General memman fixups & address review

app/src/main/cpp/skyline/kernel/memory.cpp

@@ -7,46 +7,36 @@
 #include "types/KProcess.h"
 
 namespace skyline::kernel {
-    MemoryManager::MemoryManager(const DeviceState &state) noexcept : state(state), setHeapSize(), chunks() {}
+    MemoryManager::MemoryManager(const DeviceState &state) noexcept : state{state}, processHeapSize{}, memRefs{} {}
 
     MemoryManager::~MemoryManager() noexcept {
         if (base.valid() && !base.empty())
             munmap(reinterpret_cast<void *>(base.data()), base.size());
+        if (addressSpaceType != memory::AddressSpaceType::AddressSpace39Bit)
+            if (codeBase36Bit.valid() && !codeBase36Bit.empty())
+                munmap(reinterpret_cast<void *>(codeBase36Bit.data()), codeBase36Bit.size());
     }
 
-    std::map<u8 *,ChunkDescriptor>::iterator MemoryManager::upper_bound(u8 *address) {
+    void MemoryManager::MapInternal(const std::pair<u8 *, ChunkDescriptor> &newDesc) {
-        std::map<u8 *,ChunkDescriptor>::iterator result{chunks.begin()};
-
-        if (chunks.size() != 1) [[likely]]
-            while (result->first <= address) {
-                ++result;
-                if (result->first + result->second.size == addressSpace.end().base())
-                    break;
-            }
-
-        return result;
-    }
-
-    void MemoryManager::MapInternal(std::pair<u8 *, ChunkDescriptor> *newDesc) {
         // The chunk that contains / precedes the new chunk base address
-        auto firstChunkBase{upper_bound(newDesc->first)};
+        auto firstChunkBase{chunks.lower_bound(newDesc.first)};
-        while (newDesc->first <= firstChunkBase->first)
+        if (newDesc.first <= firstChunkBase->first)
             --firstChunkBase;
 
         // The chunk that contains / follows the end address of the new chunk
-        auto lastChunkBase{upper_bound(newDesc->first + newDesc->second.size)};
+        auto lastChunkBase{chunks.lower_bound(newDesc.first + newDesc.second.size)};
-        while ((newDesc->first + newDesc->second.size) < lastChunkBase->first)
+        if ((newDesc.first + newDesc.second.size) < lastChunkBase->first)
             --lastChunkBase;
 
         ChunkDescriptor firstChunk{firstChunkBase->second};
         ChunkDescriptor lastChunk{lastChunkBase->second};
 
         bool needsReprotection{false};
-        bool isUnmapping{newDesc->second.state == memory::states::Unmapped};
+        bool isUnmapping{newDesc.second.state == memory::states::Unmapped};
 
         // We cut a hole in a single chunk
         if (firstChunkBase->first == lastChunkBase->first) {
-            if (firstChunk.IsCompatible(newDesc->second)) [[unlikely]]
+            if (firstChunk.IsCompatible(newDesc.second)) [[unlikely]]
                 // No editing necessary
                 return;
 
@@ -54,15 +44,15 @@ namespace skyline::kernel {
                 needsReprotection = true;
 
             // We edit the chunk's first half
-            firstChunk.size = static_cast<size_t>(newDesc->first - firstChunkBase->first);
+            firstChunk.size = static_cast<size_t>(newDesc.first - firstChunkBase->first);
             chunks[firstChunkBase->first] = firstChunk;
 
             // We create the chunk's second half
-            lastChunk.size = static_cast<size_t>((lastChunkBase->first + lastChunk.size) - (newDesc->first + newDesc->second.size));
+            lastChunk.size = static_cast<size_t>((lastChunkBase->first + lastChunk.size) - (newDesc.first + newDesc.second.size));
-            chunks[newDesc->first + newDesc->second.size] = lastChunk;
+            chunks.insert({newDesc.first + newDesc.second.size, lastChunk});
 
             // Insert new chunk in between
-            chunks[newDesc->first] = newDesc->second;
+            chunks.insert(newDesc);
         } else {
             // If there are descriptors between first and last chunk, delete them
             if ((firstChunkBase->first + firstChunk.size) != lastChunkBase->first) {
@@ -79,13 +69,13 @@ namespace skyline::kernel {
 
             bool shouldInsert{true};
 
-            if (firstChunk.IsCompatible(newDesc->second)) {
+            if (firstChunk.IsCompatible(newDesc.second)) {
                 shouldInsert = false;
 
-                firstChunk.size = static_cast<size_t>((newDesc->first + newDesc->second.size) - firstChunkBase->first);
+                firstChunk.size = static_cast<size_t>((newDesc.first + newDesc.second.size) - firstChunkBase->first);
                 chunks[firstChunkBase->first] = firstChunk;
-            } else if ((firstChunkBase->first + firstChunk.size) != newDesc->first) {
+            } else if ((firstChunkBase->first + firstChunk.size) != newDesc.first) {
-                firstChunk.size = static_cast<size_t>(newDesc->first - firstChunkBase->first);
+                firstChunk.size = static_cast<size_t>(newDesc.first - firstChunkBase->first);
 
                 chunks[firstChunkBase->first] = firstChunk;
 
@@ -93,25 +83,25 @@ namespace skyline::kernel {
                     needsReprotection = true;
             }
 
