BAN/include/BAN/HashMap.h

@@ -52,14 +52,11 @@ namespace BAN
 		ErrorOr<void> reserve(size_type);
 
 		void remove(const Key&);
-		void remove(iterator it);
 		void clear();
 
 		T& operator[](const Key&);
 		const T& operator[](const Key&) const;
 
-		iterator find(const Key& key);
-		const_iterator find(const Key& key) const;
 		bool contains(const Key&) const;
 
 		bool empty() const;
@@ -69,8 +66,6 @@ namespace BAN
 		ErrorOr<void> rebucket(size_type);
 		LinkedList<Entry>& get_bucket(const Key&);
 		const LinkedList<Entry>& get_bucket(const Key&) const;
-		Vector<LinkedList<Entry>>::iterator get_bucket_iterator(const Key&);
-		Vector<LinkedList<Entry>>::const_iterator get_bucket_iterator(const Key&) const;
 
 	private:
 		Vector<LinkedList<Entry>> m_buckets;
@@ -150,16 +145,17 @@ namespace BAN
 	template<typename Key, typename T, typename HASH>
 	void HashMap<Key, T, HASH>::remove(const Key& key)
 	{
-		auto it = find(key);
-		if (it != end())
-			remove(it);
-	}
-
-	template<typename Key, typename T, typename HASH>
-	void HashMap<Key, T, HASH>::remove(iterator it)
-	{
-		it.outer_current()->remove(it.inner_current());
-		m_size--;
+		if (empty()) return;
+		auto& bucket = get_bucket(key);
+		for (auto it = bucket.begin(); it != bucket.end(); it++)
+		{
+			if (it->key == key)
+			{
+				bucket.remove(it);
+				m_size--;
+				return;
+			}
+		}
 	}
 
 	template<typename Key, typename T, typename HASH>
@@ -191,34 +187,15 @@ namespace BAN
 		ASSERT(false);
 	}
 
-	template<typename Key, typename T, typename HASH>
-	typename HashMap<Key, T, HASH>::iterator HashMap<Key, T, HASH>::find(const Key& key)
-	{
-		if (empty())
-			return end();
-		auto bucket_it = get_bucket_iterator(key);
-		for (auto it = bucket_it->begin(); it != bucket_it->end(); it++)
-			if (it->key == key)
-				return iterator(m_buckets.end(), bucket_it, it);
-		return end();
-	}
-
-	template<typename Key, typename T, typename HASH>
-	typename HashMap<Key, T, HASH>::const_iterator HashMap<Key, T, HASH>::find(const Key& key) const
-	{
-		if (empty())
-			return end();
-		auto bucket_it = get_bucket_iterator(key);
-		for (auto it = bucket_it->begin(); it != bucket_it->end(); it++)
-			if (it->key == key)
-				return const_iterator(m_buckets.end(), bucket_it, it);
-		return end();
-	}
-
 	template<typename Key, typename T, typename HASH>
 	bool HashMap<Key, T, HASH>::contains(const Key& key) const
 	{
-		return find(key) != end();
+		if (empty()) return false;
+		const auto& bucket = get_bucket(key);
+		for (const Entry& entry : bucket)
+			if (entry.key == key)
+				return true;
+		return false;
 	}
 
 	template<typename Key, typename T, typename HASH>
@@ -259,29 +236,17 @@ namespace BAN
 	template<typename Key, typename T, typename HASH>
 	LinkedList<typename HashMap<Key, T, HASH>::Entry>& HashMap<Key, T, HASH>::get_bucket(const Key& key)
 	{
-		return *get_bucket_iterator(key);
+		ASSERT(!m_buckets.empty());
+		auto index = HASH()(key) % m_buckets.size();
+		return m_buckets[index];
 	}
 
 	template<typename Key, typename T, typename HASH>
 	const LinkedList<typename HashMap<Key, T, HASH>::Entry>& HashMap<Key, T, HASH>::get_bucket(const Key& key) const
-	{
-		return *get_bucket_iterator(key);
-	}
-
-	template<typename Key, typename T, typename HASH>
-	Vector<LinkedList<typename HashMap<Key, T, HASH>::Entry>>::iterator HashMap<Key, T, HASH>::get_bucket_iterator(const Key& key)
 	{
 		ASSERT(!m_buckets.empty());
 		auto index = HASH()(key) % m_buckets.size();
-		return next(m_buckets.begin(), index);
-	}
-
-	template<typename Key, typename T, typename HASH>
-	Vector<LinkedList<typename HashMap<Key, T, HASH>::Entry>>::const_iterator HashMap<Key, T, HASH>::get_bucket_iterator(const Key& key) const
-	{
-		ASSERT(!m_buckets.empty());
-		auto index = HASH()(key) % m_buckets.size();
-		return next(m_buckets.begin(), index);
+		return m_buckets[index];
 	}
 
 }

BAN/include/BAN/Iterators.h

@@ -284,14 +284,6 @@ namespace BAN
 			}
 		}
 
-		IteratorDoubleGeneral(const OuterIterator& outer_end, const OuterIterator& outer_current, const InnerIterator& inner_current)
-			: m_outer_end(outer_end)
-			, m_outer_current(outer_current)
-			, m_inner_current(inner_current)
-		{
-			find_valid_or_end();
-		}
-
 		void find_valid_or_end()
 		{
 			while (m_inner_current == m_outer_current->end())
@@ -303,9 +295,6 @@ namespace BAN
 			}
 		}
 
-		OuterIterator outer_current() { return m_outer_current; }
-		InnerIterator inner_current() { return m_inner_current; }
-
 	private:
 		OuterIterator m_outer_end;
 		OuterIterator m_outer_current;

LibELF/LibELF/ELF.cpp

@@ -25,7 +25,7 @@ namespace LibELF
 		BAN::Vector<uint8_t> buffer;
 		TRY(buffer.resize(inode->size()));
 
-		TRY(inode->read(0, buffer.data(), inode->size()));
+		TRY(inode->read(0, { buffer.data(), inode->size() }));
 
 		ELF* elf_ptr = new ELF(BAN::move(buffer));
 		if (elf_ptr == nullptr)

LibELF/LibELF/LoadableELF.cpp

@@ -1,5 +1,4 @@
 #include <BAN/ScopeGuard.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Lock/LockGuard.h>
 #include <LibELF/LoadableELF.h>
@@ -282,6 +281,10 @@ namespace LibELF
 
 		elf->reserve_address_space();
 
+		ASSERT(&PageTable::current() == &m_page_table);
+		LockGuard _(m_page_table);
+		ASSERT(m_page_table.is_page_free(0));
+
 		for (const auto& program_header : m_program_headers)
 		{
 			switch (program_header.p_type)

kernel/CMakeLists.txt

@@ -42,7 +42,6 @@ set(KERNEL_SOURCES
 	kernel/Input/PS2/Mouse.cpp
 	kernel/InterruptController.cpp
 	kernel/kernel.cpp
-	kernel/Lock/SpinLock.cpp
 	kernel/Memory/DMARegion.cpp
 	kernel/Memory/FileBackedRegion.cpp
 	kernel/Memory/Heap.cpp
@@ -69,6 +68,8 @@ set(KERNEL_SOURCES
 	kernel/Random.cpp
 	kernel/Scheduler.cpp
 	kernel/Semaphore.cpp
+	kernel/Lock/Mutex.cpp
+	kernel/Lock/SpinLock.cpp
 	kernel/SSP.cpp
 	kernel/Storage/ATA/AHCI/Controller.cpp
 	kernel/Storage/ATA/AHCI/Device.cpp

kernel/arch/x86_64/PageTable.cpp

@@ -1,7 +1,7 @@
 #include <kernel/Arch.h>
 #include <kernel/CPUID.h>
 #include <kernel/InterruptController.h>
-#include <kernel/Lock/SpinLock.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/kmalloc.h>
 #include <kernel/Memory/PageTable.h>
 
@@ -17,13 +17,13 @@ extern uint8_t g_userspace_end[];
 namespace Kernel
 {
 
-	SpinLock PageTable::s_fast_page_lock;
-
 	static PageTable* s_kernel = nullptr;
 	static PageTable* s_current = nullptr;
 	static bool s_has_nxe = false;
 	static bool s_has_pge = false;
 
+	SpinLock PageTable::s_fast_page_lock;
+
 	// PML4 entry for kernel memory
 	static paddr_t s_global_pml4e = 0;
 
@@ -252,7 +252,7 @@ namespace Kernel
 
 	BAN::ErrorOr<PageTable*> PageTable::create_userspace()
 	{
-		SpinLockGuard _(s_kernel->m_lock);
+		LockGuard _(s_kernel->m_lock);
 		PageTable* page_table = new PageTable;
 		if (page_table == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
@@ -333,7 +333,7 @@ namespace Kernel
 		uint64_t pde   = (uc_vaddr >> 21) & 0x1FF;
 		uint64_t pte   = (uc_vaddr >> 12) & 0x1FF;
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 
 		if (is_page_free(vaddr))
 		{
@@ -355,7 +355,7 @@ namespace Kernel
 		vaddr_t s_page = vaddr / PAGE_SIZE;
 		vaddr_t e_page = BAN::Math::div_round_up<vaddr_t>(vaddr + size, PAGE_SIZE);
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		for (vaddr_t page = s_page; page < e_page; page++)
 			unmap_page(page * PAGE_SIZE);
 	}
@@ -394,7 +394,7 @@ namespace Kernel
 		// NOTE: we add present here, since it has to be available in higher level structures
 		flags_t uwr_flags = (flags & (Flags::UserSupervisor | Flags::ReadWrite)) | Flags::Present;
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 
 		uint64_t* pml4 = (uint64_t*)P2V(m_highest_paging_struct);
 		if ((pml4[pml4e] & uwr_flags) != uwr_flags)
@@ -439,7 +439,7 @@ namespace Kernel
 
 		size_t page_count = range_page_count(vaddr, size);
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		for (size_t page = 0; page < page_count; page++)
 			map_page_at(paddr + page * PAGE_SIZE, vaddr + page * PAGE_SIZE, flags);
 	}
@@ -456,7 +456,7 @@ namespace Kernel
 		uint64_t pde   = (uc_vaddr >> 21) & 0x1FF;
 		uint64_t pte   = (uc_vaddr >> 12) & 0x1FF;
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 
 		uint64_t* pml4 = (uint64_t*)P2V(m_highest_paging_struct);
 		if (!(pml4[pml4e] & Flags::Present))
@@ -490,7 +490,7 @@ namespace Kernel
 
 	bool PageTable::reserve_page(vaddr_t vaddr, bool only_free)
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		ASSERT(vaddr % PAGE_SIZE == 0);
 		if (only_free && !is_page_free(vaddr))
 			return false;
@@ -504,7 +504,7 @@ namespace Kernel
 			bytes += PAGE_SIZE - rem;
 		ASSERT(vaddr % PAGE_SIZE == 0);
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		if (only_free && !is_range_free(vaddr, bytes))
 			return false;
 		for (size_t offset = 0; offset < bytes; offset += PAGE_SIZE)
@@ -536,7 +536,7 @@ namespace Kernel
 		const uint16_t e_pde   = (uc_vaddr_end >> 21) & 0x1FF;
 		const uint16_t e_pte   = (uc_vaddr_end >> 12) & 0x1FF;
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 
 		// Try to find free page that can be mapped without
 		// allocations (page table with unused entries)
@@ -609,7 +609,7 @@ namespace Kernel
 		ASSERT(is_canonical(first_address));
 		ASSERT(is_canonical(last_address));
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 
 		for (vaddr_t vaddr = first_address; vaddr < last_address;)
 		{
@@ -650,7 +650,7 @@ namespace Kernel
 		vaddr_t s_page = vaddr / PAGE_SIZE;
 		vaddr_t e_page = BAN::Math::div_round_up<vaddr_t>(vaddr + size, PAGE_SIZE);
 
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		for (vaddr_t page = s_page; page < e_page; page++)
 			if (!is_page_free(page * PAGE_SIZE))
 				return false;
@@ -673,7 +673,7 @@ namespace Kernel
 
 	void PageTable::debug_dump()
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 
 		flags_t flags = 0;
 		vaddr_t start = 0;

kernel/icxxabi.cpp

@@ -1,4 +1,3 @@
-#include <BAN/Atomic.h>
 #include <kernel/Panic.h>
 
 #define ATEXIT_MAX_FUNCS 128
@@ -114,18 +113,18 @@ void __cxa_finalize(void *f)
 
 namespace __cxxabiv1
 {
-	using __guard = uint64_t;
+
+	/* The ABI requires a 64-bit type.  */
+	__extension__ typedef int __guard __attribute__((mode(__DI__)));
 
 	int __cxa_guard_acquire (__guard* g)
 	{
-		auto& atomic = *reinterpret_cast<BAN::Atomic<__guard>*>(g);
-		return atomic == 0;
+		return !*(int*)g;
 	}
 
 	void __cxa_guard_release (__guard* g)
 	{
-		auto& atomic = *reinterpret_cast<BAN::Atomic<__guard>*>(g);
-		atomic = 1;
+		*(int*)g = 1;
 	}
 
 	void __cxa_guard_abort (__guard*)

kernel/include/kernel/APIC.h

@@ -2,6 +2,7 @@
 
 #include <BAN/Vector.h>
 #include <kernel/InterruptController.h>
+#include <kernel/Lock/SpinLock.h>
 #include <kernel/Memory/Types.h>
 
 namespace Kernel
@@ -58,6 +59,7 @@ namespace Kernel
 		BAN::Vector<IOAPIC>		m_io_apics;
 		uint8_t					m_irq_overrides[0x100] {};
 		uint8_t					m_reserved_gsis[0x100 / 8] {};
+		SpinLock				m_lock;
 	};
 
 }

kernel/include/kernel/CriticalScope.h

@@ -1,30 +0,0 @@
-#pragma once
-
-#include <BAN/NoCopyMove.h>
-
-#include <stddef.h>
-
-namespace Kernel
-{
-
-	class CriticalScope
-	{
-		BAN_NON_COPYABLE(CriticalScope);
-		BAN_NON_MOVABLE(CriticalScope);
-
-	public:
-		CriticalScope()
-		{
-			asm volatile("pushf; cli; pop %0" : "=r"(m_flags) :: "memory");
-		}
-
-		~CriticalScope()
-		{
-			asm volatile("push %0; popf" :: "rm"(m_flags) : "memory", "cc");
-		}
-
-	private:
-		size_t m_flags;
-	};
-
-}

kernel/include/kernel/Debug.h

@@ -5,26 +5,29 @@
 
 #define dprintln(...)										\
 	do {													\
-		Kernel::SpinLockGuard _(Debug::s_debug_lock);		\
+		Debug::s_debug_lock.lock();							\
 		Debug::print_prefix(__FILE__, __LINE__);			\
 		BAN::Formatter::print(Debug::putchar, __VA_ARGS__);	\
 		BAN::Formatter::print(Debug::putchar, "\r\n");		\
+		Debug::s_debug_lock.unlock();						\
 	} while(false)
 
 #define dwarnln(...)										\
 	do {													\
-		Kernel::SpinLockGuard _(Debug::s_debug_lock);		\
+		Debug::s_debug_lock.lock();							\
 		BAN::Formatter::print(Debug::putchar, "\e[33m");	\
 		dprintln(__VA_ARGS__);								\
 		BAN::Formatter::print(Debug::putchar, "\e[m");		\
+		Debug::s_debug_lock.unlock();						\
 	} while(false)
 
