Add include/libc-misc.h

Add include/libc-misc.h to provide miscellaneous definitions for both
glibc build and test:

1. Move inhibit_stack_protector to libc-misc.h and add Clang support.
2. Add test_inhibit_stack_protector for glibc testing.
3. Move inhibit_loop_to_libcall to libc-misc.h.
4. Add test_cc_inhibit_loop_to_libcall to handle TEST_CC != CC and
replace inhibit_loop_to_libcall with test_cc_inhibit_loop_to_libcall
in glibc tests.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Co-Authored-By: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Sam James <sam@gentoo.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/include/libc-misc.h b/include/libc-misc.h
new file mode 100644
index 0000000000..23fc1c1f60
--- /dev/null
+++ b/include/libc-misc.h
@@ -0,0 +1,67 @@
+/* Miscellaneous definitions for both glibc build and test.
+   Copyright (C) 2024 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 _INCLUDE_MISC_H
+#define _INCLUDE_MISC_H
+
+#include <config.h>
+
+/* Add the compiler optimization to inhibit loop transformation to library
+   calls.  This is used to avoid recursive calls in memset and memmove
+   default implementations in tests.  */
+#ifdef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
+# define inhibit_loop_to_libcall \
+    __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
+#else
+# define inhibit_loop_to_libcall
+#endif
+
+#ifdef HAVE_TEST_CC_INHIBIT_LOOP_TO_LIBCALL
+# define test_cc_inhibit_loop_to_libcall \
+    __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
+#else
+# define test_cc_inhibit_loop_to_libcall
+#endif
+
+/* Used to disable stack protection in sensitive places, like ifunc
+   resolvers and early static TLS init.  */
+#ifdef __clang__
+# define cc_inhibit_stack_protector \
+    __attribute__((no_stack_protector))
+#else
+# define cc_inhibit_stack_protector \
+   __attribute__ ((__optimize__ ("-fno-stack-protector")))
+#endif
+
+#if IS_IN (testsuite) || IS_IN (testsuite_internal)
+# ifdef HAVE_TEST_CC_NO_STACK_PROTECTOR
+#  define test_inhibit_stack_protector cc_inhibit_stack_protector
+#  define inhibit_stack_protector cc_inhibit_stack_protector
+# else
+#  define test_inhibit_stack_protector
+#  define inhibit_stack_protector
+# endif
+#else
+# ifdef HAVE_CC_NO_STACK_PROTECTOR
+#  define inhibit_stack_protector cc_inhibit_stack_protector
+# else
+#  define test_inhibit_stack_protector
+# endif
+#endif
+
+#endif