From a9401068d7e96f8b9607486924be6890ecc1aeac Mon Sep 17 00:00:00 2001
From: nakst <>
Date: Fri, 19 Nov 2021 19:02:02 +0000
Subject: [PATCH] permissions for shared regions

---
 desktop/api.cpp      |  4 ++--
 desktop/desktop.cpp  |  2 +-
 desktop/os.header    | 16 ++++++++++------
 desktop/posix.cpp    |  3 ++-
 desktop/syscall.cpp  |  8 ++++----
 desktop/text.cpp     |  2 +-
 desktop/theme.cpp    |  4 ++--
 kernel/elf.cpp       |  4 ++--
 kernel/memory.cpp    | 10 +++++-----
 kernel/objects.cpp   |  2 +-
 kernel/scheduler.cpp |  7 ++++---
 kernel/syscall.cpp   | 23 +++++++++++++++++------
 util/api_table.ini   |  2 +-
 13 files changed, 52 insertions(+), 35 deletions(-)

diff --git a/desktop/api.cpp b/desktop/api.cpp
index 3f74c91..649c29e 100644
--- a/desktop/api.cpp
+++ b/desktop/api.cpp
@@ -1512,8 +1512,8 @@ extern "C" void _start(EsProcessStartupInformation *_startupInformation) {
 		ThreadInitialise(&api.firstThreadLocalStorage);
 		EsMessageMutexAcquire();
 
-		api.global = (GlobalData *) EsObjectMap(api.startupInformation->globalDataRegion, 
-				0, sizeof(GlobalData), desktop ? ES_MAP_OBJECT_READ_WRITE : ES_MAP_OBJECT_READ_ONLY);
+		api.global = (GlobalData *) EsMemoryMapObject(api.startupInformation->globalDataRegion, 
+				0, sizeof(GlobalData), desktop ? ES_MEMORY_MAP_OBJECT_READ_WRITE : ES_MEMORY_MAP_OBJECT_READ_ONLY);
 	}
 
 	bool uiProcess = true; // TODO Determine this properly.
diff --git a/desktop/desktop.cpp b/desktop/desktop.cpp
index 72df698..eced823 100644
--- a/desktop/desktop.cpp
+++ b/desktop/desktop.cpp
@@ -1504,7 +1504,7 @@ void InstanceBlankTabCreate(EsMessage *message) {
 			// TODO Generic icon and thumbnail cache in the API, based off the one from File Manager?
 
 			size_t fileBytes;
-			void *file = EsFileMap(application->cExecutable, -1, &fileBytes, ES_MAP_OBJECT_READ_ONLY);
+			void *file = EsFileMap(application->cExecutable, -1, &fileBytes, ES_MEMORY_MAP_OBJECT_READ_ONLY);
 			EsBundle bundle = { .base = (const BundleHeader *) file, .bytes = (ptrdiff_t) fileBytes };
 
 			if (file) {
diff --git a/desktop/os.header b/desktop/os.header
index a20fef2..46989d9 100644
--- a/desktop/os.header
+++ b/desktop/os.header
@@ -360,8 +360,6 @@ define ES_REJECTED    (-2)
 define ES_LIST_VIEW_COLUMN_SORT_ASCENDING  (1)
 define ES_LIST_VIEW_COLUMN_SORT_DESCENDING (2)
 
-define ES_MAP_OBJECT_ALL (0)
-
 define ES_TEXT_H_LEFT 	                   (1 <<  0)
 define ES_TEXT_H_CENTER                    (1 <<  1)
 define ES_TEXT_H_RIGHT 	                   (1 <<  2)
@@ -407,9 +405,12 @@ define _ES_NODE_NO_WRITE_BASE		(0x080000)
 
 define ES_DIRECTORY_CHILDREN_UNKNOWN	((EsFileOffsetDifference) (-1))
 