-            if (lastChunk.IsCompatible(newDesc->second)) {
+            if (lastChunk.IsCompatible(newDesc.second)) {
                 u8 *oldBase{lastChunkBase->first};
                 chunks.erase(lastChunkBase);
 
                 if (shouldInsert) {
                     shouldInsert = false;
 
-                    lastChunk.size = static_cast<size_t>((lastChunk.size + oldBase) - (newDesc->first));
+                    lastChunk.size = static_cast<size_t>((lastChunk.size + oldBase) - (newDesc.first));
 
-                    chunks[newDesc->first] = lastChunk;
+                    chunks[newDesc.first] = lastChunk;
                 } else {
                     firstChunk.size = static_cast<size_t>((lastChunk.size + oldBase) - firstChunkBase->first);
                     chunks[firstChunkBase->first] = firstChunk;
                 }
-            } else if ((newDesc->first + newDesc->second.size) != lastChunkBase->first) {
+            } else if ((newDesc.first + newDesc.second.size) != lastChunkBase->first) {
-                lastChunk.size = static_cast<size_t>((lastChunk.size + lastChunkBase->first) - (newDesc->first + newDesc->second.size));
+                lastChunk.size = static_cast<size_t>((lastChunk.size + lastChunkBase->first) - (newDesc.first + newDesc.second.size));
 
                 chunks.erase(lastChunkBase);
-                chunks[newDesc->first + newDesc->second.size] = lastChunk;
+                chunks[newDesc.first + newDesc.second.size] = lastChunk;
 
                 if ((lastChunk.state == memory::states::Unmapped) != isUnmapping)
                     needsReprotection = true;
@@ -119,49 +109,45 @@ namespace skyline::kernel {
 
             // Insert if not merged
             if (shouldInsert)
-                chunks[newDesc->first] = newDesc->second;
+                chunks.insert(newDesc);
         }
 
         if (needsReprotection)
-            if (mprotect(newDesc->first, newDesc->second.size, !isUnmapping ? PROT_READ | PROT_WRITE | PROT_EXEC : PROT_NONE)) [[unlikely]]
+            if (mprotect(newDesc.first, newDesc.second.size, !isUnmapping ? PROT_READ | PROT_WRITE | PROT_EXEC : PROT_NONE)) [[unlikely]]
                 Logger::Warn("Reprotection failed: {}", strerror(errno));
     }
 
-    void MemoryManager::ForeachChunkinRange(span<skyline::u8> memory, auto editCallback) {
+    void MemoryManager::ForeachChunkinRange(span<u8> memory, auto editCallback) {
-        auto chunkBase{upper_bound(memory.data())};
+        auto chunkBase{chunks.lower_bound(memory.data())};
         if (memory.data() < chunkBase->first)
             --chunkBase;
 
-        ChunkDescriptor resultChunk{chunkBase->second};
-
         size_t sizeLeft{memory.size()};
 
-        if (chunkBase->first < memory.data()) {
+        if (chunkBase->first < memory.data()) [[unlikely]] {
-            size_t copySize{std::min<size_t>(resultChunk.size - (static_cast<size_t>(memory.data() - chunkBase->first)), memory.size())};
+            size_t chunkSize{std::min<size_t>(chunkBase->second.size - (static_cast<size_t>(memory.data() - chunkBase->first)), memory.size())};
 
-            std::pair<u8 *, ChunkDescriptor> temp(memory.data(), resultChunk);
+            std::pair<u8 *, ChunkDescriptor> temp{memory.data(), chunkBase->second};
-            temp.second.size = copySize;
+            temp.second.size = chunkSize;
             editCallback(temp);
 
             ++chunkBase;
-            resultChunk = chunkBase->second;
+            sizeLeft -= chunkSize;
-            sizeLeft -= copySize;
         }
 
         while (sizeLeft) {
-            if (sizeLeft < resultChunk.size) {
+            if (sizeLeft < chunkBase->second.size) {
-                std::pair<u8 *, ChunkDescriptor> temp(chunkBase->first, resultChunk);
+                std::pair<u8 *, ChunkDescriptor> temp(*chunkBase);
                 temp.second.size = sizeLeft;
                 editCallback(temp);
                 break;
             } else [[likely]] {
-                std::pair<u8 *, ChunkDescriptor> temp(chunkBase->first, resultChunk);
+                std::pair<u8 *, ChunkDescriptor> temp(*chunkBase);
 
                 editCallback(temp);
 
-                sizeLeft = sizeLeft - resultChunk.size;
+                sizeLeft = sizeLeft - chunkBase->second.size;
                 ++chunkBase;
-                resultChunk = chunkBase->second;
             }
         }
     }
@@ -233,32 +219,27 @@ namespace skyline::kernel {
 
