Hurd: fix port leak in TLS

Depending on whether the thread is the main thread or not, the threading
library can have trouble determining whether the thread reference in the
TCB is valid. The simple solution is to let the threading library
initialize the TCB, and use a temporary reference when initializing TLS.

* sysdeps/mach/hurd/i386/tls.h (_hurd_tls_init): Use a temporary thread
reference.

Gbp-Pq: Topic hurd-i386
Gbp-Pq: Name git-tls_thread_leak.diff

diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index 51c26457d8d30a8759af2e5d6ae09bda1c372ef9..7f7fbfd6642074d579e8f1e7ef47883f28dc08ad 100644 (file)
--- a/sysdeps/mach/hurd/i386/tls.h
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -107,36 +107,41 @@ 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);
+  error_t err = __i386_set_gdt (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