-define ES_MAP_OBJECT_READ_WRITE         (0)
-define ES_MAP_OBJECT_READ_ONLY          (1)
-define ES_MAP_OBJECT_COPY_ON_WRITE      (2)
+define ES_MEMORY_MAP_OBJECT_ALL (0) // Set size to this to map the entire object.
+define ES_MEMORY_MAP_OBJECT_READ_WRITE    (1 << 0)
+define ES_MEMORY_MAP_OBJECT_READ_ONLY     (1 << 1)
+define ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE (1 << 2) // Files only.
+
+define ES_SHARED_MEMORY_READ_WRITE (1 << 0)
 
 define ES_STRING_FORMAT_ENOUGH_SPACE	(-1)
 
@@ -740,6 +741,9 @@ define ES_SCROLL_X_DRAG (1 << 0)
 define ES_SCROLL_Y_DRAG (1 << 1)
 private define ES_SCROLL_MANUAL (1 << 2) // The parent is responsible for updating the position of the scroll bars.
 
+define ES_SUBSYSTEM_ID_NATIVE (0)
+define ES_SUBSYSTEM_ID_POSIX (1)
+
 include desktop/icons.header
 
 enum EsFatalError {
@@ -2101,7 +2105,7 @@ function uint8_t EsMemorySumBytes(uint8_t *data, size_t bytes);
 function void EsMemoryUnreserve(void *pointer, size_t size = 0); // Must cover the entire reserved region. Leave size 0 if you don't know the size.
 function void EsMemoryZero(void *destination, size_t bytes); 
 
-function void *EsObjectMap(EsHandle object, uintptr_t offset, size_t size, unsigned flags); 
+function void *EsMemoryMapObject(EsHandle object, uintptr_t offset, size_t size, uint32_t flags); 
 
 // Standard functions.
 
diff --git a/desktop/posix.cpp b/desktop/posix.cpp
index d3ae675..f16458a 100644
--- a/desktop/posix.cpp
+++ b/desktop/posix.cpp
@@ -697,10 +697,11 @@ void EsPOSIXInitialise(int *argc, char ***argv) {
 
 	// Get the arguments and environment.
 
-	EsHandle environmentHandle = startupInformation->data.environment;
+	EsHandle environmentHandle = startupInformation->data.subsystemData;
 	char *environmentBuffer = (char *) "./application\0\0LANG=en_US.UTF-8\0PWD=/\0HOME=/\0PATH=/Applications/POSIX/bin\0TMPDIR=/Applications/POSIX/tmp\0\0";
 
 	if (environmentHandle) {
+		EsAssert(startupInformation->data.subsystemID == ES_SUBSYSTEM_ID_POSIX);
 		environmentBuffer = (char *) EsHeapAllocate(ARG_MAX, false);
 		EsConstantBufferRead((EsHandle) environmentHandle, environmentBuffer);
 		EsHandleClose((EsHandle) environmentHandle);
diff --git a/desktop/syscall.cpp b/desktop/syscall.cpp
index 6dd7015..3e8f031 100644
--- a/desktop/syscall.cpp
+++ b/desktop/syscall.cpp
@@ -299,7 +299,7 @@ EsHandle EsMemoryShare(EsHandle sharedMemoryRegion, EsHandle targetProcess, bool
 	return EsSyscall(ES_SYSCALL_HANDLE_SHARE, sharedMemoryRegion, targetProcess, readOnly, 0);
 }
 
-void *EsObjectMap(EsHandle sharedMemoryRegion, uintptr_t offset, size_t size, unsigned flags) {
+void *EsMemoryMapObject(EsHandle sharedMemoryRegion, uintptr_t offset, size_t size, unsigned flags) {
 	intptr_t result = EsSyscall(ES_SYSCALL_MEMORY_MAP_OBJECT, sharedMemoryRegion, offset, size, flags);
 
