refactor syscall ABI and FAT32 driver to use request structs and string views natively, enforce handle access rights on object lookup, add scheduler statistics tracking, fix KiSchedule to prevent 50% idle throttling on CPU-bound threads, better document x64 initial user stack alignment, fix process teardown to properly signal exit events and manage thread counts, optimize doom file I/O with a custom handle struct to internally track position and size, add SubsystemData to TEB for generic thread-local state, apply PAGE_NX to non-executable PE sections in the loader, update native apps, tests, and shells to match new APIs, update kernel32 directory retrieval.

code/kernel/ldr_image.c

@@ -107,6 +107,10 @@ typedef struct {
 #pragma pack(pop)
 
 #define IMAGE_REL_BASED_DIR64 10
+#define IMAGE_SCN_CNT_CODE               0x00000020u
+#define IMAGE_SCN_MEM_EXECUTE            0x20000000u
+#define IMAGE_SCN_MEM_READ               0x40000000u
+#define IMAGE_SCN_MEM_WRITE              0x80000000u
 
 // ---------------------------------------------------------------------------
 // Module registry
@@ -248,6 +252,40 @@ size_t LdrGetImageSize(uintptr_t base) {
     return (size_t)pe->OptionalHeader.SizeOfImage;
 }
 
+
+static void KiFreeLoadedImage(uintptr_t imageBase, bool user) {
+    if (!imageBase) return;
+    size_t imageSize = LdrGetImageSize(imageBase);
+    if (user) MmFreeUserImage((void*)imageBase, imageSize);
+    else MmFreePool((void*)imageBase);
+}
+
+
+KSTATUS LdrProtectImage(uintptr_t imageBase, bool user) {
+    if (!imageBase) return STATUS_INVALID_PARAMETER;
+
+    uint32_t peOffset = *(uint32_t *)(imageBase + 0x3C);
+    PE_HEADER* pe = (PE_HEADER *)(imageBase + peOffset);
+    if (pe->Signature != PE_SIGNATURE) return STATUS_FAILURE;
+
+    SECTION_HEADER* sec = (SECTION_HEADER *)((uint8_t *)&pe->OptionalHeader + pe->SizeOfOptionalHeader);
+    for (int i = 0; i < pe->NumberOfSections; i++) {
+        size_t protectSize = sec[i].VirtualSize ? sec[i].VirtualSize : sec[i].SizeOfRawData;
+        if (!protectSize) continue;
+
+        uint64_t prot = PAGE_PRESENT | (user ? PAGE_USER : 0);
+        if (sec[i].Characteristics & IMAGE_SCN_MEM_WRITE)
+            prot |= PAGE_WRITE;
+        if (!((sec[i].Characteristics & IMAGE_SCN_MEM_EXECUTE) ||
+              (sec[i].Characteristics & IMAGE_SCN_CNT_CODE)))
+            prot |= PAGE_NX;
+
+        KSTATUS s = MmSetPageProtect(imageBase + sec[i].VirtualAddress, protectSize, prot);
+        if (!KSUCCESS(s)) return s;
+    }
+    return STATUS_SUCCESS;
+}
+
 // ---------------------------------------------------------------------------
 // Entry point lookup
 // ---------------------------------------------------------------------------
@@ -470,13 +508,13 @@ KSTATUS LdrLoadModuleForProcess(PROCESS* process, const char* filename, uintptr_
     }
 
     FILE_OBJECT* f;
-    KSTATUS s = IoOpenFile(filename, &f);
+    KSTATUS s = IoOpenFile(SysSvFromCstr(filename), &f);
     if (!KSUCCESS(s)) {
         char path[260];
         memcpy(path, "0:/system/", 10);
         memcpy(path + 10, filename, strnlen(filename, 248) + 1);
         path[259] = '\0';
-        s = IoOpenFile(path, &f);
+        s = IoOpenFile(SysSvFromCstr(path), &f);
         if (!KSUCCESS(s)) {
             DbgPrint("LdrLoadModuleForProcess: Failed to open %s (%d)\n", filename, s);
             return s;
@@ -509,7 +547,13 @@ KSTATUS LdrLoadModuleForProcess(PROCESS* process, const char* filename, uintptr_
 
     s = LdrResolveImportsForProcess(process, imageBase);
     if (!KSUCCESS(s)) {
-        MmFreeUserMemory((void*)imageBase);
+        KiFreeLoadedImage(imageBase, true);
+        return s;
+    }
+
+    s = LdrProtectImage(imageBase, true);
+    if (!KSUCCESS(s)) {
+        KiFreeLoadedImage(imageBase, true);
         return s;
     }
 
@@ -517,7 +561,7 @@ KSTATUS LdrLoadModuleForProcess(PROCESS* process, const char* filename, uintptr_
 
     s = LdrRegisterProcessModule(process, filename, imageBase);
     if (!KSUCCESS(s)) {
-        MmFreeUserMemory((void*)imageBase);
+        KiFreeLoadedImage(imageBase, true);
         return s;
     }
 
@@ -561,7 +605,7 @@ KSTATUS LdrLoadImage(const void* buffer, size_t size, uintptr_t* baseOut, bool u
     OPT_HEADER64* opt = &pe->OptionalHeader;
     size_t imageSize = opt->SizeOfImage;
 
-    void* mem = user ? MmAllocateUserMemory(imageSize) : MmAllocatePool(imageSize);
+    void* mem = user ? MmAllocateUserImage(imageSize) : MmAllocatePool(imageSize);
     if (!mem) return STATUS_NO_MEMORY;
     memset(mem, 0, imageSize);
 
@@ -575,7 +619,9 @@ KSTATUS LdrLoadImage(const void* buffer, size_t size, uintptr_t* baseOut, bool u
         }
 
         uint64_t prot = PAGE_PRESENT | PAGE_WRITE | (user ? PAGE_USER : 0);
-        MmSetPageProtect((uintptr_t)mem + sec[i].VirtualAddress, sec[i].VirtualSize, prot);
+        MmSetPageProtect((uintptr_t)mem + sec[i].VirtualAddress,
+                         sec[i].VirtualSize ? sec[i].VirtualSize : sec[i].SizeOfRawData,
+                         prot);
     }
 
     uintptr_t delta = (uintptr_t)mem - opt->ImageBase;