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Atmosphere/libraries/libmesosphere/source/kern_k_page_table_base.cpp

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kern: begin skeletoning page table types
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/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <mesosphere.hpp>
#include <mesosphere/kern_select_page_table.hpp>
namespace ams::kern {
Result KPageTableBase::InitializeForKernel(bool is_64_bit, void *table, KVirtualAddress start, KVirtualAddress end) {
/* Initialize our members. */
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this->address_space_size = (is_64_bit) ? BITSIZEOF(u64) : BITSIZEOF(u32);
this->address_space_start = KProcessAddress(GetInteger(start));
this->address_space_end = KProcessAddress(GetInteger(end));
this->is_kernel = true;
this->enable_aslr = true;
this->heap_region_start = 0;
this->heap_region_end = 0;
this->current_heap_end = 0;
this->alias_region_start = 0;
this->alias_region_end = 0;
this->stack_region_start = 0;
this->stack_region_end = 0;
this->kernel_map_region_start = 0;
this->kernel_map_region_end = 0;
this->alias_code_region_start = 0;
this->alias_code_region_end = 0;
this->code_region_start = 0;
this->code_region_end = 0;
this->max_heap_size = 0;
this->max_physical_memory_size = 0;
this->memory_block_slab_manager = std::addressof(Kernel::GetSystemMemoryBlockManager());
this->block_info_manager = std::addressof(Kernel::GetBlockInfoManager());
this->allocate_option = KMemoryManager::EncodeOption(KMemoryManager::Pool_System, KMemoryManager::Direction_FromFront);
this->heap_fill_value = MemoryFillValue_Zero;
this->ipc_fill_value = MemoryFillValue_Zero;
this->stack_fill_value = MemoryFillValue_Zero;
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this->cached_physical_linear_region = nullptr;
this->cached_physical_heap_region = nullptr;
this->cached_virtual_heap_region = nullptr;
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/* Initialize our implementation. */
this->impl.InitializeForKernel(table, start, end);
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/* Initialize our memory block manager. */
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return this->memory_block_manager.Initialize(this->address_space_start, this->address_space_end, this->memory_block_slab_manager);
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return ResultSuccess();
}
void KPageTableBase::Finalize() {
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this->memory_block_manager.Finalize(this->memory_block_slab_manager);
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MESOSPHERE_TODO("cpu::InvalidateEntireInstructionCache();");
}
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KProcessAddress KPageTableBase::GetRegionAddress(KMemoryState state) const {
switch (state) {
case KMemoryState_Free:
case KMemoryState_Kernel:
return this->address_space_start;
case KMemoryState_Normal:
return this->heap_region_start;
case KMemoryState_Ipc:
case KMemoryState_NonSecureIpc:
case KMemoryState_NonDeviceIpc:
return this->alias_region_start;
case KMemoryState_Stack:
return this->stack_region_start;
case KMemoryState_Io:
case KMemoryState_Static:
case KMemoryState_ThreadLocal:
return this->kernel_map_region_start;
case KMemoryState_Shared:
case KMemoryState_AliasCode:
case KMemoryState_AliasCodeData:
case KMemoryState_Transfered:
case KMemoryState_SharedTransfered:
case KMemoryState_SharedCode:
case KMemoryState_GeneratedCode:
case KMemoryState_CodeOut:
return this->alias_code_region_start;
case KMemoryState_Code:
case KMemoryState_CodeData:
return this->code_region_start;
MESOSPHERE_UNREACHABLE_DEFAULT_CASE();
}
}
size_t KPageTableBase::GetRegionSize(KMemoryState state) const {
switch (state) {
case KMemoryState_Free:
case KMemoryState_Kernel:
return this->address_space_end - this->address_space_start;
case KMemoryState_Normal:
return this->heap_region_end - this->heap_region_start;
case KMemoryState_Ipc:
case KMemoryState_NonSecureIpc:
case KMemoryState_NonDeviceIpc:
return this->alias_region_end - this->alias_region_start;
case KMemoryState_Stack:
return this->stack_region_end - this->stack_region_start;
case KMemoryState_Io:
case KMemoryState_Static:
case KMemoryState_ThreadLocal:
return this->kernel_map_region_end - this->kernel_map_region_start;
case KMemoryState_Shared:
case KMemoryState_AliasCode:
case KMemoryState_AliasCodeData:
case KMemoryState_Transfered:
case KMemoryState_SharedTransfered:
case KMemoryState_SharedCode:
case KMemoryState_GeneratedCode:
case KMemoryState_CodeOut:
return this->alias_code_region_end - this->alias_code_region_start;
case KMemoryState_Code:
case KMemoryState_CodeData:
return this->code_region_end - this->code_region_start;
MESOSPHERE_UNREACHABLE_DEFAULT_CASE();
}
}
bool KPageTableBase::Contains(KProcessAddress addr, size_t size, KMemoryState state) const {
const KProcessAddress end = addr + size;
const KProcessAddress last = end - 1;
const KProcessAddress region_start = this->GetRegionAddress(state);
const size_t region_size = this->GetRegionSize(state);
const bool is_in_region = region_start <= addr && addr < end && last <= region_start + region_size - 1;
const bool is_in_heap = !(end <= this->heap_region_start || this->heap_region_end <= addr);
const bool is_in_alias = !(end <= this->alias_region_start || this->alias_region_end <= addr);
switch (state) {
case KMemoryState_Free:
case KMemoryState_Kernel:
return is_in_region;
case KMemoryState_Io:
case KMemoryState_Static:
case KMemoryState_Code:
case KMemoryState_CodeData:
case KMemoryState_Shared:
case KMemoryState_AliasCode:
case KMemoryState_AliasCodeData:
case KMemoryState_Stack:
case KMemoryState_ThreadLocal:
case KMemoryState_Transfered:
case KMemoryState_SharedTransfered:
case KMemoryState_SharedCode:
case KMemoryState_GeneratedCode:
case KMemoryState_CodeOut:
return is_in_region && !is_in_heap && !is_in_alias;
case KMemoryState_Normal:
MESOSPHERE_ASSERT(is_in_heap);
return is_in_region && !is_in_alias;
case KMemoryState_Ipc:
case KMemoryState_NonSecureIpc:
case KMemoryState_NonDeviceIpc:
MESOSPHERE_ASSERT(is_in_alias);
return is_in_region && !is_in_heap;
default:
return false;
}
}
Result KPageTableBase::CheckMemoryState(const KMemoryInfo &info, u32 state_mask, u32 state, u32 perm_mask, u32 perm, u32 attr_mask, u32 attr) const {
/* Validate the states match expectation. */
R_UNLESS((info.state & state_mask) == state, svc::ResultInvalidCurrentMemory());
R_UNLESS((info.perm & perm_mask) == perm, svc::ResultInvalidCurrentMemory());
R_UNLESS((info.attribute & attr_mask) == attr, svc::ResultInvalidCurrentMemory());
return ResultSuccess();
}
Result KPageTableBase::CheckMemoryState(KMemoryState *out_state, KMemoryPermission *out_perm, KMemoryAttribute *out_attr, KProcessAddress addr, size_t size, u32 state_mask, u32 state, u32 perm_mask, u32 perm, u32 attr_mask, u32 attr, u32 ignore_attr) const {
MESOSPHERE_ASSERT(this->IsLockedByCurrentThread());
/* Get information about the first block. */
const KProcessAddress last_addr = addr + size - 1;
KMemoryBlockManager::const_iterator it = this->memory_block_manager.FindIterator(addr);
KMemoryInfo info = it->GetMemoryInfo();
/* Validate all blocks in the range have correct state. */
const KMemoryState first_state = info.state;
const KMemoryPermission first_perm = info.perm;
const KMemoryAttribute first_attr = info.attribute;
while (true) {
/* Validate the current block. */
R_UNLESS(info.state == first_state, svc::ResultInvalidCurrentMemory());
R_UNLESS(info.perm == first_perm, svc::ResultInvalidCurrentMemory());
R_UNLESS((info.attribute | ignore_attr) == (first_attr | ignore_attr), svc::ResultInvalidCurrentMemory());
/* Validate against the provided masks. */
R_TRY(this->CheckMemoryState(info, state_mask, state, perm_mask, perm, attr_mask, attr));
/* Break once we're done. */
if (last_addr <= info.GetLastAddress()) {
break;
}
/* Advance our iterator. */
it++;
MESOSPHERE_ASSERT(it != this->memory_block_manager.cend());
info = it->GetMemoryInfo();
}
/* Write output state. */
if (out_state) {
*out_state = first_state;
}
if (out_perm) {
*out_perm = first_perm;
}
if (out_attr) {
*out_attr = static_cast<KMemoryAttribute>(first_attr & ~ignore_attr);
}
return ResultSuccess();
}
Result KPageTableBase::QueryInfoImpl(KMemoryInfo *out_info, ams::svc::PageInfo *out_page, KProcessAddress address) const {
MESOSPHERE_ASSERT(this->IsLockedByCurrentThread());
MESOSPHERE_ASSERT(out_info != nullptr);
