hurd: Replace threadvars with TLS

This gets rid of a lot of kludge and gets closer to other ports.

	* hurd/Makefile (headers): Remove threadvar.h.
	(inline-headers): Remove threadvar.h.
	* hurd/Versions (GLIBC_2.0: Remove __hurd_sigthread_stack_base,
	__hurd_sigthread_stack_end, __hurd_sigthread_variables,
	__hurd_threadvar_max, __hurd_errno_location.
	(HURD_CTHREADS_0.3): Add pthread_getattr_np, pthread_attr_getstack.
	* hurd/hurd/signal.h: Do not include <hurd/threadvar.h>.
	(_hurd_self_sigstate): Use THREAD_SELF to get _hurd_sigstate.
	(_HURD_SIGNAL_H_EXTERN_INLINE): Use THREAD_SELF to get _hurd_sigstate,
	unless TLS is not initialized yet, in which case we do not need a
	critical section yet anyway.
	* hurd/hurd/threadvar.h: Include <tls.h>, do not include
	<machine-sp.h>.
	(__hurd_sigthread_variables, __hurd_threadvar_max): Remove variables
	declarations.
	(__hurd_threadvar_index): Remove enum.
	(_HURD_THREADVAR_H_EXTERN_INLINE): Remove macro.
	(__hurd_threadvar_location_from_sp,__hurd_threadvar_location): Remove
	inlines.
	(__hurd_reply_port0): New variable declaration.
	(__hurd_local_reply_port): New macro.
	* hurd/hurdsig.c (__hurd_sigthread_variables): Remove variable.
	(interrupted_reply_port_location): Add thread_t parameter.  Use it
	with THREAD_TCB to access thread-local variables.
	(_hurdsig_abort_rpcs): Pass ss->thread to
	interrupted_reply_port_location.
	(_hurd_internal_post_signal): Likewise.
	(_hurdsig_init): Use presence of cthread_fork instead of
	__hurd_threadvar_stack_mask to start signal thread by hand.
	Remove signal thread threadvar initialization.
	* hurd/hurdstartup.c: Do not include <hurd/threadvar.h>
	* hurd/sigunwind.c: Include <hurd/threadvar.h>
	(_hurdsig_longjmp_from_handler): Use __hurd_local_reply_port instead
	of threadvar.
	* sysdeps/mach/hurd/Versions (libc.GLIBC_PRIVATE): Add
	__libc_lock_self0.
	(ld.GLIBC_2.0): Remove __hurd_sigthread_stack_base,
	__hurd_sigthread_stack_end, __hurd_sigthread_variables.
	(ld.GLIBC_PRIVATE): Add __libc_lock_self0.
	* sysdeps/mach/hurd/cthreads.c: Add __libc_lock_self0.
	* sysdeps/mach/hurd/dl-sysdep.c (errno, __hurd_sigthread_stack_base,
	__hurd_sigthread_stack_end, __hurd_sigthread_variables, threadvars,
	__hurd_threadvar_stack_offset, __hurd_threadvar_stack_mask): Do not
	define variables.
	* sysdeps/mach/hurd/errno-loc.c: Do not include <errno.h> and
	<hurd/threadvar.h>.
	[IS_IN(rtld)] (rtld_errno): New variable.
	[IS_IN(rtld)] (__errno_location): New weak function.
	[!IS_IN(rtld)]: Include "../../../csu/errno-loc.c".
	* sysdeps/mach/hurd/errno.c: Remove file.
	* sysdeps/mach/hurd/fork.c: Include <hurd/threadvar.h>
	(__fork): Remove THREADVAR_SPACE macro and its use.
	* sysdeps/mach/hurd/i386/init-first.c (__hurd_threadvar_max): Remove
	variable.
	(init): Do not initialize threadvar.
	* sysdeps/mach/hurd/i386/libc.abilist (__hurd_threadvar_max): Remove
	symbol.
	* sysdeps/mach/hurd/i386/sigreturn.c (__sigreturn): Use
	__hurd_local_reply_port instead of threadvar.
	* sysdeps/mach/hurd/i386/tls.h (tcbhead_t): Add reply_port and
	_hurd_sigstate fields.
	(HURD_DESC_TLS, __LIBC_NO_TLS, THREAD_TCB): New macro.
	* sysdeps/mach/hurd/i386/trampoline.c: Remove outdated comment.
	* sysdeps/mach/hurd/libc-lock.h: Do not include <hurd/threadvar.h>.
	(__libc_lock_owner_self): Use &__libc_lock_self0 and THREAD_SELF
	instead of threadvar.
	* sysdeps/mach/hurd/libc-tsd.h: Remove file.
	* sysdeps/mach/hurd/mig-reply.c (GETPORT, reply_port): Remove macros.
	(use_threadvar, global_reply_port): Remove variables.
	(__hurd_reply_port0): New variable.
	(__mig_get_reply_port): Use __hurd_local_reply_port and
	__hurd_reply_port0 instead of threadvar.
	(__mig_dealloc_reply_port): Likewise.
	(__mig_init): Do not initialize threadvar.
	* sysdeps/mach/hurd/profil.c: Fix comment.

