Kernel: Rewrite all read/write functions to use BAN::ByteSpan

This allows us to not work with raw pointers and use sized containers
for reading and writing.

LibELF/LibELF/LoadableELF.cpp

@@ -62,7 +62,7 @@ namespace LibELF
 			return BAN::Error::from_errno(ENOEXEC);
 		}
 
-		size_t nread = TRY(m_inode->read(0, &m_file_header, sizeof(m_file_header)));
+		size_t nread = TRY(m_inode->read(0, BAN::ByteSpan::from(m_file_header)));
 		ASSERT(nread == sizeof(m_file_header));
 
 		if (m_file_header.e_ident[EI_MAG0] != ELFMAG0 || 
@@ -113,7 +113,7 @@ namespace LibELF
 		TRY(m_program_headers.resize(m_file_header.e_phnum));
 		for (size_t i = 0; i < m_file_header.e_phnum; i++)
 		{
-			TRY(m_inode->read(m_file_header.e_phoff + m_file_header.e_phentsize * i, &m_program_headers[i], m_file_header.e_phentsize));
+			TRY(m_inode->read(m_file_header.e_phoff + m_file_header.e_phentsize * i, BAN::ByteSpan::from(m_program_headers[i])));
 
 			const auto& pheader = m_program_headers[i];
 			if (pheader.p_type != PT_NULL && pheader.p_type != PT_LOAD)
@@ -242,7 +242,7 @@ namespace LibELF
 							file_offset = vaddr - program_header.p_vaddr;
 
 						size_t bytes = BAN::Math::min<size_t>(PAGE_SIZE - vaddr_offset, program_header.p_filesz - file_offset);
-						TRY(m_inode->read(program_header.p_offset + file_offset, (void*)(vaddr + vaddr_offset), bytes));
+						TRY(m_inode->read(program_header.p_offset + file_offset, { (uint8_t*)vaddr + vaddr_offset, bytes }));
 					}
 
 					return {};

kernel/include/kernel/Device/NullDevice.h

@@ -20,8 +20,8 @@ namespace Kernel
 			, m_rdev(rdev)
 		{ }
 
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override { return 0; }
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override { return 0; }
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t size) override { return size; };
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan buffer) override { return buffer.size(); };
 
 	private:
 		const dev_t m_rdev;

kernel/include/kernel/Device/ZeroDevice.h

@@ -18,8 +18,8 @@ namespace Kernel
 			, m_rdev(rdev)
 		{ }
 
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t size) override { return size; };
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan buffer) override { return buffer.size(); };
 
 	private:
 		const dev_t m_rdev;

kernel/include/kernel/FS/Ext2/FileSystem.h

@@ -33,6 +33,9 @@ namespace Kernel
 			uint8_t* data() { return m_buffer.data(); }
 			const uint8_t* data() const { return m_buffer.data(); }
 
+			BAN::ByteSpan span() { return m_buffer; }
+			BAN::ConstByteSpan span() const { return m_buffer.as_const(); }
+
 			uint8_t& operator[](size_t index) { return m_buffer[index]; }
 			uint8_t operator[](size_t index) const { return m_buffer[index]; }
 

kernel/include/kernel/FS/Ext2/Inode.h

@@ -34,8 +34,8 @@ namespace Kernel
 		
 		virtual BAN::ErrorOr<BAN::String> link_target_impl() override;
 
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
 		virtual BAN::ErrorOr<void> truncate_impl(size_t) override;
 
 	private:

kernel/include/kernel/FS/Inode.h

@@ -1,10 +1,11 @@
 #pragma once
 
+#include <BAN/ByteSpan.h>
 #include <BAN/RefPtr.h>
 #include <BAN/String.h>
 #include <BAN/StringView.h>
-#include <BAN/WeakPtr.h>
 #include <BAN/Vector.h>
+#include <BAN/WeakPtr.h>
 
 #include <kernel/API/DirectoryEntry.h>
 #include <kernel/Credentials.h>
@@ -95,8 +96,8 @@ namespace Kernel
 		BAN::ErrorOr<BAN::String> link_target();
 
 		// General API
-		BAN::ErrorOr<size_t> read(off_t, void*, size_t);
+		BAN::ErrorOr<size_t> read(off_t, BAN::ByteSpan buffer);
-		BAN::ErrorOr<size_t> write(off_t, const void*, size_t);
+		BAN::ErrorOr<size_t> write(off_t, BAN::ConstByteSpan buffer);
 		BAN::ErrorOr<void> truncate(size_t);
 		bool has_data() const;
 
@@ -111,8 +112,8 @@ namespace Kernel
 		virtual BAN::ErrorOr<BAN::String> link_target_impl()				{ return BAN::Error::from_errno(ENOTSUP); }
 
 		// General API
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t)		{ return BAN::Error::from_errno(ENOTSUP); }
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan)		{ return BAN::Error::from_errno(ENOTSUP); }
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t)	{ return BAN::Error::from_errno(ENOTSUP); }
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan)	{ return BAN::Error::from_errno(ENOTSUP); }
 		virtual BAN::ErrorOr<void> truncate_impl(size_t)					{ return BAN::Error::from_errno(ENOTSUP); }
 		virtual bool has_data_impl() const { dwarnln("nonblock not supported"); return true; }
 

kernel/include/kernel/FS/Pipe.h

@@ -31,8 +31,8 @@ namespace Kernel
 		virtual dev_t rdev() const override { return 0; } // FIXME
 
 	protected:
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
 
 	private:
 		Pipe(const Credentials&);