 #define derrorln(...)										\
 	do {													\
-		Kernel::SpinLockGuard _(Debug::s_debug_lock);		\
+		Debug::s_debug_lock.lock();							\
 		BAN::Formatter::print(Debug::putchar, "\e[31m");	\
 		dprintln(__VA_ARGS__);								\
 		BAN::Formatter::print(Debug::putchar, "\e[m");		\
+		Debug::s_debug_lock.unlock();						\
 	} while(false)
 
 #define dprintln_if(cond, ...)		\

kernel/include/kernel/FS/DevFS/FileSystem.h

@@ -3,7 +3,6 @@
 #include <BAN/Vector.h>
 #include <kernel/Device/Device.h>
 #include <kernel/FS/TmpFS/FileSystem.h>
-#include <kernel/Lock/Mutex.h>
 #include <kernel/Semaphore.h>
 
 namespace Kernel

kernel/include/kernel/FS/Inode.h

@@ -9,7 +9,6 @@
 
 #include <kernel/API/DirectoryEntry.h>
 #include <kernel/Credentials.h>
-#include <kernel/Debug.h>
 #include <kernel/Lock/Mutex.h>
 
 #include <sys/socket.h>
@@ -158,7 +157,7 @@ namespace Kernel
 		virtual BAN::ErrorOr<long> ioctl_impl(int request, void* arg)		{ return BAN::Error::from_errno(ENOTSUP); }
 
 	protected:
-		mutable PriorityMutex m_mutex;
+		mutable Mutex m_mutex;
 
 	private:
 		BAN::WeakPtr<SharedFileData> m_shared_region;

kernel/include/kernel/Input/KeyboardLayout.h

@@ -20,6 +20,8 @@ namespace Kernel::Input
 		KeyboardLayout();
 
 	private:
+		SpinLock m_lock;
+
 		BAN::Array<Key, 0xFF> m_keycode_to_key_normal;
 		BAN::Array<Key, 0xFF> m_keycode_to_key_shift;
 		BAN::Array<Key, 0xFF> m_keycode_to_key_altgr;

kernel/include/kernel/Input/PS2/Controller.h

@@ -5,7 +5,6 @@
 #include <kernel/Device/Device.h>
 #include <kernel/Input/PS2/Config.h>
 #include <kernel/InterruptController.h>
-#include <kernel/Lock/Mutex.h>
 
 namespace Kernel::Input
 {
@@ -61,6 +60,7 @@ namespace Kernel::Input
 	private:
 		BAN::RefPtr<PS2Device> m_devices[2];
 		Mutex m_mutex;
+		RecursiveSpinLock m_cmd_lock;
 
 		BAN::CircularQueue<Command, 128> m_command_queue;
 		uint64_t m_command_send_time { 0 };

kernel/include/kernel/Input/PS2/Keyboard.h

@@ -45,6 +45,7 @@ namespace Kernel::Input
 		PS2Keymap m_keymap;
 
 		Semaphore m_semaphore;
+		SpinLock m_event_lock;
 
 	protected:
 		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;

kernel/include/kernel/Input/PS2/Mouse.h

@@ -38,6 +38,7 @@ namespace Kernel::Input
 
 		BAN::CircularQueue<MouseEvent, 128> m_event_queue;
 
+		SpinLock m_event_lock;
 		Semaphore m_semaphore;
 
 	protected:

kernel/include/kernel/InterruptController.h

@@ -51,11 +51,6 @@ namespace Kernel
 		bool m_using_apic { false };
 	};
 
-	inline bool interrupts_enabled()
-	{
-		uintptr_t flags;
-		asm volatile("pushf; pop %0" : "=r"(flags) :: "memory");
-		return flags & (1 << 9);
-	}
+	bool interrupts_enabled();
 
 }

kernel/include/kernel/Lock/Mutex.h

@@ -2,7 +2,6 @@
 
 #include <BAN/Atomic.h>
 #include <BAN/NoCopyMove.h>
-#include <kernel/Scheduler.h>
 
 #include <sys/types.h>
 
@@ -17,49 +16,17 @@ namespace Kernel
 	public:
 		Mutex() = default;
 
-		void lock()
-		{
-			auto tid = Scheduler::current_tid();
-			if (tid == m_locker)
-				ASSERT_GT(m_lock_depth, 0);
-			else
-			{
-				while (!m_locker.compare_exchange(-1, tid))
-					Scheduler::get().reschedule();
-				ASSERT_EQ(m_lock_depth, 0);
-			}
-			m_lock_depth++;
-		}
-
-		bool try_lock()
-		{
-			auto tid = Scheduler::current_tid();
-			if (tid == m_locker)
-				ASSERT_GT(m_lock_depth, 0);
-			else
-			{
-				if (!m_locker.compare_exchange(-1, tid))
-					return false;
-				ASSERT_EQ(m_lock_depth, 0);
-			}
-			m_lock_depth++;
-		}
-
-		void unlock()
-		{
-			ASSERT_EQ(m_locker.load(), Scheduler::current_tid());
-			ASSERT_GT(m_lock_depth, 0);
-			if (--m_lock_depth == 0)
-				m_locker = -1;
-		}
+		void lock();
+		bool try_lock();
+		void unlock();
 
 		pid_t locker() const { return m_locker; }
 		bool is_locked() const { return m_locker != -1; }
 		uint32_t lock_depth() const { return m_lock_depth; }
 
 	private:
-		BAN::Atomic<pid_t>	m_locker		{ -1 };
-		uint32_t			m_lock_depth	{  0 };
+		BAN::Atomic<pid_t> m_locker { -1 };
+		uint32_t m_lock_depth { 0 };
 	};
 
 	class PriorityMutex
@@ -70,62 +37,18 @@ namespace Kernel
 	public:
 		PriorityMutex() = default;
 
-		void lock()
-		{
-			auto tid = Scheduler::current_tid();
-			if (tid == m_locker)
-				ASSERT_GT(m_lock_depth, 0);
-			else
-			{
-				bool has_priority = tid ? !Thread::current().is_userspace() : true;
-				if (has_priority)
-					m_queue_length++;
-				while (!(has_priority || m_queue_length == 0) || !m_locker.compare_exchange(-1, tid))
-					Scheduler::get().reschedule();
-				ASSERT_EQ(m_lock_depth, 0);
-			}
-			m_lock_depth++;
-		}
-
-		bool try_lock()
-		{
-			auto tid = Scheduler::current_tid();
-			if (tid == m_locker)
-				ASSERT_GT(m_lock_depth, 0);
-			else
-			{
-				bool has_priority = tid ? !Thread::current().is_userspace() : true;
-				if (!(has_priority || m_queue_length == 0) || !m_locker.compare_exchange(-1, tid))
-					return false;
-				if (has_priority)
-					m_queue_length++;
-				ASSERT_EQ(m_lock_depth, 0);
-			}
-			m_lock_depth++;
-		}
-
-		void unlock()
-		{
-			auto tid = Scheduler::current_tid();
-			ASSERT_EQ(m_locker.load(), tid);
-			ASSERT_GT(m_lock_depth, 0);
-			if (--m_lock_depth == 0)
-			{
-				bool has_priority = tid ? !Thread::current().is_userspace() : true;
-				if (has_priority)
-					m_queue_length--;
-				m_locker = -1;
-			}
-		}
+		void lock();
+		bool try_lock();
+		void unlock();
 
 		pid_t locker() const { return m_locker; }
 		bool is_locked() const { return m_locker != -1; }
 		uint32_t lock_depth() const { return m_lock_depth; }
 
 	private:
-		BAN::Atomic<pid_t>		m_locker		{ -1 };
-		uint32_t				m_lock_depth	{  0 };
-		BAN::Atomic<uint32_t>	m_queue_length	{  0 };
+		BAN::Atomic<pid_t> m_locker { -1 };
+		uint32_t m_lock_depth { 0 };
+		BAN::Atomic<uint32_t> m_queue_depth { 0 };
 	};
 
 }

kernel/include/kernel/Lock/SpinLock.h

@@ -8,8 +8,6 @@
 namespace Kernel
 {
 
-	using InterruptState = bool;
-
 	class SpinLock
 	{
 		BAN_NON_COPYABLE(SpinLock);
@@ -18,11 +16,17 @@ namespace Kernel
 	public:
 		SpinLock() = default;
 
-		InterruptState lock();
-		void unlock(InterruptState state);
+		void lock();
+		bool try_lock();
+		void unlock();
+
+		pid_t locker() const { return m_locker; }
+		bool is_locked() const { return m_locker != -1; }
+		uint32_t lock_depth() const { return is_locked(); }
 
 	private:
 		BAN::Atomic<pid_t> m_locker { -1 };
+		uintptr_t m_flags { 0 };
 	};
 
 	class RecursiveSpinLock
@@ -33,35 +37,18 @@ namespace Kernel
 	public:
 		RecursiveSpinLock() = default;
 
-		InterruptState lock();
-		void unlock(InterruptState state);
+		void lock();
+		bool try_lock();
+		void unlock();
+
+		pid_t locker() const { return m_locker; }
+		bool is_locked() const { return m_locker != -1; }
+		uint32_t lock_depth() const { return m_lock_depth; }
 
 	private:
 		BAN::Atomic<pid_t> m_locker { -1 };
 		uint32_t m_lock_depth { 0 };
-	};
-
-	template<typename Lock>
-	class SpinLockGuard
-	{
-		BAN_NON_COPYABLE(SpinLockGuard);
-		BAN_NON_MOVABLE(SpinLockGuard);
-
-	public:
-		SpinLockGuard(Lock& lock)
-			: m_lock(lock)
-		{
-			m_state = m_lock.lock();
-		}
-
-		~SpinLockGuard()
-		{
-			m_lock.unlock(m_state);
-		}
-
-	private:
-		Lock& m_lock;
-		InterruptState m_state;
+		uintptr_t m_flags { 0 };
 	};
 
 }

kernel/include/kernel/Memory/PageTable.h

@@ -2,7 +2,6 @@
 
 #include <BAN/Errors.h>
 #include <BAN/Traits.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/Lock/SpinLock.h>
 #include <kernel/Memory/Types.h>
 
@@ -43,27 +42,30 @@ namespace Kernel
 		static PageTable& kernel();
 		static PageTable& current();
 
-		static constexpr vaddr_t fast_page() { return KERNEL_OFFSET; }
-
+	public:
 		template<with_fast_page_callback F>
 		static void with_fast_page(paddr_t paddr, F callback)
 		{
-			SpinLockGuard _(s_fast_page_lock);
+			s_fast_page_lock.lock();
 			map_fast_page(paddr);
 			callback();
 			unmap_fast_page();
+			s_fast_page_lock.unlock();
 		}
 
 		template<with_fast_page_callback_error F>
 		static BAN::ErrorOr<void> with_fast_page(paddr_t paddr, F callback)
 		{
-			SpinLockGuard _(s_fast_page_lock);
+			s_fast_page_lock.lock();
 			map_fast_page(paddr);
 			auto ret = callback();
 			unmap_fast_page();
+			s_fast_page_lock.unlock();
 			return ret;
 		}
 
+		static constexpr vaddr_t fast_page() { return KERNEL_OFFSET; }
+
 		// FIXME: implement sized checks, return span, etc
 		static void* fast_page_as_ptr(size_t offset = 0)
 		{
@@ -111,8 +113,8 @@ namespace Kernel
 
 		void load();
 
-		InterruptState lock() const { return m_lock.lock(); }
-		void unlock(InterruptState state) const { m_lock.unlock(state); }
+		void lock() const { m_lock.lock(); }
+		void unlock() const { m_lock.unlock(); }
 
 		void debug_dump();
 

kernel/include/kernel/Memory/VirtualRange.h

@@ -18,6 +18,8 @@ namespace Kernel
 		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_to_vaddr(PageTable&, vaddr_t, size_t, PageTable::flags_t flags, bool preallocate_pages);
 		// Create virtual range to virtual address range
 		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_to_vaddr_range(PageTable&, vaddr_t vaddr_start, vaddr_t vaddr_end, size_t, PageTable::flags_t flags, bool preallocate_pages);
+		// Create virtual range in kernel memory with kmalloc
+		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_kmalloc(size_t);
 		~VirtualRange();
 
 		BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> clone(PageTable&);
@@ -33,13 +35,14 @@ namespace Kernel
 		void copy_from(size_t offset, const uint8_t* buffer, size_t bytes);
 
 	private:
-		VirtualRange(PageTable&, bool preallocated);
+		VirtualRange(PageTable&, bool preallocated, bool kmalloc);
 
 		void set_zero();
 
 	private:
 		PageTable&				m_page_table;
 		const bool				m_preallocated;
+		const bool				m_kmalloc;
 		vaddr_t					m_vaddr { 0 };
 		size_t					m_size { 0 };
 		PageTable::flags_t		m_flags { 0 };

kernel/include/kernel/Networking/ARPTable.h

@@ -51,6 +51,7 @@ namespace Kernel
 		};
 
 	private:
+		SpinLock m_pending_lock;
 		SpinLock m_table_lock;
 
 		BAN::HashMap<BAN::IPv4Address, BAN::MACAddress> m_arp_table;

kernel/include/kernel/Networking/E1000/E1000.h

@@ -67,6 +67,8 @@ namespace Kernel
 		bool							m_has_eerprom { false };
 
 	private:
+		SpinLock m_lock;
+
 		BAN::UniqPtr<DMARegion>	m_rx_buffer_region;
 		BAN::UniqPtr<DMARegion>	m_tx_buffer_region;
 		BAN::UniqPtr<DMARegion>	m_rx_descriptor_region;

kernel/include/kernel/Networking/IPv4Layer.h

@@ -67,7 +67,8 @@ namespace Kernel
 		};
 
 	private:
-		RecursiveSpinLock		m_bound_socket_lock;
+		RecursiveSpinLock m_packet_lock;
+		RecursiveSpinLock m_socket_lock;
 
 		BAN::UniqPtr<ARPTable>	m_arp_table;
 		Process*				m_process { nullptr };

kernel/include/kernel/Networking/TCPSocket.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include <BAN/Endianness.h>
-#include <kernel/Lock/Mutex.h>
 #include <kernel/Memory/VirtualRange.h>
 #include <kernel/Networking/NetworkInterface.h>
 #include <kernel/Networking/NetworkSocket.h>
@@ -120,8 +119,7 @@ namespace Kernel
 
 		uint64_t m_time_wait_start_ms { 0 };
 
-		Mutex		m_lock;
-		Semaphore	m_semaphore;
+		Semaphore m_semaphore;
 