15 files changed, 74 insertions, 144 deletions

diff --git a/sysdeps/mach/hurd/Versions b/sysdeps/mach/hurd/Versions
index 89e19061af..7cab8e8551 100644
--- a/sysdeps/mach/hurd/Versions
+++ b/sysdeps/mach/hurd/Versions
@@ -6,6 +6,7 @@ libc {
   GLIBC_PRIVATE {
     # Functions shared with the dynamic linker
     __libc_read; __libc_write; __libc_lseek64;
+    __libc_lock_self0;
 
     _dl_init_first;
   }
@@ -14,8 +15,6 @@ libc {
 ld {
   GLIBC_2.0 {
     # variables that must be shared with libc
-    __hurd_sigthread_stack_base; __hurd_sigthread_stack_end;
-    __hurd_sigthread_variables;
     __hurd_threadvar_stack_mask;  __hurd_threadvar_stack_offset;
 
     # functions that must be shared with libc
@@ -33,5 +32,6 @@ ld {
 
     # functions that must be shared with libc
     __libc_read; __libc_write; __libc_lseek64;
+    __libc_lock_self0;
   }
 }
diff --git a/sysdeps/mach/hurd/cthreads.c b/sysdeps/mach/hurd/cthreads.c
index e0cf4ddca7..640c97ec1d 100644
--- a/sysdeps/mach/hurd/cthreads.c
+++ b/sysdeps/mach/hurd/cthreads.c
@@ -19,6 +19,10 @@
 #include <errno.h>
 #include <stdlib.h>
 
+/* This serves as stub "self" pointer for libc locks when TLS is not initialized
+   yet.  */
+char __libc_lock_self0[0];
+
 /* Placeholder for key creation routine from Hurd cthreads library.  */
 int
 weak_function
diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c
index 1317fd5328..cbf4e05862 100644
--- a/sysdeps/mach/hurd/dl-sysdep.c
+++ b/sysdeps/mach/hurd/dl-sysdep.c
@@ -70,25 +70,6 @@ void *_dl_random attribute_relro = NULL;
 
 struct hurd_startup_data *_dl_hurd_data;
 