kernel/include/kernel/FS/ProcFS/Inode.h

@@ -23,23 +23,23 @@ namespace Kernel
 	class ProcROInode final : public RamInode
 	{
 	public:
-		static BAN::ErrorOr<BAN::RefPtr<ProcROInode>> create(Process&, size_t (Process::*callback)(off_t, void*, size_t) const, RamFileSystem&, mode_t, uid_t, gid_t);
+		static BAN::ErrorOr<BAN::RefPtr<ProcROInode>> create(Process&, size_t (Process::*callback)(off_t, BAN::ByteSpan) const, RamFileSystem&, mode_t, uid_t, gid_t);
 		~ProcROInode() = default;
 
 	protected:
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
 
 		// You may not write here and this is always non blocking
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t)	override	{ return BAN::Error::from_errno(EINVAL); }
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan)	override	{ return BAN::Error::from_errno(EINVAL); }
 		virtual BAN::ErrorOr<void> truncate_impl(size_t) override						{ return BAN::Error::from_errno(EINVAL); }
 		virtual bool has_data_impl() const override										{ return true; }
 
 	private:
-		ProcROInode(Process&, size_t (Process::*)(off_t, void*, size_t) const, RamFileSystem&, const FullInodeInfo&);
+		ProcROInode(Process&, size_t (Process::*)(off_t, BAN::ByteSpan) const, RamFileSystem&, const FullInodeInfo&);
 	
 	private:
 		Process& m_process;
-		size_t (Process::*m_callback)(off_t, void*, size_t) const;
+		size_t (Process::*m_callback)(off_t, BAN::ByteSpan) const;
 	};
 
 }

kernel/include/kernel/FS/RamFS/Inode.h

@@ -70,8 +70,8 @@ namespace Kernel
 	protected:
 		RamFileInode(RamFileSystem&, const FullInodeInfo&);
 
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
 		virtual BAN::ErrorOr<void> truncate_impl(size_t) override;
 
 	private:

kernel/include/kernel/Input/PS2Keyboard.h

@@ -63,7 +63,7 @@ namespace Kernel::Input
 		virtual dev_t rdev() const override { return m_rdev; }
 
 	protected:
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
 
 	private:
 		const dev_t m_rdev;

kernel/include/kernel/OpenFileDescriptorSet.h

@@ -41,8 +41,8 @@ namespace Kernel
 		void close_all();
 		void close_cloexec();
 
-		BAN::ErrorOr<size_t> read(int fd, void* buffer, size_t count);
+		BAN::ErrorOr<size_t> read(int fd, BAN::ByteSpan);
-		BAN::ErrorOr<size_t> write(int fd, const void* buffer, size_t count);
+		BAN::ErrorOr<size_t> write(int fd, BAN::ConstByteSpan);
 
 		BAN::ErrorOr<void> read_dir_entries(int fd, DirectoryEntryList* list, size_t list_size);
 

kernel/include/kernel/Process.h

@@ -139,9 +139,9 @@ namespace Kernel
 
 		PageTable& page_table() { return m_page_table ? *m_page_table : PageTable::kernel(); }
 
-		size_t proc_meminfo(off_t offset, void* buffer, size_t buffer_size) const;
+		size_t proc_meminfo(off_t offset, BAN::ByteSpan) const;
-		size_t proc_cmdline(off_t offset, void* buffer, size_t buffer_size) const;
+		size_t proc_cmdline(off_t offset, BAN::ByteSpan) const;
-		size_t proc_environ(off_t offset, void* buffer, size_t buffer_size) const;
+		size_t proc_environ(off_t offset, BAN::ByteSpan) const;
 
 		bool is_userspace() const { return m_is_userspace; }
 		const userspace_info_t& userspace_info() const { return m_userspace_info; }

kernel/include/kernel/Storage/ATA/AHCI/Device.h

@@ -23,8 +23,8 @@ namespace Kernel
 		BAN::ErrorOr<void> rebase();
 		BAN::ErrorOr<void> read_identify_data();
 
-		virtual BAN::ErrorOr<void> read_sectors_impl(uint64_t lba, uint64_t sector_count, uint8_t* buffer) override;
+		virtual BAN::ErrorOr<void> read_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<void> write_sectors_impl(uint64_t lba, uint64_t sector_count, const uint8_t* buffer) override;
+		virtual BAN::ErrorOr<void> write_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan) override;
 		BAN::ErrorOr<void> send_command_and_block(uint64_t lba, uint64_t sector_count, Command command);
 
 		BAN::Optional<uint32_t> find_free_command_slot();

kernel/include/kernel/Storage/ATA/ATABus.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <BAN/ByteSpan.h>
 #include <BAN/RefPtr.h>
 #include <BAN/Vector.h>
 #include <kernel/InterruptController.h>
@@ -22,8 +23,8 @@ namespace Kernel
 	public:
 		static BAN::ErrorOr<BAN::RefPtr<ATABus>> create(uint16_t base, uint16_t ctrl, uint8_t irq);
 
-		BAN::ErrorOr<void> read(ATADevice&, uint64_t, uint8_t, uint8_t*);
+		BAN::ErrorOr<void> read(ATADevice&, uint64_t lba, uint64_t sector_count, BAN::ByteSpan);
-		BAN::ErrorOr<void> write(ATADevice&, uint64_t, uint8_t, const uint8_t*);
+		BAN::ErrorOr<void> write(ATADevice&, uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan);
 
 		virtual void handle_irq() override;
 

kernel/include/kernel/Storage/ATA/ATADevice.h

@@ -32,8 +32,8 @@ namespace Kernel
 
 			virtual dev_t rdev() const override { return m_rdev; }
 
-			virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+			virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
-			virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t) override;
+			virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
 
 		protected:
 			ATABaseDevice();
@@ -63,8 +63,8 @@ namespace Kernel
 	private:
 		ATADevice(BAN::RefPtr<ATABus>, ATABus::DeviceType, bool is_secodary);
 		