 		BAN::Atomic<bool> m_should_ack { false };
 

kernel/include/kernel/Networking/UDPSocket.h

@@ -2,7 +2,6 @@
 
 #include <BAN/CircularQueue.h>
 #include <BAN/Endianness.h>
-#include <kernel/Lock/SpinLock.h>
 #include <kernel/Memory/VirtualRange.h>
 #include <kernel/Networking/NetworkInterface.h>
 #include <kernel/Networking/NetworkSocket.h>

kernel/include/kernel/Networking/UNIX/Socket.h

@@ -4,7 +4,6 @@
 #include <BAN/WeakPtr.h>
 #include <kernel/FS/Socket.h>
 #include <kernel/FS/TmpFS/Inode.h>
-#include <kernel/Lock/SpinLock.h>
 
 namespace Kernel
 {
@@ -66,7 +65,6 @@ namespace Kernel
 		BAN::CircularQueue<size_t, 128>	m_packet_sizes;
 		size_t							m_packet_size_total { 0 };
 		BAN::UniqPtr<VirtualRange>		m_packet_buffer;
-		SpinLock						m_packet_lock;
 		Semaphore						m_packet_semaphore;
 
 		friend class BAN::RefPtr<UnixDomainSocket>;

kernel/include/kernel/PIC.h

@@ -20,8 +20,11 @@ namespace Kernel
 
 	private:
 		static PIC* create();
-		friend class InterruptController;
+
+	private:
+		SpinLock m_lock;
 		uint16_t m_reserved_irqs { 0 };
+		friend class InterruptController;
 	};
 
 }

kernel/include/kernel/Process.h

@@ -7,7 +7,6 @@
 #include <BAN/Vector.h>
 #include <kernel/Credentials.h>
 #include <kernel/FS/Inode.h>
-#include <kernel/Lock/Mutex.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/MemoryRegion.h>
 #include <kernel/OpenFileDescriptorSet.h>
@@ -51,6 +50,9 @@ namespace Kernel
 		void register_to_scheduler();
 		void exit(int status, int signal);
 
+		static void for_each_process(const BAN::Function<BAN::Iteration(Process&)>& callback);
+		static void for_each_process_in_session(pid_t sid, const BAN::Function<BAN::Iteration(Process&)>& callback);
+
 		void add_thread(Thread*);
 		void on_thread_exit(Thread&);
 
@@ -219,7 +221,8 @@ namespace Kernel
 		const pid_t m_pid;
 		const pid_t m_parent;
 
-		mutable Mutex m_process_lock;
+		mutable Mutex m_big_mutex;
+		SpinLock m_signal_lock;
 
 		BAN::String m_working_directory;
 		BAN::Vector<Thread*> m_threads;

kernel/include/kernel/Scheduler.h

@@ -7,6 +7,21 @@
 namespace Kernel
 {
 
+	class SchedulerLock
+	{
+	public:
+		void lock();
+		void unlock();
+		void unlock_all();
+		pid_t locker() const;
+
+	private:
+		BAN::Atomic<pid_t> m_locker { -1 };
+		uint32_t m_lock_depth { 0 };
+
+		friend class Scheduler;
+	};
+
 	class Scheduler
 	{
 	public:
@@ -19,6 +34,8 @@ namespace Kernel
 		void reschedule();
 		void reschedule_if_idling();
 
+		void reschedule_current_no_save();
+
 		void set_current_thread_sleeping(uint64_t wake_time);
 
 		void block_current_thread(Semaphore*, uint64_t wake_time);
@@ -29,8 +46,8 @@ namespace Kernel
 		Thread& current_thread();
 		static pid_t current_tid();
 
-		[[noreturn]] void execute_current_thread();
-		[[noreturn]] void _execute_current_thread();
+		BAN::ErrorOr<void> add_thread(Thread*);
+
 		[[noreturn]] void delete_current_process_and_thread();
 
 	private:
@@ -43,7 +60,8 @@ namespace Kernel
 		void remove_and_advance_current_thread();
 		void advance_current_thread();
 
-		BAN::ErrorOr<void> add_thread(Thread*);
+		[[noreturn]] void execute_current_thread();
+		[[noreturn]] void _execute_current_thread();
 
 	private:
 		struct SchedulerThread
@@ -57,13 +75,13 @@ namespace Kernel
 			Semaphore*	semaphore;
 		};
 
+		SchedulerLock m_lock;
+
 		Thread* m_idle_thread { nullptr };
 		BAN::LinkedList<SchedulerThread> m_active_threads;
 		BAN::LinkedList<SchedulerThread> m_sleeping_threads;
 
 		BAN::LinkedList<SchedulerThread>::iterator m_current_thread;
-
-		friend class Process;
 	};
 
 }

kernel/include/kernel/Storage/StorageDevice.h

@@ -2,7 +2,6 @@
 
 #include <BAN/Vector.h>
 #include <kernel/Device/Device.h>
-#include <kernel/Lock/Mutex.h>
 #include <kernel/Storage/DiskCache.h>
 #include <kernel/Storage/Partition.h>
 

kernel/include/kernel/Terminal/Serial.h

@@ -59,6 +59,7 @@ namespace Kernel
 		bool initialize();
 
 	private:
+		SpinLock m_lock;
 		BAN::String m_name;
 		Serial m_serial;
 		BAN::CircularQueue<uint8_t, 128> m_input;

kernel/include/kernel/Terminal/TTY.h

@@ -3,7 +3,6 @@
 #include <BAN/Array.h>
 #include <kernel/Device/Device.h>
 #include <kernel/Input/KeyEvent.h>
-#include <kernel/Lock/SpinLock.h>
 #include <kernel/Terminal/TerminalDriver.h>
 #include <kernel/Terminal/termios.h>
 #include <kernel/Semaphore.h>
@@ -84,8 +83,6 @@ namespace Kernel
 			Semaphore semaphore;
 		};
 		Buffer m_output;
-
-		RecursiveSpinLock m_write_lock;
 	};
 
 }

kernel/include/kernel/Terminal/VirtualTTY.h

@@ -69,6 +69,8 @@ namespace Kernel
 	private:
 		BAN::String m_name;
 
+		RecursiveSpinLock m_write_lock;
+
 		State m_state { State::Normal };
 		AnsiState m_ansi_state { };
 		UTF8State m_utf8_state { };

kernel/include/kernel/Thread.h

@@ -113,6 +113,8 @@ namespace Kernel
 		Process*					m_process			{ nullptr };
 		bool						m_is_userspace		{ false };
 
+		mutable RecursiveSpinLock	m_lock;
+
 		uintptr_t*					m_return_rsp		{ nullptr };
 		uintptr_t*					m_return_rip		{ nullptr };
 

kernel/include/kernel/Timer/HPET.h

@@ -30,6 +30,8 @@ namespace Kernel
 		uint64_t read_main_counter() const;
 
 	private:
+		mutable SpinLock m_lock;
+
 		bool m_is_64bit { false };
 
 		uint64_t m_last_ticks	{ 0 };

kernel/kernel/APIC.cpp

@@ -4,6 +4,7 @@
 #include <kernel/CPUID.h>
 #include <kernel/Debug.h>
 #include <kernel/IDT.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/PageTable.h>
 #include <kernel/MMIO.h>
 
@@ -223,7 +224,7 @@ namespace Kernel
 
 	void APIC::enable_irq(uint8_t irq)
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 
 		uint32_t gsi = m_irq_overrides[irq];
 
@@ -268,7 +269,7 @@ namespace Kernel
 
 	BAN::ErrorOr<void> APIC::reserve_irq(uint8_t irq)
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 
 		uint32_t gsi = m_irq_overrides[irq];
 
@@ -301,7 +302,7 @@ namespace Kernel
 
 	BAN::Optional<uint8_t> APIC::get_free_irq()
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 		for (int irq = 0; irq <= 0xFF; irq++)
 		{
 			uint32_t gsi = m_irq_overrides[irq];

kernel/kernel/Debug.cpp

@@ -1,6 +1,5 @@
 #include <kernel/Debug.h>
 #include <kernel/InterruptController.h>
-#include <kernel/Lock/SpinLock.h>
 #include <kernel/Memory/PageTable.h>
 #include <kernel/Terminal/Serial.h>
 #include <kernel/Terminal/TTY.h>

kernel/kernel/Device/DebugDevice.cpp

@@ -20,7 +20,7 @@ namespace Kernel
 	BAN::ErrorOr<size_t> DebugDevice::write_impl(off_t, BAN::ConstByteSpan buffer)
 	{
 		auto ms_since_boot = SystemTimer::get().ms_since_boot();
-		SpinLockGuard _(Debug::s_debug_lock);
+		Debug::s_debug_lock.lock();
 		BAN::Formatter::print(Debug::putchar, "[{5}.{3}] {}: ",
 			ms_since_boot / 1000,
 			ms_since_boot % 1000,
@@ -28,6 +28,7 @@ namespace Kernel
 		);
 		for (size_t i = 0; i < buffer.size(); i++)
 			Debug::putchar(buffer[i]);
+		Debug::s_debug_lock.unlock();
 		return buffer.size();
 	}
 

kernel/kernel/FS/DevFS/FileSystem.cpp

@@ -56,9 +56,12 @@ namespace Kernel
 		sync_process->add_thread(MUST(Thread::create_kernel(
 			[](void*)
 			{
+				// NOTE: we lock the device lock here and unlock
+				//       it only while semaphore is blocking
+				s_instance->m_device_lock.lock();
+
 				while (true)
 				{
-					LockGuard _(s_instance->m_device_lock);
 					while (!s_instance->m_should_sync)
 					{
 						LockFreeGuard _(s_instance->m_device_lock);

kernel/kernel/FS/Pipe.cpp

@@ -42,7 +42,6 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> Pipe::read_impl(off_t, BAN::ByteSpan buffer)
 	{
-		LockGuard _(m_mutex);
 		while (m_buffer.empty())
 		{
 			if (m_writing_count == 0)
@@ -66,8 +65,6 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> Pipe::write_impl(off_t, BAN::ConstByteSpan buffer)
 	{
-		LockGuard _(m_mutex);
-
 		size_t old_size = m_buffer.size();
 
 		TRY(m_buffer.resize(old_size + buffer.size()));

kernel/kernel/FS/ProcFS/FileSystem.cpp

@@ -1,6 +1,5 @@
 #include <kernel/FS/ProcFS/FileSystem.h>
 #include <kernel/FS/ProcFS/Inode.h>
-#include <kernel/Lock/LockGuard.h>
 
 namespace Kernel
 {

kernel/kernel/FS/VirtualFileSystem.cpp

@@ -44,6 +44,8 @@ namespace Kernel
 
 	BAN::ErrorOr<void> VirtualFileSystem::mount(const Credentials& credentials, BAN::StringView block_device_path, BAN::StringView target)
 	{
+		LockGuard _(m_mutex);
+
 		auto block_device_file = TRY(file_from_absolute_path(credentials, block_device_path, true));
 		if (!block_device_file.inode->is_device())
 			return BAN::Error::from_errno(ENOTBLK);

kernel/kernel/Input/KeyboardLayout.cpp

@@ -1,7 +1,7 @@
 #include <BAN/HashMap.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/FS/VirtualFileSystem.h>
 #include <kernel/Input/KeyboardLayout.h>
+#include <kernel/Lock/LockGuard.h>
 
 #include <ctype.h>
 
@@ -74,6 +74,7 @@ namespace Kernel::Input
 
 	Key KeyboardLayout::get_key_from_event(KeyEvent event)
 	{
+		LockGuard _(m_lock);
 		if (event.shift())
 			return m_keycode_to_key_shift[event.keycode];
 		if (event.ralt())
@@ -256,7 +257,7 @@ namespace Kernel::Input
 			}
 		}
 
-		CriticalScope _;
+		LockGuard _(m_lock);
 
 		for (size_t i = 0; i < new_layout->m_keycode_to_key_normal.size(); i++)
 			if (new_layout->m_keycode_to_key_normal[i] != Key::None)

kernel/kernel/Input/PS2/Controller.cpp

@@ -101,8 +101,7 @@ namespace Kernel::Input
 
 	bool PS2Controller::append_command_queue(PS2Device* device, uint8_t command, uint8_t response_size)
 	{
-		// NOTE: command queue push/pop must be done without interrupts
-		CriticalScope _;
+		LockGuard _(m_cmd_lock);
 		if (m_command_queue.size() + 1 >= m_command_queue.capacity())
 		{
 			dprintln("PS/2 command queue full");
@@ -121,8 +120,7 @@ namespace Kernel::Input
 
 	bool PS2Controller::append_command_queue(PS2Device* device, uint8_t command, uint8_t data, uint8_t response_size)
 	{
-		// NOTE: command queue push/pop must be done without interrupts
-		CriticalScope _;
+		LockGuard _(m_cmd_lock);
 		if (m_command_queue.size() + 1 >= m_command_queue.capacity())
 		{
 			dprintln("PS/2 command queue full");
@@ -143,6 +141,9 @@ namespace Kernel::Input
 	{
 		ASSERT(interrupts_enabled());
 
+		// NOTE: CircularQueue reads don't need locking, as long as
+		//       we can guarantee that read element is not popped
+
 		if (m_command_queue.empty())
 			return;
 		auto& command = m_command_queue.front();
@@ -152,6 +153,8 @@ namespace Kernel::Input
 			{
 				dwarnln_if(DEBUG_PS2, "Command timedout");
 				m_devices[command.device_index]->command_timedout(command.out_data, command.out_count);
+
+				LockGuard _(m_cmd_lock);
 				m_command_queue.pop();
 			}
 			return;

kernel/kernel/Input/PS2/Keyboard.cpp

@@ -1,5 +1,4 @@
 #include <BAN/ScopeGuard.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/Input/KeyboardLayout.h>
 #include <kernel/Input/PS2/Config.h>
@@ -165,6 +164,7 @@ namespace Kernel::Input
 		event.modifier = m_modifiers | (released ? 0 : KeyEvent::Modifier::Pressed);
 		event.keycode = keycode.value();
 
+		LockGuard _(m_event_lock);
 		if (m_event_queue.full())
 		{
 			dwarnln("PS/2 event queue full");
@@ -197,7 +197,7 @@ namespace Kernel::Input
 			if (m_event_queue.empty())
 				TRY(Thread::current().block_or_eintr_indefinite(m_semaphore));
 
-			CriticalScope _;
+			LockGuard _(m_event_lock);
 			if (m_event_queue.empty())
 				continue;
 

kernel/kernel/Input/PS2/Mouse.cpp

@@ -1,5 +1,4 @@
 #include <BAN/ScopeGuard.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/Input/PS2/Config.h>
 #include <kernel/Input/PS2/Mouse.h>
@@ -158,6 +157,7 @@ namespace Kernel::Input
 			event.scroll_event.scroll = rel_z;
 		}
 
+		LockGuard _(m_event_lock);
 		for (int i = 0; i < event_count; i++)
 		{
 			if (m_event_queue.full())
@@ -181,7 +181,7 @@ namespace Kernel::Input
 			if (m_event_queue.empty())
 				TRY(Thread::current().block_or_eintr_indefinite(m_semaphore));
 
-			CriticalScope _;
+			LockGuard _(m_event_lock);
 			if (m_event_queue.empty())
 				continue;
 

kernel/kernel/InterruptController.cpp

@@ -67,4 +67,11 @@ namespace Kernel
 			dwarnln("could not enter acpi mode");
 	}
 