 	if (result >= 0) {
@@ -425,7 +425,7 @@ void *EsFileStoreMap(EsFileStore *file, size_t *fileSize, uint32_t flags) {
 		EsFileOffsetDifference size = EsFileStoreGetSize(file);
 		if (size == -1) return nullptr;
 		*fileSize = size;
-		return EsObjectMap(file->handle, 0, size, flags); 
+		return EsMemoryMapObject(file->handle, 0, size, flags); 
 	} else if (file->type == FILE_STORE_PATH) {
 		return EsFileMap(file->path, file->pathBytes, fileSize, flags);
 	} else if (file->type == FILE_STORE_EMBEDDED_FILE) {
@@ -530,13 +530,13 @@ EsError EsFileDelete(EsHandle handle) {
 
 void *EsFileMap(const char *path, ptrdiff_t pathBytes, size_t *fileSize, uint32_t flags) {
 	EsFileInformation information = EsFileOpen(path, pathBytes, 
-			ES_NODE_FAIL_IF_NOT_FOUND | ((flags & ES_MAP_OBJECT_READ_WRITE) ? ES_FILE_WRITE : ES_FILE_READ));
+			ES_NODE_FAIL_IF_NOT_FOUND | ((flags & ES_MEMORY_MAP_OBJECT_READ_WRITE) ? ES_FILE_WRITE : ES_FILE_READ));
 
 	if (ES_CHECK_ERROR(information.error)) {
 		return nullptr;
 	}
 
-	void *base = EsObjectMap(information.handle, 0, information.size, flags); 
+	void *base = EsMemoryMapObject(information.handle, 0, information.size, flags); 
 	EsHandleClose(information.handle);
 	if (fileSize) *fileSize = information.size;
 	return base;
diff --git a/desktop/text.cpp b/desktop/text.cpp
index fe3d721..99dea7f 100644
--- a/desktop/text.cpp
+++ b/desktop/text.cpp
@@ -758,7 +758,7 @@ Font FontGet(EsFont key) {
 	// EsPrint("Loading font from '%z' (f%d/w%d/i%d).\n", file, key.family, key.weight, key.italic);
 
 	size_t size;
-	void *data = EsFileStoreMap(file, &size, ES_MAP_OBJECT_READ_ONLY);
+	void *data = EsFileStoreMap(file, &size, ES_MEMORY_MAP_OBJECT_READ_ONLY);
 
 	if (!data) {
 		EsPrint("Could not load font (f%d/w%d/i%d).\n", key.family, key.weight, key.italic);
diff --git a/desktop/theme.cpp b/desktop/theme.cpp
index ec431b4..11fccce 100644
--- a/desktop/theme.cpp
+++ b/desktop/theme.cpp
@@ -1312,7 +1312,7 @@ bool ThemeInitialise() {
 		size_t cursorsBitmapBytes;
 		const void *cursorsBitmap = EsBundleFind(&bundleDesktop, EsLiteral("Cursors.png"), &cursorsBitmapBytes);
 		theming.cursorData = EsMemoryCreateShareableRegion(ES_THEME_CURSORS_WIDTH * ES_THEME_CURSORS_HEIGHT * 4);
-		void *destination = EsObjectMap(theming.cursorData, 0, ES_THEME_CURSORS_WIDTH * ES_THEME_CURSORS_HEIGHT * 4, ES_MAP_OBJECT_READ_WRITE);
+		void *destination = EsMemoryMapObject(theming.cursorData, 0, ES_THEME_CURSORS_WIDTH * ES_THEME_CURSORS_HEIGHT * 4, ES_MEMORY_MAP_OBJECT_READ_WRITE);
 		LoadImage(cursorsBitmap, cursorsBitmapBytes, destination, ES_THEME_CURSORS_WIDTH, ES_THEME_CURSORS_HEIGHT, true);
 		EsObjectUnmap(destination);
 	}
@@ -1320,7 +1320,7 @@ bool ThemeInitialise() {
 	theming.cursors.width = ES_THEME_CURSORS_WIDTH;
 	theming.cursors.height = ES_THEME_CURSORS_HEIGHT;
 	theming.cursors.stride = ES_THEME_CURSORS_WIDTH * 4;
-	theming.cursors.bits = EsObjectMap(theming.cursorData, 0, ES_MAP_OBJECT_ALL, ES_MAP_OBJECT_READ_ONLY);
+	theming.cursors.bits = EsMemoryMapObject(theming.cursorData, 0, ES_MEMORY_MAP_OBJECT_ALL, ES_MEMORY_MAP_OBJECT_READ_ONLY);
 	theming.cursors.fullAlpha = true;
 	theming.cursors.readOnly = true;
 
