
   /* Fetch the selector set by _hurd_tls_init.  */
   int sel;
@@ -161,11 +228,13 @@ _hurd_tls_fork (thread_t child, struct i386_thread_state *state)
   if (sel == state->ds)		/* _hurd_tls_init was never called.  */
     return 0;
 
-  tcbhead_t *const tcb = THREAD_SELF;
   HURD_TLS_DESC_DECL (desc, tcb);
-  error_t err;
+  kern_return_t err;
+
+  tcb->tcb = tcb;
+  tcb->self = child;
 
-  if (__builtin_expect (sel, 0x50) & 4) /* LDT selector */
+  if (__glibc_unlikely (__i386_selector_is_ldt(sel)))
     err = __i386_set_ldt (child, sel, &desc, 1);
   else
     err = __i386_set_gdt (child, &sel, desc);