+	bool interrupts_enabled()
+	{
+		uintptr_t flags;
+		asm volatile("pushf; pop %0" : "=r"(flags) :: "memory");
+		return flags & (1 << 9);
+	}
+
 }

kernel/kernel/Lock/Mutex.cpp

@@ -0,0 +1,68 @@
+#include <kernel/Lock/Mutex.h>
+#include <kernel/Scheduler.h>
+
+namespace Kernel
+{
+
+	void Mutex::lock()
+	{
+		auto tid = Scheduler::current_tid();
+		if (tid != m_locker)
+			while (!m_locker.compare_exchange(-1, tid))
+				Scheduler::get().reschedule();
+		m_lock_depth++;
+	}
+
+	bool Mutex::try_lock()
+	{
+		auto tid = Scheduler::current_tid();
+		if (tid != m_locker)
+			if (!m_locker.compare_exchange(-1, tid))
+				return false;
+		m_lock_depth++;
+		return true;
+	}
+
+	void Mutex::unlock()
+	{
+		ASSERT_EQ(m_locker.load(), Scheduler::current_tid());
+		if (--m_lock_depth == 0)
+			m_locker = -1;
+	}
+
+	void PriorityMutex::lock()
+	{
+		const auto tid = Scheduler::current_tid();
+		const bool has_priority = tid ? !Thread::current().is_userspace() : true;
+		if (has_priority)
+			m_queue_depth++;
+		if (tid != m_locker)
+			while ((!has_priority && m_queue_depth > 0) || !m_locker.compare_exchange(-1, tid))
+				asm volatile("pause");
+		m_lock_depth++;
+	}
+
+	bool PriorityMutex::try_lock()
+	{
+		const auto tid = Scheduler::current_tid();
+		const bool has_priority = tid ? !Thread::current().is_userspace() : true;
+		if (tid != m_locker)
+			while ((!has_priority && m_queue_depth > 0) || !m_locker.compare_exchange(-1, tid))
+				return false;
+		if (has_priority)
+			m_queue_depth++;
+		m_lock_depth++;
+		return true;
+	}
+
+	void PriorityMutex::unlock()
+	{
+		const auto tid = Scheduler::current_tid();
+		const bool has_priority = tid ? !Thread::current().is_userspace() : true;
+		if (has_priority)
+			m_queue_depth--;
+		if (--m_lock_depth)
+			m_locker = -1;
+	}
+
+}

kernel/kernel/Lock/SpinLock.cpp

@@ -1,64 +1,80 @@
-#include <kernel/InterruptController.h>
 #include <kernel/Lock/SpinLock.h>
 #include <kernel/Scheduler.h>
 
-// FIXME: try to move these to header
-
 namespace Kernel
 {
 
-	InterruptState SpinLock::lock()
+	static inline uintptr_t get_flags_and_disable_interrupts()
 	{
-		auto tid = Scheduler::current_tid();
-		ASSERT_NEQ(m_locker.load(), tid);
-
-		InterruptState state = interrupts_enabled();
-		DISABLE_INTERRUPTS();
-
-		if (!m_locker.compare_exchange(-1, tid))
-			ASSERT_NOT_REACHED();
-
-		return state;
+		uintptr_t flags;
+		asm volatile("pushf; cli; pop %0" : "=r"(flags) :: "memory");
+		return flags;
 	}
 
-	void SpinLock::unlock(InterruptState state)
+	static inline void restore_flags(uintptr_t flags)
+	{
+		asm volatile("push %0; popf" :: "rm"(flags) : "memory", "cc");
+	}
+
+	void SpinLock::lock()
+	{
+		const auto tid = Scheduler::current_tid();
+		ASSERT_NEQ(m_locker.load(), tid);
+		while (!m_locker.compare_exchange(-1, tid))
+			__builtin_ia32_pause();
+		m_flags = get_flags_and_disable_interrupts();
+	}
+
+	bool SpinLock::try_lock()
+	{
+		const auto tid = Scheduler::current_tid();
+		ASSERT_NEQ(m_locker.load(), tid);
+		if (!m_locker.compare_exchange(-1, tid))
+			return false;
+		m_flags = get_flags_and_disable_interrupts();
+		return true;
+	}
+
+	void SpinLock::unlock()
 	{
 		ASSERT_EQ(m_locker.load(), Scheduler::current_tid());
-		m_locker.store(-1);
-		if (state)
-			ENABLE_INTERRUPTS();
+		restore_flags(m_flags);
+		m_locker = -1;
 	}
 
-	InterruptState RecursiveSpinLock::lock()
+	void RecursiveSpinLock::lock()
 	{
 		auto tid = Scheduler::current_tid();
+		if (m_locker != tid)
+		{
+			while (!m_locker.compare_exchange(-1, tid))
+				__builtin_ia32_pause();
+			m_flags = get_flags_and_disable_interrupts();
+		}
+		m_lock_depth++;
+	}
 
-		InterruptState state = interrupts_enabled();
-		DISABLE_INTERRUPTS();
-
-		if (tid == m_locker)
-			ASSERT_GT(m_lock_depth, 0);
-		else
+	bool RecursiveSpinLock::try_lock()
+	{
+		auto tid = Scheduler::current_tid();
+		if (m_locker != tid)
 		{
 			if (!m_locker.compare_exchange(-1, tid))
-				ASSERT_NOT_REACHED();
-			ASSERT_EQ(m_lock_depth, 0);
+				return false;
+			m_flags = get_flags_and_disable_interrupts();
 		}
-
 		m_lock_depth++;
-
-		return state;
+		return true;
 	}
 
-	void RecursiveSpinLock::unlock(InterruptState state)
+	void RecursiveSpinLock::unlock()
 	{
-		auto tid = Scheduler::current_tid();
-		ASSERT_EQ(m_locker.load(), tid);
-		ASSERT_GT(m_lock_depth, 0);
+		ASSERT_EQ(m_locker.load(), Scheduler::current_tid());
 		if (--m_lock_depth == 0)
+		{
+			restore_flags(m_flags);
 			m_locker = -1;
-		if (state)
-			ENABLE_INTERRUPTS();
+		}
 	}
 
 }

kernel/kernel/Memory/FileBackedRegion.cpp

@@ -1,4 +1,3 @@
-#include <kernel/CriticalScope.h>
 #include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/FileBackedRegion.h>
 #include <kernel/Memory/Heap.h>
@@ -83,12 +82,9 @@ namespace Kernel
 		if (pages[page_index] == 0)
 			return;
 
-		{
-			CriticalScope _;
-			PageTable::with_fast_page(pages[page_index], [&] {
-				memcpy(page_buffer, PageTable::fast_page_as_ptr(), PAGE_SIZE);
-			});
-		}
+		PageTable::with_fast_page(pages[page_index], [&] {
+			memcpy(page_buffer, PageTable::fast_page_as_ptr(), PAGE_SIZE);
+		});
 
 		if (auto ret = inode->write(page_index * PAGE_SIZE, BAN::ConstByteSpan::from(page_buffer)); ret.is_error())
 			dwarnln("{}", ret.error());

kernel/kernel/Memory/Heap.cpp

@@ -1,4 +1,5 @@
 #include <kernel/BootInfo.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/PageTable.h>
 
@@ -66,7 +67,7 @@ namespace Kernel
 
 	paddr_t Heap::take_free_page()
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		for (auto& range : m_physical_ranges)
 			if (range.free_pages() >= 1)
 				return range.reserve_page();
@@ -75,7 +76,7 @@ namespace Kernel
 
 	void Heap::release_page(paddr_t paddr)
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		for (auto& range : m_physical_ranges)
 			if (range.contains(paddr))
 				return range.release_page(paddr);
@@ -84,7 +85,7 @@ namespace Kernel
 
 	paddr_t Heap::take_free_contiguous_pages(size_t pages)
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		for (auto& range : m_physical_ranges)
 			if (range.free_pages() >= pages)
 				if (paddr_t paddr = range.reserve_contiguous_pages(pages))
@@ -94,7 +95,7 @@ namespace Kernel
 
 	void Heap::release_contiguous_pages(paddr_t paddr, size_t pages)
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		for (auto& range : m_physical_ranges)
 			if (range.contains(paddr))
 				return range.release_contiguous_pages(paddr, pages);
@@ -103,7 +104,7 @@ namespace Kernel
 
 	size_t Heap::used_pages() const
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		size_t result = 0;
 		for (const auto& range : m_physical_ranges)
 			result += range.used_pages();
@@ -112,7 +113,7 @@ namespace Kernel
 
 	size_t Heap::free_pages() const
 	{
-		SpinLockGuard _(m_lock);
+		LockGuard _(m_lock);
 		size_t result = 0;
 		for (const auto& range : m_physical_ranges)
 			result += range.free_pages();

kernel/kernel/Memory/MemoryBackedRegion.cpp

@@ -1,4 +1,3 @@
-#include <kernel/CriticalScope.h>
 #include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/MemoryBackedRegion.h>
@@ -57,9 +56,10 @@ namespace Kernel
 		m_page_table.map_page_at(paddr, vaddr, m_flags);
 
 		// Zero out the new page
-		PageTable::with_fast_page(paddr, [&] {
-			memset(PageTable::fast_page_as_ptr(), 0x00, PAGE_SIZE);
-		});
+		if (&PageTable::current() == &m_page_table)
+			memset((void*)vaddr, 0x00, PAGE_SIZE);
+		else
+			PageTable::with_fast_page(paddr, [] { memset(PageTable::fast_page_as_ptr(), 0x00, PAGE_SIZE); });
 
 		return true;
 	}
@@ -94,9 +94,13 @@ namespace Kernel
 
 			TRY(allocate_page_containing(write_vaddr));
 
-			PageTable::with_fast_page(m_page_table.physical_address_of(write_vaddr & PAGE_ADDR_MASK), [&] {
-				memcpy(PageTable::fast_page_as_ptr(page_offset), (void*)(buffer + written), bytes);
-			});
+			if (&PageTable::current() == &m_page_table)
+				memcpy((void*)write_vaddr, (void*)(buffer + written), bytes);
+			else
+				PageTable::with_fast_page(
+					m_page_table.physical_address_of(write_vaddr & PAGE_ADDR_MASK),
+					[&] { memcpy(PageTable::fast_page_as_ptr(page_offset), (void*)(buffer + written), bytes); }
+				);
 
 			written += bytes;
 		}

kernel/kernel/Memory/VirtualRange.cpp

@@ -1,4 +1,3 @@
-#include <kernel/CriticalScope.h>
 #include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/VirtualRange.h>
@@ -12,7 +11,7 @@ namespace Kernel
 		ASSERT(vaddr % PAGE_SIZE == 0);
 		ASSERT(vaddr > 0);
 
-		VirtualRange* result_ptr = new VirtualRange(page_table, preallocate_pages);
+		VirtualRange* result_ptr = new VirtualRange(page_table, preallocate_pages, false);
 		if (result_ptr == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
 
@@ -68,14 +67,31 @@ namespace Kernel
 		}
 		ASSERT(vaddr + size <= vaddr_end);
 
-		SpinLockGuard _(page_table);
+		LockGuard _(page_table);
 		page_table.unmap_range(vaddr, size); // We have to unmap here to allow reservation in create_to_vaddr()
 		return create_to_vaddr(page_table, vaddr, size, flags, preallocate_pages);
 	}
 
-	VirtualRange::VirtualRange(PageTable& page_table, bool preallocated)
+	BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> VirtualRange::create_kmalloc(size_t size)
+	{
+		auto* result_ptr = new VirtualRange(PageTable::kernel(), false, true);
+		if (!result_ptr)
+			return BAN::Error::from_errno(ENOMEM);
+
+		auto result = BAN::UniqPtr<VirtualRange>::adopt(result_ptr);
+		result->m_size = size;
+		result->m_flags = PageTable::Flags::ReadWrite | PageTable::Flags::Present;
+		result->m_vaddr = (vaddr_t)kmalloc(size);
+		if (result->m_vaddr == 0)
+			return BAN::Error::from_errno(ENOMEM);
+		result->set_zero();
+		return result;
+	}
+
+	VirtualRange::VirtualRange(PageTable& page_table, bool preallocated, bool kmalloc)
 		: m_page_table(page_table)
 		, m_preallocated(preallocated)
+		, m_kmalloc(kmalloc)
 	{ }
 
 	VirtualRange::~VirtualRange()
@@ -83,13 +99,18 @@ namespace Kernel
 		if (m_vaddr == 0)
 			return;
 
-		for (size_t offset = 0; offset < size(); offset += PAGE_SIZE)
+		if (m_kmalloc)
+			kfree((void*)m_vaddr);
+		else
 		{
-			paddr_t paddr = m_page_table.physical_address_of(vaddr() + offset);
-			if (paddr)
-				Heap::get().release_page(paddr);
+			for (size_t offset = 0; offset < size(); offset += PAGE_SIZE)
+			{
+				paddr_t paddr = m_page_table.physical_address_of(vaddr() + offset);
+				if (paddr)
+					Heap::get().release_page(paddr);
+			}
+			m_page_table.unmap_range(vaddr(), size());
 		}
-		m_page_table.unmap_range(vaddr(), size());
 	}
 
 	BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> VirtualRange::clone(PageTable& page_table)
@@ -99,7 +120,7 @@ namespace Kernel
 
 		auto result = TRY(create_to_vaddr(page_table, vaddr(), size(), flags(), m_preallocated));
 
-		SpinLockGuard _(m_page_table);
+		LockGuard _(m_page_table);
 		for (size_t offset = 0; offset < size(); offset += PAGE_SIZE)
 		{
 			if (!m_preallocated && m_page_table.physical_address_of(vaddr() + offset))
@@ -120,6 +141,7 @@ namespace Kernel
 
 	BAN::ErrorOr<void> VirtualRange::allocate_page_for_demand_paging(vaddr_t address)
 	{
+		ASSERT(!m_kmalloc);
 		ASSERT(!m_preallocated);
 		ASSERT(contains(address));
 		ASSERT(&PageTable::current() == &m_page_table);
@@ -139,7 +161,9 @@ namespace Kernel
 
 	void VirtualRange::set_zero()
 	{
-		if (&PageTable::current() == &m_page_table || &PageTable::kernel() == &m_page_table)
+		PageTable& page_table = PageTable::current();
+
+		if (m_kmalloc || &page_table == &m_page_table)
 		{
 			memset((void*)vaddr(), 0, size());
 			return;
@@ -163,7 +187,7 @@ namespace Kernel
 		ASSERT_LTE(offset, size());
 		ASSERT_LTE(offset, size() - bytes);
 
-		if (&PageTable::current() == &m_page_table || &PageTable::kernel() == &m_page_table)
+		if (m_kmalloc || &PageTable::current() == &m_page_table)
 		{
 			memcpy((void*)(vaddr() + offset), buffer, bytes);
 			return;

kernel/kernel/Memory/kmalloc.cpp

@@ -1,10 +1,13 @@
 #include <BAN/Errors.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/kprint.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/kmalloc.h>
 
 #include <kernel/Thread.h>
 
+using Kernel::LockGuard;
+using Kernel::SpinLock;
+
 #define MB (1 << 20)
 
 extern uint8_t g_kernel_end[];
@@ -81,6 +84,8 @@ struct kmalloc_info
 };
 static kmalloc_info s_kmalloc_info;
 