diff --git a/kernel/elf.cpp b/kernel/elf.cpp
index c2bd160..90c704b 100644
--- a/kernel/elf.cpp
+++ b/kernel/elf.cpp
@@ -154,7 +154,7 @@ EsError KLoadELF(KNode *node, KLoadedExecutable *executable) {
 			// Map the bundle file.
 
 			if (!MMMapFile(thisProcess->vmm, (FSFile *) node, 
-					0, fileSize, ES_MAP_OBJECT_READ_ONLY, 
+					0, fileSize, ES_MEMORY_MAP_OBJECT_READ_ONLY, 
 					(uint8_t *) header.mapAddress)) {
 				return ES_ERROR_INSUFFICIENT_RESOURCES;
 			}
@@ -239,7 +239,7 @@ EsError KLoadELF(KNode *node, KLoadedExecutable *executable) {
 
 			success = MMMapFile(thisProcess->vmm, (FSFile *) node, 
 					executableOffset + fileOffset, zeroStart - fileStart, 
-					ES_MAP_OBJECT_COPY_ON_WRITE, 
+					ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE, 
 					(uint8_t *) fileStart, end - zeroStart);
 
 			if (success) {
diff --git a/kernel/memory.cpp b/kernel/memory.cpp
index 0764d79..3d6482d 100644
--- a/kernel/memory.cpp
+++ b/kernel/memory.cpp
@@ -1015,7 +1015,7 @@ void MMUnreserve(MMSpace *space, MMRegion *remove, bool unmapPages, bool guardRe
 }
 
 void *MMMapFile(MMSpace *space, FSFile *node, EsFileOffset offset, size_t bytes, int protection, void *baseAddress, size_t zeroedBytes, uint32_t additionalFlags) {
-	if (protection != ES_MAP_OBJECT_READ_ONLY && protection != ES_MAP_OBJECT_COPY_ON_WRITE) {
+	if (protection != ES_MEMORY_MAP_OBJECT_READ_ONLY && protection != ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE) {
 		return nullptr;
 	}
 
@@ -1025,7 +1025,7 @@ void *MMMapFile(MMSpace *space, FSFile *node, EsFileOffset offset, size_t bytes,
 
 	MMRegion *region = nullptr;
 	uint64_t fileHandleFlags = ES_NODE_PREVENT_RESIZE 
-		| (protection == ES_MAP_OBJECT_READ_WRITE ? ES_FILE_WRITE_SHARED : ES_FILE_READ_SHARED);
+		| (protection == ES_MEMORY_MAP_OBJECT_READ_WRITE ? ES_FILE_WRITE_SHARED : ES_FILE_READ_SHARED);
 	bool decommit = false;
 
 	// Register a handle to the node.
@@ -1056,8 +1056,8 @@ void *MMMapFile(MMSpace *space, FSFile *node, EsFileOffset offset, size_t bytes,
 	// Reserve the region.
 
 	region = MMReserve(space, bytes + zeroedBytes, MM_REGION_FILE | additionalFlags
-			| ((protection == ES_MAP_OBJECT_READ_ONLY || protection == ES_MAP_OBJECT_COPY_ON_WRITE) ? MM_REGION_READ_ONLY : 0)
-			| (protection == ES_MAP_OBJECT_COPY_ON_WRITE ? MM_REGION_COPY_ON_WRITE : 0),
+			| ((protection == ES_MEMORY_MAP_OBJECT_READ_ONLY || protection == ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE) ? MM_REGION_READ_ONLY : 0)
+			| (protection == ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE ? MM_REGION_COPY_ON_WRITE : 0),
 			baseAddress ? (uintptr_t) baseAddress - offsetIntoPage : 0);
 
 	if (!region) {
@@ -1066,7 +1066,7 @@ void *MMMapFile(MMSpace *space, FSFile *node, EsFileOffset offset, size_t bytes,
 
 	// Commit copy on write regions.
 
