diff options
author | Florian Weimer <fweimer@redhat.com> | 2022-10-18 17:00:07 +0200 |
---|---|---|
committer | Florian Weimer <fweimer@redhat.com> | 2022-10-18 17:03:55 +0200 |
commit | 88f4b6929c26f9240a4b0b7dcc62922f02544a09 (patch) | |
tree | 72acb4a359d3ec56729a910386bd1a002bd69e3c /sysdeps/arm | |
parent | 246f37d6b1c4c6c0a6365df8783e62e3adf208e8 (diff) | |
download | glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.tar glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.tar.gz glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.tar.bz2 glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.zip |
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/arm')
-rw-r--r-- | sysdeps/arm/__longjmp.S | 1 | ||||
-rw-r--r-- | sysdeps/arm/jmpbuf-unwind.h | 1 | ||||
-rw-r--r-- | sysdeps/arm/pointer_guard.h | 67 | ||||
-rw-r--r-- | sysdeps/arm/setjmp.S | 1 | ||||
-rw-r--r-- | sysdeps/arm/sysdep.h | 44 |
5 files changed, 70 insertions, 44 deletions
diff --git a/sysdeps/arm/__longjmp.S b/sysdeps/arm/__longjmp.S index 5f1cf3643f..411055b9b3 100644 --- a/sysdeps/arm/__longjmp.S +++ b/sysdeps/arm/__longjmp.S @@ -17,6 +17,7 @@ <https://www.gnu.org/licenses/>. */ #include <sysdep.h> +#include <pointer_guard.h> #include <stap-probe.h> #include <bits/setjmp.h> #include <rtld-global-offsets.h> diff --git a/sysdeps/arm/jmpbuf-unwind.h b/sysdeps/arm/jmpbuf-unwind.h index e6b118f4d0..641444eaf3 100644 --- a/sysdeps/arm/jmpbuf-unwind.h +++ b/sysdeps/arm/jmpbuf-unwind.h @@ -18,6 +18,7 @@ #include <setjmp.h> #include <stdint.h> #include <sysdep.h> +#include <pointer_guard.h> #include <unwind.h> /* Test if longjmp to JMPBUF would unwind the frame diff --git a/sysdeps/arm/pointer_guard.h b/sysdeps/arm/pointer_guard.h new file mode 100644 index 0000000000..6b90cec2f3 --- /dev/null +++ b/sysdeps/arm/pointer_guard.h @@ -0,0 +1,67 @@ +/* Pointer guard implementation. Arm version. + Copyright (C) 2013-2022 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. */ +#if (IS_IN (rtld) \ + || (!defined SHARED && (IS_IN (libc) || IS_IN (libpthread)))) +# ifdef __ASSEMBLER__ +# define PTR_MANGLE_LOAD(guard, tmp) \ + LDR_HIDDEN (guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local), 0) +# define PTR_MANGLE(dst, src, guard, tmp) \ + PTR_MANGLE_LOAD(guard, tmp); \ + PTR_MANGLE2(dst, src, guard) +/* Use PTR_MANGLE2 for efficiency if guard is already loaded. */ +# define PTR_MANGLE2(dst, src, guard) \ + eor dst, src, guard +# define PTR_DEMANGLE(dst, src, guard, tmp) \ + PTR_MANGLE (dst, src, guard, tmp) +# define PTR_DEMANGLE2(dst, src, guard) \ + PTR_MANGLE2 (dst, src, guard) +# else +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) +# define PTR_DEMANGLE(var) PTR_MANGLE (var) +# endif +#else +# ifdef __ASSEMBLER__ +# define PTR_MANGLE_LOAD(guard, tmp) \ + LDR_GLOBAL (guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard), 0); +# define PTR_MANGLE(dst, src, guard, tmp) \ + PTR_MANGLE_LOAD(guard, tmp); \ + PTR_MANGLE2(dst, src, guard) +/* Use PTR_MANGLE2 for efficiency if guard is already loaded. */ +# define PTR_MANGLE2(dst, src, guard) \ + eor dst, src, guard +# define PTR_DEMANGLE(dst, src, guard, tmp) \ + PTR_MANGLE (dst, src, guard, tmp) +# define PTR_DEMANGLE2(dst, src, guard) \ + PTR_MANGLE2 (dst, src, guard) +# else +# include <stdint.h> +extern uintptr_t __pointer_chk_guard attribute_relro; +# define PTR_MANGLE(var) \ + (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard) +# define PTR_DEMANGLE(var) PTR_MANGLE (var) +# endif +#endif + +#endif /* POINTER_GUARD_H */ diff --git a/sysdeps/arm/setjmp.S b/sysdeps/arm/setjmp.S index 1c26227437..271454d769 100644 --- a/sysdeps/arm/setjmp.S +++ b/sysdeps/arm/setjmp.S @@ -17,6 +17,7 @@ <https://www.gnu.org/licenses/>. */ #include <sysdep.h> +#include <pointer_guard.h> #include <stap-probe.h> #include <bits/setjmp.h> #include <rtld-global-offsets.h> diff --git a/sysdeps/arm/sysdep.h b/sysdeps/arm/sysdep.h index f19146b85f..ffd848de88 100644 --- a/sysdeps/arm/sysdep.h +++ b/sysdeps/arm/sysdep.h @@ -293,47 +293,3 @@ #else # define PC_OFS 8 #endif - -/* Pointer mangling support. */ -#if (IS_IN (rtld) \ - || (!defined SHARED && (IS_IN (libc) || IS_IN (libpthread)))) -# ifdef __ASSEMBLER__ -# define PTR_MANGLE_LOAD(guard, tmp) \ - LDR_HIDDEN (guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local), 0) -# define PTR_MANGLE(dst, src, guard, tmp) \ - PTR_MANGLE_LOAD(guard, tmp); \ - PTR_MANGLE2(dst, src, guard) -/* Use PTR_MANGLE2 for efficiency if guard is already loaded. */ -# define PTR_MANGLE2(dst, src, guard) \ - eor dst, src, guard -# define PTR_DEMANGLE(dst, src, guard, tmp) \ - PTR_MANGLE (dst, src, guard, tmp) -# define PTR_DEMANGLE2(dst, src, guard) \ - PTR_MANGLE2 (dst, src, guard) -# else -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) -# define PTR_DEMANGLE(var) PTR_MANGLE (var) -# endif -#else -# ifdef __ASSEMBLER__ -# define PTR_MANGLE_LOAD(guard, tmp) \ - LDR_GLOBAL (guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard), 0); -# define PTR_MANGLE(dst, src, guard, tmp) \ - PTR_MANGLE_LOAD(guard, tmp); \ - PTR_MANGLE2(dst, src, guard) -/* Use PTR_MANGLE2 for efficiency if guard is already loaded. */ -# define PTR_MANGLE2(dst, src, guard) \ - eor dst, src, guard -# define PTR_DEMANGLE(dst, src, guard, tmp) \ - PTR_MANGLE (dst, src, guard, tmp) -# define PTR_DEMANGLE2(dst, src, guard) \ - PTR_MANGLE2 (dst, src, guard) -# else -extern uintptr_t __pointer_chk_guard attribute_relro; -# define PTR_MANGLE(var) \ - (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard) -# define PTR_DEMANGLE(var) PTR_MANGLE (var) -# endif -#endif |