libcruft-util/cruft/util/debug/memory.cpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2019 Danny Robson <danny@nerdcruft.net>
 */

#include "memory.hpp"

#include <cruft/util/std.hpp>
#include <cruft/util/maths.hpp>
#include <cruft/util/debug/panic.hpp>


///////////////////////////////////////////////////////////////////////////////
#ifndef __has_feature
#define __has_feature(X) 0
#endif


//-----------------------------------------------------------------------------
#if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
#include <sanitizer/asan_interface.h>
static std::align_val_t asan_alignment (void)
{
    return std::align_val_t {8u};
}


static void asan_undefined (void const volatile *addr, std::size_t size)
{
    return ASAN_POISON_MEMORY_REGION ((addr), (size));
}


static void asan_defined (void const volatile *addr, std::size_t size)
{
    return ASAN_UNPOISON_MEMORY_REGION ((addr), (size));
}
#else
static std::align_val_t asan_alignment (void)
{
    return std::align_val_t {1u};
}


static void asan_undefined (void const volatile *addr, std::size_t size)
{
    (void)addr;
    (void)size;
}


static void asan_defined (void const volatile *addr, std::size_t size)
{
    (void)addr;
    (void)size;
}
#endif


///////////////////////////////////////////////////////////////////////////////
static std::align_val_t vg_alignment (void)
{
    return std::align_val_t {1u};
}


//-----------------------------------------------------------------------------
#if __has_include("valgrind/memcheck.h")
#include <valgrind/memcheck.h>
static void vg_undefined (void const volatile *addr, std::size_t len)
{
    VALGRIND_MAKE_MEM_UNDEFINED (addr, len);
}


//-----------------------------------------------------------------------------
static void vg_defined (void const volatile *addr, std::size_t len)
{
    VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (addr, len);
}
#else
//-----------------------------------------------------------------------------
static void vg_undefined (void const volatile *addr, std::size_t len)
{
    (void)addr;
    (void)len;
}


//-----------------------------------------------------------------------------
static void vg_defined (void const volatile *addr, std::size_t len)
{
    (void)addr;
    (void)len;
}
#endif


///////////////////////////////////////////////////////////////////////////////
std::align_val_t
cruft::debug::memory::instrumentation_alignment (void)
{
    return cruft::max (
        asan_alignment (),
        vg_alignment (),
        std::align_val_t {1u}
    );
}


//-----------------------------------------------------------------------------
void
cruft::debug::memory::mark_undefined (void const volatile *ptr, std::size_t len)
{
    asan_undefined (ptr, len);
    vg_undefined (ptr, len);
}


//-----------------------------------------------------------------------------
void
cruft::debug::memory::mark_defined (void const volatile *ptr, std::size_t len)
{
    asan_defined (ptr, len);
    vg_defined (ptr, len);
}