-/* This is used only within ld.so, via dl-minimal.c's __errno_location.  */
-#undef errno
-int errno attribute_hidden;
-
-/* Defining these variables here avoids the inclusion of hurdsig.c.  */
-unsigned long int __hurd_sigthread_stack_base;
-unsigned long int __hurd_sigthread_stack_end;
-unsigned long int *__hurd_sigthread_variables;
-
-/* Defining these variables here avoids the inclusion of init-first.c.
-   We need to provide temporary storage for the per-thread variables
-   of the main user thread here, since it is used for storing the
-   `errno' variable.  Note that this information is lost once we
-   relocate the dynamic linker.  */
-static unsigned long int threadvars[_HURD_THREADVAR_MAX];
-unsigned long int __hurd_threadvar_stack_offset
-  = (unsigned long int) &threadvars;
-unsigned long int __hurd_threadvar_stack_mask;
-
 #define FMH defined(__i386__)
 #if ! FMH
 # define fmh()		((void)0)
diff --git a/sysdeps/mach/hurd/errno-loc.c b/sysdeps/mach/hurd/errno-loc.c
index 7b1e7ce347..95d0fe47c4 100644
--- a/sysdeps/mach/hurd/errno-loc.c
+++ b/sysdeps/mach/hurd/errno-loc.c
@@ -16,13 +16,21 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <hurd/threadvar.h>
-
-int *
+#if IS_IN (rtld)
+/*
+ * rtld can not access TLS too early, thus rtld_errno.
+ *
+ * Instead of making __open/__close pass errno from TLS to rtld_errno, simply
+ * use a weak __errno_location using rtld_errno, which will be overriden by the
+ * libc definition.
+ */
+static int rtld_errno;
+int * weak_function
 __errno_location (void)
 {
-  return (int *) __hurd_threadvar_location (_HURD_THREADVAR_ERRNO);
+  return &rtld_errno;
 }
-strong_alias (__errno_location, __hurd_errno_location)
-libc_hidden_def (__errno_location)
+libc_hidden_weak (__errno_location)
+#else
+#include "../../../csu/errno-loc.c"
+#endif
diff --git a/sysdeps/mach/hurd/errno.c b/sysdeps/mach/hurd/errno.c
deleted file mode 100644
index a29091b5e2..0000000000
--- a/sysdeps/mach/hurd/errno.c
+++ /dev/null
@@ -1 +0,0 @@
-/* No definition of `errno' variable on the Hurd.  */
diff --git a/sysdeps/mach/hurd/fork.c b/sysdeps/mach/hurd/fork.c
index cc322ebee5..2d1e64c8d1 100644
--- a/sysdeps/mach/hurd/fork.c
+++ b/sysdeps/mach/hurd/fork.c
@@ -19,6 +19,7 @@
 #include <unistd.h>
 #include <hurd.h>
 #include <hurd/signal.h>
+#include <hurd/threadvar.h>
 #include <setjmp.h>
 #include <thread_state.h>
 #include <sysdep.h>		/* For stack growth direction.  */
@@ -483,19 +484,17 @@ __fork (void)
 				    (natural_t *) &state, &statecount))
 	LOSE;
 #ifdef STACK_GROWTH_UP
-#define THREADVAR_SPACE (__hurd_threadvar_max \
-			 * sizeof *__hurd_sightread_variables)
       if (__hurd_sigthread_stack_base == 0)
 	{
 	  state.SP &= __hurd_threadvar_stack_mask;
-	  state.SP += __hurd_threadvar_stack_offset + THREADVAR_SPACE;
+	  state.SP += __hurd_threadvar_stack_offset;
 	}
       else
 	state.SP = __hurd_sigthread_stack_base;
 #else
       if (__hurd_sigthread_stack_end == 0)
 	{
-	  /* The signal thread has a normal stack assigned by cthreads.
+	  /* The signal thread has a stack assigned by cthreads.
 	     The threadvar_stack variables conveniently tell us how
 	     to get to the highest address in the stack, just below
 	     the per-thread variables.  */
diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/i386/init-first.c
index 965b53ca9e..f4a4df33de 100644
--- a/sysdeps/mach/hurd/i386/init-first.c
+++ b/sysdeps/mach/hurd/i386/init-first.c
@@ -35,7 +35,6 @@ extern void __mach_init (void);
 extern void __init_misc (int, char **, char **);
 extern void __libc_global_ctors (void);
 
-unsigned int __hurd_threadvar_max;
 unsigned long int __hurd_threadvar_stack_offset;
 unsigned long int __hurd_threadvar_stack_mask;
 
@@ -169,15 +168,6 @@ init (int *data)
   char **argv = (void *) (data + 1);
   char **envp = &argv[argc + 1];
   struct hurd_startup_data *d;
-  unsigned long int threadvars[_HURD_THREADVAR_MAX];
-
-  /* Provide temporary storage for thread-specific variables on the
-     startup stack so the cthreads initialization code can use them
-     for malloc et al, or so we can use malloc below for the real
-     threadvars array.  */
-  memset (threadvars, 0, sizeof threadvars);
-  threadvars[_HURD_THREADVAR_LOCALE] = (unsigned long int) &_nl_global_locale;
-  __hurd_threadvar_stack_offset = (unsigned long int) threadvars;
 