-		virtual BAN::ErrorOr<void> read_sectors_impl(uint64_t, uint64_t, uint8_t*) override;
+		virtual BAN::ErrorOr<void> read_sectors_impl(uint64_t, uint64_t, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<void> write_sectors_impl(uint64_t, uint64_t, const uint8_t*) override;
+		virtual BAN::ErrorOr<void> write_sectors_impl(uint64_t, uint64_t, BAN::ConstByteSpan) override;
 
 	private:
 		BAN::RefPtr<ATABus> m_bus;

kernel/include/kernel/Storage/DiskCache.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <BAN/Array.h>
+#include <BAN/ByteSpan.h>
 #include <kernel/Memory/Types.h>
 #include <kernel/SpinLock.h>
 
@@ -15,8 +16,8 @@ namespace Kernel
 		DiskCache(size_t sector_size, StorageDevice&);
 		~DiskCache();
 
-		bool read_from_cache(uint64_t sector, uint8_t* buffer);
+		bool read_from_cache(uint64_t sector, BAN::ByteSpan);
-		BAN::ErrorOr<void> write_to_cache(uint64_t sector, const uint8_t* buffer, bool dirty);
+		BAN::ErrorOr<void> write_to_cache(uint64_t sector, BAN::ConstByteSpan, bool dirty);
 
 		BAN::ErrorOr<void> sync();
 		size_t release_clean_pages(size_t);

kernel/include/kernel/Storage/StorageDevice.h

@@ -30,8 +30,8 @@ namespace Kernel
 		const char* label() const { return m_label; }
 		const StorageDevice& device() const { return m_device; }
 
-		BAN::ErrorOr<void> read_sectors(uint64_t lba, uint8_t sector_count, uint8_t* buffer);
+		BAN::ErrorOr<void> read_sectors(uint64_t lba, uint8_t sector_count, BAN::ByteSpan);
-		BAN::ErrorOr<void> write_sectors(uint64_t lba, uint8_t sector_count, const uint8_t* buffer);
+		BAN::ErrorOr<void> write_sectors(uint64_t lba, uint8_t sector_count, BAN::ConstByteSpan);
 		
 		virtual BAN::StringView name() const override { return m_name; }
 
@@ -57,7 +57,7 @@ namespace Kernel
 		virtual dev_t rdev() const override { return m_rdev; }
 
 	protected:
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
 
 	private:
 		const dev_t m_rdev;
@@ -73,8 +73,8 @@ namespace Kernel
 
 		BAN::ErrorOr<void> initialize_partitions();
 
-		BAN::ErrorOr<void> read_sectors(uint64_t lba, uint64_t sector_count, uint8_t* buffer);
+		BAN::ErrorOr<void> read_sectors(uint64_t lba, uint64_t sector_count, BAN::ByteSpan);
-		BAN::ErrorOr<void> write_sectors(uint64_t lba, uint64_t sector_count, const uint8_t* buffer);
+		BAN::ErrorOr<void> write_sectors(uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan);
 
 		virtual uint32_t sector_size() const = 0;
 		virtual uint64_t total_size() const = 0;
@@ -86,8 +86,8 @@ namespace Kernel
 		virtual bool is_storage_device() const override { return true; }
 
 	protected:
-		virtual BAN::ErrorOr<void> read_sectors_impl(uint64_t lba, uint64_t sector_count, uint8_t* buffer) = 0;
+		virtual BAN::ErrorOr<void> read_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ByteSpan) = 0;
-		virtual BAN::ErrorOr<void> write_sectors_impl(uint64_t lba, uint64_t sector_count, const uint8_t* buffer) = 0;
+		virtual BAN::ErrorOr<void> write_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan) = 0;
 		void add_disk_cache();
 
 	private:

kernel/include/kernel/Terminal/TTY.h

@@ -49,8 +49,8 @@ namespace Kernel
 		{ }
 
 		virtual void putchar_impl(uint8_t ch) = 0;
-		virtual BAN::ErrorOr<size_t> read_impl(off_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
-		virtual BAN::ErrorOr<size_t> write_impl(off_t, const void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
 
 	private:
 		void do_backspace();

kernel/kernel/Device/ZeroDevice.cpp

@@ -12,10 +12,10 @@ namespace Kernel
 		return BAN::RefPtr<ZeroDevice>::adopt(result);
 	}
 
-	BAN::ErrorOr<size_t> ZeroDevice::read_impl(off_t, void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> ZeroDevice::read_impl(off_t, BAN::ByteSpan buffer)
 	{
-		memset(buffer, 0, bytes);
+		memset(buffer.data(), 0, buffer.size());
-		return bytes;
+		return buffer.size();
 	}
 
 }

kernel/kernel/FS/Ext2/FileSystem.cpp

@@ -33,7 +33,7 @@ namespace Kernel
 			BAN::Vector<uint8_t> superblock_buffer;
 			TRY(superblock_buffer.resize(sector_count * sector_size));
 
-			TRY(m_partition.read_sectors(lba, sector_count, superblock_buffer.data()));
+			TRY(m_partition.read_sectors(lba, sector_count, superblock_buffer.span()));
 
 			memcpy(&m_superblock, superblock_buffer.data(), sizeof(Ext2::Superblock));
 		}
@@ -223,7 +223,7 @@ namespace Kernel
 
 		ASSERT(block >= 2);
 		ASSERT(buffer.size() >= block_size);
-		MUST(m_partition.read_sectors(sectors_before + (block - 2) * sectors_per_block, sectors_per_block, buffer.data()));
+		MUST(m_partition.read_sectors(sectors_before + (block - 2) * sectors_per_block, sectors_per_block, buffer.span()));
 	}
 
 	void Ext2FS::write_block(uint32_t block, const BlockBufferWrapper& buffer)
@@ -237,7 +237,7 @@ namespace Kernel
 