+static SpinLock s_kmalloc_lock;
+
 template<size_t SIZE>
 struct kmalloc_fixed_node
 {
@@ -144,6 +149,8 @@ void kmalloc_initialize()
 
 void kmalloc_dump_info()
 {
+	LockGuard _(s_kmalloc_lock);
+
 	kprintln("kmalloc:               0x{8H}->0x{8H}", s_kmalloc_info.base, s_kmalloc_info.end);
 	kprintln("  used: 0x{8H}", s_kmalloc_info.used);
 	kprintln("  free: 0x{8H}", s_kmalloc_info.free);
@@ -155,14 +162,18 @@ void kmalloc_dump_info()
 
 static bool is_corrupted()
 {
+	LockGuard _(s_kmalloc_lock);
 	auto& info = s_kmalloc_info;
 	auto* temp = info.first();
-	for (; temp->end() <= info.end; temp = temp->after());
+	for (; temp->end() <= info.end; temp = temp->after())
+		continue;
 	return (uintptr_t)temp != info.end;
 }
 
 [[maybe_unused]] static void debug_dump()
 {
+	LockGuard _(s_kmalloc_lock);
+
 	auto& info = s_kmalloc_info;
 
 	uint32_t used = 0;
@@ -183,6 +194,8 @@ static void* kmalloc_fixed()
 {
 	auto& info = s_kmalloc_fixed_info;
 
+	LockGuard _(s_kmalloc_lock);
+
 	if (!info.free_list_head)
 		return nullptr;
 
@@ -225,6 +238,8 @@ static void* kmalloc_impl(size_t size, size_t align)
 
 	auto& info = s_kmalloc_info;
 
+	LockGuard _(s_kmalloc_lock);
+
 	for (auto* node = info.first(); node->end() <= info.end; node = node->after())
 	{
 		if (node->used())
@@ -304,8 +319,6 @@ void* kmalloc(size_t size, size_t align, bool force_identity_map)
 		align = s_kmalloc_min_align;
 	ASSERT(align <= PAGE_SIZE);
 
-	Kernel::CriticalScope critical;
-
 	if (size == 0 || size >= info.size)
 		goto no_memory;
 
@@ -338,7 +351,7 @@ void kfree(void* address)
 	uintptr_t address_uint = (uintptr_t)address;
 	ASSERT(address_uint % s_kmalloc_min_align == 0);
 
-	Kernel::CriticalScope critical;
+	LockGuard _(s_kmalloc_lock);
 
 	if (s_kmalloc_fixed_info.base <= address_uint && address_uint < s_kmalloc_fixed_info.end)
 	{
@@ -399,10 +412,9 @@ void kfree(void* address)
 
 BAN::Optional<Kernel::paddr_t> kmalloc_paddr_of(Kernel::vaddr_t vaddr)
 {
-	using namespace Kernel;
-
+	using Kernel::vaddr_t;
+	LockGuard _(s_kmalloc_lock);
 	if ((vaddr_t)s_kmalloc_storage <= vaddr && vaddr < (vaddr_t)s_kmalloc_storage + sizeof(s_kmalloc_storage))
 		return V2P(vaddr);
-
 	return {};
 }

kernel/kernel/Networking/ARPTable.cpp

@@ -1,3 +1,4 @@
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Networking/ARPTable.h>
 #include <kernel/Scheduler.h>
 #include <kernel/Timer/Timer.h>
@@ -51,10 +52,9 @@ namespace Kernel
 			ipv4_address = interface.get_gateway();
 
 		{
-			SpinLockGuard _(m_table_lock);
-			auto it = m_arp_table.find(ipv4_address);
-			if (it != m_arp_table.end())
-				return it->value;
+			LockGuard _(m_table_lock);
+			if (m_arp_table.contains(ipv4_address))
+				return m_arp_table[ipv4_address];
 		}
 
 		ARPPacket arp_request;
@@ -74,10 +74,9 @@ namespace Kernel
 		while (SystemTimer::get().ms_since_boot() < timeout)
 		{
 			{
-				SpinLockGuard _(m_table_lock);
-				auto it = m_arp_table.find(ipv4_address);
-				if (it != m_arp_table.end())
-					return it->value;
+				LockGuard _(m_table_lock);
+				if (m_arp_table.contains(ipv4_address))
+					return m_arp_table[ipv4_address];
 			}
 			Scheduler::get().reschedule();
 		}
@@ -115,15 +114,13 @@ namespace Kernel
 			}
 			case ARPOperation::Reply:
 			{
-				SpinLockGuard _(m_table_lock);
-				auto it = m_arp_table.find(packet.spa);
-
-				if (it != m_arp_table.end())
+				LockGuard _(m_table_lock);
+				if (m_arp_table.contains(packet.spa))
 				{
-					if (it->value != packet.sha)
+					if (m_arp_table[packet.spa] != packet.sha)
 					{
 						dprintln("Update IPv4 {} MAC to {}", packet.spa, packet.sha);
-						it->value = packet.sha;
+						m_arp_table[packet.spa] = packet.sha;
 					}
 				}
 				else
@@ -148,7 +145,7 @@ namespace Kernel
 			BAN::Optional<PendingArpPacket> pending;
 
 			{
-				CriticalScope _;
+				LockGuard _(m_pending_lock);
 				if (!m_pending_packets.empty())
 				{
 					pending = m_pending_packets.front();
@@ -171,12 +168,12 @@ namespace Kernel
 	{
 		auto& arp_packet = buffer.as<const ARPPacket>();
 
+		LockGuard _(m_pending_lock);
 		if (m_pending_packets.full())
 		{
 			dprintln("arp packet queue full");
 			return;
 		}
-
 		m_pending_packets.push({ .interface = interface, .packet = arp_packet });
 		m_pending_semaphore.unblock();
 	}

kernel/kernel/Networking/E1000/E1000.cpp

@@ -261,7 +261,7 @@ namespace Kernel
 	{
 		ASSERT_LTE(buffer.size() + sizeof(EthernetHeader), E1000_TX_BUFFER_SIZE);
 
-		CriticalScope _;
+		LockGuard _(m_lock);
 
 		size_t tx_current = read32(REG_TDT) % E1000_TX_DESCRIPTOR_COUNT;
 

kernel/kernel/Networking/IPv4Layer.cpp

@@ -70,14 +70,12 @@ namespace Kernel
 
 	void IPv4Layer::unbind_socket(BAN::RefPtr<NetworkSocket> socket, uint16_t port)
 	{
+		LockGuard _(m_socket_lock);
+		if (m_bound_sockets.contains(port))
 		{
-			SpinLockGuard _(m_bound_socket_lock);
-			auto it = m_bound_sockets.find(port);
-			if (it != m_bound_sockets.end())
-			{
-				ASSERT(it->value.lock() == socket);
-				m_bound_sockets.remove(it);
-			}
+			ASSERT(m_bound_sockets[port].valid());
+			ASSERT(m_bound_sockets[port].lock() == socket);
+			m_bound_sockets.remove(port);
 		}
 		NetworkManager::get().TmpFileSystem::remove_from_cache(socket);
 	}
@@ -90,11 +88,11 @@ namespace Kernel
 			return BAN::Error::from_errno(EAFNOSUPPORT);
 		auto& sockaddr_in = *reinterpret_cast<const struct sockaddr_in*>(address);
 
-		SpinLockGuard _(m_bound_socket_lock);
+		LockGuard _(m_socket_lock);
 
 		uint16_t port = NetworkSocket::PORT_NONE;
 		for (uint32_t i = 0; i < 100 && port == NetworkSocket::PORT_NONE; i++)
-			if (uint32_t temp = 0xC000 | (Random::get_u32() & 0x3FFF); !m_bound_sockets.contains(temp))
+			if (uint32_t temp = 0xC000 | (Random::get_u32() & 0x3FFF); !m_bound_sockets.contains(temp) || !m_bound_sockets[temp].valid())
 				port = temp;
 		for (uint32_t temp = 0xC000; temp < 0xFFFF && port == NetworkSocket::PORT_NONE; temp++)
 			if (!m_bound_sockets.contains(temp))
@@ -126,11 +124,17 @@ namespace Kernel
 		auto& sockaddr_in = *reinterpret_cast<const struct sockaddr_in*>(address);
 		uint16_t port = BAN::host_to_network_endian(sockaddr_in.sin_port);
 
-		SpinLockGuard _(m_bound_socket_lock);
+		LockGuard _(m_socket_lock);
 
-		if (m_bound_sockets.contains(port))
-			return BAN::Error::from_errno(EADDRINUSE);
-		TRY(m_bound_sockets.insert(port, TRY(socket->get_weak_ptr())));
+		if (!m_bound_sockets.contains(port))
+			TRY(m_bound_sockets.insert(port, TRY(socket->get_weak_ptr())));
+		else
+		{
+			auto& bound = m_bound_sockets[port];
+			if (bound.valid())
+				return BAN::Error::from_errno(EADDRINUSE);
+			bound = TRY(socket->get_weak_ptr());
+		}
 
 		// FIXME: actually determine proper interface
 		auto interface = NetworkManager::get().interfaces().front();
@@ -252,14 +256,13 @@ namespace Kernel
 		BAN::RefPtr<Kernel::NetworkSocket> bound_socket;
 
 		{
-			SpinLockGuard _(m_bound_socket_lock);
-			auto it = m_bound_sockets.find(dst_port);
-			if (it == m_bound_sockets.end())
+			LockGuard _(m_socket_lock);
+			if (!m_bound_sockets.contains(dst_port))
 			{
 				dprintln_if(DEBUG_IPV4, "no one is listening on port {}", dst_port);
 				return {};
 			}
-			bound_socket = it->value.lock();
+			bound_socket = m_bound_sockets[dst_port].lock();
 		}
 
 		if (!bound_socket)
@@ -290,7 +293,7 @@ namespace Kernel
 			BAN::Optional<PendingIPv4Packet> pending;
 
 			{
-				CriticalScope _;
+				LockGuard _(m_packet_lock);
 				if (!m_pending_packets.empty())
 				{
 					pending = m_pending_packets.front();
@@ -310,7 +313,7 @@ namespace Kernel
 			if (auto ret = handle_ipv4_packet(pending->interface, BAN::ByteSpan(buffer_start, ipv4_packet_size)); ret.is_error())
 				dwarnln("{}", ret.error());
 
-			CriticalScope _;
+			LockGuard _(m_packet_lock);
 			m_pending_total_size -= ipv4_packet_size;
 			if (m_pending_total_size)
 				memmove(buffer_start, buffer_start + ipv4_packet_size, m_pending_total_size);
@@ -319,6 +322,8 @@ namespace Kernel
 
 	void IPv4Layer::add_ipv4_packet(NetworkInterface& interface, BAN::ConstByteSpan buffer)
 	{
+		LockGuard _(m_packet_lock);
+
 		if (m_pending_packets.full())
 		{
 			dwarnln("IPv4 packet queue full");

kernel/kernel/Networking/TCPSocket.cpp

@@ -68,8 +68,6 @@ namespace Kernel
 
 	void TCPSocket::on_close_impl()
 	{
-		LockGuard _(m_mutex);
-
 		if (!is_bound())
 			return;
 
@@ -103,8 +101,6 @@ namespace Kernel
 		if (address_len > (socklen_t)sizeof(sockaddr_storage))
 			address_len = sizeof(sockaddr_storage);
 
-		LockGuard _(m_mutex);
-
 		ASSERT(!m_connection_info.has_value());
 
 		switch (m_state)
@@ -195,6 +191,8 @@ namespace Kernel
 
 	void TCPSocket::add_protocol_header(BAN::ByteSpan packet, uint16_t dst_port, PseudoHeader pseudo_header)
 	{
+		LockGuard _(m_mutex);
+
 		auto& header = packet.as<TCPHeader>();
 		memset(&header, 0, sizeof(TCPHeader));
 		memset(header.options, TCPOption::End, m_tcp_options_bytes);
@@ -212,7 +210,6 @@ namespace Kernel
 		{
 			case State::Closed:
 			{
-				LockGuard _(m_mutex);
 				header.syn = 1;
 				add_tcp_header_option<0, TCPOption::MaximumSeqmentSize>(header, m_interface->payload_mtu() - m_network_layer.header_size());
 				add_tcp_header_option<4, TCPOption::WindowScale>(header, 0);
@@ -233,7 +230,6 @@ namespace Kernel
 				break;
 			case State::CloseWait:
 			{
-				LockGuard _(m_mutex);
 				header.ack = 1;
 				header.fin = 1;
 				m_state = State::LastAck;
@@ -242,7 +238,6 @@ namespace Kernel
 			}
 			case State::FinWait1:
 			{
-				LockGuard _(m_mutex);
 				header.ack = 1;
 				header.fin = 1;
 				m_state = State::FinWait2;
@@ -250,7 +245,6 @@ namespace Kernel
 			}
 			case State::FinWait2:
 			{
-				LockGuard _(m_mutex);
 				header.ack = 1;
 				m_state = State::TimeWait;
 				m_time_wait_start_ms = SystemTimer::get().ms_since_boot();
@@ -303,6 +297,10 @@ namespace Kernel
 
 		auto payload = buffer.slice(header.data_offset * sizeof(uint32_t));
 
+		// FIXME: Internet layer packet receive thread should not be able to be
+		//        blocked by inode's mutex
+		LockGuard _(m_mutex);
+
 		switch (m_state)
 		{
 			case State::Closed:
@@ -312,7 +310,6 @@ namespace Kernel
 				if (!header.ack || !header.syn)
 					break;
 
-				LockGuard _(m_mutex);
 
 				if (header.ack_number != m_send_window.current_seq)
 				{
@@ -345,8 +342,6 @@ namespace Kernel
 				if (!header.ack)
 					break;
 
-				LockGuard _(m_mutex);
-
 				if (header.fin)
 				{
 					if (m_recv_window.start_seq + m_recv_window.data_size != header.seq_number)

kernel/kernel/Networking/UDPSocket.cpp

@@ -1,3 +1,4 @@
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Networking/UDPSocket.h>
 #include <kernel/Thread.h>
@@ -45,7 +46,7 @@ namespace Kernel
 		//auto& header = packet.as<const UDPHeader>();
 		auto payload = packet.slice(sizeof(UDPHeader));
 
-		SpinLockGuard _(m_packet_lock);
+		LockGuard _(m_packet_lock);
 
 		if (m_packets.full())
 		{
@@ -87,12 +88,12 @@ namespace Kernel
 		}
 		ASSERT(m_port != PORT_NONE);
 
-		auto state = m_packet_lock.lock();
+		LockGuard _(m_packet_lock);
+
 		while (m_packets.empty())
 		{
-			m_packet_lock.unlock(state);
+			LockFreeGuard free(m_packet_lock);
 			TRY(Thread::current().block_or_eintr_indefinite(m_packet_semaphore));
-			state = m_packet_lock.lock();
 		}
 
 		auto packet_info = m_packets.front();
@@ -114,8 +115,6 @@ namespace Kernel
 
 		m_packet_total_size -= packet_info.packet_size;
 
-		m_packet_lock.unlock(state);
-
 		if (address && address_len)
 		{
 			if (*address_len > (socklen_t)sizeof(sockaddr_storage))

kernel/kernel/Networking/UNIX/Socket.cpp

@@ -51,10 +51,9 @@ namespace Kernel
 	{
 		if (is_bound() && !is_bound_to_unused())
 		{
-			SpinLockGuard _(s_bound_socket_lock);
-			auto it = s_bound_sockets.find(m_bound_path);
-			if (it != s_bound_sockets.end())
-				s_bound_sockets.remove(it);
+			LockGuard _(s_bound_socket_lock);
+			if (s_bound_sockets.contains(m_bound_path))
+				s_bound_sockets.remove(m_bound_path);
 		}
 	}
 
