glibc/ports/sysdeps/arm/jmpbuf-unwind.h
Will Newton b7f2d27dbd 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.
2013-10-03 11:35:50 +01:00

46 lines
1.6 KiB
C

/* Copyright (C) 2005-2013 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
<http://www.gnu.org/licenses/>. */
#include <setjmp.h>
#include <stdint.h>
#include <sysdep.h>
#include <unwind.h>
/* Test if longjmp to JMPBUF would unwind the frame
containing a local variable at ADDRESS. */
#define _JMPBUF_UNWINDS(jmpbuf, address, demangle) \
((void *) (address) < (void *) demangle (jmpbuf[__JMP_BUF_SP]))
#define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
_JMPBUF_UNWINDS_ADJ (_jmpbuf, (void *) _Unwind_GetCFA (_context), _adj)
static inline uintptr_t __attribute__ ((unused))
_jmpbuf_sp (__jmp_buf regs)
{
uintptr_t sp = regs[__JMP_BUF_SP];
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (sp);
#endif
return sp;
}
#define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
((uintptr_t) (_address) - (_adj) < _jmpbuf_sp (_jmpbuf) - (_adj))
/* We use the normal longjmp for unwinding. */
#define __libc_unwind_longjmp(buf, val) __libc_longjmp (buf, val)