 		ASSERT(block >= 2);
 		ASSERT(buffer.size() >= block_size);
-		MUST(m_partition.write_sectors(sectors_before + (block - 2) * sectors_per_block, sectors_per_block, buffer.data()));
+		MUST(m_partition.write_sectors(sectors_before + (block - 2) * sectors_per_block, sectors_per_block, buffer.span()));
 	}
 
 	void Ext2FS::sync_superblock()
@@ -258,11 +258,11 @@ namespace Kernel
 		BAN::Vector<uint8_t> superblock_buffer;
 		MUST(superblock_buffer.resize(sector_count * sector_size));
 
-		MUST(m_partition.read_sectors(lba, sector_count, superblock_buffer.data()));
+		MUST(m_partition.read_sectors(lba, sector_count, superblock_buffer.span()));
 		if (memcmp(superblock_buffer.data(), &m_superblock, superblock_bytes))
 		{
 			memcpy(superblock_buffer.data(), &m_superblock, superblock_bytes);
-			MUST(m_partition.write_sectors(lba, sector_count, superblock_buffer.data()));
+			MUST(m_partition.write_sectors(lba, sector_count, superblock_buffer.span()));
 		}
 	}
 

kernel/kernel/FS/Ext2/Inode.cpp

@@ -100,19 +100,21 @@ namespace Kernel
 		return BAN::Error::from_errno(ENOTSUP);
 	}
 
-	BAN::ErrorOr<size_t> Ext2Inode::read_impl(off_t offset, void* buffer, size_t count)
+	BAN::ErrorOr<size_t> Ext2Inode::read_impl(off_t offset, BAN::ByteSpan buffer)
 	{
 		// FIXME: update atime if needed
 
 		ASSERT(!mode().ifdir());
 		ASSERT(offset >= 0);
 
-		if (offset >= UINT32_MAX || count >= UINT32_MAX || offset + count >= UINT32_MAX)
+		if (offset >= UINT32_MAX || buffer.size() >= UINT32_MAX || buffer.size() >= (size_t)(UINT32_MAX - offset))
 			return BAN::Error::from_errno(EOVERFLOW);
 
 		if (offset >= m_inode.size)
 			return 0;
-		if (offset + count > m_inode.size)
+		
+		uint32_t count = buffer.size();
+		if (offset + buffer.size() > m_inode.size)
 			count = m_inode.size - offset;
 
 		const uint32_t block_size = blksize();
@@ -131,7 +133,7 @@ namespace Kernel
 
 			uint32_t copy_offset = (offset + n_read) % block_size;
 			uint32_t to_copy = BAN::Math::min<uint32_t>(block_size - copy_offset, count - n_read);
-			memcpy((uint8_t*)buffer + n_read, block_buffer.data() + copy_offset, to_copy);
+			memcpy(buffer.data() + n_read, block_buffer.data() + copy_offset, to_copy);
 
 			n_read += to_copy;
 		}
@@ -139,26 +141,25 @@ namespace Kernel
 		return n_read;
 	}
 
-	BAN::ErrorOr<size_t> Ext2Inode::write_impl(off_t offset, const void* buffer, size_t count)
+	BAN::ErrorOr<size_t> Ext2Inode::write_impl(off_t offset, BAN::ConstByteSpan buffer)
 	{
 		// FIXME: update atime if needed
 
 		ASSERT(!mode().ifdir());
 		ASSERT(offset >= 0);
 
-		if (offset >= UINT32_MAX || count >= UINT32_MAX || offset + count >= UINT32_MAX)
+		if (offset >= UINT32_MAX || buffer.size() >= UINT32_MAX || buffer.size() >= (size_t)(UINT32_MAX - offset))
 			return BAN::Error::from_errno(EOVERFLOW);
 
-		if (m_inode.size < offset + count)
+		if (m_inode.size < offset + buffer.size())
-			TRY(truncate_impl(offset + count));
+			TRY(truncate_impl(offset + buffer.size()));
 
 		const uint32_t block_size = blksize();
 
 		auto block_buffer = m_fs.get_block_buffer();
 
-		const uint8_t* u8buffer = (const uint8_t*)buffer;
+		size_t written = 0;
-
+		size_t to_write = buffer.size();
-		size_t to_write = count;
 
 		// Write partial block
 		if (offset % block_size)
@@ -169,10 +170,10 @@ namespace Kernel
 			uint32_t to_copy = BAN::Math::min<uint32_t>(block_size - block_offset, to_write);
 
 			m_fs.read_block(block_index, block_buffer);
-			memcpy(block_buffer.data() + block_offset, u8buffer, to_copy);
+			memcpy(block_buffer.data() + block_offset, buffer.data(), to_copy);
 			m_fs.write_block(block_index, block_buffer);
 
-			u8buffer += to_copy;
+			written += to_copy;
 			offset += to_copy;
 			to_write -= to_copy;
 		}
@@ -181,10 +182,10 @@ namespace Kernel
 		{
 			uint32_t block_index = fs_block_of_data_block_index(offset / block_size);
 
-			memcpy(block_buffer.data(), u8buffer, block_buffer.size());
+			memcpy(block_buffer.data(), buffer.data() + written, block_buffer.size());
 			m_fs.write_block(block_index, block_buffer);
 
-			u8buffer += block_size;
+			written += block_size;
 			offset += block_size;
 			to_write -= block_size;
 		}
@@ -194,11 +195,11 @@ namespace Kernel
 			uint32_t block_index = fs_block_of_data_block_index(offset / block_size);
 
 			m_fs.read_block(block_index, block_buffer);
-			memcpy(block_buffer.data(), u8buffer, to_write);
+			memcpy(block_buffer.data(), buffer.data() + written, to_write);
 			m_fs.write_block(block_index, block_buffer);
 		}
 