@@ -72,7 +71,7 @@ namespace Kernel
 		BAN::RefPtr<UnixDomainSocket> pending;
 
 		{
-			SpinLockGuard _(connection_info.pending_lock);
+			LockGuard _(connection_info.pending_lock);
 			pending = connection_info.pending_connections.front();
 			connection_info.pending_connections.pop();
 			connection_info.pending_semaphore.unblock();
@@ -121,11 +120,10 @@ namespace Kernel
 		BAN::RefPtr<UnixDomainSocket> target;
 
 		{
-			SpinLockGuard _(s_bound_socket_lock);
-			auto it = s_bound_sockets.find(file.canonical_path);
-			if (it == s_bound_sockets.end())
+			LockGuard _(s_bound_socket_lock);
+			if (!s_bound_sockets.contains(file.canonical_path))
 				return BAN::Error::from_errno(ECONNREFUSED);
-			target = it->value.lock();
+			target = s_bound_sockets[file.canonical_path].lock();
 			if (!target)
 				return BAN::Error::from_errno(ECONNREFUSED);
 		}
@@ -152,7 +150,7 @@ namespace Kernel
 		{
 			auto& target_info = target->m_info.get<ConnectionInfo>();
 			{
-				SpinLockGuard _(target_info.pending_lock);
+				LockGuard _(target_info.pending_lock);
 				if (target_info.pending_connections.size() < target_info.pending_connections.capacity())
 				{
 					MUST(target_info.pending_connections.push(this));
@@ -207,7 +205,7 @@ namespace Kernel
 			O_RDWR
 		));
 
-		SpinLockGuard _(s_bound_socket_lock);
+		LockGuard _(s_bound_socket_lock);
 		ASSERT(!s_bound_sockets.contains(file.canonical_path));
 		TRY(s_bound_sockets.emplace(file.canonical_path, TRY(get_weak_ptr())));
 		m_bound_path = BAN::move(file.canonical_path);
@@ -231,12 +229,12 @@ namespace Kernel
 
 	BAN::ErrorOr<void> UnixDomainSocket::add_packet(BAN::ConstByteSpan packet)
 	{
-		auto state = m_packet_lock.lock();
+		LockGuard _(m_mutex);
+
 		while (m_packet_sizes.full() || m_packet_size_total + packet.size() > s_packet_buffer_size)
 		{
-			m_packet_lock.unlock(state);
+			LockFreeGuard _(m_mutex);
 			TRY(Thread::current().block_or_eintr_indefinite(m_packet_semaphore));
-			state = m_packet_lock.lock();
 		}
 
 		uint8_t* packet_buffer = reinterpret_cast<uint8_t*>(m_packet_buffer->vaddr() + m_packet_size_total);
@@ -247,7 +245,6 @@ namespace Kernel
 			m_packet_sizes.push(packet.size());
 
 		m_packet_semaphore.unblock();
-		m_packet_lock.unlock(state);
 		return {};
 	}
 
@@ -321,11 +318,10 @@ namespace Kernel
 				canonical_path = BAN::move(file.canonical_path);
 			}
 
-			SpinLockGuard _(s_bound_socket_lock);
-			auto it = s_bound_sockets.find(canonical_path);
-			if (it == s_bound_sockets.end())
+			LockGuard _(s_bound_socket_lock);
+			if (!s_bound_sockets.contains(canonical_path))
 				return BAN::Error::from_errno(EDESTADDRREQ);
-			auto target = it->value.lock();
+			auto target = s_bound_sockets[canonical_path].lock();
 			if (!target)
 				return BAN::Error::from_errno(EDESTADDRREQ);
 			TRY(target->add_packet(message));
@@ -342,12 +338,10 @@ namespace Kernel
 				return BAN::Error::from_errno(ENOTCONN);
 		}
 
-		auto state = m_packet_lock.lock();
 		while (m_packet_size_total == 0)
 		{
-			m_packet_lock.unlock(state);
+			LockFreeGuard _(m_mutex);
 			TRY(Thread::current().block_or_eintr_indefinite(m_packet_semaphore));
-			state = m_packet_lock.lock();
 		}
 
 		uint8_t* packet_buffer = reinterpret_cast<uint8_t*>(m_packet_buffer->vaddr());
@@ -366,7 +360,6 @@ namespace Kernel
 		m_packet_size_total -= nread;
 
 		m_packet_semaphore.unblock();
-		m_packet_lock.unlock(state);
 
 		return nread;
 	}

kernel/kernel/PIC.cpp

@@ -1,6 +1,6 @@
-#include <kernel/CriticalScope.h>
 #include <kernel/IDT.h>
 #include <kernel/IO.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/PIC.h>
 
 #include <string.h>
@@ -79,7 +79,7 @@ namespace Kernel
 
 	void PIC::enable_irq(uint8_t irq)
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 		ASSERT(irq < 16);
 		ASSERT(m_reserved_irqs & (1 << irq));
 
@@ -99,7 +99,7 @@ namespace Kernel
 			dwarnln("PIC only supports 16 irqs");
 			return BAN::Error::from_errno(EFAULT);
 		}
-		CriticalScope _;
+		LockGuard _(m_lock);
 		if (m_reserved_irqs & (1 << irq))
 		{
 			dwarnln("irq {} is already reserved", irq);
@@ -111,7 +111,7 @@ namespace Kernel
 
 	BAN::Optional<uint8_t> PIC::get_free_irq()
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 		for (int irq = 0; irq < 16; irq++)
 		{
 			if (m_reserved_irqs & (1 << irq))

kernel/kernel/Process.cpp

@@ -1,6 +1,5 @@
 #include <BAN/ScopeGuard.h>
 #include <BAN/StringView.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/FS/ProcFS/FileSystem.h>
 #include <kernel/FS/VirtualFileSystem.h>
@@ -32,9 +31,9 @@ namespace Kernel
 	static BAN::Vector<Process*> s_processes;
 	static RecursiveSpinLock s_process_lock;
 
-	static void for_each_process(const BAN::Function<BAN::Iteration(Process&)>& callback)
+	void Process::for_each_process(const BAN::Function<BAN::Iteration(Process&)>& callback)
 	{
-		SpinLockGuard _(s_process_lock);
+		LockGuard _(s_process_lock);
 
 		for (auto* process : s_processes)
 		{
@@ -45,9 +44,9 @@ namespace Kernel
 		}
 	}
 
-	static void for_each_process_in_session(pid_t sid, const BAN::Function<BAN::Iteration(Process&)>& callback)
+	void Process::for_each_process_in_session(pid_t sid, const BAN::Function<BAN::Iteration(Process&)>& callback)
 	{
-		SpinLockGuard _(s_process_lock);
+		LockGuard _(s_process_lock);
 
 		for (auto* process : s_processes)
 		{
@@ -66,7 +65,7 @@ namespace Kernel
 
 		pid_t pid;
 		{
-			CriticalScope _;
+			LockGuard _(s_process_lock);
 			pid = s_next_id;
 			if (sid == 0 && pgrp == 0)
 			{
@@ -89,10 +88,9 @@ namespace Kernel
 
 	void Process::register_to_scheduler()
 	{
-		{
-			SpinLockGuard _(s_process_lock);
-			MUST(s_processes.push_back(this));
-		}
+		s_process_lock.lock();
+		MUST(s_processes.push_back(this));
+		s_process_lock.unlock();
 		for (auto* thread : m_threads)
 			MUST(Scheduler::get().add_thread(thread));
 	}
@@ -194,14 +192,14 @@ namespace Kernel
 
 	void Process::add_thread(Thread* thread)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		MUST(m_threads.push_back(thread));
 	}
 
 	void Process::cleanup_function()
 	{
 		{
-			SpinLockGuard _(s_process_lock);
+			LockGuard _(s_process_lock);
 			for (size_t i = 0; i < s_processes.size(); i++)
 				if (s_processes[i] == this)
 					s_processes.remove(i);
@@ -215,7 +213,8 @@ namespace Kernel
 		while (m_exit_status.waiting > 0)
 			Scheduler::get().reschedule();
 
-		m_process_lock.lock();
+		// This mutex will no longer be freed
+		m_big_mutex.lock();
 
 		m_open_file_descriptors.close_all();
 
@@ -236,7 +235,7 @@ namespace Kernel
 			m_threads.clear();
 
 			thread.setup_process_cleanup();
-			Scheduler::get().execute_current_thread();
+			Scheduler::get().reschedule_current_no_save();
 			ASSERT_NOT_REACHED();
 		}
 
@@ -254,7 +253,7 @@ namespace Kernel
 
 	void Process::exit(int status, int signal)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		m_exit_status.exit_code = __WGENEXITCODE(status, signal);
 		for (auto* thread : m_threads)
 			if (thread != &Thread::current())
@@ -275,7 +274,7 @@ namespace Kernel
 		meminfo.phys_pages = 0;
 
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			for (auto* thread : m_threads)
 			{
 				meminfo.virt_pages += thread->virtual_page_count();
@@ -324,13 +323,13 @@ namespace Kernel
 
 	size_t Process::proc_cmdline(off_t offset, BAN::ByteSpan buffer) const
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return read_from_vec_of_str(m_cmdline, offset, buffer);
 	}
 
 	size_t Process::proc_environ(off_t offset, BAN::ByteSpan buffer) const
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return read_from_vec_of_str(m_environ, offset, buffer);
 	}
 
@@ -343,7 +342,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_gettermios(::termios* termios)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		TRY(validate_pointer_access(termios, sizeof(::termios)));
 
@@ -362,7 +361,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_settermios(const ::termios* termios)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		TRY(validate_pointer_access(termios, sizeof(::termios)));
 
@@ -401,7 +400,7 @@ namespace Kernel
 	{
 		auto page_table = BAN::UniqPtr<PageTable>::adopt(TRY(PageTable::create_userspace()));
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		BAN::String working_directory;
 		TRY(working_directory.append(m_working_directory));
@@ -441,7 +440,7 @@ namespace Kernel
 	{
 		// NOTE: We scope everything for automatic deletion
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 
 			TRY(validate_string_access(path));
 			auto loadable_elf = TRY(load_elf_for_exec(m_credentials, path, m_working_directory, page_table()));
@@ -540,7 +539,7 @@ namespace Kernel
 		m_has_called_exec = true;
 
 		m_threads.front()->setup_exec();
-		Scheduler::get().execute_current_thread();
+		Scheduler::get().reschedule_current_no_save();
 		ASSERT_NOT_REACHED();
 	}
 
@@ -577,7 +576,7 @@ namespace Kernel
 	BAN::ErrorOr<long> Process::sys_wait(pid_t pid, int* stat_loc, int options)
 	{
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(validate_pointer_access(stat_loc, sizeof(int)));
 		}
 
@@ -610,7 +609,7 @@ namespace Kernel
 	BAN::ErrorOr<long> Process::sys_nanosleep(const timespec* rqtp, timespec* rmtp)
 	{
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(validate_pointer_access(rqtp, sizeof(timespec)));
 			if (rmtp)
 				TRY(validate_pointer_access(rmtp, sizeof(timespec)));
@@ -652,7 +651,7 @@ namespace Kernel
 				return BAN::Error::from_errno(ENOTSUP);
 		}
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		auto absolute_path = TRY(absolute_path_of(path));
 
@@ -681,7 +680,7 @@ namespace Kernel
 	{
 		ASSERT(&Process::current() == this);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		if (Thread::current().stack().contains(address))
 		{
@@ -709,13 +708,13 @@ namespace Kernel
 	BAN::ErrorOr<long> Process::open_inode(BAN::RefPtr<Inode> inode, int flags)
 	{
 		ASSERT(inode);
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return TRY(m_open_file_descriptors.open(inode, flags));
 	}
 
 	BAN::ErrorOr<long> Process::open_file(BAN::StringView path, int flags, mode_t mode)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		BAN::String absolute_path = TRY(absolute_path_of(path));
 
@@ -748,14 +747,14 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_open(const char* path, int flags, mode_t mode)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 		return open_file(path, flags, mode);
 	}
 
 	BAN::ErrorOr<long> Process::sys_openat(int fd, const char* path, int flags, mode_t mode)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		TRY(validate_string_access(path));
 
@@ -771,28 +770,28 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_close(int fd)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(m_open_file_descriptors.close(fd));
 		return 0;
 	}
 
 	BAN::ErrorOr<long> Process::sys_read(int fd, void* buffer, size_t count)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(buffer, count));
 		return TRY(m_open_file_descriptors.read(fd, BAN::ByteSpan((uint8_t*)buffer, count)));
 	}
 
 	BAN::ErrorOr<long> Process::sys_write(int fd, const void* buffer, size_t count)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(buffer, count));
 		return TRY(m_open_file_descriptors.write(fd, BAN::ByteSpan((uint8_t*)buffer, count)));
 	}
 
 	BAN::ErrorOr<long> Process::sys_create(const char* path, mode_t mode)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 		TRY(create_file_or_dir(path, mode));
 		return 0;
@@ -800,7 +799,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_create_dir(const char* path, mode_t mode)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 		BAN::StringView path_sv(path);
 		if (!path_sv.empty() && path_sv.back() == '/')
@@ -811,7 +810,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_unlink(const char* path)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 
 		auto absolute_path = TRY(absolute_path_of(path));
@@ -844,7 +843,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_readlink(const char* path, char* buffer, size_t bufsize)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 		TRY(validate_pointer_access(buffer, bufsize));
 
@@ -855,7 +854,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_readlinkat(int fd, const char* path, char* buffer, size_t bufsize)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 		TRY(validate_pointer_access(buffer, bufsize));
 
@@ -872,7 +871,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_pread(int fd, void* buffer, size_t count, off_t offset)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(buffer, count));
 		auto inode = TRY(m_open_file_descriptors.inode_of(fd));
 		return TRY(inode->read(offset, { (uint8_t*)buffer, count }));
@@ -883,7 +882,7 @@ namespace Kernel
 		if (mode & S_IFMASK)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 
 		auto absolute_path = TRY(absolute_path_of(path));
@@ -895,7 +894,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_chown(const char* path, uid_t uid, gid_t gid)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 
 		auto absolute_path = TRY(absolute_path_of(path));
@@ -907,7 +906,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_socket(int domain, int type, int protocol)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return TRY(m_open_file_descriptors.socket(domain, type, protocol));
 	}
 
@@ -918,7 +917,7 @@ namespace Kernel
 		if (!address && address_len)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		if (address)
 		{
 			TRY(validate_pointer_access(address_len, sizeof(*address_len)));
@@ -934,7 +933,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_bind(int socket, const sockaddr* address, socklen_t address_len)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(address, address_len));
 
 		auto inode = TRY(m_open_file_descriptors.inode_of(socket));
@@ -947,7 +946,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_connect(int socket, const sockaddr* address, socklen_t address_len)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(address, address_len));
 
 		auto inode = TRY(m_open_file_descriptors.inode_of(socket));
@@ -960,7 +959,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_listen(int socket, int backlog)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		auto inode = TRY(m_open_file_descriptors.inode_of(socket));
 		if (!inode->mode().ifsock())
@@ -972,7 +971,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_sendto(const sys_sendto_t* arguments)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(arguments, sizeof(sys_sendto_t)));
 		TRY(validate_pointer_access(arguments->message, arguments->length));
 		TRY(validate_pointer_access(arguments->dest_addr, arguments->dest_len));
@@ -992,7 +991,7 @@ namespace Kernel
 		if (!arguments->address && arguments->address_len)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(arguments, sizeof(sys_recvfrom_t)));
 		TRY(validate_pointer_access(arguments->buffer, arguments->length));
 		if (arguments->address)
@@ -1011,14 +1010,14 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_ioctl(int fildes, int request, void* arg)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
 		return TRY(inode->ioctl(request, arg));
 	}
 
