// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include "core/hle/kernel/k_process.h"
#include "core/hle/service/ro/ro_nro_utils.h"
#include "core/hle/service/ro/ro_results.h"
namespace Service::RO {
namespace {
struct ProcessMemoryRegion {
u64 address;
u64 size;
};
size_t GetTotalProcessMemoryRegionSize(const ProcessMemoryRegion* regions, size_t num_regions) {
size_t total = 0;
for (size_t i = 0; i < num_regions; ++i) {
total += regions[i].size;
}
return total;
}
size_t SetupNroProcessMemoryRegions(ProcessMemoryRegion* regions, u64 nro_heap_address,
u64 nro_heap_size, u64 bss_heap_address, u64 bss_heap_size) {
// Reset region count.
size_t num_regions = 0;
// We always want a region for the nro.
regions[num_regions++] = {nro_heap_address, nro_heap_size};
// If we have bss, create a region for bss.
if (bss_heap_size > 0) {
regions[num_regions++] = {bss_heap_address, bss_heap_size};
}
return num_regions;
}
Result SetProcessMemoryPermission(Kernel::KProcess* process, u64 address, u64 size,
Kernel::Svc::MemoryPermission permission) {
auto& page_table = process->GetPageTable();
// Set permission.
R_RETURN(page_table.SetProcessMemoryPermission(address, size, permission));
}
Result UnmapProcessCodeMemory(Kernel::KProcess* process, u64 process_code_address,
const ProcessMemoryRegion* regions, size_t num_regions) {
// Get the total process memory region size.
const size_t total_size = GetTotalProcessMemoryRegionSize(regions, num_regions);
auto& page_table = process->GetPageTable();
// Unmap each region in order.
size_t cur_offset = total_size;
for (size_t i = 0; i < num_regions; ++i) {
// We want to unmap in reverse order.
const auto& cur_region = regions[num_regions - 1 - i];
// Subtract to update the current offset.
cur_offset -= cur_region.size;
// Unmap.
R_TRY(page_table.UnmapCodeMemory(process_code_address + cur_offset, cur_region.address,
cur_region.size));
}
R_SUCCEED();
}
Result EnsureGuardPages(Kernel::KProcessPageTable& page_table, u64 map_address, u64 map_size) {
Kernel::KMemoryInfo memory_info;
Kernel::Svc::PageInfo page_info;
// Ensure page before mapping is unmapped.
R_TRY(page_table.QueryInfo(std::addressof(memory_info), std::addressof(page_info),
map_address - 1));
R_UNLESS(memory_info.GetSvcState() == Kernel::Svc::MemoryState::Free,
Kernel::ResultInvalidState);
// Ensure page after mapping is unmapped.
R_TRY(page_table.QueryInfo(std::addressof(memory_info), std::addressof(page_info),
map_address + map_size));
R_UNLESS(memory_info.GetSvcState() == Kernel::Svc::MemoryState::Free,
Kernel::ResultInvalidState);
// Successfully verified guard pages.
R_SUCCEED();
}
Result MapProcessCodeMemory(u64* out, Kernel::KProcess* process, const ProcessMemoryRegion* regions,
size_t num_regions, std::mt19937_64& generate_random) {
auto& page_table = process->GetPageTable();
const u64 alias_code_start =
GetInteger(page_table.GetAliasCodeRegionStart()) / Kernel::PageSize;
const u64 alias_code_size = page_table.GetAliasCodeRegionSize() / Kernel::PageSize;
for (size_t trial = 0; trial < 64; trial++) {
// Generate a new trial address.
const u64 mapped_address =
(alias_code_start + (generate_random() % alias_code_size)) * Kernel::PageSize;
const auto MapRegions = [&] {
// Map the regions in order.
u64 mapped_size = 0;
for (size_t i = 0; i < num_regions; ++i) {
// If we fail, unmap up to where we've mapped.
ON_RESULT_FAILURE {
R_ASSERT(UnmapProcessCodeMemory(process, mapped_address, regions, i));
};
// Map the current region.
R_TRY(page_table.MapCodeMemory(mapped_address + mapped_size, regions[i].address,
regions[i].size));
mapped_size += regions[i].size;
}
// If we fail, unmap all mapped regions.
ON_RESULT_FAILURE {
R_ASSERT(UnmapProcessCodeMemory(process, mapped_address, regions, num_regions));
};
// Ensure guard pages.
R_RETURN(EnsureGuardPages(page_table, mapped_address, mapped_size));
};
if (R_SUCCEEDED(MapRegions())) {
// Set the output address.
*out = mapped_address;
R_SUCCEED();
}
}
// We failed to map anything.
R_THROW(RO::ResultOutOfAddressSpace);
}
} // namespace
Result MapNro(u64* out_base_address, Kernel::KProcess* process, u64 nro_heap_address,
u64 nro_heap_size, u64 bss_heap_address, u64 bss_heap_size,
std::mt19937_64& generate_random) {
// Set up the process memory regions.
std::array<ProcessMemoryRegion, 2> regions{};
const size_t num_regions = SetupNroProcessMemoryRegions(
regions.data(), nro_heap_address, nro_heap_size, bss_heap_address, bss_heap_size);
// Re-map the nro/bss as code memory in the destination process.
R_RETURN(MapProcessCodeMemory(out_base_address, process, regions.data(), num_regions,
generate_random));
}
Result SetNroPerms(Kernel::KProcess* process, u64 base_address, u64 rx_size, u64 ro_size,
u64 rw_size) {
const u64 rx_offset = 0;
const u64 ro_offset = rx_offset + rx_size;
const u64 rw_offset = ro_offset + ro_size;
R_TRY(SetProcessMemoryPermission(process, base_address + rx_offset, rx_size,
Kernel::Svc::MemoryPermission::ReadExecute));
R_TRY(SetProcessMemoryPermission(process, base_address + ro_offset, ro_size,
Kernel::Svc::MemoryPermission::Read));
R_TRY(SetProcessMemoryPermission(process, base_address + rw_offset, rw_size,
Kernel::Svc::MemoryPermission::ReadWrite));
R_SUCCEED();
}
Result UnmapNro(Kernel::KProcess* process, u64 base_address, u64 nro_heap_address,
u64 nro_heap_size, u64 bss_heap_address, u64 bss_heap_size) {
// Set up the process memory regions.
std::array<ProcessMemoryRegion, 2> regions{};
const size_t num_regions = SetupNroProcessMemoryRegions(
regions.data(), nro_heap_address, nro_heap_size, bss_heap_address, bss_heap_size);
// Unmap the nro/bss.
R_RETURN(UnmapProcessCodeMemory(process, base_address, regions.data(), num_regions));
}
} // namespace Service::RO