   /* Since the cthreads initialization code uses malloc, and the
      malloc initialization code needs to get at the environment, make
@@ -190,13 +180,6 @@ init (int *data)
     ++envp;
   d = (void *) ++envp;
 
-  /* The user might have defined a value for this, to get more variables.
-     Otherwise it will be zero on startup.  We must make sure it is set
-     properly before before cthreads initialization, so cthreads can know
-     how much space to leave for thread variables.  */
-  if (__hurd_threadvar_max < _HURD_THREADVAR_MAX)
-    __hurd_threadvar_max = _HURD_THREADVAR_MAX;
-
 
   /* After possibly switching stacks, call `init1' (above) with the user
      code as the return address, and the argument data immediately above
@@ -212,11 +195,6 @@ init (int *data)
 
       __libc_stack_end = newsp;
 
-      /* Copy per-thread variables from that temporary
-	 area onto the new cthread stack.  */
-      memcpy (__hurd_threadvar_location_from_sp (0, newsp),
-	      threadvars, sizeof threadvars);
-
       /* Copy the argdata from the old stack to the new one.  */
       newsp = memcpy (newsp - ((char *) &d[1] - (char *) data), data,
 		      (char *) d - (char *) data);
@@ -257,25 +235,10 @@ init (int *data)
     }
   else
     {
-      /* We are not using cthreads, so we will have just a single allocated
-	 area for the per-thread variables of the main user thread.  */
-      unsigned long int *array;
-      unsigned int i;
       int usercode;
 
       void call_init1 (void);
 
-      array = malloc (__hurd_threadvar_max * sizeof (unsigned long int));
-      if (array == NULL)
-	__libc_fatal ("Can't allocate single-threaded thread variables.");
-
-      /* Copy per-thread variables from the temporary array into the
-	 newly malloc'd space.  */
-      memcpy (array, threadvars, sizeof threadvars);
-      __hurd_threadvar_stack_offset = (unsigned long int) array;
-      for (i = _HURD_THREADVAR_MAX; i < __hurd_threadvar_max; ++i)
-	array[i] = 0;
-
       /* The argument data is just above the stack frame we will unwind by
 	 returning.  Mutate our own return address to run the code below.  */
       /* The following expression would typically be written as
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index 991c41b374..9545e898c1 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -285,7 +285,6 @@ GLIBC_2.2.6 __gettimeofday F
 GLIBC_2.2.6 __gmtime_r F
 GLIBC_2.2.6 __h_errno_location F
 GLIBC_2.2.6 __hurd_fail F
-GLIBC_2.2.6 __hurd_threadvar_max D 0x4
 GLIBC_2.2.6 __hurd_threadvar_stack_mask D 0x4
 GLIBC_2.2.6 __hurd_threadvar_stack_offset D 0x4
 GLIBC_2.2.6 __isalnum_l F
diff --git a/sysdeps/mach/hurd/i386/sigreturn.c b/sysdeps/mach/hurd/i386/sigreturn.c
index 8ec1d4b91f..07633e17c8 100644
--- a/sysdeps/mach/hurd/i386/sigreturn.c
+++ b/sysdeps/mach/hurd/i386/sigreturn.c
@@ -68,7 +68,7 @@ __sigreturn (struct sigcontext *scp)
 
   if (scp->sc_onstack)
     {
-      ss->sigaltstack.ss_flags &= ~SS_ONSTACK; /* XXX threadvars */
+      ss->sigaltstack.ss_flags &= ~SS_ONSTACK;
       /* XXX cannot unlock until off sigstack */
       abort ();
     }
@@ -77,8 +77,7 @@ __sigreturn (struct sigcontext *scp)
 
   /* Destroy the MiG reply port used by the signal handler, and restore the
      reply port in use by the thread when interrupted.  */
-  reply_port =
-    (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY);
+  reply_port = &__hurd_local_reply_port;
   if (*reply_port)
     {
       mach_port_t port = *reply_port;
diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index 4c78685045..6cd1730887 100644
--- a/sysdeps/mach/hurd/i386/tls.h
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -43,9 +43,27 @@ typedef struct
   void *__private_tm[4];
   /* GCC split stack support.  */
   void *__private_ss;
+
+  /* Keep this field last, so fields above can continue being compatible with
+     the Linux version. */
+  mach_port_t reply_port;      /* This thread's reply port.  */
+  struct hurd_sigstate *_hurd_sigstate;
 } tcbhead_t;
 #endif
 