 	BAN::ErrorOr<long> Process::sys_pselect(sys_pselect_t* arguments)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		TRY(validate_pointer_access(arguments, sizeof(sys_pselect_t)));
 		if (arguments->readfds)
@@ -1087,7 +1086,7 @@ namespace Kernel
 			if (set_bits > 0)
 				break;
 
-			LockFreeGuard free(m_process_lock);
+			LockFreeGuard free(m_big_mutex);
 			SystemTimer::get().sleep(1);
 		}
 
@@ -1113,7 +1112,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_pipe(int fildes[2])
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(fildes, sizeof(int) * 2));
 		TRY(m_open_file_descriptors.pipe(fildes));
 		return 0;
@@ -1121,32 +1120,32 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_dup(int fildes)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return TRY(m_open_file_descriptors.dup(fildes));
 	}
 
 	BAN::ErrorOr<long> Process::sys_dup2(int fildes, int fildes2)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return TRY(m_open_file_descriptors.dup2(fildes, fildes2));
 	}
 
 	BAN::ErrorOr<long> Process::sys_fcntl(int fildes, int cmd, int extra)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return TRY(m_open_file_descriptors.fcntl(fildes, cmd, extra));
 	}
 
 	BAN::ErrorOr<long> Process::sys_seek(int fd, off_t offset, int whence)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(m_open_file_descriptors.seek(fd, offset, whence));
 		return 0;
 	}
 
 	BAN::ErrorOr<long> Process::sys_tell(int fd)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		return TRY(m_open_file_descriptors.tell(fd));
 	}
 
@@ -1154,7 +1153,7 @@ namespace Kernel
 	{
 		BAN::String absolute_source, absolute_target;
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(absolute_source.append(TRY(absolute_path_of(source))));
 			TRY(absolute_target.append(TRY(absolute_path_of(target))));
 		}
@@ -1164,7 +1163,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_fstat(int fd, struct stat* buf)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(buf, sizeof(struct stat)));
 		TRY(m_open_file_descriptors.fstat(fd, buf));
 		return 0;
@@ -1172,7 +1171,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_fstatat(int fd, const char* path, struct stat* buf, int flag)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(buf, sizeof(struct stat)));
 		TRY(m_open_file_descriptors.fstatat(fd, path, buf, flag));
 		return 0;
@@ -1180,7 +1179,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_stat(const char* path, struct stat* buf, int flag)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(buf, sizeof(struct stat)));
 		TRY(m_open_file_descriptors.stat(TRY(absolute_path_of(path)), buf, flag));
 		return 0;
@@ -1233,7 +1232,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_readdir(int fd, DirectoryEntryList* list, size_t list_size)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_pointer_access(list, list_size));
 		TRY(m_open_file_descriptors.read_dir_entries(fd, list, list_size));
 		return 0;
@@ -1244,7 +1243,7 @@ namespace Kernel
 		BAN::String absolute_path;
 
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(validate_string_access(path));
 			absolute_path = TRY(absolute_path_of(path));
 		}
@@ -1253,7 +1252,7 @@ namespace Kernel
 		if (!file.inode->mode().ifdir())
 			return BAN::Error::from_errno(ENOTDIR);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		m_working_directory = BAN::move(file.canonical_path);
 
 		return 0;
@@ -1261,7 +1260,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_getpwd(char* buffer, size_t size)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		TRY(validate_pointer_access(buffer, size));
 
@@ -1277,7 +1276,7 @@ namespace Kernel
 	BAN::ErrorOr<long> Process::sys_mmap(const sys_mmap_t* args)
 	{
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(validate_pointer_access(args, sizeof(sys_mmap_t)));
 		}
 
@@ -1318,7 +1317,7 @@ namespace Kernel
 				region_type, page_flags
 			));
 
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(m_mapped_regions.push_back(BAN::move(region)));
 			return m_mapped_regions.back()->vaddr();
 		}
@@ -1326,7 +1325,7 @@ namespace Kernel
 		if (args->addr != nullptr)
 			return BAN::Error::from_errno(ENOTSUP);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		auto inode = TRY(m_open_file_descriptors.inode_of(args->fildes));
 
@@ -1374,7 +1373,7 @@ namespace Kernel
 		if (vaddr % PAGE_SIZE != 0)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		// FIXME: We should only map partial regions
 		for (size_t i = 0; i < m_mapped_regions.size(); i++)
@@ -1393,7 +1392,7 @@ namespace Kernel
 		if (vaddr % PAGE_SIZE != 0)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		for (auto& mapped_region : m_mapped_regions)
 			if (mapped_region->overlaps(vaddr, len))
@@ -1404,7 +1403,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_tty_ctrl(int fildes, int command, int flags)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
 		if (!inode->is_tty())
@@ -1417,7 +1416,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_termid(char* buffer)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		TRY(validate_string_access(buffer));
 
@@ -1438,7 +1437,7 @@ namespace Kernel
 	BAN::ErrorOr<long> Process::sys_clock_gettime(clockid_t clock_id, timespec* tp)
 	{
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(validate_pointer_access(tp, sizeof(timespec)));
 		}
 
@@ -1463,7 +1462,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_load_keymap(const char* path)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 		TRY(validate_string_access(path));
 
 		if (!m_credentials.is_superuser())
@@ -1480,11 +1479,11 @@ namespace Kernel
 			return BAN::Error::from_errno(EINVAL);
 
 		{
-			LockGuard _(m_process_lock);
+			LockGuard _(m_big_mutex);
 			TRY(validate_pointer_access((void*)handler, sizeof(handler)));
 		}
 
-		CriticalScope _;
+		LockGuard _(m_signal_lock);
 		m_signal_handlers[signal] = (vaddr_t)handler;
 		return 0;
 	}
@@ -1498,7 +1497,7 @@ namespace Kernel
 
 		if (pid == Process::current().pid())
 		{
-			CriticalScope _;
+			LockGuard _(m_signal_lock);
 			Process::current().m_signal_pending_mask |= 1 << signal;
 			return 0;
 		}
@@ -1512,7 +1511,7 @@ namespace Kernel
 					found = true;
 					if (signal)
 					{
-						CriticalScope _;
+						LockGuard _(m_signal_lock);
 						process.m_signal_pending_mask |= 1 << signal;
 						// FIXME: This is super hacky
 						Scheduler::get().unblock_thread(process.m_threads.front()->tid());
@@ -1530,7 +1529,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_tcsetpgrp(int fd, pid_t pgrp)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		if (!m_controlling_terminal)
 			return BAN::Error::from_errno(ENOTTY);
@@ -1566,7 +1565,7 @@ namespace Kernel
 		if (uid < 0 || uid >= 1'000'000'000)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		// If the process has appropriate privileges, setuid() shall set the real user ID, effective user ID, and the saved
 		// set-user-ID of the calling process to uid.
@@ -1596,7 +1595,7 @@ namespace Kernel
 		if (gid < 0 || gid >= 1'000'000'000)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		// If the process has appropriate privileges, setgid() shall set the real group ID, effective group ID, and the saved
 		// set-group-ID of the calling process to gid.
@@ -1624,7 +1623,7 @@ namespace Kernel
 		if (uid < 0 || uid >= 1'000'000'000)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		// If uid is equal to the real user ID or the saved set-user-ID, or if the process has appropriate privileges, seteuid()
 		// shall set the effective user ID of the calling process to uid; the real user ID and saved set-user-ID shall remain unchanged.
@@ -1643,7 +1642,7 @@ namespace Kernel
 		if (gid < 0 || gid >= 1'000'000'000)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		// If gid is equal to the real group ID or the saved set-group-ID, or if the process has appropriate privileges, setegid()
 		// shall set the effective group ID of the calling process to gid; the real group ID, saved set-group-ID, and any
@@ -1671,7 +1670,7 @@ namespace Kernel
 		// by the ruid and euid arguments. If ruid or euid is -1, the corresponding effective or real user ID of the current
 		// process shall be left unchanged.
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		// A process with appropriate privileges can set either ID to any value.
 		if (!m_credentials.is_superuser())
@@ -1719,7 +1718,7 @@ namespace Kernel
 
 		// The real and effective group IDs may be set to different values in the same call.
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		// Only a process with appropriate privileges can set the real group ID and the effective group ID to any valid value.
 		if (!m_credentials.is_superuser())
@@ -1752,7 +1751,7 @@ namespace Kernel
 		if (pgid < 0)
 			return BAN::Error::from_errno(EINVAL);
 
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		if (pid == 0)
 			pid = m_pid;
@@ -1817,7 +1816,7 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_getpgid(pid_t pid)
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		if (pid == 0 || pid == m_pid)
 			return m_pgrp;
@@ -1849,7 +1848,7 @@ namespace Kernel
 
 	BAN::ErrorOr<BAN::String> Process::absolute_path_of(BAN::StringView path) const
 	{
-		LockGuard _(m_process_lock);
+		LockGuard _(m_big_mutex);
 
 		if (path.empty() || path == "."sv)
 			return m_working_directory;

kernel/kernel/Scheduler.cpp

@@ -1,8 +1,8 @@
 #include <kernel/Arch.h>
 #include <kernel/Attributes.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/GDT.h>
 #include <kernel/InterruptController.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
 #include <kernel/Timer/Timer.h>
@@ -32,13 +32,45 @@ namespace Kernel
 		asm volatile("movq %0, %%rsp" :: "r"(s_temp_stack + sizeof(s_temp_stack)));
 	}
 
+	void SchedulerLock::lock()
+	{
+		auto tid = Scheduler::current_tid();
+		if (tid != m_locker)
+		{
+			while (!m_locker.compare_exchange(-1, tid))
+				__builtin_ia32_pause();
+			ASSERT_EQ(m_lock_depth, 0);
+		}
+		m_lock_depth++;
+	}
+
+	void SchedulerLock::unlock()
+	{
+		ASSERT_EQ(m_locker.load(), Scheduler::current_tid());
+		ASSERT_GT(m_lock_depth, 0);
+		if (--m_lock_depth == 0)
+			m_locker = -1;
+	}
+
+	void SchedulerLock::unlock_all()
+	{
+		ASSERT_EQ(m_locker.load(), Scheduler::current_tid());
+		ASSERT_GT(m_lock_depth, 0);
+		m_lock_depth = 0;
+		m_locker = -1;
+	}
+
+	pid_t SchedulerLock::locker() const
+	{
+		return m_locker;
+	}
+
 	BAN::ErrorOr<void> Scheduler::initialize()
 	{
 		ASSERT(s_instance == nullptr);
-		Scheduler* scheduler = new Scheduler();
-		ASSERT(scheduler);
-		scheduler->m_idle_thread = TRY(Thread::create_kernel([](void*) { for (;;) asm volatile("hlt"); }, nullptr, nullptr));
-		s_instance = scheduler;
+		s_instance = new Scheduler();
+		ASSERT(s_instance);
+		s_instance->m_idle_thread = TRY(Thread::create_kernel([](void*) { for (;;) asm volatile("hlt"); }, nullptr, nullptr));
 		return {};
 	}
 
@@ -53,6 +85,7 @@ namespace Kernel
 		VERIFY_CLI();
 		ASSERT(!m_active_threads.empty());
 		m_current_thread = m_active_threads.begin();
+		m_lock.lock();
 		execute_current_thread();
 		ASSERT_NOT_REACHED();
 	}
@@ -64,7 +97,7 @@ namespace Kernel
 
 	pid_t Scheduler::current_tid()
 	{
-		if (s_instance == nullptr)
+		if (s_instance == nullptr || s_instance->m_idle_thread == nullptr)
 			return 0;
 		return Scheduler::get().current_thread().tid();
 	}
@@ -72,6 +105,7 @@ namespace Kernel
 	void Scheduler::timer_reschedule()
 	{
 		VERIFY_CLI();
+		m_lock.lock();
 
 		wake_threads();
 
@@ -85,6 +119,7 @@ namespace Kernel
 	void Scheduler::reschedule()
 	{
 		DISABLE_INTERRUPTS();
+		m_lock.lock();
 
 		if (save_current_thread())
 		{
@@ -99,20 +134,30 @@ namespace Kernel
 	void Scheduler::reschedule_if_idling()
 	{
 		VERIFY_CLI();
+		m_lock.lock();
 
 		if (m_active_threads.empty() || &current_thread() != m_idle_thread)
-			return;
+			return m_lock.unlock();
 
 		if (save_current_thread())
 			return;
-		m_current_thread = m_active_threads.begin();
+		m_current_thread = {};
+		advance_current_thread();
 		execute_current_thread();
 		ASSERT_NOT_REACHED();
 	}
 
+	void Scheduler::reschedule_current_no_save()
+	{
+		VERIFY_CLI();
+		m_lock.lock();
+		execute_current_thread();
+	}
+
 	void Scheduler::wake_threads()
 	{
 		VERIFY_CLI();
+		ASSERT_EQ(m_lock.locker(), current_tid());
 
 		uint64_t current_time = SystemTimer::get().ms_since_boot();
 		while (!m_sleeping_threads.empty() && m_sleeping_threads.front().wake_time <= current_time)
@@ -127,7 +172,7 @@ namespace Kernel
 
 	BAN::ErrorOr<void> Scheduler::add_thread(Thread* thread)
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 		TRY(m_active_threads.emplace_back(thread));
 		return {};
 	}
@@ -135,19 +180,20 @@ namespace Kernel
 	void Scheduler::advance_current_thread()
 	{
 		VERIFY_CLI();
+		ASSERT_EQ(m_lock.locker(), current_tid());
 
 		if (m_active_threads.empty())
-		{
 			m_current_thread = {};
-			return;
-		}
-		if (!m_current_thread || ++m_current_thread == m_active_threads.end())
+		else if (!m_current_thread || ++m_current_thread == m_active_threads.end())
 			m_current_thread = m_active_threads.begin();
+
+		m_lock.m_locker = current_tid();
 	}
 
 	void Scheduler::remove_and_advance_current_thread()
 	{
 		VERIFY_CLI();
+		ASSERT_EQ(m_lock.locker(), current_tid());
 
 		ASSERT(m_current_thread);
 
@@ -162,6 +208,8 @@ namespace Kernel
 			advance_current_thread();
 			m_active_threads.remove(temp);
 		}
+
+		m_lock.m_locker = current_tid();
 	}
 
