[PATCH 1/2] hurd: Don't migrate reply port into __init1_tcbhead

[Sergey Bugaev]

Properly differentiate between setting up the real TLS with
TLS_INIT_TP, and setting up the early TLS (__init1_tcbhead) in static
builds. In the latter case, don't yet migrate the reply port into the
TCB, and don't yet set __libc_tls_initialized to 1.

This also lets us move the __init1_desc assignment inside
_hurd_tls_init ().

Fixes cd019ddd892e182277fadd6aedccc57fa3923c8d
"hurd: Don't leak __hurd_reply_port0"

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
---
 sysdeps/mach/hurd/i386/tls.h       | 18 ++++++++++++------
 sysdeps/mach/hurd/x86/init-first.c |  7 +------
 sysdeps/mach/hurd/x86_64/tls.h     | 11 ++++++-----
 3 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index 0ac8917a..e124fb10 100644
--- a/sysdeps/mach/hurd/i386/tls.h
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -136,7 +136,7 @@ __LIBC_NO_TLS (void)
    special attention since 'errno' is not yet available and if the
    operation can cause a failure 'errno' must not be touched.  */
 static inline bool __attribute__ ((unused))
-_hurd_tls_init (tcbhead_t *tcb)
+_hurd_tls_init (tcbhead_t *tcb, bool full)
 {
   HURD_TLS_DESC_DECL (desc, tcb);
   thread_t self = __mach_thread_self ();
@@ -148,8 +148,9 @@ _hurd_tls_init (tcbhead_t *tcb)
   tcb->tcb = tcb;
   /* We always at least start the sigthread anyway.  */
   tcb->multiple_threads = 1;
-  /* Take over the reply port we've been using.  */
-  tcb->reply_port = __hurd_reply_port0;
+  if (full)
+    /* Take over the reply port we've been using.  */
+    tcb->reply_port = __hurd_reply_port0;
 
   /* Get the first available selector.  */
   int sel = -1;
@@ -175,15 +176,20 @@ _hurd_tls_init (tcbhead_t *tcb)
 
   /* Now install the new selector.  */
   asm volatile ("mov %w0, %%gs" :: "q" (sel));
-  /* This port is now owned by the TCB.  */
-  __hurd_reply_port0 = MACH_PORT_NULL;
+  if (full)
+    /* This port is now owned by the TCB.  */
+    __hurd_reply_port0 = MACH_PORT_NULL;
+#ifndef SHARED
+  else
+    __init1_desc = sel;
+#endif
 
 out:
   __mach_port_deallocate (__mach_task_self (), self);
   return success;
 }
 
-# define TLS_INIT_TP(descr) _hurd_tls_init ((tcbhead_t *) (descr))
+# define TLS_INIT_TP(descr) _hurd_tls_init ((tcbhead_t *) (descr), 1)
 #else /* defined (SHARED) && !IS_IN (rtld) */
 # define __LIBC_NO_TLS() 0
 #endif
diff --git a/sysdeps/mach/hurd/x86/init-first.c 
b/sysdeps/mach/hurd/x86/init-first.c
index 89a5f44c..d74a3c86 100644
--- a/sysdeps/mach/hurd/x86/init-first.c
+++ b/sysdeps/mach/hurd/x86/init-first.c
@@ -156,12 +156,7 @@ first_init (void)
 #ifndef SHARED
   /* In the static case, we need to set up TLS early so that the stack
      protection guard can be read at gs:0x14 by the gcc-generated snippets.  */
-  _hurd_tls_init (&__init1_tcbhead);
-
-  /* Make sure __LIBC_NO_TLS () keeps evaluating to 1.  */
-# ifndef __x86_64__
-  asm ("movw %%gs,%w0" : "=m" (__init1_desc));
-# endif
+  _hurd_tls_init (&__init1_tcbhead, 0);
 #endif
 
   RUN_RELHOOK (_hurd_preinit_hook, ());
diff --git a/sysdeps/mach/hurd/x86_64/tls.h b/sysdeps/mach/hurd/x86_64/tls.h
index 2b7135f6..1274723a 100644
--- a/sysdeps/mach/hurd/x86_64/tls.h
+++ b/sysdeps/mach/hurd/x86_64/tls.h
@@ -173,7 +173,7 @@ extern unsigned char __libc_tls_initialized;
 #  define __LIBC_NO_TLS() __builtin_expect (!__libc_tls_initialized, 0)
 
 static inline bool __attribute__ ((unused))
-_hurd_tls_init (tcbhead_t *tcb)
+_hurd_tls_init (tcbhead_t *tcb, bool full)
 {
   error_t err;
   thread_t self = __mach_thread_self ();
@@ -181,11 +181,12 @@ _hurd_tls_init (tcbhead_t *tcb)
 
   /* We always at least start the sigthread anyway.  */
   tcb->multiple_threads = 1;
-  /* Take over the reply port we've been using.  */
-  tcb->reply_port = __hurd_reply_port0;
+  if (full)
+    /* Take over the reply port we've been using.  */
+    tcb->reply_port = __hurd_reply_port0;
 
   err = _hurd_tls_new (self, tcb);
-  if (err == 0)
+  if (err == 0 && full)
     {
       __libc_tls_initialized = 1;
       /* This port is now owned by the TCB.  */
@@ -195,7 +196,7 @@ _hurd_tls_init (tcbhead_t *tcb)
   return err == 0;
 }
 
-#  define TLS_INIT_TP(descr) _hurd_tls_init ((tcbhead_t *) (descr))
+#  define TLS_INIT_TP(descr) _hurd_tls_init ((tcbhead_t *) (descr), 1)
 # else /* defined (SHARED) && !IS_IN (rtld) */
 #  define __LIBC_NO_TLS() 0
 # endif
-- 
2.40.0