4 files changed, 131 insertions, 1 deletions

diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index e5d4d6b55..0aa2e358e 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -1189,6 +1189,74 @@ static ResultCode QueryMemory(Core::System& system, VAddr memory_info_address,
                               query_address);
 }
 
+static ResultCode MapProcessCodeMemory(Core::System& system, Handle process_handle, u64 dst_address,
+                                       u64 src_address, u64 size) {
+    LOG_DEBUG(Kernel_SVC,
+              "called. process_handle=0x{:08X}, dst_address=0x{:016X}, "
+              "src_address=0x{:016X}, size=0x{:016X}",
+              process_handle, dst_address, src_address, size);
+
+    if (!Common::Is4KBAligned(src_address)) {
+        LOG_ERROR(Kernel_SVC, "src_address is not page-aligned (src_address=0x{:016X}).",
+                  src_address);
+        return ERR_INVALID_ADDRESS;
+    }
+
+    if (!Common::Is4KBAligned(dst_address)) {
+        LOG_ERROR(Kernel_SVC, "dst_address is not page-aligned (dst_address=0x{:016X}).",
+                  dst_address);
+        return ERR_INVALID_ADDRESS;
+    }
+
+    if (size == 0 || !Common::Is4KBAligned(size)) {
+        LOG_ERROR(Kernel_SVC, "Size is zero or not page-aligned (size=0x{:016X})", size);
+        return ERR_INVALID_SIZE;
+    }
+
+    if (!IsValidAddressRange(dst_address, size)) {
+        LOG_ERROR(Kernel_SVC,
+                  "Destination address range overflows the address space (dst_address=0x{:016X}, "
+                  "size=0x{:016X}).",
+                  dst_address, size);
+        return ERR_INVALID_ADDRESS_STATE;
+    }
+
+    if (!IsValidAddressRange(src_address, size)) {
+        LOG_ERROR(Kernel_SVC,
+                  "Source address range overflows the address space (src_address=0x{:016X}, "
+                  "size=0x{:016X}).",
+                  src_address, size);
+        return ERR_INVALID_ADDRESS_STATE;
+    }
+
+    const auto& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
+    auto process = handle_table.Get<Process>(process_handle);
+    if (!process) {
+        LOG_ERROR(Kernel_SVC, "Invalid process handle specified (handle=0x{:08X}).",
+                  process_handle);
+        return ERR_INVALID_HANDLE;
+    }
+
+    auto& vm_manager = process->VMManager();
+    if (!vm_manager.IsWithinAddressSpace(src_address, size)) {
+        LOG_ERROR(Kernel_SVC,
+                  "Source address range is not within the address space (src_address=0x{:016X}, "
+                  "size=0x{:016X}).",
+                  src_address, size);
+        return ERR_INVALID_ADDRESS_STATE;
+    }
+
+    if (!vm_manager.IsWithinASLRRegion(dst_address, size)) {
+        LOG_ERROR(Kernel_SVC,
+                  "Destination address range is not within the ASLR region (dst_address=0x{:016X}, "
+                  "size=0x{:016X}).",
+                  dst_address, size);
+        return ERR_INVALID_MEMORY_RANGE;
+    }
+
+    return vm_manager.MapCodeMemory(dst_address, src_address, size);
+}
+
 /// Exits the current process
 static void ExitProcess(Core::System& system) {
     auto* current_process = system.Kernel().CurrentProcess();
@@ -2217,7 +2285,7 @@ static const FunctionDef SVC_Table[] = {
     {0x74, nullptr, "MapProcessMemory"},
     {0x75, nullptr, "UnmapProcessMemory"},
     {0x76, SvcWrap<QueryProcessMemory>, "QueryProcessMemory"},
-    {0x77, nullptr, "MapProcessCodeMemory"},
+    {0x77, SvcWrap<MapProcessCodeMemory>, "MapProcessCodeMemory"},
     {0x78, nullptr, "UnmapProcessCodeMemory"},
     {0x79, nullptr, "CreateProcess"},
     {0x7A, nullptr, "StartProcess"},
diff --git a/src/core/hle/kernel/svc_wrap.h b/src/core/hle/kernel/svc_wrap.h
index b3690b5f3..865473c6f 100644
--- a/src/core/hle/kernel/svc_wrap.h
+++ b/src/core/hle/kernel/svc_wrap.h
@@ -44,6 +44,13 @@ void SvcWrap(Core::System& system) {
         func(system, static_cast<u32>(Param(system, 0)), static_cast<u32>(Param(system, 1))).raw);
 }
 
