glibc/sysdeps/mips/jmpbuf-unwind.h
Florian Weimer 88f4b6929c 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>
2022-10-18 17:03:55 +02:00

49 lines
1.7 KiB
C

/* Copyright (C) 2003-2022 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/>. */
#include <setjmp.h>
#include <stdint.h>
#include <unwind.h>
#include <sysdep.h>
#include <pointer_guard.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)[0].__sp))
#define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
_JMPBUF_UNWINDS_ADJ (_jmpbuf, \
(void *) (_Unwind_Ptr) _Unwind_GetCFA (_context), \
_adj)
static inline uintptr_t __attribute__ ((unused))
_jmpbuf_sp (__jmp_buf regs)
{
uintptr_t sp = (uintptr_t) regs[0].__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)