         // Qualcomm KGSL (Kernel Graphic Support Layer/Kernel GPU driver) maps below 35-bits, reserving it causes KGSL to go OOM
         static constexpr size_t KgslReservedRegionSize{1ULL << 35};
+
+        base = AllocateMappedRange(baseSize, RegionAlignment, KgslReservedRegionSize, addressSpace.size(), false);
+
         if (type != memory::AddressSpaceType::AddressSpace36Bit) {
-            base = AllocateMappedRange(baseSize, RegionAlignment, KgslReservedRegionSize, addressSpace.size(), false);
-
-            chunks[addressSpace.data()] = ChunkDescriptor{
-                .size = addressSpace.size(),
-                .state = memory::states::Unmapped,
-            };
-
             code = base;
-
         } else {
-            codeBase36Bit = AllocateMappedRange(0x78000000, RegionAlignment, 0x8000000, KgslReservedRegionSize, false);
+            code = codeBase36Bit = AllocateMappedRange(0x78000000, RegionAlignment, 0x8000000, KgslReservedRegionSize, false);
-            base = AllocateMappedRange(baseSize, RegionAlignment, KgslReservedRegionSize, addressSpace.size(), false);
 
             if ((reinterpret_cast<u64>(base.data()) + baseSize) > (1ULL << 36)) {
-                Logger::Warn("Couldn't fit regions into AS! Resizing AS instead!");
+                Logger::Warn("Couldn't fit regions into 36 bit AS! Resizing AS to 39 bits!");
                 addressSpace = span<u8>{reinterpret_cast<u8 *>(0), 1ULL << 39};
             }
-
-            chunks[addressSpace.data()] = ChunkDescriptor{
-                .size = addressSpace.size(),
-                .state = memory::states::Unmapped,
-            };
-
-            code = codeBase36Bit;
         }
+
+        // Insert a placeholder element at the end of the map to make sure upper_bound/lower_bound never triggers std::map::end() which is broken
+        chunks = {{addressSpace.data(),{
+            .size = addressSpace.size(),
+            .state = memory::states::Unmapped,
+        }}, {reinterpret_cast<u8 *>(UINT64_MAX), {
+            .state = memory::states::Reserved,
+        }}};
     }
 
     void MemoryManager::InitializeRegions(span<u8> codeRegion) {
@@ -270,11 +251,10 @@ namespace skyline::kernel {
 
                 // As a workaround if we can't place the code region at the base of the AS we mark it as inaccessible heap so rtld doesn't crash
                 if (codeBase36Bit.data() != reinterpret_cast<u8 *>(0x8000000)) {
-                    std::pair<u8 *, ChunkDescriptor> tmp(reinterpret_cast<u8 *>(0x8000000), ChunkDescriptor{
+                    MapInternal(std::pair<u8 *, ChunkDescriptor>(reinterpret_cast<u8 *>(0x8000000),{
                         .size = reinterpret_cast<size_t>(codeBase36Bit.data() - 0x8000000),
-                        .state = memory::states::Heap,
+                        .state = memory::states::Heap
-                    });
+                    }));
-                    MapInternal(&tmp);
                 }
 
                 // Place code, stack and TLS/IO in the lower 36-bits of the host AS and heap and alias past that
@@ -298,7 +278,7 @@ namespace skyline::kernel {
                 if (newSize > base.size()) [[unlikely]]
                     throw exception("Guest VMM size has exceeded host carveout size: 0x{:X}/0x{:X} (Code: 0x{:X}/0x{:X})", newSize, base.size(), code.size(), CodeRegionSize);
 
-                if (newSize != base.size())
+                if (newSize != base.size()) [[likely]]
                     munmap(base.end().base(), newSize - base.size());
 
                 break;
@@ -364,166 +344,151 @@ namespace skyline::kernel {
         return span<u8>{reinterpret_cast<u8 *>(mirrorBase), totalSize};
     }
 
-    void MemoryManager::SetLockOnChunks(span<u8> memory, bool value) {
+    void MemoryManager::SetRegionBorrowed(span<u8> memory, bool value) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
         ForeachChunkinRange(memory, [&](std::pair<u8 *, ChunkDescriptor> &desc) __attribute__((always_inline)) {
             desc.second.attributes.isBorrowed = value;
-            MapInternal(&desc);
+            MapInternal(desc);
         });
     }
 
-    void MemoryManager::SetCPUCachingOnChunks(span<u8> memory, bool value) {
+    void MemoryManager::SetRegionCpuCaching(span<u8> memory, bool value) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
         ForeachChunkinRange(memory, [&](std::pair<u8 *, ChunkDescriptor> &desc) __attribute__((always_inline)) {
             desc.second.attributes.isUncached = value;
-            MapInternal(&desc);
+            MapInternal(desc);
         });
     }
 
-    void MemoryManager::SetChunkPermission(span<u8> memory, memory::Permission permission) {
+    void MemoryManager::SetRegionPermission(span<u8> memory, memory::Permission permission) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
         ForeachChunkinRange(memory, [&](std::pair<u8 *, ChunkDescriptor> &desc) __attribute__((always_inline)) {
             desc.second.permission = permission;
-            MapInternal(&desc);
+            MapInternal(desc);
         });
     }
 
     std::optional<std::pair<u8 *, ChunkDescriptor>> MemoryManager::GetChunk(u8 *addr) {
-        std::shared_lock lock(mutex);
+        std::shared_lock lock{mutex};
 
         if (!addressSpace.contains(addr)) [[unlikely]]
             return std::nullopt;
 
-        auto chunkBase = upper_bound(addr);
+        auto chunkBase = chunks.lower_bound(addr);
-        if (addr < chunkBase->first) [[likely]]
+        if (addr < chunkBase->first)
             --chunkBase;
 
         return std::make_optional(*chunkBase);
     }
 
     __attribute__((always_inline)) void MemoryManager::MapCodeMemory(span<u8> memory, memory::Permission permission) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = permission,
-                .state = memory::states::Code});
+                .state = memory::states::Code
-
+        }));
-        MapInternal(&temp);
     }
 
