diff options
| author | Will Newton <will.newton@linaro.org> | 2013-08-07 13:55:30 +0100 |
|---|---|---|
| committer | Will Newton <will.newton@linaro.org> | 2013-10-03 11:35:50 +0100 |
| commit | b7f2d27dbd85f6a0966dc389ad4f8205085b7ae8 (patch) | |
| tree | 5d08889f9d642580e01d529303ed56409982a221 /ports/sysdeps/unix | |
| parent | 29c793b3c2947badd9d05e45736e406fb12021e8 (diff) | |
| download | glibc-b7f2d27dbd85f6a0966dc389ad4f8205085b7ae8.tar.gz | |
ARM: Add pointer encryption support.
Add support for pointer encryption in glibc internal structures in C
and assembler code. Pointer encryption is a glibc security feature
described here:
https://sourceware.org/glibc/wiki/PointerEncryption
The ARM implementation uses global variables instead of thread pointer
relative accesses to get the value of the pointer encryption guard
because accessing the thread pointer can be very expensive on older
ARM cores.
ports/ChangeLog.arm:
2013-10-03 Will Newton <will.newton@linaro.org>
* sysdeps/arm/__longjmp.S (__longjmp): Demangle fp, sp
and lr when restoring register values.
* sysdeps/arm/include/bits/setjmp.h (JMP_BUF_REGLIST): Remove
sp and lr from list and replace fp with a4.
* sysdeps/arm/jmpbuf-unwind.h (_jmpbuf_sp): New function.
(_JMPBUF_UNWINDS_ADJ): Call _jmpbuf_sp.
* sysdeps/arm/setjmp.S (__sigsetjmp): Mangle fp, sp and lr
before storing register values.
* sysdeps/arm/sysdep.h (LDST_GLOBAL): New macro.
* sysdeps/unix/sysv/linux/arm/sysdep.h (PTR_MANGLE): New macro.
(PTR_DEMANGLE): Likewise. (PTR_MANGLE2): Likewise.
(PTR_DEMANGLE2): Likewise.
Diffstat (limited to 'ports/sysdeps/unix')
| -rw-r--r-- | ports/sysdeps/unix/sysv/linux/arm/sysdep.h | 42 |
1 files changed, 39 insertions, 3 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/arm/sysdep.h b/ports/sysdeps/unix/sysv/linux/arm/sysdep.h index b195d8ea1d..6cfe4e08a7 100644 --- a/ports/sysdeps/unix/sysv/linux/arm/sysdep.h +++ b/ports/sysdeps/unix/sysv/linux/arm/sysdep.h @@ -435,8 +435,44 @@ __local_syscall_error: \ #endif /* __ASSEMBLER__ */ -/* Pointer mangling is not yet supported for ARM. */ -#define PTR_MANGLE(var) (void) (var) -#define PTR_DEMANGLE(var) (void) (var) +/* Pointer mangling support. */ +#if (defined NOT_IN_libc && defined IS_IN_rtld) || \ + (!defined SHARED && (!defined NOT_IN_libc || defined IS_IN_libpthread)) +# ifdef __ASSEMBLER__ +# define PTR_MANGLE(dst, src, guard, tmp) \ + LDST_PCREL(ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local)); \ + 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(dst, src, guard, tmp) \ + LDST_GLOBAL(ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard)); \ + 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 #endif /* linux/arm/sysdep.h */ |