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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "MmapRegion.h"
#include "Emulator.h"
#include <string.h>
#include <sys/mman.h>
namespace UserspaceEmulator {
static void* mmap_initialized(size_t bytes, char initial_value, const char* name)
{
auto* ptr = mmap_with_name(nullptr, bytes, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0, name);
VERIFY(ptr != MAP_FAILED);
memset(ptr, initial_value, bytes);
return ptr;
}
static void free_pages(void* ptr, size_t bytes)
{
int rc = munmap(ptr, bytes);
VERIFY(rc == 0);
}
NonnullOwnPtr<MmapRegion> MmapRegion::create_anonymous(u32 base, u32 size, u32 prot, String name)
{
auto data = (u8*)mmap_initialized(size, 0, nullptr);
auto shadow_data = (u8*)mmap_initialized(size, 1, "MmapRegion ShadowData");
auto region = adopt_own(*new MmapRegion(base, size, prot, data, shadow_data));
region->m_name = move(name);
return region;
}
NonnullOwnPtr<MmapRegion> MmapRegion::create_file_backed(u32 base, u32 size, u32 prot, int flags, int fd, off_t offset, String name)
{
// Since we put the memory to an arbitrary location, do not pass MAP_FIXED to the Kernel.
auto real_flags = flags & ~MAP_FIXED;
auto data = (u8*)mmap_with_name(nullptr, size, prot, real_flags, fd, offset, name.is_empty() ? nullptr : name.characters());
VERIFY(data != MAP_FAILED);
auto shadow_data = (u8*)mmap_initialized(size, 1, "MmapRegion ShadowData");
auto region = adopt_own(*new MmapRegion(base, size, prot, data, shadow_data));
region->m_file_backed = true;
region->m_name = move(name);
return region;
}
MmapRegion::MmapRegion(u32 base, u32 size, int prot, u8* data, u8* shadow_data)
: Region(base, size, true)
, m_data(data)
, m_shadow_data(shadow_data)
{
set_prot(prot);
}
MmapRegion::~MmapRegion()
{
free_pages(m_data, size());
free_pages(m_shadow_data, size());
}
ValueWithShadow<u8> MmapRegion::read8(FlatPtr offset)
{
if (!is_readable()) {
reportln("8-bit read from unreadable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_read(*this, base() + offset, 1);
}
VERIFY(offset < size());
return { *reinterpret_cast<const u8*>(m_data + offset), *reinterpret_cast<const u8*>(m_shadow_data + offset) };
}
ValueWithShadow<u16> MmapRegion::read16(u32 offset)
{
if (!is_readable()) {
reportln("16-bit read from unreadable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_read(*this, base() + offset, 2);
}
VERIFY(offset + 1 < size());
return { *reinterpret_cast<const u16*>(m_data + offset), *reinterpret_cast<const u16*>(m_shadow_data + offset) };
}
ValueWithShadow<u32> MmapRegion::read32(u32 offset)
{
if (!is_readable()) {
reportln("32-bit read from unreadable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_read(*this, base() + offset, 4);
}
VERIFY(offset + 3 < size());
return { *reinterpret_cast<const u32*>(m_data + offset), *reinterpret_cast<const u32*>(m_shadow_data + offset) };
}
ValueWithShadow<u64> MmapRegion::read64(u32 offset)
{
if (!is_readable()) {
reportln("64-bit read from unreadable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_read(*this, base() + offset, 8);
}
VERIFY(offset + 7 < size());
return { *reinterpret_cast<const u64*>(m_data + offset), *reinterpret_cast<const u64*>(m_shadow_data + offset) };
}
void MmapRegion::write8(u32 offset, ValueWithShadow<u8> value)
{
if (!is_writable()) {
reportln("8-bit write from unwritable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_write(*this, base() + offset, 1);
}
VERIFY(offset < size());
*reinterpret_cast<u8*>(m_data + offset) = value.value();
*reinterpret_cast<u8*>(m_shadow_data + offset) = value.shadow();
}
void MmapRegion::write16(u32 offset, ValueWithShadow<u16> value)
{
if (!is_writable()) {
reportln("16-bit write from unwritable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_write(*this, base() + offset, 2);
}
VERIFY(offset + 1 < size());
*reinterpret_cast<u16*>(m_data + offset) = value.value();
*reinterpret_cast<u16*>(m_shadow_data + offset) = value.shadow();
}
void MmapRegion::write32(u32 offset, ValueWithShadow<u32> value)
{
if (!is_writable()) {
reportln("32-bit write from unwritable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_write(*this, base() + offset, 4);
}
VERIFY(offset + 3 < size());
VERIFY(m_data != m_shadow_data);
*reinterpret_cast<u32*>(m_data + offset) = value.value();
*reinterpret_cast<u32*>(m_shadow_data + offset) = value.shadow();
}
void MmapRegion::write64(u32 offset, ValueWithShadow<u64> value)
{
if (!is_writable()) {
reportln("64-bit write from unwritable MmapRegion @ {:p}", base() + offset);
emulator().dump_backtrace();
TODO();
}
if (is_malloc_block()) {
if (auto* tracer = emulator().malloc_tracer())
tracer->audit_write(*this, base() + offset, 8);
}
VERIFY(offset + 7 < size());
VERIFY(m_data != m_shadow_data);
*reinterpret_cast<u64*>(m_data + offset) = value.value();
*reinterpret_cast<u64*>(m_shadow_data + offset) = value.shadow();
}
NonnullOwnPtr<MmapRegion> MmapRegion::split_at(VirtualAddress offset)
{
VERIFY(!m_malloc);
VERIFY(!m_malloc_metadata);
Range new_range = range();
Range other_range = new_range.split_at(offset);
auto other_region = adopt_own(*new MmapRegion(other_range.base().get(), other_range.size(), prot(), data() + new_range.size(), shadow_data() + new_range.size()));
other_region->m_file_backed = m_file_backed;
other_region->m_name = m_name;
set_range(new_range);
return other_region;
}
void MmapRegion::set_prot(int prot)
{
set_readable(prot & PROT_READ);
set_writable(prot & PROT_WRITE);
set_executable(prot & PROT_EXEC);
if (m_file_backed) {
if (mprotect(m_data, size(), prot & ~PROT_EXEC) < 0) {
perror("MmapRegion::set_prot: mprotect");
exit(1);
}
}
}
}
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