     __attribute__((always_inline)) void MemoryManager::MapMutableCodeMemory(span<u8> memory) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = {true, true, false},
-                .state = memory::states::CodeMutable});
+                .state = memory::states::CodeMutable
-
+        }));
-        MapInternal(&temp);
     }
 
     __attribute__((always_inline)) void MemoryManager::MapStackMemory(span<u8> memory) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = {true, true, false},
                 .state = memory::states::Stack,
-                .isSrcMergeDisallowed = true});
+                .isSrcMergeDisallowed = true
-
+        }));
-        MapInternal(&temp);
     }
 
     __attribute__((always_inline)) void MemoryManager::MapHeapMemory(span<u8> memory) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = {true, true, false},
-                .state = memory::states::Heap});
+                .state = memory::states::Heap
-
+        }));
-        MapInternal(&temp);
     }
 
     __attribute__((always_inline)) void MemoryManager::MapSharedMemory(span<u8> memory, memory::Permission permission) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = permission,
                 .state = memory::states::SharedMemory,
-                .isSrcMergeDisallowed = true});
+                .isSrcMergeDisallowed = true
-
+        }));
-        MapInternal(&temp);
     }
 
     __attribute__((always_inline)) void MemoryManager::MapTransferMemory(span<u8> memory, memory::Permission permission) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = permission,
                 .state = permission.raw ? memory::states::TransferMemory : memory::states::TransferMemoryIsolated,
-                .isSrcMergeDisallowed = true});
+                .isSrcMergeDisallowed = true
-
+        }));
-        MapInternal(&temp);
     }
 
     __attribute__((always_inline)) void MemoryManager::MapThreadLocalMemory(span<u8> memory) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = {true, true, false},
-                .state = memory::states::ThreadLocal});
+                .state = memory::states::ThreadLocal
-        MapInternal(&temp);
+        }));
     }
 
     __attribute__((always_inline)) void MemoryManager::Reserve(span<u8> memory) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
                 .size = memory.size(),
                 .permission = {false, false, false},
-                .state = memory::states::Reserved});
+                .state = memory::states::Reserved
-        MapInternal(&temp);
+        }));
     }
 
     __attribute__((always_inline)) void MemoryManager::UnmapMemory(span<u8> memory) {
-        std::unique_lock lock(mutex);
+        std::unique_lock lock{mutex};
 
-        ForeachChunkinRange(memory, [&](std::pair<u8 *, ChunkDescriptor> &desc) {
+        ForeachChunkinRange(memory, [&](const std::pair<u8 *, ChunkDescriptor> &desc) {
             if (desc.second.state != memory::states::Unmapped)
-                FreeMemory(span<u8>((u8 *)desc.first, desc.second.size));
+                FreeMemory(span<u8>(desc.first, desc.second.size));
         });
 
-        std::pair<u8 *, ChunkDescriptor> temp(
+        MapInternal(std::pair<u8 *, ChunkDescriptor>(
-            memory.data(),
+            memory.data(),{
-            ChunkDescriptor{
+                .size = memory.size(),
-            .size = memory.size(),
+                .permission = {false, false, false},
-            .permission = {false, false, false},
+                .state = memory::states::Unmapped
-            .state = memory::states::Unmapped});
+        }));
-        MapInternal(&temp);
     }
 
     __attribute__((always_inline)) void MemoryManager::FreeMemory(span<u8> memory) {
@@ -535,25 +500,23 @@ namespace skyline::kernel {
                 Logger::Error("Failed to free memory: {}", strerror(errno));
     }
 
-    void MemoryManager::AddRef(const std::shared_ptr<type::KMemory> &ptr) {
+    void MemoryManager::AddRef(std::shared_ptr<type::KMemory> ptr) {
-        memRefs.push_back(ptr);
+        memRefs.push_back(std::move(ptr));
     }
 
-    void MemoryManager::RemoveRef(const std::shared_ptr<type::KMemory> &ptr) {
+    void MemoryManager::RemoveRef(std::shared_ptr<type::KMemory> ptr) {
-        std::vector<std::shared_ptr<type::KMemory>>::iterator i{std::find(memRefs.begin(), memRefs.end(), ptr)};
+        auto i = std::find(memRefs.begin(), memRefs.end(), ptr);
 
-        if (*i == ptr) {
+        if (*i == ptr) [[likely]]
             memRefs.erase(i);
-        }
     }
 
     size_t MemoryManager::GetUserMemoryUsage() {
-        std::shared_lock lock(mutex);
+        std::shared_lock lock{mutex};
         size_t size{};
 
-        auto currChunk = upper_bound(heap.data());
+        auto currChunk = chunks.lower_bound(heap.data());
-        if (heap.data() < currChunk->first) [[likely]]
+
-            --currChunk;
         while (currChunk->first < heap.end().base()) {
             if (currChunk->second.state == memory::states::Heap)
                 size += currChunk->second.size;
@@ -564,7 +527,7 @@ namespace skyline::kernel {
     }
 
     size_t MemoryManager::GetSystemResourceUsage() {
-        std::shared_lock lock(mutex);
+        std::shared_lock lock{mutex};
         constexpr size_t KMemoryBlockSize{0x40};
         return std::min(static_cast<size_t>(state.process->npdm.meta.systemResourceSize), util::AlignUp(chunks.size() * KMemoryBlockSize, constant::PageSize));
     }

app/src/main/cpp/skyline/kernel/memory.h

@@ -18,19 +18,19 @@ namespace skyline {
             /**
              * @brief Initializes all permissions to false
              */
-            constexpr Permission() : raw() {}
+            constexpr Permission() : raw{} {}
 
