8sa1-gcc/gcc/cppbuiltin.c
Matthew Malcomson 3bd8783207 libsanitizer: options: Add hwasan flags and argument parsing
These flags can't be used at the same time as any of the other
sanitizers.
We add an equivalent flag to -static-libasan in -static-libhwasan to
ensure static linking.

The -fsanitize=kernel-hwaddress option is for compiling targeting the
kernel.  This flag has defaults to match the LLVM implementation and
sets some other behaviors to work in the kernel (e.g. accounting for
the fact that the stack pointer will have 0xff in the top byte and to not
call the userspace library initialisation routines).
The defaults are that we do not sanitize variables on the stack and
always recover from a detected bug.

Since we are introducing a few more conflicts between sanitizer flags we
refactor the checking for such conflicts to use a helper function which
makes checking for such conflicts more easy and consistent.

We introduce a backend hook `targetm.memtag.can_tag_addresses` that
indicates to the mid-end whether a target has a feature like AArch64 TBI
where the top byte of an address is ignored.
Without this feature hwasan sanitization is not done.

gcc/ChangeLog:

	* common.opt (flag_sanitize_recover): Default for kernel
	hwaddress.
	(static-libhwasan): New cli option.
	* config/aarch64/aarch64.c (aarch64_can_tag_addresses): New.
	(TARGET_MEMTAG_CAN_TAG_ADDRESSES): New.
	* config/gnu-user.h (LIBHWASAN_EARLY_SPEC): hwasan equivalent of
	asan command line flags.
	* cppbuiltin.c (define_builtin_macros_for_compilation_flags):
	Add hwasan equivalent of __SANITIZE_ADDRESS__.
	* doc/invoke.texi: Document hwasan command line flags.
	* doc/tm.texi: Document new hook.
	* doc/tm.texi.in: Document new hook.
	* flag-types.h (enum sanitize_code): New sanitizer values.
	* gcc.c (STATIC_LIBHWASAN_LIBS): New macro.
	(LIBHWASAN_SPEC): New macro.
	(LIBHWASAN_EARLY_SPEC): New macro.
	(SANITIZER_EARLY_SPEC): Update to include hwasan.
	(SANITIZER_SPEC): Update to include hwasan.
	(sanitize_spec_function): Use hwasan options.
	* opts.c (finish_options): Describe conflicts between address
	sanitizers.
	(find_sanitizer_argument): New.
	(report_conflicting_sanitizer_options): New.
	(sanitizer_opts): Introduce new sanitizer flags.
	(common_handle_option): Add defaults for kernel sanitizer.
	* params.opt (hwasan--instrument-stack): New
	(hwasan-random-frame-tag): New
	(hwasan-instrument-allocas): New
	(hwasan-instrument-reads): New
	(hwasan-instrument-writes): New
	(hwasan-instrument-mem-intrinsics): New
	* target.def (HOOK_PREFIX): Add new hook.
	(can_tag_addresses): Add new hook under memtag prefix.
	* targhooks.c (default_memtag_can_tag_addresses): New.
	* targhooks.h (default_memtag_can_tag_addresses): New decl.
	* toplev.c (process_options): Ensure hwasan only on
	architectures that advertise the possibility.
2020-11-25 16:35:39 +00:00