-		return count;
+		return buffer.size();
 	}
 
 	BAN::ErrorOr<void> Ext2Inode::truncate_impl(size_t new_size)

kernel/kernel/FS/Inode.cpp

@@ -102,22 +102,22 @@ namespace Kernel
 		return link_target_impl();
 	}
 
-	BAN::ErrorOr<size_t> Inode::read(off_t offset, void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> Inode::read(off_t offset, BAN::ByteSpan buffer)
 	{
 		LockGuard _(m_lock);
 		Thread::TerminateBlocker blocker(Thread::current());
 		if (mode().ifdir())
 			return BAN::Error::from_errno(EISDIR);
-		return read_impl(offset, buffer, bytes);
+		return read_impl(offset, buffer);
 	}
 
-	BAN::ErrorOr<size_t> Inode::write(off_t offset, const void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> Inode::write(off_t offset, BAN::ConstByteSpan buffer)
 	{
 		LockGuard _(m_lock);
 		Thread::TerminateBlocker blocker(Thread::current());
 		if (mode().ifdir())
 			return BAN::Error::from_errno(EISDIR);
-		return write_impl(offset, buffer, bytes);
+		return write_impl(offset, buffer);
 	}
 
 	BAN::ErrorOr<void> Inode::truncate(size_t size)

kernel/kernel/FS/Pipe.cpp

@@ -39,7 +39,7 @@ namespace Kernel
 			m_semaphore.unblock();
 	}
 
-	BAN::ErrorOr<size_t> Pipe::read_impl(off_t, void* buffer, size_t count)
+	BAN::ErrorOr<size_t> Pipe::read_impl(off_t, BAN::ByteSpan buffer)
 	{
 		LockGuard _(m_lock);
 		while (m_buffer.empty())
@@ -51,8 +51,8 @@ namespace Kernel
 			m_lock.lock();
 		}
 
-		size_t to_copy = BAN::Math::min<size_t>(count, m_buffer.size());
+		size_t to_copy = BAN::Math::min<size_t>(buffer.size(), m_buffer.size());
-		memcpy(buffer, m_buffer.data(), to_copy);
+		memcpy(buffer.data(), m_buffer.data(), to_copy);
 
 		memmove(m_buffer.data(), m_buffer.data() + to_copy, m_buffer.size() - to_copy);
 		MUST(m_buffer.resize(m_buffer.size() - to_copy));
@@ -64,14 +64,14 @@ namespace Kernel
 		return to_copy;
 	}
 
-	BAN::ErrorOr<size_t> Pipe::write_impl(off_t, const void* buffer, size_t count)
+	BAN::ErrorOr<size_t> Pipe::write_impl(off_t, BAN::ConstByteSpan buffer)
 	{
 		LockGuard _(m_lock);
 
 		size_t old_size = m_buffer.size();
 
-		TRY(m_buffer.resize(old_size + count));
+		TRY(m_buffer.resize(old_size + buffer.size()));
-		memcpy(m_buffer.data() + old_size, buffer, count);
+		memcpy(m_buffer.data() + old_size, buffer.data(), buffer.size());
 
 		timespec current_time = SystemTimer::get().real_time();
 		m_mtime = current_time;
@@ -79,7 +79,7 @@ namespace Kernel
 
 		m_semaphore.unblock();
 
-		return count;
+		return buffer.size();
 	}
 
 }

kernel/kernel/FS/ProcFS/Inode.cpp

@@ -25,7 +25,7 @@ namespace Kernel
 	{
 	}
 
-	BAN::ErrorOr<BAN::RefPtr<ProcROInode>> ProcROInode::create(Process& process, size_t (Process::*callback)(off_t, void*, size_t) const, RamFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
+	BAN::ErrorOr<BAN::RefPtr<ProcROInode>> ProcROInode::create(Process& process, size_t (Process::*callback)(off_t, BAN::ByteSpan) const, RamFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
 	{
 		FullInodeInfo inode_info(fs, mode, uid, gid);
 
@@ -35,7 +35,7 @@ namespace Kernel
 		return BAN::RefPtr<ProcROInode>::adopt(inode_ptr);
 	}
 
-	ProcROInode::ProcROInode(Process& process, size_t (Process::*callback)(off_t, void*, size_t) const, RamFileSystem& fs, const FullInodeInfo& inode_info)
+	ProcROInode::ProcROInode(Process& process, size_t (Process::*callback)(off_t, BAN::ByteSpan) const, RamFileSystem& fs, const FullInodeInfo& inode_info)
 		: RamInode(fs, inode_info)
 		, m_process(process)
 		, m_callback(callback)
@@ -43,12 +43,12 @@ namespace Kernel
 		m_inode_info.mode |= Inode::Mode::IFREG;
 	}
 
-	BAN::ErrorOr<size_t> ProcROInode::read_impl(off_t offset, void* buffer, size_t buffer_size)
+	BAN::ErrorOr<size_t> ProcROInode::read_impl(off_t offset, BAN::ByteSpan buffer)
 	{
 		ASSERT(offset >= 0);
 		if ((size_t)offset >= sizeof(proc_meminfo_t))
 			return 0;
-		return (m_process.*m_callback)(offset, buffer, buffer_size);
+		return (m_process.*m_callback)(offset, buffer);
 	}
 
 }

kernel/kernel/FS/RamFS/Inode.cpp

@@ -48,23 +48,23 @@ namespace Kernel
 		m_inode_info.mode |= Inode::Mode::IFREG;
 	}
 