-	if (protection == ES_MAP_OBJECT_COPY_ON_WRITE) {
+	if (protection == ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE) {
 		if (!MMCommit(bytes + zeroedBytes, false)) {
 			goto fail;
 		}
diff --git a/kernel/objects.cpp b/kernel/objects.cpp
index 41fa53b..08344fe 100644
--- a/kernel/objects.cpp
+++ b/kernel/objects.cpp
@@ -373,7 +373,7 @@ uintptr_t HandleShare(Handle share, Process *process, uint32_t mode, EsHandle at
 	// TODO Sort out flag modes.
 
 	if (share.type == KERNEL_OBJECT_SHMEM) {
-		sharedFlags = mode; 
+		sharedFlags &= mode;
 	} else if (share.type == KERNEL_OBJECT_NODE) {
 		sharedFlags = (mode & 1) && (share.flags & (ES_FILE_WRITE_SHARED | ES_FILE_WRITE)) ? ES_FILE_READ_SHARED : share.flags;
 		if (mode & 2) sharedFlags &= ~_ES_NODE_DIRECTORY_WRITE;
diff --git a/kernel/scheduler.cpp b/kernel/scheduler.cpp
index b7c5952..eb240b0 100644
--- a/kernel/scheduler.cpp
+++ b/kernel/scheduler.cpp
@@ -762,9 +762,10 @@ void ProcessLoadExecutable() {
 			startupInformation->tlsBytes = application.tlsBytes;
 			startupInformation->timeStampTicksPerMs = timeStampTicksPerMs;
 
-			if (OpenHandleToObject(mmGlobalDataRegion, KERNEL_OBJECT_SHMEM, ES_FLAGS_DEFAULT)) {
-				// TODO Write protection.
-				startupInformation->globalDataRegion = thisProcess->handleTable.OpenHandle(mmGlobalDataRegion, ES_FLAGS_DEFAULT, KERNEL_OBJECT_SHMEM);
+			uint32_t globalDataRegionFlags = thisProcess->type == PROCESS_DESKTOP ? ES_SHARED_MEMORY_READ_WRITE : ES_FLAGS_DEFAULT;
+
+			if (OpenHandleToObject(mmGlobalDataRegion, KERNEL_OBJECT_SHMEM, globalDataRegionFlags)) {
+				startupInformation->globalDataRegion = thisProcess->handleTable.OpenHandle(mmGlobalDataRegion, globalDataRegionFlags, KERNEL_OBJECT_SHMEM);
 			}
 
 			EsMemoryCopy(&startupInformation->data, &thisProcess->data, sizeof(EsProcessCreateData));
diff --git a/kernel/syscall.cpp b/kernel/syscall.cpp
index 7525566..e55b2f1 100644
--- a/kernel/syscall.cpp
+++ b/kernel/syscall.cpp
@@ -63,7 +63,7 @@ SYSCALL_IMPLEMENT(ES_SYSCALL_MEMORY_ALLOCATE) {
 		if (argument0 > ES_SHARED_MEMORY_MAXIMUM_SIZE) SYSCALL_RETURN(ES_FATAL_ERROR_OUT_OF_RANGE, true);
 		MMSharedRegion *region = MMSharedCreateRegion(argument0, false, 0);
 		if (!region) SYSCALL_RETURN(ES_ERROR_INSUFFICIENT_RESOURCES, false);
-		SYSCALL_RETURN(currentProcess->handleTable.OpenHandle(region, 0, KERNEL_OBJECT_SHMEM), false);
+		SYSCALL_RETURN(currentProcess->handleTable.OpenHandle(region, ES_SHARED_MEMORY_READ_WRITE, KERNEL_OBJECT_SHMEM), false);
 	} else {
 		EsMemoryProtection protection = (EsMemoryProtection) argument2;
 		uint32_t flags = MM_REGION_USER;
@@ -546,22 +546,33 @@ SYSCALL_IMPLEMENT(ES_SYSCALL_THREAD_CREATE) {
 SYSCALL_IMPLEMENT(ES_SYSCALL_MEMORY_MAP_OBJECT) {
 	SYSCALL_HANDLE_2(argument0, (KernelObjectType) (KERNEL_OBJECT_SHMEM | KERNEL_OBJECT_NODE), object);
 
