nptl: Move part of TCB initialization from libpthread to __tls_init_tp

This initalization should only happen once for the main thread's TCB.
At present, auditors can achieve this by not linking against
libpthread.  If libpthread becomes part of libc, doing this
initialization in libc would happen for every audit namespace,
or too late (if it happens from the main libc only).  That's why
moving this code into ld.so seems the right thing to do, right after
the TCB initialization.

For !__ASSUME_SET_ROBUST_LIST ports, this also moves the symbol
__set_robust_list_avail into ld.so, as __nptl_set_robust_list_avail.
It also turned into a proper boolean flag.

Inline the __pthread_initialize_pids function because it seems no
longer useful as a separate function.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

2 files changed, 37 insertions, 29 deletions

diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c
index 8983808233..c5172b7613 100644
--- a/sysdeps/nptl/dl-tls_init_tp.c
+++ b/sysdeps/nptl/dl-tls_init_tp.c
@@ -16,10 +16,17 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <kernel-features.h>
 #include <ldsodefs.h>
 #include <list.h>
+#include <nptl/pthreadP.h>
 #include <tls.h>
 
+#ifndef __ASSUME_SET_ROBUST_LIST
+bool __nptl_set_robust_list_avail;
+rtld_hidden_data_def (__nptl_set_robust_list_avail)
+#endif
+
 void
 __tls_init_tp (void)
 {
@@ -27,4 +34,34 @@ __tls_init_tp (void)
   INIT_LIST_HEAD (&GL (dl_stack_used));
   INIT_LIST_HEAD (&GL (dl_stack_user));
   list_add (&THREAD_SELF->list, &GL (dl_stack_user));
+
+   /* Early initialization of the TCB.   */
+   struct pthread *pd = THREAD_SELF;
+   pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid);
+   THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
+   THREAD_SETMEM (pd, user_stack, true);
+
+  /* Initialize the robust mutex data.  */
+  {
+#if __PTHREAD_MUTEX_HAVE_PREV
+    pd->robust_prev = &pd->robust_head;
+#endif
+    pd->robust_head.list = &pd->robust_head;
+    pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock)
+                                    - offsetof (pthread_mutex_t,
+                                                __data.__list.__next));
+    int res = INTERNAL_SYSCALL_CALL (set_robust_list, &pd->robust_head,
+                                     sizeof (struct robust_list_head));
+    if (!INTERNAL_SYSCALL_ERROR_P (res))
+      {
+#ifndef __ASSUME_SET_ROBUST_LIST
+        __nptl_set_robust_list_avail = true;
+#endif
+      }
+  }
+
+  /* Set initial thread's stack block from 0 up to __libc_stack_end.
+     It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
+     purposes this is good enough.  */
+  THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
 }
diff --git a/sysdeps/unix/sysv/linux/pthread-pids.h b/sysdeps/unix/sysv/linux/pthread-pids.h
deleted file mode 100644
index 10b58899f5..0000000000
--- a/sysdeps/unix/sysv/linux/pthread-pids.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/* Initialize pid and tid fields of struct pthread.  Linux version.
-   Copyright (C) 2015-2021 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/>.  */
-
-#include <pthreadP.h>
-#include <sysdep.h>
-
-/* Initialize PD->pid and PD->tid for the initial thread.  If there is
-   setup required to arrange that __exit_thread causes PD->tid to be
-   cleared and futex-woken, then this function should do that as well.  */
-static inline void
-__pthread_initialize_pids (struct pthread *pd)
-{
-  pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid);
-}