-	BAN::ErrorOr<size_t> RamFileInode::read_impl(off_t offset, void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> RamFileInode::read_impl(off_t offset, BAN::ByteSpan buffer)
 	{
 		ASSERT(offset >= 0);
 		if (offset >= size())
 			return 0;
-		size_t to_copy = BAN::Math::min<size_t>(m_inode_info.size - offset, bytes);
+		size_t to_copy = BAN::Math::min<size_t>(m_inode_info.size - offset, buffer.size());
-		memcpy(buffer, m_data.data(), to_copy);
+		memcpy(buffer.data(), m_data.data(), to_copy);
 		return to_copy;
 	}
 
-	BAN::ErrorOr<size_t> RamFileInode::write_impl(off_t offset, const void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> RamFileInode::write_impl(off_t offset, BAN::ConstByteSpan buffer)
 	{
 		ASSERT(offset >= 0);
-		if (offset + bytes > (size_t)size())
+		if (offset + buffer.size() > (size_t)size())
-			TRY(truncate_impl(offset + bytes));
+			TRY(truncate_impl(offset + buffer.size()));
-		memcpy(m_data.data() + offset, buffer, bytes);
+		memcpy(m_data.data() + offset, buffer.data(), buffer.size());
-		return bytes;
+		return buffer.size();
 	}
 
 	BAN::ErrorOr<void> RamFileInode::truncate_impl(size_t new_size)

kernel/kernel/Font.cpp

@@ -43,7 +43,7 @@ namespace Kernel
 		BAN::Vector<uint8_t> file_data;
 		TRY(file_data.resize(inode->size()));
 	
-		TRY(inode->read(0, file_data.data(), file_data.size()));
+		TRY(inode->read(0, file_data.span()));
 
 		if (file_data.size() < 4)
 			return BAN::Error::from_error_code(ErrorCode::Font_FileTooSmall);

kernel/kernel/Input/PS2Keyboard.cpp

@@ -217,9 +217,9 @@ namespace Kernel::Input
 		append_command_queue(Command::SET_LEDS, new_leds);
 	}
 
-	BAN::ErrorOr<size_t> PS2Keyboard::read_impl(off_t, void* buffer, size_t size)
+	BAN::ErrorOr<size_t> PS2Keyboard::read_impl(off_t, BAN::ByteSpan buffer)
 	{
-		if (size < sizeof(KeyEvent))
+		if (buffer.size() < sizeof(KeyEvent))
 			return BAN::Error::from_errno(ENOBUFS);
 
 		while (true)
@@ -231,7 +231,7 @@ namespace Kernel::Input
 			if (m_event_queue.empty())
 				continue;
 
-			*(KeyEvent*)buffer = m_event_queue.front();
+			buffer.as<KeyEvent>() = m_event_queue.front();
 			m_event_queue.pop();
 
 			return sizeof(KeyEvent);

kernel/kernel/Memory/FileBackedRegion.cpp

@@ -80,7 +80,7 @@ namespace Kernel
 				page_table.unmap_page(0);
 			}
 
-			if (auto ret = inode->write(i * PAGE_SIZE, page_buffer, PAGE_SIZE); ret.is_error())
+			if (auto ret = inode->write(i * PAGE_SIZE, BAN::ConstByteSpan::from(page_buffer)); ret.is_error())
 				dwarnln("{}", ret.error());
 		}
 	}
@@ -109,7 +109,7 @@ namespace Kernel
 
 			// Zero out the new page
 			if (&PageTable::current() == &m_page_table)
-				read_ret = m_inode->read(file_offset, (void*)vaddr, bytes);
+				read_ret = m_inode->read(file_offset, BAN::ByteSpan((uint8_t*)vaddr, bytes));
 			else
 			{
 				auto& page_table = PageTable::current();
@@ -118,7 +118,7 @@ namespace Kernel
 				ASSERT(page_table.is_page_free(0));
 
 				page_table.map_page_at(paddr, 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
-				read_ret = m_inode->read(file_offset, (void*)0, bytes);
+				read_ret = m_inode->read(file_offset, BAN::ByteSpan((uint8_t*)0, bytes));
 				memset((void*)0, 0x00, PAGE_SIZE);
 				page_table.unmap_page(0);
 			}
@@ -156,7 +156,7 @@ namespace Kernel
 				size_t offset = vaddr - m_vaddr;
 				size_t bytes = BAN::Math::min<size_t>(m_size - offset, PAGE_SIZE);
 
-				TRY(m_inode->read(offset, m_shared_data->page_buffer, bytes));
+				TRY(m_inode->read(offset, BAN::ByteSpan(m_shared_data->page_buffer, bytes)));
 
 				auto& page_table = PageTable::current();
 

kernel/kernel/OpenFileDescriptorSet.cpp

@@ -264,24 +264,24 @@ namespace Kernel
 		}
 	}
 
-	BAN::ErrorOr<size_t> OpenFileDescriptorSet::read(int fd, void* buffer, size_t count)
+	BAN::ErrorOr<size_t> OpenFileDescriptorSet::read(int fd, BAN::ByteSpan buffer)
 	{
 		TRY(validate_fd(fd));
 		auto& open_file = m_open_files[fd];
 		if ((open_file->flags & O_NONBLOCK) && !open_file->inode->has_data())
 			return 0;
-		size_t nread = TRY(open_file->inode->read(open_file->offset, buffer, count));
+		size_t nread = TRY(open_file->inode->read(open_file->offset, buffer));
 		open_file->offset += nread;
 		return nread;
 	}
 