             /**
              * @brief Initializes permissions where the first three bits correspond to RWX
              */
-            constexpr explicit Permission(u8 raw) : raw(raw) {}
+            constexpr explicit Permission(u8 raw) : raw{raw} {}
 
             /**
              * @param read If memory has read permission
              * @param write If memory has write permission
              * @param execute If memory has execute permission
              */
-            constexpr Permission(bool read, bool write, bool execute) : r(read), w(write), x(execute) {}
+            constexpr Permission(bool read, bool write, bool execute) : r{read}, w{write}, x{execute} {}
 
             inline bool operator==(const Permission &rhs) const { return r == rhs.r && w == rhs.w && x == rhs.x; }
 
@@ -63,13 +63,18 @@ namespace skyline {
          * @url https://switchbrew.org/wiki/SVC#MemoryAttribute
          */
         union MemoryAttribute {
+
+            constexpr MemoryAttribute() : value{} {}
+
+            constexpr explicit MemoryAttribute(u8 value) : value{value} {}
+
             struct {
                 bool isBorrowed : 1; //!< This is required for async IPC user buffers
                 bool isIpcLocked : 1; //!< True when IpcRefCount > 0
                 bool isDeviceShared : 1; //!< True when DeviceRefCount > 0
                 bool isUncached : 1; //!< This is used to disable memory caching to share memory with the GPU
             };
-            u32 value{};
+            u8 value;
         };
 
         /**
@@ -122,9 +127,9 @@ namespace skyline {
          * @url https://switchbrew.org/wiki/SVC#MemoryState
          */
         union MemoryState {
-            constexpr MemoryState(const u32 value) : value(value) {}
+            constexpr MemoryState(const u32 value) : value{value} {}
 
-            constexpr MemoryState() : value(0) {}
+            constexpr MemoryState() : value{} {}
 
             constexpr bool operator==(const MemoryState &other) const {
                 return value == other.value;
@@ -156,7 +161,7 @@ namespace skyline {
                 bool codeMemoryAllowed : 1; //!< If the application can use svcCreateCodeMemory on this block
                 bool isLinearMapped : 1; //!< If this block is mapped linearly
             };
-            u32 value{};
+            u32 value;
         };
         static_assert(sizeof(MemoryState) == sizeof(u32));
 
@@ -202,10 +207,10 @@ namespace skyline {
     namespace kernel {
         struct ChunkDescriptor {
             bool isSrcMergeDisallowed;
-            size_t size;
             memory::Permission permission;
-            memory::MemoryState state;
             memory::MemoryAttribute attributes;
+            memory::MemoryState state;
+            size_t size;
 
             constexpr bool IsCompatible(const ChunkDescriptor &chunk) const noexcept {
                 return chunk.permission == permission && chunk.state.value == state.value && chunk.attributes.value == attributes.value && !isSrcMergeDisallowed;
@@ -222,10 +227,7 @@ namespace skyline {
 
             std::vector<std::shared_ptr<type::KMemory>> memRefs;
 
-            // Workaround for broken std implementation
+            void MapInternal(const std::pair<u8 *, ChunkDescriptor> &newDesc);
-            std::map<u8 *, ChunkDescriptor>::iterator upper_bound(u8 *address);
-
-            void MapInternal(std::pair<u8 *, ChunkDescriptor> *newDesc);
 
             void ForeachChunkinRange(span<u8> memory, auto editCallback);
 
@@ -240,7 +242,7 @@ namespace skyline {
             span<u8> stack{};
             span<u8> tlsIo{}; //!< TLS/IO
 
-            size_t setHeapSize; //!< For use by svcSetHeapSize
+            size_t processHeapSize; //!< For use by svcSetHeapSize
 
             std::shared_mutex mutex; //!< Synchronizes any operations done on the VMM, it's locked in shared mode by readers and exclusive mode by writers
 
@@ -272,27 +274,27 @@ namespace skyline {
             span<u8> CreateMirrors(const std::vector<span<u8>> &regions);
 
             /**
-             * @brief Sets the attributes for chunks within a certain range
+             * @brief Sets the isBorrowed attribute for chunks within a certain range
              */
-            void SetLockOnChunks(span<u8> memory, bool value);
+            void SetRegionBorrowed(span<u8> memory, bool value);
-
-            void SetCPUCachingOnChunks(span<u8> memory, bool value);
 
             /**
-             * @brief Sets the permission for chunks within a certain range
+             * @brief Sets the isUncached attribute for chunks within a certain range
+             */
+            void SetRegionCpuCaching(span<u8> memory, bool value);
+
+            /**
+             * @brief Sets the permissions for chunks within a certain range
              * @note The permissions set here are not accurate to the actual permissions set on the chunk and are only for the guest
              */
-            void SetChunkPermission(span<u8> memory, memory::Permission permission);
+            void SetRegionPermission(span<u8> memory, memory::Permission permission);
 
