Introduce <pointer_guard.h>, extracted from <sysdep.h>

This allows us to define a generic no-op version of PTR_MANGLE and
PTR_DEMANGLE.  In the future, we can use PTR_MANGLE and PTR_DEMANGLE
unconditionally in C sources, avoiding an unintended loss of hardening
due to missing include files or unlucky header inclusion ordering.

In i386 and x86_64, we can avoid a <tls.h> dependency in the C
code by using the computed constant from <tcb-offsets.h>.  <sysdep.h>
no longer includes these definitions, so there is no cyclic dependency
anymore when computing the <tcb-offsets.h> constants.

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

5 files changed, 47 insertions, 20 deletions

diff --git a/sysdeps/unix/sysv/linux/ia64/__ia64_longjmp.S b/sysdeps/unix/sysv/linux/ia64/__ia64_longjmp.S
index 9511c15945..4ef5129623 100644
--- a/sysdeps/unix/sysv/linux/ia64/__ia64_longjmp.S
+++ b/sysdeps/unix/sysv/linux/ia64/__ia64_longjmp.S
@@ -15,6 +15,7 @@
    <https://www.gnu.org/licenses/>.  */
 
 #include <sysdep.h>
+#include <pointer_guard.h>
 #include <features.h>
 
 LEAF(__ia64_flush_rbs)
diff --git a/sysdeps/unix/sysv/linux/ia64/__longjmp.S b/sysdeps/unix/sysv/linux/ia64/__longjmp.S
index 793dc98cc1..da9653d8a7 100644
--- a/sysdeps/unix/sysv/linux/ia64/__longjmp.S
+++ b/sysdeps/unix/sysv/linux/ia64/__longjmp.S
@@ -31,6 +31,7 @@
 		bits into ar.rnat after setting ar.bspstore. */
 
 #include <sysdep.h>
+#include <pointer_guard.h>
 #include <features.h>
 
 #	define	pPos	p6	/* is rotate count positive? */
diff --git a/sysdeps/unix/sysv/linux/ia64/pointer_guard.h b/sysdeps/unix/sysv/linux/ia64/pointer_guard.h
new file mode 100644
index 0000000000..8631f39374
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ia64/pointer_guard.h
@@ -0,0 +1,44 @@
+/* Pointer obfuscation implenentation.  ia64 version.
+   Copyright (C) 2005-2022 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/>.  */
+
+#ifndef POINTER_GUARD_H
+#define POINTER_GUARD_H
+
+#if IS_IN (rtld)
+/* We cannot use the thread descriptor because in ld.so we use setjmp
+   earlier than the descriptor is initialized.  */
+# include <sysdeps/generic/pointer_guard.h>
+#else
+# ifdef __ASSEMBLER__
+#  define PTR_MANGLE(reg, tmpreg) \
+        add     tmpreg=-16,r13          \
+        ;;                              \
+        ld8     tmpreg=[tmpreg]         \
+        ;;                              \
+        xor     reg=reg, tmpreg
+#  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
+# else
+#  include <stdint.h>
+#  include <tls.h>
+#  define PTR_MANGLE(var) \
+  (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
+#  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
+# endif
+#endif
+
+#endif /* POINTER_GUARD_H */
diff --git a/sysdeps/unix/sysv/linux/ia64/setjmp.S b/sysdeps/unix/sysv/linux/ia64/setjmp.S
index c29a31f7a6..a978dd4360 100644
--- a/sysdeps/unix/sysv/linux/ia64/setjmp.S
+++ b/sysdeps/unix/sysv/linux/ia64/setjmp.S
@@ -63,6 +63,7 @@
 	0x1c0	f31 */
 
 #include <sysdep.h>
+#include <pointer_guard.h>
 #include <features.h>
 
 	/* The following two entry points are the traditional entry points: */
diff --git a/sysdeps/unix/sysv/linux/ia64/sysdep.h b/sysdeps/unix/sysv/linux/ia64/sysdep.h
index 14adbdf4ff..b450c6c224 100644
--- a/sysdeps/unix/sysv/linux/ia64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/ia64/sysdep.h
@@ -324,24 +324,4 @@
 
 #endif /* not __ASSEMBLER__ */
 
-/* Pointer mangling support.  */
-#if IS_IN (rtld)
-/* We cannot use the thread descriptor because in ld.so we use setjmp
-   earlier than the descriptor is initialized.  */
-#else
-# ifdef __ASSEMBLER__
-#  define PTR_MANGLE(reg, tmpreg) \
-        add	tmpreg=-16,r13		\
-        ;;				\
-        ld8	tmpreg=[tmpreg]		\
-        ;;				\
-        xor	reg=reg, tmpreg
-#  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
-# else
-#  define PTR_MANGLE(var) \
-  (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
-#  define PTR_DEMANGLE(var)	PTR_MANGLE (var)
-# endif
-#endif
-
 #endif /* linux/ia64/sysdep.h */