+template <ResultCode func(Core::System&, u32, u64, u64, u64)>
+void SvcWrap(Core::System& system) {
+    FuncReturn(system, func(system, static_cast<u32>(Param(system, 0)), Param(system, 1),
+                            Param(system, 2), Param(system, 3))
+                           .raw);
+}
+
 template <ResultCode func(Core::System&, u32*)>
 void SvcWrap(Core::System& system) {
     u32 param = 0;
diff --git a/src/core/hle/kernel/vm_manager.cpp b/src/core/hle/kernel/vm_manager.cpp
index ec0a480ce..76b491c47 100644
--- a/src/core/hle/kernel/vm_manager.cpp
+++ b/src/core/hle/kernel/vm_manager.cpp
@@ -302,6 +302,35 @@ ResultVal<VAddr> VMManager::SetHeapSize(u64 size) {
     return MakeResult<VAddr>(heap_region_base);
 }
 
+ResultCode VMManager::MapCodeMemory(VAddr dst_address, VAddr src_address, u64 size) {
+    constexpr auto ignore_attribute = MemoryAttribute::LockedForIPC | MemoryAttribute::DeviceMapped;
+    const auto src_check_result = CheckRangeState(
+        src_address, size, MemoryState::All, MemoryState::Heap, VMAPermission::All,
+        VMAPermission::ReadWrite, MemoryAttribute::Mask, MemoryAttribute::None, ignore_attribute);
+
+    if (src_check_result.Failed()) {
+        return src_check_result.Code();
+    }
+
+    const auto mirror_result =
+        MirrorMemory(dst_address, src_address, size, MemoryState::ModuleCode);
+    if (mirror_result.IsError()) {
+        return mirror_result;
+    }
+
+    // Ensure we lock the source memory region.
+    const auto src_vma_result = CarveVMARange(src_address, size);
+    if (src_vma_result.Failed()) {
+        return src_vma_result.Code();
+    }
+    auto src_vma_iter = *src_vma_result;
+    src_vma_iter->second.attribute = MemoryAttribute::Locked;
+    Reprotect(src_vma_iter, VMAPermission::Read);
+
+    // The destination memory region is fine as is, however we need to make it read-only.
+    return ReprotectRange(dst_address, size, VMAPermission::Read);
+}
+
 MemoryInfo VMManager::QueryMemory(VAddr address) const {
     const auto vma = FindVMA(address);
     MemoryInfo memory_info{};
diff --git a/src/core/hle/kernel/vm_manager.h b/src/core/hle/kernel/vm_manager.h
index 6f484b7bf..27120d3b1 100644
--- a/src/core/hle/kernel/vm_manager.h
+++ b/src/core/hle/kernel/vm_manager.h
@@ -43,6 +43,9 @@ enum class VMAPermission : u8 {
     ReadExecute = Read | Execute,
     WriteExecute = Write | Execute,
     ReadWriteExecute = Read | Write | Execute,
+
+    // Used as a wildcard when checking permissions across memory ranges
+    All = 0xFF,
 };
 
 constexpr VMAPermission operator|(VMAPermission lhs, VMAPermission rhs) {
@@ -152,6 +155,9 @@ enum class MemoryState : u32 {
     FlagUncached                    = 1U << 24,
     FlagCodeMemory                  = 1U << 25,
 
+    // Wildcard used in range checking to indicate all states.
+    All                             = 0xFFFFFFFF,
+
     // Convenience flag sets to reduce repetition
     IPCFlags = FlagIPC0 | FlagIPC3 | FlagIPC1,
 
@@ -415,6 +421,26 @@ public:
     ///
     ResultVal<VAddr> SetHeapSize(u64 size);
 
+    /// Maps a region of memory as code memory.
+    ///
+    /// @param dst_address The base address of the region to create the aliasing memory region.
+    /// @param src_address The base address of the region to be aliased.
+    /// @param size        The total amount of memory to map in bytes.
+    ///
+    /// @pre Both memory regions lie within the actual addressable address space.
+    ///
+    /// @post After this function finishes execution, assuming success, then the address range
+    ///       [dst_address, dst_address+size) will alias the memory region,
+    ///       [src_address, src_address+size).
+    ///       <p>
+    ///       What this also entails is as follows:
+    ///          1. The aliased region gains the Locked memory attribute.
+    ///          2. The aliased region becomes read-only.
+    ///          3. The aliasing region becomes read-only.
+    ///          4. The aliasing region is created with a memory state of MemoryState::CodeModule.
+    ///
+    ResultCode MapCodeMemory(VAddr dst_address, VAddr src_address, u64 size);
+
     /// Queries the memory manager for information about the given address.
     ///
     /// @param address The address to query the memory manager about for information.