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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/sparc32 | |
parent | 246f37d6b1c4c6c0a6365df8783e62e3adf208e8 (diff) | |
download | glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.zip glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.tar.gz glibc-88f4b6929c26f9240a4b0b7dcc62922f02544a09.tar.bz2 |
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/sparc32')
-rw-r--r-- | sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S | 1 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/sparc/sparc32/pointer_guard.h | 44 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h | 20 |
3 files changed, 45 insertions, 20 deletions
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S b/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S index 8e8cb4d..ad23840b 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/____longjmp_chk.S @@ -16,6 +16,7 @@ <https://www.gnu.org/licenses/>. */ #include <sysdep.h> +#include <pointer_guard.h> #include <jmpbuf-offsets.h> #define ENV(base,reg) [%base + (reg * 4)] diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/pointer_guard.h b/sysdeps/unix/sysv/linux/sparc/sparc32/pointer_guard.h new file mode 100644 index 0000000..4063513 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/pointer_guard.h @@ -0,0 +1,44 @@ +/* Pointer obfuscation implenentation. 32-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) \ + ld [%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 */ diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h b/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h index 032608a..1783af8 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h @@ -125,24 +125,4 @@ ENTRY(name); \ #endif /* __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(dreg, reg, tmpreg) \ - ld [%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 -# define PTR_MANGLE(var) \ - (var) = (__typeof (var)) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ()) -# define PTR_DEMANGLE(var) PTR_MANGLE (var) -# endif -#endif - #endif /* linux/sparc/sysdep.h */ |