             /**
              * @brief Gets the highest chunk's descriptor that contains this address
              */
             std::optional<std::pair<u8 *, ChunkDescriptor>> GetChunk(u8 *addr);
 
-            /**
+            // Various mapping functions for use by the guest
-             * Various mapping functions for use by the guest
-             * @note UnmapMemory frees the underlying memory as well
-             */
             void MapCodeMemory(span<u8> memory, memory::Permission permission);
 
             void MapMutableCodeMemory(span<u8> memory);
@@ -309,6 +311,9 @@ namespace skyline {
 
             void Reserve(span<u8> memory);
 
+            /**
+             * @note `UnmapMemory` also calls `FreeMemory` on the unmapped memory range
+             */
             void UnmapMemory(span<u8> memory);
 
             /**
@@ -318,11 +323,14 @@ namespace skyline {
             void FreeMemory(span<u8> memory);
 
             /**
-             * Allows you to add/remove references to shared/transfer memory
+             * @brief Adds a reference to shared memory, extending its lifetime until `RemoveRef` is called
              */
-            void AddRef(const std::shared_ptr<type::KMemory> &ptr);
+            void AddRef(std::shared_ptr<type::KMemory> ptr);
 
-            void RemoveRef(const std::shared_ptr<type::KMemory> &ptr);
+            /**
+             * @brief Removes the reference added by `AddRef`
+             */
+            void RemoveRef(std::shared_ptr<type::KMemory> ptr);
 
             /**
              * @return The cumulative size of all heap (Physical Memory + Process Heap) memory mappings, the code region and the main thread stack in bytes
@@ -347,3 +355,16 @@ namespace skyline {
         };
     }
 }
+
+template<> struct fmt::formatter<skyline::memory::Permission> {
+    template<typename ParseContext>
+    constexpr auto parse(ParseContext& ctx)
+    {
+        return ctx.begin();
+    }
+    template<typename FormatContext>
+    constexpr auto format(skyline::memory::Permission const& permission, FormatContext& ctx)
+    {
+        return fmt::format_to(ctx.out(), "{}{}{}", permission.r ? 'R' : '-', permission.w ? 'W' : '-', permission.x ? 'X' : '-');
+    }
+};

app/src/main/cpp/skyline/kernel/svc.cpp

@@ -11,7 +11,7 @@
 
 namespace skyline::kernel::svc {
     void SetHeapSize(const DeviceState &state) {
-        u64 size{state.ctx->gpr.w1};
+        u32 size{state.ctx->gpr.w1};
 
         if (!util::IsAligned(size, 0x200000)) [[unlikely]] {
             state.ctx->gpr.w0 = result::InvalidSize;
@@ -27,7 +27,7 @@ namespace skyline::kernel::svc {
             return;
         }
 
-        size_t heapCurrSize{state.process->memory.setHeapSize};
+        size_t heapCurrSize{state.process->memory.processHeapSize};
         u8 *heapBaseAddr{state.process->memory.heap.data()};
 
         if (heapCurrSize < size)
@@ -35,7 +35,7 @@ namespace skyline::kernel::svc {
         else if (size < heapCurrSize)
             state.process->memory.UnmapMemory(span<u8>{heapBaseAddr + size, heapCurrSize - size});
 
-        state.process->memory.setHeapSize = size;
+        state.process->memory.processHeapSize = size;
 
         state.ctx->gpr.w0 = Result{};
         state.ctx->gpr.x1 = reinterpret_cast<u64>(heapBaseAddr);
@@ -67,7 +67,7 @@ namespace skyline::kernel::svc {
         memory::Permission newPermission(static_cast<u8>(state.ctx->gpr.w2));
         if ((!newPermission.r && newPermission.w) || newPermission.x) [[unlikely]] {
             state.ctx->gpr.w0 = result::InvalidNewMemoryPermission;
-            Logger::Warn("'permission' invalid: {}{}{}", newPermission.r ? 'R' : '-', newPermission.w ? 'W' : '-', newPermission.x ? 'X' : '-');
+            Logger::Warn("'permission' invalid: {}", newPermission);
             return;
         }
 
@@ -78,7 +78,7 @@ namespace skyline::kernel::svc {
             return;
         }
 
-        state.process->memory.SetChunkPermission(span<u8>(address, size), newPermission);
+        state.process->memory.SetRegionPermission(span<u8>(address, size), newPermission);
 
         Logger::Debug("Set permission to {}{}{} at 0x{:X} - 0x{:X} (0x{:X} bytes)", newPermission.r ? 'R' : '-', newPermission.w ? 'W' : '-', newPermission.x ? 'X' : '-', address, address + size, size);
         state.ctx->gpr.w0 = Result{};
@@ -105,8 +105,8 @@ namespace skyline::kernel::svc {
             return;
         }
 
-        memory::MemoryAttribute mask{.value = state.ctx->gpr.w2};
+        memory::MemoryAttribute mask{static_cast<u8>(state.ctx->gpr.w2)};
-        memory::MemoryAttribute value{.value = state.ctx->gpr.w3};
+        memory::MemoryAttribute value{static_cast<u8>(state.ctx->gpr.w3)};
 
         auto maskedValue{mask.value | value.value};
         if (maskedValue != mask.value || !mask.isUncached || mask.isDeviceShared || mask.isBorrowed || mask.isIpcLocked) [[unlikely]] {
@@ -124,7 +124,7 @@ namespace skyline::kernel::svc {
             return;
         }
 