-	BAN::ErrorOr<size_t> OpenFileDescriptorSet::write(int fd, const void* buffer, size_t count)
+	BAN::ErrorOr<size_t> OpenFileDescriptorSet::write(int fd, BAN::ConstByteSpan buffer)
 	{
 		TRY(validate_fd(fd));
 		auto& open_file = m_open_files[fd];
 		if (open_file->flags & O_APPEND)
 			open_file->offset = open_file->inode->size();
-		size_t nwrite = TRY(open_file->inode->write(open_file->offset, buffer, count));
+		size_t nwrite = TRY(open_file->inode->write(open_file->offset, buffer));
 		open_file->offset += nwrite;
 		return nwrite;
 	}

kernel/kernel/Process.cpp

@@ -260,7 +260,7 @@ namespace Kernel
 			thread->set_terminating();
 	}
 
-	size_t Process::proc_meminfo(off_t offset, void* buffer, size_t buffer_size) const
+	size_t Process::proc_meminfo(off_t offset, BAN::ByteSpan buffer) const
 	{
 		ASSERT(offset >= 0);
 		if ((size_t)offset >= sizeof(proc_meminfo_t))
@@ -290,12 +290,12 @@ namespace Kernel
 			}
 		}
 
-		size_t bytes = BAN::Math::min<size_t>(sizeof(proc_meminfo_t) - offset, buffer_size);
+		size_t bytes = BAN::Math::min<size_t>(sizeof(proc_meminfo_t) - offset, buffer.size());
-		memcpy(buffer, (uint8_t*)&meminfo + offset, bytes);
+		memcpy(buffer.data(), (uint8_t*)&meminfo + offset, bytes);
 		return bytes;
 	}
 
-	static size_t read_from_vec_of_str(const BAN::Vector<BAN::String>& container, size_t start, void* buffer, size_t buffer_size)
+	static size_t read_from_vec_of_str(const BAN::Vector<BAN::String>& container, size_t start, BAN::ByteSpan buffer)
 	{
 		size_t offset = 0;
 		size_t written = 0;
@@ -307,11 +307,11 @@ namespace Kernel
 				if (offset < start)
 					elem_offset = start - offset;
 
-				size_t bytes = BAN::Math::min<size_t>(elem.size() + 1 - elem_offset, buffer_size - written);
+				size_t bytes = BAN::Math::min<size_t>(elem.size() + 1 - elem_offset, buffer.size() - written);
-				memcpy((uint8_t*)buffer + written, elem.data() + elem_offset, bytes);
+				memcpy(buffer.data() + written, elem.data() + elem_offset, bytes);
 
 				written += bytes;
-				if (written >= buffer_size)
+				if (written >= buffer.size())
 					break;
 			}
 			offset += elem.size() + 1;
@@ -319,16 +319,16 @@ namespace Kernel
 		return written;
 	}
 
-	size_t Process::proc_cmdline(off_t offset, void* buffer, size_t buffer_size) const
+	size_t Process::proc_cmdline(off_t offset, BAN::ByteSpan buffer) const
 	{
 		LockGuard _(m_lock);
-		return read_from_vec_of_str(m_cmdline, offset, buffer, buffer_size);
+		return read_from_vec_of_str(m_cmdline, offset, buffer);
 	}
 
-	size_t Process::proc_environ(off_t offset, void* buffer, size_t buffer_size) const
+	size_t Process::proc_environ(off_t offset, BAN::ByteSpan buffer) const
 	{
 		LockGuard _(m_lock);
-		return read_from_vec_of_str(m_environ, offset, buffer, buffer_size);
+		return read_from_vec_of_str(m_environ, offset, buffer);
 	}
 
 	BAN::ErrorOr<long> Process::sys_exit(int status)
@@ -723,14 +723,14 @@ namespace Kernel
 	{
 		LockGuard _(m_lock);
 		validate_pointer_access(buffer, count);
-		return TRY(m_open_file_descriptors.read(fd, 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_lock);
 		validate_pointer_access(buffer, count);
-		return TRY(m_open_file_descriptors.write(fd, buffer, count));
+		return TRY(m_open_file_descriptors.write(fd, BAN::ByteSpan((uint8_t*)buffer, count)));
 	}
 
 	BAN::ErrorOr<long> Process::sys_pipe(int fildes[2])

kernel/kernel/Storage/ATA/AHCI/Device.cpp

@@ -158,28 +158,30 @@ namespace Kernel
 			__builtin_ia32_pause();
 	}
 
-	BAN::ErrorOr<void> AHCIDevice::read_sectors_impl(uint64_t lba, uint64_t sector_count, uint8_t* buffer)
+	BAN::ErrorOr<void> AHCIDevice::read_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= sector_count * sector_size());
 		const size_t sectors_per_page = PAGE_SIZE / sector_size();
 		for (uint64_t sector_off = 0; sector_off < sector_count; sector_off += sectors_per_page)
 		{
 			uint64_t to_read = BAN::Math::min<uint64_t>(sector_count - sector_off, sectors_per_page);
 
 			TRY(send_command_and_block(lba + sector_off, to_read, Command::Read));
-			memcpy(buffer + sector_off * sector_size(), (void*)m_data_dma_region->vaddr(), to_read * sector_size());
+			memcpy(buffer.data() + sector_off * sector_size(), (void*)m_data_dma_region->vaddr(), to_read * sector_size());
 		}
 
 		return {};
 	}
 
-	BAN::ErrorOr<void> AHCIDevice::write_sectors_impl(uint64_t lba, uint64_t sector_count, const uint8_t* buffer)
+	BAN::ErrorOr<void> AHCIDevice::write_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= sector_count * sector_size());
 		const size_t sectors_per_page = PAGE_SIZE / sector_size();
 		for (uint64_t sector_off = 0; sector_off < sector_count; sector_off += sectors_per_page)
 		{
 			uint64_t to_read = BAN::Math::min<uint64_t>(sector_count - sector_off, sectors_per_page);
 