MESOSPHERE_ASSERT(out_page != nullptr);
const KMemoryBlock *block = this->memory_block_manager.FindBlock(address);
R_UNLESS(block != nullptr, svc::ResultInvalidCurrentMemory());
*out_info = block->GetMemoryInfo();
out_page->flags = 0;
return ResultSuccess();
}
KProcessAddress KPageTableBase::FindFreeArea(KProcessAddress region_start, size_t region_num_pages, size_t num_pages, size_t alignment, size_t offset, size_t guard_pages) const {
KProcessAddress address = Null<KProcessAddress>;
if (num_pages <= region_num_pages) {
if (this->IsAslrEnabled()) {
/* Try to directly find a free area up to 8 times. */
for (size_t i = 0; i < 8; i++) {
const size_t random_offset = KSystemControl::GenerateRandomRange(0, (region_num_pages - num_pages - guard_pages) * PageSize / alignment) * alignment;
const KProcessAddress candidate = util::AlignDown(GetInteger(region_start + random_offset), alignment) + offset;
KMemoryInfo info;
ams::svc::PageInfo page_info;
MESOSPHERE_R_ABORT_UNLESS(this->QueryInfoImpl(&info, &page_info, candidate));
if (info.state != KMemoryState_Free) { continue; }
if (!(region_start <= candidate)) { continue; }
if (!(info.GetAddress() + guard_pages * PageSize <= GetInteger(candidate))) { continue; }
if (!(candidate + (num_pages + guard_pages) * PageSize - 1 <= info.GetLastAddress())) { continue; }
if (!(candidate + (num_pages + guard_pages) * PageSize - 1 <= region_start + region_num_pages * PageSize - 1)) { continue; }
address = candidate;
break;
}
/* Fall back to finding the first free area with a random offset. */
if (address == Null<KProcessAddress>) {
/* NOTE: Nintendo does not account for guard pages here. */
/* This may theoretically cause an offset to be chosen that cannot be mapped. */
/* TODO: Should we account for guard pages? */
const size_t offset_pages = KSystemControl::GenerateRandomRange(0, region_num_pages - num_pages);
address = this->memory_block_manager.FindFreeArea(region_start + offset_pages * PageSize, region_num_pages - offset_pages, num_pages, alignment, offset, guard_pages);
}
}
/* Find the first free area. */
if (address == Null<KProcessAddress>) {
address = this->memory_block_manager.FindFreeArea(region_start, region_num_pages, num_pages, alignment, offset, guard_pages);
}
}
return address;
}
Result KPageTableBase::AllocateAndMapPagesImpl(PageLinkedList *page_list, KProcessAddress address, size_t num_pages, const KPageProperties properties) {
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MESOSPHERE_ASSERT(this->IsLockedByCurrentThread());
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/* Create a page group to hold the pages we allocate. */
KPageGroup pg(this->block_info_manager);
/* Allocate the pages. */
R_TRY(Kernel::GetMemoryManager().Allocate(std::addressof(pg), num_pages, this->allocate_option));
/* Ensure that the page group is open while we work with it. */
KScopedPageGroup spg(pg);
/* Clear all pages. */
for (const auto &it : pg) {
std::memset(GetVoidPointer(it.GetAddress()), this->heap_fill_value, it.GetSize());
}
/* Map the pages. */
return this->Operate(page_list, address, num_pages, std::addressof(pg), properties, OperationType_MapGroup, false);
}
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Result KPageTableBase::MapPageGroupImpl(PageLinkedList *page_list, KProcessAddress address, const KPageGroup &pg, const KPageProperties properties, bool reuse_ll) {
MESOSPHERE_ASSERT(this->IsLockedByCurrentThread());
/* Note the current address, so that we can iterate. */
const KProcessAddress start_address = address;
KProcessAddress cur_address = address;
/* Ensure that we clean up on failure. */
auto mapping_guard = SCOPE_GUARD {
MESOSPHERE_ABORT_UNLESS(!reuse_ll);
if (cur_address != start_address) {
const KPageProperties unmap_properties = {};
MESOSPHERE_R_ABORT_UNLESS(this->Operate(page_list, start_address, (cur_address - start_address) / PageSize, Null<KPhysicalAddress>, false, unmap_properties, OperationType_Unmap, true));
}
};
/* Iterate, mapping all pages in the group. */
for (const auto &block : pg) {
/* We only allow mapping pages in the heap, and we require we're mapping non-empty blocks. */
MESOSPHERE_ABORT_UNLESS(block.GetAddress() < block.GetLastAddress());