-        state.process->memory.SetCPUCachingOnChunks(span<u8>{address, size}, value.isUncached);
+        state.process->memory.SetRegionCpuCaching(span<u8>{address, size}, value.isUncached);
 
         Logger::Debug("Set CPU caching to {} at 0x{:X} - 0x{:X} (0x{:X} bytes)", static_cast<bool>(value.isUncached), address, address + size, size);
         state.ctx->gpr.w0 = Result{};
@@ -175,8 +175,8 @@ namespace skyline::kernel::svc {
         state.process->memory.MapStackMemory(span<u8>{destination, size});
         std::memcpy(destination, source, size);
 
-        state.process->memory.SetChunkPermission(span<u8>{source, size}, {false, false, false});
+        state.process->memory.SetRegionPermission(span<u8>{source, size}, {false, false, false});
-        state.process->memory.SetLockOnChunks(span<u8>{source, size}, true);
+        state.process->memory.SetRegionBorrowed(span<u8>{source, size}, true);
 
         Logger::Debug("Mapped range 0x{:X} - 0x{:X} to 0x{:X} - 0x{:X} (Size: 0x{:X} bytes)", source, source + size, destination, destination + size, size);
         state.ctx->gpr.w0 = Result{};
@@ -210,8 +210,8 @@ namespace skyline::kernel::svc {
             dstChunk = state.process->memory.GetChunk(dstChunk.first + dstChunk.second.size).value();
 
         if ((destination + size) > dstChunk.first) [[likely]] {
-            state.process->memory.SetChunkPermission(span<u8>{source + (dstChunk.first - destination), dstChunk.second.size}, dstChunk.second.permission);
+            state.process->memory.SetRegionPermission(span<u8>{source + (dstChunk.first - destination), dstChunk.second.size}, dstChunk.second.permission);
-            state.process->memory.SetLockOnChunks(span<u8>{source + (dstChunk.first - destination), dstChunk.second.size}, false);
+            state.process->memory.SetRegionBorrowed(span<u8>{source + (dstChunk.first - destination), dstChunk.second.size}, false);
 
             std::memcpy(source + (dstChunk.first - destination), dstChunk.first, dstChunk.second.size);
 
@@ -239,7 +239,7 @@ namespace skyline::kernel::svc {
                 .ipcRefCount = 0,
             };
 
-            Logger::Debug("Address: 0x{:X}, Region Start: 0x{:X}, Size: 0x{:X}, Type: 0x{:X}, Attributes: 0x{:X}, Permissions: {}{}{}", address, memInfo.address, memInfo.size, memInfo.type, memInfo.attributes, chunk->second.permission.r ? 'R' : '-', chunk->second.permission.w ? 'W' : '-', chunk->second.permission.x ? 'X' : '-');
+            Logger::Debug("Address: 0x{:X}, Region Start: 0x{:X}, Size: 0x{:X}, Type: 0x{:X}, Attributes: 0x{:X}, Permissions: {}", address, memInfo.address, memInfo.size, memInfo.type, memInfo.attributes, chunk->second.permission);
         } else {
             u64 addressSpaceEnd{reinterpret_cast<u64>(state.process->memory.addressSpace.end().base())};
 
@@ -254,7 +254,7 @@ namespace skyline::kernel::svc {
 
         *reinterpret_cast<memory::MemoryInfo *>(state.ctx->gpr.x0) = memInfo;
         // The page info, which is always 0
-        state.ctx->gpr.x1 = 0;
+        state.ctx->gpr.w1 = 0;
 
         state.ctx->gpr.w0 = Result{};
     }
@@ -537,7 +537,7 @@ namespace skyline::kernel::svc {
             memory::Permission permission(static_cast<u8>(state.ctx->gpr.w3));
             if ((!permission.r && !permission.w && !permission.x) || (permission.w && !permission.r) || permission.x) [[unlikely]] {
                 state.ctx->gpr.w0 = result::InvalidNewMemoryPermission;
-                Logger::Warn("'permission' invalid: {}{}{}", permission.r ? 'R' : '-', permission.w ? 'W' : '-', permission.x ? 'X' : '-');
+                Logger::Warn("'permission' invalid: {}", permission);
                 return;
             }
 
@@ -613,7 +613,7 @@ namespace skyline::kernel::svc {
 
         memory::Permission permission(static_cast<u8>(state.ctx->gpr.w3));
         if ((permission.w && !permission.r) || permission.x) [[unlikely]] {
-            Logger::Warn("'permission' invalid: {}{}{}", permission.r ? 'R' : '-', permission.w ? 'W' : '-', permission.x ? 'X' : '-');
+            Logger::Warn("'permission' invalid: {}", permission);
             state.ctx->gpr.w0 = result::InvalidNewMemoryPermission;
             return;
         }

app/src/main/cpp/skyline/kernel/types/KMemory.cpp

@@ -8,12 +8,12 @@
 #include "KProcess.h"
 
 namespace skyline::kernel::type {
-    KMemory::KMemory(const DeviceState &state, KType objectType, size_t size) : KObject(state, objectType), guest() {
+    KMemory::KMemory(const DeviceState &state, KType objectType, size_t size) : KObject{state, objectType}, guest{} {
-        fd = ASharedMemory_create(objectType == KType::KSharedMemory ? "HOS-KSharedMemory" : "HOS-KTransferMemory", size);
+        fileDescriptor = ASharedMemory_create(objectType == KType::KSharedMemory ? "HOS-KSharedMemory" : "HOS-KTransferMemory", size);
-        if (fd < 0) [[unlikely]]
+        if (fileDescriptor < 0) [[unlikely]]
-            throw exception("An error occurred while creating shared memory: {}", fd);
+            throw exception("An error occurred while creating shared memory: {}", fileDescriptor);
 
