elf: Introduce <dl-call_tls_init_tp.h> and call_tls_init_tp (bug 29249)

This makes it more likely that the compiler can compute the strlen
argument in _startup_fatal at compile time, which is required to
avoid a dependency on strlen this early during process startup.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>

2 files changed, 35 insertions, 1 deletions

diff --git a/sysdeps/generic/dl-call_tls_init_tp.h b/sysdeps/generic/dl-call_tls_init_tp.h
new file mode 100644
index 0000000..411feda
--- /dev/null
+++ b/sysdeps/generic/dl-call_tls_init_tp.h
@@ -0,0 +1,34 @@
+/* Invoke TLS_INIT_TP and __tls_init_tp with error handling.
+   Copyright (C) 2022 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 <startup.h>
+#include <tls.h>
+
+static inline void
+_startup_fatal_tls_error (void)
+{
+  _startup_fatal ("Fatal glibc error: Cannot allocate TLS block\n");
+}
+
+static inline void
+call_tls_init_tp (void *addr)
+{
+  if (!TLS_INIT_TP (addr))
+    _startup_fatal_tls_error ();
+  __tls_init_tp ();
+}
diff --git a/sysdeps/generic/startup.h b/sysdeps/generic/startup.h
index 45979ab..4b44451 100644
--- a/sysdeps/generic/startup.h
+++ b/sysdeps/generic/startup.h
@@ -19,7 +19,7 @@
 /* Targets should override this file if the default definitions below
    will not work correctly very early before TLS is initialized.  */
 
-#include <unistd.h>
+#include <stdio.h>
 
 /* Use macro instead of inline function to avoid including <stdio.h>.  */
 #define _startup_fatal(message) __libc_fatal ((message))