MESOSPHERE_ABORT_UNLESS(IsHeapVirtualAddress(block.GetAddress(), block.GetSize()));
/* Map and advance. */
R_TRY(this->Operate(page_list, cur_address, block.GetNumPages(), GetHeapPhysicalAddress(block.GetAddress()), true, properties, OperationType_Map, reuse_ll));
cur_address += block.GetSize();
}
/* We succeeded! */
mapping_guard.Cancel();
return ResultSuccess();
}
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bool KPageTableBase::IsValidPageGroup(const KPageGroup &pg, KProcessAddress addr, size_t num_pages) {
/* Empty groups are necessarily invalid. */
if (pg.empty()) {
return false;
}
auto &impl = this->GetImpl();
/* We're going to validate that the group we'd expect is the group we see. */
auto cur_it = pg.begin();
KVirtualAddress cur_block_address = cur_it->GetAddress();
size_t cur_block_pages = cur_it->GetNumPages();
auto UpdateCurrentIterator = [&]() ALWAYS_INLINE_LAMBDA {
if (cur_block_pages == 0) {
if ((++cur_it) == pg.end()) {
return false;
}
cur_block_address = cur_it->GetAddress();
cur_block_pages = cur_it->GetNumPages();
}
return true;
};
/* Begin traversal. */
TraversalContext context;
TraversalEntry next_entry;
if (!impl.BeginTraversal(std::addressof(next_entry), std::addressof(context), addr)) {
return false;
}
/* Prepare tracking variables. */
KPhysicalAddress cur_addr = next_entry.phys_addr;
size_t cur_size = next_entry.block_size - (GetInteger(cur_addr) & (next_entry.block_size - 1));
size_t tot_size = cur_size;
/* Iterate, comparing expected to actual. */
while (tot_size < num_pages * PageSize) {
if (!impl.ContinueTraversal(std::addressof(next_entry), std::addressof(context))) {
return false;
}
if (next_entry.phys_addr != (cur_addr + cur_size)) {
const size_t cur_pages = cur_size / PageSize;
if (!IsHeapPhysicalAddress(cur_addr)) {
return false;
}
if (!UpdateCurrentIterator()) {
return false;
}
if (cur_block_address != GetHeapVirtualAddress(cur_addr) || cur_block_pages < cur_pages) {
return false;
}
cur_block_address += cur_size;
cur_block_pages -= cur_pages;
cur_addr = next_entry.phys_addr;
cur_size = next_entry.block_size;
} else {
cur_size += next_entry.block_size;
}
tot_size += next_entry.block_size;
}
/* Ensure we compare the right amount for the last block. */
if (tot_size > num_pages * PageSize) {
cur_size -= (tot_size - num_pages * PageSize);
}
if (!IsHeapPhysicalAddress(cur_addr)) {
return false;
}
if (!UpdateCurrentIterator()) {
return false;
}
return cur_block_address == GetHeapVirtualAddress(cur_addr) && cur_block_pages == (cur_size / PageSize);
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}
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Result KPageTableBase::MapPages(KProcessAddress *out_addr, size_t num_pages, size_t alignment, KPhysicalAddress phys_addr, bool is_pa_valid, KProcessAddress region_start, size_t region_num_pages, KMemoryState state, KMemoryPermission perm) {
MESOSPHERE_ASSERT(util::IsAligned(alignment, PageSize) && alignment >= PageSize);
/* Ensure this is a valid map request. */
R_UNLESS(this->Contains(region_start, region_num_pages * PageSize, state), svc::ResultInvalidCurrentMemory());
R_UNLESS(num_pages < region_num_pages, svc::ResultOutOfMemory());
/* Lock the table. */
KScopedLightLock lk(this->general_lock);
/* Find a random address to map at. */
KProcessAddress addr = this->FindFreeArea(region_start, region_num_pages, num_pages, alignment, 0, this->GetNumGuardPages());
R_UNLESS(addr != Null<KProcessAddress>, svc::ResultOutOfMemory());
MESOSPHERE_ASSERT(util::IsAligned(GetInteger(addr), alignment));
MESOSPHERE_ASSERT(this->Contains(addr, num_pages * PageSize, state));
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MESOSPHERE_R_ASSERT(this->CheckMemoryState(addr, num_pages * PageSize, KMemoryState_All, KMemoryState_Free, KMemoryPermission_None, KMemoryPermission_None, KMemoryAttribute_None, KMemoryAttribute_None));
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/* Create an update allocator. */
KMemoryBlockManagerUpdateAllocator allocator(this->memory_block_slab_manager);
R_TRY(allocator.GetResult());
/* We're going to perform an update, so create a helper. */
KScopedPageTableUpdater updater(this);
/* Perform mapping operation. */
const KPageProperties properties = { perm, false, false, false };
