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author | Florian Weimer <fweimer@redhat.com> | 2022-10-18 17:00:07 +0200 |
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committer | Florian Weimer <fweimer@redhat.com> | 2022-10-18 17:03:55 +0200 |
commit | 88f4b6929c26f9240a4b0b7dcc62922f02544a09 (patch) | |
tree | 72acb4a359d3ec56729a910386bd1a002bd69e3c /sysdeps/unix/sysv/linux/sparc/sparc64/pointer_guard.h | |
parent | 246f37d6b1c4c6c0a6365df8783e62e3adf208e8 (diff) | |
download | glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.tar.gz glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.tar.xz 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/unix/sysv/linux/sparc/sparc64/pointer_guard.h')
-rw-r--r-- | sysdeps/unix/sysv/linux/sparc/sparc64/pointer_guard.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/pointer_guard.h b/sysdeps/unix/sysv/linux/sparc/sparc64/pointer_guard.h new file mode 100644 index 0000000000..7865e87c73 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/pointer_guard.h @@ -0,0 +1,44 @@ +/* Pointer obfuscation implenentation. 64-bit SPARC 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 + +#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(dreg, reg, tmpreg) \ + ldx [%g7 + POINTER_GUARD], tmpreg; \ + xor reg, tmpreg, dreg +# define PTR_DEMANGLE(dreg, reg, tmpreg) PTR_MANGLE (dreg, reg, tmpreg) +# define PTR_MANGLE2(dreg, reg, tmpreg) \ + xor reg, tmpreg, dreg +# define PTR_DEMANGLE2(dreg, reg, tmpreg) PTR_MANGLE2 (dreg, reg, tmpreg) +# else +# include <stdint.h> +# include <tls.h> +# define PTR_MANGLE(var) \ + (var) = (__typeof (var)) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ()) +# define PTR_DEMANGLE(var) PTR_MANGLE (var) +# endif +#endif + +#endif /* POINTER_GUARD_H */ |