 	// NOTE: this is declared always inline, so we don't corrupt the stack
@@ -169,6 +217,7 @@ namespace Kernel
 	ALWAYS_INLINE bool Scheduler::save_current_thread()
 	{
 		VERIFY_CLI();
+		ASSERT_EQ(m_lock.locker(), current_tid());
 
 		uintptr_t rsp, rip;
 		push_callee_saved();
@@ -191,6 +240,7 @@ namespace Kernel
 	void Scheduler::delete_current_process_and_thread()
 	{
 		DISABLE_INTERRUPTS();
+		m_lock.lock();
 
 		load_temp_stack();
 		PageTable::kernel().load();
@@ -211,6 +261,7 @@ namespace Kernel
 	void Scheduler::execute_current_thread()
 	{
 		VERIFY_CLI();
+		ASSERT_EQ(m_lock.locker(), current_tid());
 
 		load_temp_stack();
 		PageTable::kernel().load();
@@ -221,6 +272,7 @@ namespace Kernel
 	NEVER_INLINE void Scheduler::_execute_current_thread()
 	{
 		VERIFY_CLI();
+		ASSERT_EQ(m_lock.locker(), current_tid());
 
 #if SCHEDULER_VERIFY_STACK
 		vaddr_t rsp;
@@ -267,10 +319,12 @@ namespace Kernel
 		{
 			case Thread::State::NotStarted:
 				current->set_started();
+				m_lock.unlock_all();
 				start_thread(current->rsp(), current->rip());
 			case Thread::State::Executing:
 				while (current->can_add_signal_to_execute())
 					current->handle_signal();
+				m_lock.unlock_all();
 				continue_thread(current->rsp(), current->rip());
 			case Thread::State::Terminated:
 				ASSERT_NOT_REACHED();
@@ -282,6 +336,7 @@ namespace Kernel
 	void Scheduler::set_current_thread_sleeping_impl(uint64_t wake_time)
 	{
 		VERIFY_CLI();
+		ASSERT_EQ(m_lock.locker(), current_tid());
 
 		if (save_current_thread())
 		{
@@ -302,6 +357,7 @@ namespace Kernel
 		);
 
 		m_current_thread = {};
+		m_lock.m_locker = current_tid();
 		advance_current_thread();
 
 		execute_current_thread();
@@ -312,6 +368,7 @@ namespace Kernel
 	{
 		VERIFY_STI();
 		DISABLE_INTERRUPTS();
+		m_lock.lock();
 
 		ASSERT(m_current_thread);
 
@@ -323,6 +380,7 @@ namespace Kernel
 	{
 		VERIFY_STI();
 		DISABLE_INTERRUPTS();
+		m_lock.lock();
 
 		ASSERT(m_current_thread);
 
@@ -332,7 +390,7 @@ namespace Kernel
 
 	void Scheduler::unblock_threads(Semaphore* semaphore)
 	{
-		CriticalScope critical;
+		LockGuard _(m_lock);
 
 		for (auto it = m_sleeping_threads.begin(); it != m_sleeping_threads.end();)
 		{
@@ -353,7 +411,7 @@ namespace Kernel
 
 	void Scheduler::unblock_thread(pid_t tid)
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 
 		for (auto it = m_sleeping_threads.begin(); it != m_sleeping_threads.end(); it++)
 		{

kernel/kernel/Storage/DiskCache.cpp

@@ -1,4 +1,3 @@
-#include <kernel/CriticalScope.h>
 #include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/PageTable.h>

kernel/kernel/Storage/StorageDevice.cpp

@@ -224,15 +224,12 @@ namespace Kernel
 	{
 		ASSERT(buffer.size() >= sector_count * sector_size());
 
-		{
-			LockGuard _(m_mutex);
-			if (!m_disk_cache.has_value())
-				return read_sectors_impl(lba, sector_count, buffer);
-		}
+		LockGuard _(m_mutex);
+		if (!m_disk_cache.has_value())
+			return read_sectors_impl(lba, sector_count, buffer);
 
 		for (uint64_t offset = 0; offset < sector_count; offset++)
 		{
-			LockGuard _(m_mutex);
 			auto sector_buffer = buffer.slice(offset * sector_size(), sector_size());
 			if (m_disk_cache->read_from_cache(lba + offset, sector_buffer))
 				continue;
@@ -247,15 +244,12 @@ namespace Kernel
 	{
 		ASSERT(buffer.size() >= sector_count * sector_size());
 
-		{
-			LockGuard _(m_mutex);
-			if (!m_disk_cache.has_value())
-				return write_sectors_impl(lba, sector_count, buffer);
-		}
+		LockGuard _(m_mutex);
+		if (!m_disk_cache.has_value())
+			return write_sectors_impl(lba, sector_count, buffer);
 
 		for (uint8_t offset = 0; offset < sector_count; offset++)
 		{
-			LockGuard _(m_mutex);
 			auto sector_buffer = buffer.slice(offset * sector_size(), sector_size());
 			if (m_disk_cache->write_to_cache(lba + offset, sector_buffer, true).is_error())
 				TRY(write_sectors_impl(lba + offset, 1, sector_buffer));

kernel/kernel/Terminal/Serial.cpp

@@ -1,5 +1,4 @@
 #include <BAN/Array.h>
-#include <kernel/CriticalScope.h>
 #include <kernel/Device/DeviceNumbers.h>
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/IDT.h>
@@ -235,7 +234,7 @@ namespace Kernel
 		uint8_t buffer[128];
 
 		{
-			CriticalScope _;
+			LockGuard _(m_lock);
 			if (m_input.empty())
 				return;
 			uint8_t* ptr = buffer;

kernel/kernel/Terminal/TTY.cpp

@@ -310,16 +310,17 @@ namespace Kernel
 
 	void TTY::putchar(uint8_t ch)
 	{
-		SpinLockGuard _(m_write_lock);
+		LockGuard _(m_mutex);
 		if (m_tty_ctrl.draw_graphics)
 			putchar_impl(ch);
 	}
 
 	BAN::ErrorOr<size_t> TTY::read_impl(off_t, BAN::ByteSpan buffer)
 	{
+		LockGuard _(m_mutex);
 		while (!m_output.flush)
 		{
-			LockFreeGuard _(m_mutex);
+			LockFreeGuard free(m_mutex);
 			TRY(Thread::current().block_or_eintr_indefinite(m_output.semaphore));
 		}
 
@@ -345,7 +346,7 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> TTY::write_impl(off_t, BAN::ConstByteSpan buffer)
 	{
-		SpinLockGuard _(m_write_lock);
+		LockGuard _(m_mutex);
 		for (size_t i = 0; i < buffer.size(); i++)
 			putchar(buffer[i]);
 		return buffer.size();
@@ -354,7 +355,7 @@ namespace Kernel
 	void TTY::putchar_current(uint8_t ch)
 	{
 		ASSERT(s_tty);
-		SpinLockGuard _(s_tty->m_write_lock);
+		LockGuard _(s_tty->m_mutex);
 		s_tty->putchar(ch);
 	}
 

kernel/kernel/Terminal/VirtualTTY.cpp

@@ -57,6 +57,7 @@ namespace Kernel
 
 	void VirtualTTY::clear()
 	{
+		LockGuard _(m_write_lock);
 		for (uint32_t i = 0; i < m_width * m_height; i++)
 			m_buffer[i] = { .foreground = m_foreground, .background = m_background, .codepoint = ' ' };
 		m_terminal_driver->clear(m_background);
@@ -64,6 +65,7 @@ namespace Kernel
 
 	void VirtualTTY::set_font(const Kernel::Font& font)
 	{
+		LockGuard _(m_write_lock);
 		m_terminal_driver->set_font(font);
 
 		uint32_t new_width = m_terminal_driver->width();
@@ -306,6 +308,8 @@ namespace Kernel
 
 	void VirtualTTY::putchar_impl(uint8_t ch)
 	{
+		LockGuard _(m_write_lock);
+
 		uint32_t codepoint = ch;
 
 		switch (m_state)

kernel/kernel/Thread.cpp

@@ -3,6 +3,7 @@
 #include <kernel/GDT.h>
 #include <kernel/InterruptController.h>
 #include <kernel/InterruptStack.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/Memory/kmalloc.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
@@ -29,10 +30,10 @@ namespace Kernel
 
 	void Thread::terminate()
 	{
-		CriticalScope _;
+		LockGuard _(m_lock);
 		m_state = Thread::State::Terminated;
 		if (this == &Thread::current())
-			Scheduler::get().execute_current_thread();
+			Scheduler::get().reschedule_current_no_save();
 	}
 
 	static pid_t s_next_tid = 1;
@@ -46,14 +47,7 @@ namespace Kernel
 		BAN::ScopeGuard thread_deleter([thread] { delete thread; });
 
 		// Initialize stack and registers
-		thread->m_stack = TRY(VirtualRange::create_to_vaddr_range(
-			PageTable::kernel(),
-			KERNEL_OFFSET,
-			~(uintptr_t)0,
-			m_kernel_stack_size,
-			PageTable::Flags::ReadWrite | PageTable::Flags::Present,
-			true
-		));
+		thread->m_stack = TRY(VirtualRange::create_kmalloc(m_kernel_stack_size));
 		thread->m_rsp = thread->stack_base() + thread->stack_size();
 		thread->m_rip = (uintptr_t)entry;
 
@@ -137,6 +131,8 @@ namespace Kernel
 
 	BAN::ErrorOr<Thread*> Thread::clone(Process* new_process, uintptr_t rsp, uintptr_t rip)
 	{
+		LockGuard _(m_lock);
+
 		ASSERT(m_is_userspace);
 		ASSERT(m_state == State::Executing);
 
@@ -162,6 +158,8 @@ namespace Kernel
 
 	void Thread::setup_exec()
 	{
+		LockGuard _(m_lock);
+
 		ASSERT(is_userspace());
 		m_state = State::NotStarted;
 		static entry_t entry_trampoline(
@@ -178,9 +176,12 @@ namespace Kernel
 		// Signal mask is inherited
 
 		// Setup stack for returning
-		ASSERT_EQ(m_rsp % PAGE_SIZE, 0u);
-		PageTable::with_fast_page(process().page_table().physical_address_of(m_rsp - PAGE_SIZE), [&] {
-			uintptr_t rsp = PageTable::fast_page() + PAGE_SIZE;
+		uintptr_t offset = m_rsp % PAGE_SIZE;
+		if (offset == 0)
+			offset = PAGE_SIZE;
+		ASSERT_GTE(offset, 4 * sizeof(uintptr_t));
+		PageTable::with_fast_page(process().page_table().physical_address_of((m_rsp - 4 * sizeof(uintptr_t)) & PAGE_ADDR_MASK), [&] {
+			uintptr_t rsp = PageTable::fast_page() + offset;
 			write_to_stack(rsp, nullptr); // alignment
 			write_to_stack(rsp, this);
 			write_to_stack(rsp, &Thread::on_exit);
@@ -191,6 +192,8 @@ namespace Kernel
 
 	void Thread::setup_process_cleanup()
 	{
+		LockGuard _(m_lock);
+
 		m_state = State::NotStarted;
 		static entry_t entry(
 			[](void* process)
@@ -206,9 +209,12 @@ namespace Kernel
 		m_signal_pending_mask = 0;
 		m_signal_block_mask = ~0ull;
 
-		ASSERT_EQ(m_rsp % PAGE_SIZE, 0u);
-		PageTable::with_fast_page(process().page_table().physical_address_of(m_rsp - PAGE_SIZE), [&] {
-			uintptr_t rsp = PageTable::fast_page() + PAGE_SIZE;
+		uintptr_t offset = m_rsp % PAGE_SIZE;
+		if (offset == 0)
+			offset = PAGE_SIZE;
+		ASSERT_GTE(offset, 4 * sizeof(uintptr_t));
+		PageTable::with_fast_page(process().page_table().physical_address_of((m_rsp - 4 * sizeof(uintptr_t)) & PAGE_ADDR_MASK), [&] {
+			uintptr_t rsp = PageTable::fast_page() + offset;
 			write_to_stack(rsp, nullptr); // alignment
 			write_to_stack(rsp, this);
 			write_to_stack(rsp, &Thread::on_exit);
@@ -219,6 +225,7 @@ namespace Kernel
 
 	bool Thread::is_interrupted_by_signal()
 	{
+		LockGuard _(m_lock);
 		while (can_add_signal_to_execute())
 			handle_signal();
 		return will_execute_signal();
@@ -226,6 +233,7 @@ namespace Kernel
 
 	bool Thread::can_add_signal_to_execute() const
 	{
+		LockGuard _(m_lock);
 		if (!is_userspace() || m_state != State::Executing)
 			return false;
 		auto& interrupt_stack = *reinterpret_cast<InterruptStack*>(interrupt_stack_base() + interrupt_stack_size() - sizeof(InterruptStack));
@@ -237,6 +245,7 @@ namespace Kernel
 
 	bool Thread::will_execute_signal() const
 	{
+		LockGuard _(m_lock);
 		if (!is_userspace() || m_state != State::Executing)
 			return false;
 		auto& interrupt_stack = *reinterpret_cast<InterruptStack*>(interrupt_stack_base() + interrupt_stack_size() - sizeof(InterruptStack));
@@ -245,6 +254,7 @@ namespace Kernel
 
 	void Thread::handle_signal(int signal)
 	{
+		LockGuard _(m_lock);
 		ASSERT(!interrupts_enabled());
 		ASSERT(&Thread::current() == this);
 		ASSERT(is_userspace());
@@ -338,6 +348,7 @@ namespace Kernel
 
 	bool Thread::add_signal(int signal)
 	{
+		LockGuard _(m_lock);
 		ASSERT(!interrupts_enabled());
 		uint64_t mask = 1ull << signal;
 		if (!(m_signal_block_mask & mask))
@@ -380,6 +391,7 @@ namespace Kernel
 
 	void Thread::validate_stack() const
 	{
+		LockGuard _(m_lock);
 		if (stack_base() <= m_rsp && m_rsp <= stack_base() + stack_size())
 			return;
 		if (interrupt_stack_base() <= m_rsp && m_rsp <= interrupt_stack_base() + interrupt_stack_size())

kernel/kernel/Timer/HPET.cpp

@@ -1,4 +1,5 @@
 #include <BAN/ScopeGuard.h>
+#include <kernel/Lock/LockGuard.h>
 #include <kernel/ACPI.h>
 #include <kernel/IDT.h>
 #include <kernel/InterruptController.h>
@@ -244,7 +245,7 @@ namespace Kernel
 		if (m_is_64bit)
 			return regs.main_counter.full;
 
-		CriticalScope _;
+		LockGuard _(m_lock);
 		uint32_t current_low = regs.main_counter.low;
 		uint32_t wraps = m_32bit_wraps;
 		if (current_low < (uint32_t)m_last_ticks)
@@ -256,19 +257,21 @@ namespace Kernel
 	{
 		auto& regs = registers();
 
-		uint64_t current_ticks;
-
-		if (m_is_64bit)
-			current_ticks = regs.main_counter.full;
-		else
 		{
-			uint32_t current_low = regs.main_counter.low;
-			if (current_low < (uint32_t)m_last_ticks)
-				m_32bit_wraps++;
-			current_ticks = ((uint64_t)m_32bit_wraps << 32) | current_low;
-		}
+			LockGuard _(m_lock);
 
-		m_last_ticks = current_ticks;
+			uint64_t current_ticks;
+			if (m_is_64bit)
+				current_ticks = regs.main_counter.full;
+			else
+			{
+				uint32_t current_low = regs.main_counter.low;
+				if (current_low < (uint32_t)m_last_ticks)
+					m_32bit_wraps++;
+				current_ticks = ((uint64_t)m_32bit_wraps << 32) | current_low;
+			}
+			m_last_ticks = current_ticks;
+		}
 
 		Scheduler::get().timer_reschedule();
 	}