if (is_pa_valid) {
R_TRY(this->Operate(updater.GetPageList(), addr, num_pages, phys_addr, true, properties, OperationType_Map, false));
} else {
R_TRY(this->AllocateAndMapPagesImpl(updater.GetPageList(), addr, num_pages, properties));
}
/* Update the blocks. */
this->memory_block_manager.Update(&allocator, addr, num_pages, state, perm, KMemoryAttribute_None);
/* We successfully mapped the pages. */
*out_addr = addr;
return ResultSuccess();
}
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Result KPageTableBase::UnmapPages(KProcessAddress address, size_t num_pages, KMemoryState state) {
MESOSPHERE_TODO_IMPLEMENT();
}
Result KPageTableBase::MapPageGroup(KProcessAddress *out_addr, const KPageGroup &pg, KProcessAddress region_start, size_t region_num_pages, KMemoryState state, KMemoryPermission perm) {
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MESOSPHERE_ASSERT(!this->IsLockedByCurrentThread());
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/* Ensure this is a valid map request. */
const size_t num_pages = pg.GetNumPages();
R_UNLESS(this->Contains(region_start, region_num_pages * PageSize, state), svc::ResultInvalidCurrentMemory());
R_UNLESS(num_pages < region_num_pages, svc::ResultOutOfMemory());
/* Lock the table. */
KScopedLightLock lk(this->general_lock);
/* Find a random address to map at. */
KProcessAddress addr = this->FindFreeArea(region_start, region_num_pages, num_pages, PageSize, 0, this->GetNumGuardPages());
R_UNLESS(addr != Null<KProcessAddress>, svc::ResultOutOfMemory());
MESOSPHERE_ASSERT(this->Contains(addr, num_pages * PageSize, state));
MESOSPHERE_R_ASSERT(this->CheckMemoryState(addr, num_pages * PageSize, KMemoryState_All, KMemoryState_Free, KMemoryPermission_None, KMemoryPermission_None, KMemoryAttribute_None, KMemoryAttribute_None));
/* Create an update allocator. */
KMemoryBlockManagerUpdateAllocator allocator(this->memory_block_slab_manager);
R_TRY(allocator.GetResult());
/* We're going to perform an update, so create a helper. */
KScopedPageTableUpdater updater(this);
/* Perform mapping operation. */
const KPageProperties properties = { perm, state == KMemoryState_Io, false, false };
R_TRY(this->MapPageGroupImpl(updater.GetPageList(), addr, pg, properties, false));
/* Update the blocks. */
this->memory_block_manager.Update(&allocator, addr, num_pages, state, perm, KMemoryAttribute_None);
/* We successfully mapped the pages. */
*out_addr = addr;
return ResultSuccess();
}
Result KPageTableBase::UnmapPageGroup(KProcessAddress address, const KPageGroup &pg, KMemoryState state) {
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MESOSPHERE_ASSERT(!this->IsLockedByCurrentThread());
/* Ensure this is a valid unmap request. */
const size_t num_pages = pg.GetNumPages();
const size_t size = num_pages * PageSize;
R_UNLESS(this->Contains(address, size, state), svc::ResultInvalidCurrentMemory());
/* Lock the table. */
KScopedLightLock lk(this->general_lock);
/* Check if state allows us to unmap. */
R_TRY(this->CheckMemoryState(address, size, KMemoryState_All, state, KMemoryPermission_None, KMemoryPermission_None, KMemoryAttribute_All, KMemoryAttribute_None));
/* Check that the page group is valid. */
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R_UNLESS(this->IsValidPageGroup(pg, address, num_pages), svc::ResultInvalidCurrentMemory());
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/* Create an update allocator. */
KMemoryBlockManagerUpdateAllocator allocator(this->memory_block_slab_manager);
R_TRY(allocator.GetResult());
/* We're going to perform an update, so create a helper. */
KScopedPageTableUpdater updater(this);
/* Perform unmapping operation. */
const KPageProperties properties = { KMemoryPermission_None, false, false, false };
R_TRY(this->Operate(updater.GetPageList(), address, num_pages, Null<KPhysicalAddress>, false, properties, OperationType_Unmap, false));
/* Update the blocks. */
this->memory_block_manager.Update(&allocator, address, num_pages, KMemoryState_Free, KMemoryPermission_None, KMemoryAttribute_None);
return ResultSuccess();
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}
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}
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