+/* Return tcbhead_t from a TLS segment descriptor.  */
+# define HURD_DESC_TLS(desc)						      \
+  ({									      \
+   (tcbhead_t *) (   (desc->low_word >> 16)				      \
+                  | ((desc->high_word & 0xff) << 16)			      \
+                  |  (desc->high_word & 0xff000000));			      \
+  })
+
+/* Return 1 if TLS is not initialized yet.  */
+#define __LIBC_NO_TLS()							      \
+  ({ unsigned short ds, gs;						      \
+     asm ("movw %%ds,%w0; movw %%gs,%w1" : "=q" (ds), "=q" (gs));	      \
+     __builtin_expect(ds == gs, 0); })
 
 /* The TCB can have any size and the memory following the address the
    thread pointer points to is unspecified.  Allocate the TCB there.  */
@@ -138,6 +156,21 @@ _hurd_tls_init (tcbhead_t *tcb)
 	      : "i" (offsetof (tcbhead_t, tcb)));			      \
      __tcb;})
 
+/* Return the TCB address of a thread given its state.
+   Note: this is expensive.  */
+# 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 (HURD_SEL_LDT(__sel))						      \
+       __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"					      \
diff --git a/sysdeps/mach/hurd/i386/trampoline.c b/sysdeps/mach/hurd/i386/trampoline.c
index 0c68759f42..0e795f9389 100644
--- a/sysdeps/mach/hurd/i386/trampoline.c
+++ b/sysdeps/mach/hurd/i386/trampoline.c
@@ -79,8 +79,6 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
     {
       sigsp = ss->sigaltstack.ss_sp + ss->sigaltstack.ss_size;
       ss->sigaltstack.ss_flags |= SS_ONSTACK;
-      /* XXX need to set up base of new stack for
-	 per-thread variables, cthreads.  */
     }
   /* This code has intimate knowledge of the special mach_msg system call
      done in intr-msg.c; that code does (see intr-msg.h):
diff --git a/sysdeps/mach/hurd/libc-lock.h b/sysdeps/mach/hurd/libc-lock.h
index 371912efb7..2dfade93eb 100644
--- a/sysdeps/mach/hurd/libc-lock.h
+++ b/sysdeps/mach/hurd/libc-lock.h
@@ -21,7 +21,6 @@
 
 #if (_LIBC - 0) || (_CTHREADS_ - 0)
 #include <cthreads.h>
-#include <hurd/threadvar.h>
 
 /* The locking here is very inexpensive, even for inlining.  */
 #define _IO_lock_inexpensive  1
@@ -35,7 +34,8 @@ typedef struct
 } __libc_lock_recursive_t;
 typedef __libc_lock_recursive_t __rtld_lock_recursive_t;
 
-#define __libc_lock_owner_self() ((void *) __hurd_threadvar_location (0))
+extern char __libc_lock_self0[0];
+#define __libc_lock_owner_self() (__LIBC_NO_TLS() ? &__libc_lock_self0 : THREAD_SELF)
 
 #else
 typedef struct __libc_lock_opaque__ __libc_lock_t;
diff --git a/sysdeps/mach/hurd/libc-tsd.h b/sysdeps/mach/hurd/libc-tsd.h
deleted file mode 100644
index fa131a2d5a..0000000000
--- a/sysdeps/mach/hurd/libc-tsd.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/* libc-internal interface for thread-specific data.  Hurd version.
-   Copyright (C) 1998-2018 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _LIBC_TSD_H
-#define _LIBC_TSD_H 1
-
-#include <hurd/threadvar.h>
-
-#define __libc_tsd_define(CLASS, TYPE, KEY) /* nothing, always have threadvars */
-
-#define __libc_tsd_address(TYPE, KEY) \
-  ((TYPE *) __hurd_threadvar_location (_HURD_THREADVAR_##KEY))
-
-#define __libc_tsd_get(TYPE, KEY) \
-  (*__libc_tsd_address (TYPE, KEY))
-#define __libc_tsd_set(TYPE, KEY, VALUE) \
-  (*__libc_tsd_address (TYPE, KEY) = (VALUE))
-
-#endif	/* libc-tsd.h */
diff --git a/sysdeps/mach/hurd/mig-reply.c b/sysdeps/mach/hurd/mig-reply.c
index ed3705dc41..ddad12e070 100644
--- a/sysdeps/mach/hurd/mig-reply.c
+++ b/sysdeps/mach/hurd/mig-reply.c
@@ -18,26 +18,20 @@
 #include <mach.h>
 #include <hurd/threadvar.h>
 