198 lines
6.3 KiB
C

/* Define builtin-in macros for all front ends that perform preprocessing
Copyright (C) 2010-2020 Free Software Foundation, Inc.
This file is part of GCC.
GCC 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.
GCC 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.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "memmodel.h"
#include "target.h"
#include "tree.h"
#include "version.h"
#include "flags.h"
#include "cpplib.h"
#include "cppbuiltin.h"
/* Parse a BASEVER version string of the format "major.minor.patchlevel"
or "major.minor" to extract its components. */
void
parse_basever (int *major, int *minor, int *patchlevel)
{
static int s_major = -1, s_minor, s_patchlevel;
if (s_major == -1)
if (sscanf (BASEVER, "%d.%d.%d", &s_major, &s_minor, &s_patchlevel) != 3)
{
sscanf (BASEVER, "%d.%d", &s_major, &s_minor);
s_patchlevel = 0;
}
if (major)
*major = s_major;
if (minor)
*minor = s_minor;
if (patchlevel)
*patchlevel = s_patchlevel;
}
/* Define __GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__ and __VERSION__. */
static void
define__GNUC__ (cpp_reader *pfile)
{
int major, minor, patchlevel;
parse_basever (&major, &minor, &patchlevel);
cpp_define_formatted (pfile, "__GNUC__=%d", major);
cpp_define_formatted (pfile, "__GNUC_MINOR__=%d", minor);
cpp_define_formatted (pfile, "__GNUC_PATCHLEVEL__=%d", patchlevel);
cpp_define_formatted (pfile, "__VERSION__=\"%s\"", version_string);
cpp_define_formatted (pfile, "__ATOMIC_RELAXED=%d", MEMMODEL_RELAXED);
cpp_define_formatted (pfile, "__ATOMIC_SEQ_CST=%d", MEMMODEL_SEQ_CST);
cpp_define_formatted (pfile, "__ATOMIC_ACQUIRE=%d", MEMMODEL_ACQUIRE);
cpp_define_formatted (pfile, "__ATOMIC_RELEASE=%d", MEMMODEL_RELEASE);
cpp_define_formatted (pfile, "__ATOMIC_ACQ_REL=%d", MEMMODEL_ACQ_REL);
cpp_define_formatted (pfile, "__ATOMIC_CONSUME=%d", MEMMODEL_CONSUME);
}
/* Define various built-in CPP macros that depend on language-independent
compilation flags. */
static void
define_builtin_macros_for_compilation_flags (cpp_reader *pfile)
{
if (flag_pic)
{
cpp_define_formatted (pfile, "__pic__=%d", flag_pic);
cpp_define_formatted (pfile, "__PIC__=%d", flag_pic);
}
if (flag_pie)
{
cpp_define_formatted (pfile, "__pie__=%d", flag_pie);
cpp_define_formatted (pfile, "__PIE__=%d", flag_pie);
}
if (flag_sanitize & SANITIZE_ADDRESS)
cpp_define (pfile, "__SANITIZE_ADDRESS__");
if (flag_sanitize & SANITIZE_HWADDRESS)
cpp_define (pfile, "__SANITIZE_HWADDRESS__");
if (flag_sanitize & SANITIZE_THREAD)
cpp_define (pfile, "__SANITIZE_THREAD__");
if (optimize_size)
cpp_define (pfile, "__OPTIMIZE_SIZE__");
if (optimize)
cpp_define (pfile, "__OPTIMIZE__");
if (fast_math_flags_set_p (&global_options))
cpp_define (pfile, "__FAST_MATH__");
if (flag_signaling_nans)
cpp_define (pfile, "__SUPPORT_SNAN__");
if (!flag_errno_math)
cpp_define (pfile, "__NO_MATH_ERRNO__");
cpp_define_formatted (pfile, "__FINITE_MATH_ONLY__=%d",
flag_finite_math_only);
}
/* Define built-in macros for LP64 targets. */
static void
define_builtin_macros_for_lp64 (cpp_reader *pfile)
{
if (TYPE_PRECISION (long_integer_type_node) == 64
&& POINTER_SIZE == 64
&& TYPE_PRECISION (integer_type_node) == 32)
{
cpp_define (pfile, "_LP64");
cpp_define (pfile, "__LP64__");
}
}
/* Define macros for size of basic C types. */
static void
define_builtin_macros_for_type_sizes (cpp_reader *pfile)
{
#define define_type_sizeof(NAME, TYPE) \
cpp_define_formatted (pfile, NAME"=" HOST_WIDE_INT_PRINT_DEC, \
tree_to_uhwi (TYPE_SIZE_UNIT (TYPE)))
define_type_sizeof ("__SIZEOF_INT__", integer_type_node);
define_type_sizeof ("__SIZEOF_LONG__", long_integer_type_node);
define_type_sizeof ("__SIZEOF_LONG_LONG__", long_long_integer_type_node);
define_type_sizeof ("__SIZEOF_SHORT__", short_integer_type_node);
define_type_sizeof ("__SIZEOF_FLOAT__", float_type_node);
define_type_sizeof ("__SIZEOF_DOUBLE__", double_type_node);
define_type_sizeof ("__SIZEOF_LONG_DOUBLE__", long_double_type_node);
define_type_sizeof ("__SIZEOF_SIZE_T__", size_type_node);
#undef define_type_sizeof
cpp_define_formatted (pfile, "__CHAR_BIT__=%u",
TYPE_PRECISION (char_type_node));
cpp_define_formatted (pfile, "__BIGGEST_ALIGNMENT__=%d",
BIGGEST_ALIGNMENT / BITS_PER_UNIT);
/* Define constants useful for implementing endian.h. */
cpp_define (pfile, "__ORDER_LITTLE_ENDIAN__=1234");
cpp_define (pfile, "__ORDER_BIG_ENDIAN__=4321");
cpp_define (pfile, "__ORDER_PDP_ENDIAN__=3412");
if (WORDS_BIG_ENDIAN == BYTES_BIG_ENDIAN)
cpp_define_formatted (pfile, "__BYTE_ORDER__=%s",
(WORDS_BIG_ENDIAN
? "__ORDER_BIG_ENDIAN__"
: "__ORDER_LITTLE_ENDIAN__"));
else
{
/* Assert that we're only dealing with the PDP11 case. */
gcc_assert (!BYTES_BIG_ENDIAN);
gcc_assert (WORDS_BIG_ENDIAN);
cpp_define (pfile, "__BYTE_ORDER__=__ORDER_PDP_ENDIAN__");
}
cpp_define_formatted (pfile, "__FLOAT_WORD_ORDER__=%s",
(targetm.float_words_big_endian ()
? "__ORDER_BIG_ENDIAN__"
: "__ORDER_LITTLE_ENDIAN__"));
/* ptr_type_node can't be used here since ptr_mode is only set when
toplev calls backend_init which is not done with -E switch. */
cpp_define_formatted (pfile, "__SIZEOF_POINTER__=%d",
1 << ceil_log2 ((POINTER_SIZE + BITS_PER_UNIT - 1) / BITS_PER_UNIT));
}
/* Define macros builtins common to all language performing CPP
preprocessing. */
void
define_language_independent_builtin_macros (cpp_reader *pfile)
{
define__GNUC__ (pfile);
define_builtin_macros_for_compilation_flags (pfile);
define_builtin_macros_for_lp64 (pfile);
define_builtin_macros_for_type_sizes (pfile);
}