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authorFlorian Weimer <fweimer@redhat.com>2022-10-18 17:00:07 +0200
committerFlorian Weimer <fweimer@redhat.com>2022-10-18 17:03:55 +0200
commit88f4b6929c26f9240a4b0b7dcc62922f02544a09 (patch)
tree72acb4a359d3ec56729a910386bd1a002bd69e3c /sysdeps/unix/sysv/linux/alpha
parent246f37d6b1c4c6c0a6365df8783e62e3adf208e8 (diff)
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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>
Diffstat (limited to 'sysdeps/unix/sysv/linux/alpha')
-rw-r--r--sysdeps/unix/sysv/linux/alpha/____longjmp_chk.S1
-rw-r--r--sysdeps/unix/sysv/linux/alpha/pointer_guard.h62
-rw-r--r--sysdeps/unix/sysv/linux/alpha/sysdep.h40
3 files changed, 63 insertions, 40 deletions
diff --git a/sysdeps/unix/sysv/linux/alpha/____longjmp_chk.S b/sysdeps/unix/sysv/linux/alpha/____longjmp_chk.S
index 610f401d45..566a3b0211 100644
--- a/sysdeps/unix/sysv/linux/alpha/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/alpha/____longjmp_chk.S
@@ -16,6 +16,7 @@
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
+#include <pointer_guard.h>
#include <jmpbuf-offsets.h>
diff --git a/sysdeps/unix/sysv/linux/alpha/pointer_guard.h b/sysdeps/unix/sysv/linux/alpha/pointer_guard.h
new file mode 100644
index 0000000000..d4d513d816
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/pointer_guard.h
@@ -0,0 +1,62 @@
+/* Pointer guard implementation. Alpha version.
+ Copyright (C) 2006-2022 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
+
+/* Pointer mangling support. Note that tls access is slow enough that
+ we don't deoptimize things by placing the pointer check value there. */
+
+#ifdef __ASSEMBLER__
+# if IS_IN (rtld)
+# define PTR_MANGLE(dst, src, tmp) \
+ ldah tmp, __pointer_chk_guard_local($29) !gprelhigh; \
+ ldq tmp, __pointer_chk_guard_local(tmp) !gprellow; \
+ xor src, tmp, dst
+# define PTR_MANGLE2(dst, src, tmp) \
+ xor src, tmp, dst
+# elif defined SHARED
+# define PTR_MANGLE(dst, src, tmp) \
+ ldq tmp, __pointer_chk_guard; \
+ xor src, tmp, dst
+# else
+# define PTR_MANGLE(dst, src, tmp) \
+ ldq tmp, __pointer_chk_guard_local; \
+ xor src, tmp, dst
+# endif
+# define PTR_MANGLE2(dst, src, tmp) \
+ xor src, tmp, dst
+# define PTR_DEMANGLE(dst, tmp) PTR_MANGLE(dst, dst, tmp)
+# define PTR_DEMANGLE2(dst, tmp) PTR_MANGLE2(dst, dst, tmp)
+#else
+# include <stdint.h>
+# if (IS_IN (rtld) \
+ || (!defined SHARED && (IS_IN (libc) \
+ || IS_IN (libpthread))))
+extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
+# define PTR_MANGLE(var) \
+ (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard_local)
+# else
+extern uintptr_t __pointer_chk_guard attribute_relro;
+# define PTR_MANGLE(var) \
+ (var) = (__typeof(var)) ((uintptr_t) (var) ^ __pointer_chk_guard)
+# endif
+# define PTR_DEMANGLE(var) PTR_MANGLE(var)
+#endif /* ASSEMBLER */
+
+#endif /* POINTER_GUARD_H */
diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
index 77ec2b5400..0ddcb58b30 100644
--- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
+++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
@@ -313,44 +313,4 @@ __LABEL(name) \
})
#endif /* ASSEMBLER */
-/* Pointer mangling support. Note that tls access is slow enough that
- we don't deoptimize things by placing the pointer check value there. */
-
-#ifdef __ASSEMBLER__
-# if IS_IN (rtld)
-# define PTR_MANGLE(dst, src, tmp) \
- ldah tmp, __pointer_chk_guard_local($29) !gprelhigh; \
- ldq tmp, __pointer_chk_guard_local(tmp) !gprellow; \
- xor src, tmp, dst
-# define PTR_MANGLE2(dst, src, tmp) \
- xor src, tmp, dst
-# elif defined SHARED
-# define PTR_MANGLE(dst, src, tmp) \
- ldq tmp, __pointer_chk_guard; \
- xor src, tmp, dst
-# else
-# define PTR_MANGLE(dst, src, tmp) \
- ldq tmp, __pointer_chk_guard_local; \
- xor src, tmp, dst
-# endif
-# define PTR_MANGLE2(dst, src, tmp) \
- xor src, tmp, dst
-# define PTR_DEMANGLE(dst, tmp) PTR_MANGLE(dst, dst, tmp)
-# define PTR_DEMANGLE2(dst, tmp) PTR_MANGLE2(dst, dst, tmp)
-#else
-# include <stdint.h>
-# if (IS_IN (rtld) \
- || (!defined SHARED && (IS_IN (libc) \
- || IS_IN (libpthread))))
-extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
-# define PTR_MANGLE(var) \
- (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard_local)
-# else
-extern uintptr_t __pointer_chk_guard attribute_relro;
-# define PTR_MANGLE(var) \
- (var) = (__typeof(var)) ((uintptr_t) (var) ^ __pointer_chk_guard)
-# endif
-# define PTR_DEMANGLE(var) PTR_MANGLE(var)
-#endif /* ASSEMBLER */
-
#endif /* _LINUX_ALPHA_SYSDEP_H */