+	if (((argument3 & ES_MEMORY_MAP_OBJECT_READ_WRITE) ? 1 : 0)
+			+ ((argument3 & ES_MEMORY_MAP_OBJECT_READ_ONLY) ? 1 : 0)
+			+ ((argument3 & ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE) ? 1 : 0) != 1) {
+		SYSCALL_RETURN(ES_FATAL_ERROR_INCORRECT_FILE_ACCESS, true);
+	}
+
 	if (object.type == KERNEL_OBJECT_SHMEM) {
-		// TODO Access permissions and modes.
 		MMSharedRegion *region = (MMSharedRegion *) object.object;
 
-		if (argument2 == ES_MAP_OBJECT_ALL) {
+		if (argument2 == ES_MEMORY_MAP_OBJECT_ALL) {
 			argument2 = region->sizeBytes;
 		}
 
-		uintptr_t address = (uintptr_t) MMMapShared(currentVMM, region, argument1, argument2, MM_REGION_USER);
+		if ((argument3 == ES_MEMORY_MAP_OBJECT_READ_WRITE && (~object.flags & ES_SHARED_MEMORY_READ_WRITE))
+				|| argument3 == ES_MEMORY_MAP_OBJECT_COPY_ON_WRITE) {
+			SYSCALL_RETURN(ES_FATAL_ERROR_INSUFFICIENT_PERMISSIONS, true);
+		}
+
+		uint32_t flags = MM_REGION_USER | ((argument3 & ES_MEMORY_MAP_OBJECT_READ_ONLY) ? MM_REGION_READ_ONLY : 0);
+		uintptr_t address = (uintptr_t) MMMapShared(currentVMM, region, argument1 /* offset */, argument2 /* bytes */, flags);
 		SYSCALL_RETURN(address, false);
 	} else if (object.type == KERNEL_OBJECT_NODE) {
 		KNode *file = (KNode *) object.object;
 
 		if (file->directoryEntry->type != ES_NODE_FILE) SYSCALL_RETURN(ES_FATAL_ERROR_INCORRECT_NODE_TYPE, true);
 
-		if (argument3 == ES_MAP_OBJECT_READ_WRITE) {
+		if (argument3 == ES_MEMORY_MAP_OBJECT_READ_WRITE) {
 			if (!(object.flags & (ES_FILE_WRITE_SHARED | ES_FILE_WRITE))) {
 				SYSCALL_RETURN(ES_FATAL_ERROR_INCORRECT_FILE_ACCESS, true);
 			}
@@ -571,7 +582,7 @@ SYSCALL_IMPLEMENT(ES_SYSCALL_MEMORY_MAP_OBJECT) {
 			}
 		}
 
-		if (argument2 == ES_MAP_OBJECT_ALL) {
+		if (argument2 == ES_MEMORY_MAP_OBJECT_ALL) {
 			argument2 = file->directoryEntry->totalSize;
 		}
 
diff --git a/util/api_table.ini b/util/api_table.ini
index 3303013..51a6db8 100644
--- a/util/api_table.ini
+++ b/util/api_table.ini
@@ -91,7 +91,7 @@ EsMemoryCreateShareableRegion=89
 EsMemoryShare=90
 EsMemorySumBytes=91
 EsMemoryZero=92
-EsObjectMap=93
+EsMemoryMapObject=93
 EsAssertionFailure=94
 EsDrawInvert=95
 EsFileControl=96