-#define GETPORT \
-  mach_port_t *portloc = \
-    (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY)
-#define reply_port (*(use_threadvar ? portloc : &global_reply_port))
-
-static int use_threadvar;
-static mach_port_t global_reply_port;
-
 /* These functions are called by MiG-generated code.  */
 
+mach_port_t __hurd_reply_port0;
+
 /* Called by MiG to get a reply port.  */
 mach_port_t
 __mig_get_reply_port (void)
 {
-  GETPORT;
-
-  if (reply_port == MACH_PORT_NULL)
-    reply_port = __mach_reply_port ();
+  if (__hurd_local_reply_port == MACH_PORT_NULL ||
+      (&__hurd_local_reply_port != &__hurd_reply_port0
+       && __hurd_local_reply_port == __hurd_reply_port0))
+    __hurd_local_reply_port = __mach_reply_port ();
 
-  return reply_port;
+  return __hurd_local_reply_port;
 }
 weak_alias (__mig_get_reply_port, mig_get_reply_port)
 
@@ -45,12 +39,8 @@ weak_alias (__mig_get_reply_port, mig_get_reply_port)
 void
 __mig_dealloc_reply_port (mach_port_t arg)
 {
-  mach_port_t port;
-
-  GETPORT;
-
-  port = reply_port;
-  reply_port = MACH_PORT_NULL;	/* So the mod_refs RPC won't use it.  */
+  mach_port_t port = __hurd_local_reply_port;
+  __hurd_local_reply_port = MACH_PORT_NULL;	/* So the mod_refs RPC won't use it.  */
 
   if (MACH_PORT_VALID (port))
     __mach_port_mod_refs (__mach_task_self (), port,
@@ -73,15 +63,6 @@ weak_alias (__mig_put_reply_port, mig_put_reply_port)
 void
 __mig_init (void *stack)
 {
-  use_threadvar = stack != 0;
-
-  if (use_threadvar)
-    {
-      /* Recycle the reply port used before multithreading was enabled.  */
-      mach_port_t *portloc = (mach_port_t *)
-	__hurd_threadvar_location_from_sp (_HURD_THREADVAR_MIG_REPLY, stack);
-      *portloc = global_reply_port;
-      global_reply_port = MACH_PORT_NULL;
-    }
+  /* Do nothing.  */
 }
 weak_alias (__mig_init, mig_init)
diff --git a/sysdeps/mach/hurd/profil.c b/sysdeps/mach/hurd/profil.c
index b3f201b016..952398b4fa 100644
--- a/sysdeps/mach/hurd/profil.c
+++ b/sysdeps/mach/hurd/profil.c
@@ -141,7 +141,7 @@ weak_alias (__profil, profil)
 static volatile error_t special_profil_failure;
 
 /* Fetch PC samples.  This function must be very careful not to depend
-   on Hurd threadvar variables.  We arrange that by using a special
+   on Hurd TLS variables.  We arrange that by using a special
    stub arranged for at the end of this file. */
 static void
 fetch_samples (void)
@@ -176,7 +176,7 @@ fetch_samples (void)
 }
 
 
-/* This function must be very careful not to depend on Hurd threadvar
+/* This function must be very careful not to depend on Hurd TLS
    variables.  We arrange that by using special stubs arranged for at the
    end of this file. */
 static void
@@ -267,7 +267,7 @@ text_set_element (_hurd_fork_child_hook, fork_profil_child);
    are fatal in profile_waiter anyhow. */
 #define __mig_put_reply_port(foo)
 
-/* Use our static variable instead of the usual threadvar mechanism for
+/* Use our static variable instead of the usual TLS mechanism for
    this. */
 #define __mig_get_reply_port() profil_reply_port