-        u8 *hostPtr{static_cast<u8 *>(mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0))};
+        u8 *hostPtr{static_cast<u8 *>(mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileDescriptor, 0))};
         if (hostPtr == MAP_FAILED) [[unlikely]]
             throw exception("An occurred while mapping shared memory: {}", strerror(errno));
 
@@ -28,7 +28,7 @@ namespace skyline::kernel::type {
         if (guest.valid()) [[unlikely]]
             throw exception("Mapping KMemory multiple times on guest is not supported: Requested Mapping: 0x{:X} - 0x{:X} (0x{:X}), Current Mapping: 0x{:X} - 0x{:X} (0x{:X})", map.data(), map.end().base(), map.size(), guest.data(), guest.end().base(), guest.size());
 
-        if (mmap(map.data(), map.size(), permission.Get() ? PROT_READ | PROT_WRITE : PROT_NONE, MAP_SHARED | (map.data() ? MAP_FIXED : 0), fd, 0) == MAP_FAILED) [[unlikely]]
+        if (mmap(map.data(), map.size(), permission.Get() ? PROT_READ | PROT_WRITE : PROT_NONE, MAP_SHARED | (map.data() ? MAP_FIXED : 0), fileDescriptor, 0) == MAP_FAILED) [[unlikely]]
             throw exception("An error occurred while mapping shared memory in guest: {}", strerror(errno));
         guest = map;
 
@@ -51,6 +51,6 @@ namespace skyline::kernel::type {
         if (host.valid())
             munmap(host.data(), host.size());
 
-        close(fd);
+        close(fileDescriptor);
     }
 }

app/src/main/cpp/skyline/kernel/types/KMemory.h

@@ -12,7 +12,7 @@ namespace skyline::kernel::type {
      */
     class KMemory : public KObject {
       private:
-        int fd; //!< A file descriptor to the underlying shared memory
+        int fileDescriptor; //!< A file descriptor to the underlying shared memory
 
       public:
         KMemory(const DeviceState &state, KType objectType, size_t size);

app/src/main/cpp/skyline/kernel/types/KProcess.cpp

@@ -50,7 +50,7 @@ namespace skyline::kernel::type {
     void KProcess::InitializeHeapTls() {
         constexpr size_t DefaultHeapSize{0x200000};
         memory.MapHeapMemory(span<u8>{state.process->memory.heap.data(), DefaultHeapSize});
-        memory.setHeapSize = DefaultHeapSize;
+        memory.processHeapSize = DefaultHeapSize;
         tlsExceptionContext = AllocateTlsSlot();
     }
 

app/src/main/cpp/skyline/kernel/types/KSharedMemory.cpp

@@ -6,7 +6,7 @@
 
 namespace skyline::kernel::type {
     KSharedMemory::KSharedMemory(const DeviceState &state, size_t size)
-        : KMemory(state, KType::KSharedMemory, size) {}
+        : KMemory{state, KType::KSharedMemory, size} {}
 
     u8 *KSharedMemory::Map(span<u8> map, memory::Permission permission) {
         u8 *result{KMemory::Map(map, permission)};

app/src/main/cpp/skyline/kernel/types/KTransferMemory.cpp

@@ -6,7 +6,7 @@
 
 namespace skyline::kernel::type {
     KTransferMemory::KTransferMemory(const DeviceState &state, size_t size)
-        : KMemory(state, KType::KTransferMemory,  size) {}
+        : KMemory{state, KType::KTransferMemory, size} {}
 
     u8 *KTransferMemory::Map(span<u8> map, memory::Permission permission) {
         std::memcpy(host.data(), map.data(), map.size());
@@ -21,7 +21,7 @@ namespace skyline::kernel::type {
             return nullptr;
         } else {
             state.process->memory.MapTransferMemory(guest, permission);
-            state.process->memory.SetLockOnChunks(guest, true);
+            state.process->memory.SetRegionBorrowed(guest, true);
             return result;
         }
     }

app/src/main/cpp/skyline/loader/loader.cpp

@@ -91,7 +91,7 @@ namespace skyline::loader {
 
         if (process->memory.addressSpaceType == memory::AddressSpaceType::AddressSpace36Bit) {
             process->memory.MapHeapMemory(span<u8>{base, patch.size + hookSize}); // ---
-            process->memory.SetChunkPermission(span<u8>{base, patch.size + hookSize}, memory::Permission{false, false, false});
+            process->memory.SetRegionPermission(span<u8>{base, patch.size + hookSize}, memory::Permission{false, false, false});
         } else {
             process->memory.Reserve(span<u8>{base, patch.size + hookSize}); // ---
         }