hurd: Make __getrandom_early_init call __mach_init

25d37948c9 ("malloc: Improve malloc initialization") moved calling malloc
initialization earlier, within _dl_sysdep_start's call to dl_main, before
__mach_init is called by _dl_init_first. But malloc initialization uses
getrandom, which needs to make RPCs.

This adds __getrandom_early_init on hurd to express that getrandom needs
__mach_init too. This also adds a guard to avoid making it create several task
and host ports.

Fixes: 25d37948c9 ("malloc: Improve malloc initialization")
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

mach/mach_init.c

@@ -35,6 +35,10 @@ __mach_init (void)
 {
   kern_return_t err;
 
+  if (__mach_host_self_)
+    /* Already initialized.  */
+    return;
+
   __mach_task_self_ = (__mach_task_self) ();
   __mach_host_self_ = (__mach_host_self) ();
   __mig_init (0);

sysdeps/mach/hurd/getrandom-internal.h

@@ -0,0 +1,30 @@
+/* Internal definitions for Hurd getrandom implementation.
+   Copyright (C) 2024-2025 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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _GETRANDOM_INTERNAL_H
+#define _GETRANDOM_INTERNAL_H
+
+extern void __mach_init (void);
+
+static inline void __getrandom_early_init (_Bool initial)
+{
+  /* getrandom needs RPCs for time etc.  */
+  __mach_init ();
+}
+
+#endif