gcc/libgcc/config/arm/unwind-arm.h
Christophe Lyon 5d727a4b20 [ARM/FDPIC v6 06/24] [ARM] FDPIC: Add support for c++ exceptions
The main difference with existing support is that function addresses
are function descriptor addresses instead. This means that all code
dealing with function pointers now has to cope with function
descriptors instead.

For the same reason, Linux kernel helpers can no longer be called by
dereferencing their address, so we implement wrappers that directly
call the kernel helpers.

When restoring a function address, we also have to restore the FDPIC
register value (r9).

2019-09-10  Christophe Lyon  <christophe.lyon@st.com>
	Mickaël Guêné <mickael.guene@st.com>

	gcc/
	* ginclude/unwind-arm-common.h (unwinder_cache): Add reserved5
	field.

	libgcc/
	* config/arm/linux-atomic.c (__kernel_cmpxchg): Add FDPIC support.
	(__kernel_dmb): Likewise.
	(__fdpic_cmpxchg): New function.
	(__fdpic_dmb): New function.
	* config/arm/unwind-arm.h (FDPIC_REGNUM): New define.
	(gnu_Unwind_Find_got): New function.
	(_Unwind_decode_typeinfo_ptr): Add FDPIC support.
	* unwind-arm-common.inc (UCB_PR_GOT): New.
	(funcdesc_t): New struct.
	(get_eit_entry): Add FDPIC support.
	(unwind_phase2): Likewise.
	(unwind_phase2_forced): Likewise.
	(__gnu_Unwind_RaiseException): Likewise.
	(__gnu_Unwind_Resume): Likewise.
	(__gnu_Unwind_Backtrace): Likewise.
	* unwind-pe.h (read_encoded_value_with_base): Likewise.

	libstdc++/
	* libsupc++/eh_personality.cc (get_ttype_entry): Add FDPIC
	support.


Co-Authored-By: Mickaël Guêné <mickael.guene@st.com>

From-SVN: r275568
2019-09-10 09:47:49 +02:00

123 lines
3.8 KiB
C

/* Header file for the ARM EABI unwinder
Copyright (C) 2003-2019 Free Software Foundation, Inc.
Contributed by Paul Brook
This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.
This file 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
General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* Language-independent unwinder header public defines. This contains both
ABI defined objects, and GNU support routines. */
#ifndef UNWIND_ARM_H
#define UNWIND_ARM_H
#include "unwind-arm-common.h"
#define UNWIND_STACK_REG 13
/* Use IP as a scratch register within the personality routine. */
#define UNWIND_POINTER_REG 12
#define FDPIC_REGNUM 9
#define STR(x) #x
#define XSTR(x) STR(x)
#ifdef __cplusplus
extern "C" {
#endif
_Unwind_Ptr __attribute__((weak)) __gnu_Unwind_Find_got (_Unwind_Ptr);
static inline _Unwind_Ptr gnu_Unwind_Find_got (_Unwind_Ptr ptr)
{
_Unwind_Ptr res;
if (__gnu_Unwind_Find_got)
res = __gnu_Unwind_Find_got (ptr);
else
{
asm volatile ("mov %[result], r" XSTR(FDPIC_REGNUM)
: [result]"=r" (res)
:
:);
}
return res;
}
/* Decode an R_ARM_TARGET2 relocation. */
static inline _Unwind_Word
_Unwind_decode_typeinfo_ptr (_Unwind_Word base __attribute__ ((unused)),
_Unwind_Word ptr)
{
_Unwind_Word tmp;
tmp = *(_Unwind_Word *) ptr;
/* Zero values are always NULL. */
if (!tmp)
return 0;
#if __FDPIC__
/* For FDPIC, we store the offset of the GOT entry. */
/* So, first get GOT from dynamic linker and then use indirect access. */
tmp += gnu_Unwind_Find_got (ptr);
tmp = *(_Unwind_Word *) tmp;
#elif (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \
|| defined(__FreeBSD__) || defined(__fuchsia__)
/* Pc-relative indirect. */
#define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel | DW_EH_PE_indirect)
tmp += ptr;
tmp = *(_Unwind_Word *) tmp;
#elif defined(__symbian__) || defined(__uClinux__)
#define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_absptr)
/* Absolute pointer. Nothing more to do. */
#else
#define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel)
/* Pc-relative pointer. */
tmp += ptr;
#endif
return tmp;
}
static inline _Unwind_Reason_Code
__gnu_unwind_24bit (_Unwind_Context * context __attribute__ ((unused)),
_uw data __attribute__ ((unused)),
int compact __attribute__ ((unused)))
{
return _URC_FAILURE;
}
#ifndef __FreeBSD__
/* Return the address of the instruction, not the actual IP value. */
#define _Unwind_GetIP(context) \
(_Unwind_GetGR (context, 15) & ~(_Unwind_Word)1)
#define _Unwind_SetIP(context, val) \
_Unwind_SetGR (context, 15, val | (_Unwind_GetGR (context, 15) & 1))
#else
#undef _Unwind_GetIPInfo
_Unwind_Ptr _Unwind_GetIP (struct _Unwind_Context *);
_Unwind_Ptr _Unwind_GetIPInfo (struct _Unwind_Context *, int *);
void _Unwind_SetIP (struct _Unwind_Context *, _Unwind_Ptr);
#endif
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* defined UNWIND_ARM_H */