-			memcpy((void*)m_data_dma_region->vaddr(), buffer + sector_off * sector_size(), to_read * sector_size());
+			memcpy((void*)m_data_dma_region->vaddr(), buffer.data() + sector_off * sector_size(), to_read * sector_size());
 			TRY(send_command_and_block(lba + sector_off, to_read, Command::Write));
 		}
 

kernel/kernel/Storage/ATA/ATABus.cpp

@@ -228,8 +228,10 @@ namespace Kernel
 		return BAN::Error::from_error_code(ErrorCode::None);
 	}
 
-	BAN::ErrorOr<void> ATABus::read(ATADevice& device, uint64_t lba, uint8_t sector_count, uint8_t* buffer)
+	BAN::ErrorOr<void> ATABus::read(ATADevice& device, uint64_t lba, uint64_t sector_count, BAN::ByteSpan buffer)
 	{
+		ASSERT(sector_count <= 0xFF);
+		ASSERT(buffer.size() >= sector_count * device.sector_size());
 		if (lba + sector_count > device.sector_count())
 			return BAN::Error::from_error_code(ErrorCode::Storage_Boundaries);
 
@@ -251,7 +253,7 @@ namespace Kernel
 			for (uint32_t sector = 0; sector < sector_count; sector++)
 			{
 				block_until_irq();
-				read_buffer(ATA_PORT_DATA, (uint16_t*)buffer + sector * device.words_per_sector(), device.words_per_sector());
+				read_buffer(ATA_PORT_DATA, (uint16_t*)buffer.data() + sector * device.words_per_sector(), device.words_per_sector());
 			}
 		}
 		else
@@ -263,8 +265,10 @@ namespace Kernel
 		return {};
 	}
 
-	BAN::ErrorOr<void> ATABus::write(ATADevice& device, uint64_t lba, uint8_t sector_count, const uint8_t* buffer)
+	BAN::ErrorOr<void> ATABus::write(ATADevice& device, uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan buffer)
 	{
+		ASSERT(sector_count <= 0xFF);
+		ASSERT(buffer.size() >= sector_count * device.sector_size());
 		if (lba + sector_count > device.sector_count())
 			return BAN::Error::from_error_code(ErrorCode::Storage_Boundaries);
 
@@ -285,7 +289,7 @@ namespace Kernel
 
 			for (uint32_t sector = 0; sector < sector_count; sector++)
 			{
-				write_buffer(ATA_PORT_DATA, (uint16_t*)buffer + sector * device.words_per_sector(), device.words_per_sector());
+				write_buffer(ATA_PORT_DATA, (uint16_t*)buffer.data() + sector * device.words_per_sector(), device.words_per_sector());
 				block_until_irq();
 			}
 		}

kernel/kernel/Storage/ATA/ATADevice.cpp

@@ -82,24 +82,24 @@ namespace Kernel
 		return {};
 	}
 
-	BAN::ErrorOr<size_t> detail::ATABaseDevice::read_impl(off_t offset, void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> detail::ATABaseDevice::read_impl(off_t offset, BAN::ByteSpan buffer)
 	{
 		if (offset % sector_size())
 			return BAN::Error::from_errno(EINVAL);
-		if (bytes % sector_size())
+		if (buffer.size() % sector_size())
 			return BAN::Error::from_errno(EINVAL);
-		TRY(read_sectors(offset / sector_size(), bytes / sector_size(), (uint8_t*)buffer));
+		TRY(read_sectors(offset / sector_size(), buffer.size() / sector_size(), buffer));
-		return bytes;
+		return buffer.size();
 	}
 
-	BAN::ErrorOr<size_t> detail::ATABaseDevice::write_impl(off_t offset, const void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> detail::ATABaseDevice::write_impl(off_t offset, BAN::ConstByteSpan buffer)
 	{
 		if (offset % sector_size())
 			return BAN::Error::from_errno(EINVAL);
-		if (bytes % sector_size())
+		if (buffer.size() % sector_size())
 			return BAN::Error::from_errno(EINVAL);
-		TRY(write_sectors(offset / sector_size(), bytes / sector_size(), (const uint8_t*)buffer));
+		TRY(write_sectors(offset / sector_size(), buffer.size() / sector_size(), buffer));
-		return bytes;
+		return buffer.size();
 	}
 
 	BAN::ErrorOr<BAN::RefPtr<ATADevice>> ATADevice::create(BAN::RefPtr<ATABus> bus, ATABus::DeviceType type, bool is_secondary, BAN::Span<const uint16_t> identify_data)
@@ -118,14 +118,16 @@ namespace Kernel
 		, m_is_secondary(is_secondary)
 	{ }
 
-	BAN::ErrorOr<void> ATADevice::read_sectors_impl(uint64_t lba, uint64_t sector_count, uint8_t* buffer)
+	BAN::ErrorOr<void> ATADevice::read_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= sector_count * sector_size());
 		TRY(m_bus->read(*this, lba, sector_count, buffer));
 		return {};
 	}
 
-	BAN::ErrorOr<void> ATADevice::write_sectors_impl(uint64_t lba, uint64_t sector_count, const uint8_t* buffer)
+	BAN::ErrorOr<void> ATADevice::write_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= sector_count * sector_size());
 		TRY(m_bus->write(*this, lba, sector_count, buffer));
 		return {};
 	}

kernel/kernel/Storage/DiskCache.cpp

@@ -24,8 +24,10 @@ namespace Kernel
 		release_all_pages();
 	}
 
-	bool DiskCache::read_from_cache(uint64_t sector, uint8_t* buffer)
+	bool DiskCache::read_from_cache(uint64_t sector, BAN::ByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= m_sector_size);
+
 		uint64_t sectors_per_page = PAGE_SIZE / m_sector_size;
 		uint64_t page_cache_offset = sector % sectors_per_page;
 		uint64_t page_cache_start = sector - page_cache_offset;
@@ -46,7 +48,7 @@ namespace Kernel
 
 			CriticalScope _;
 			page_table.map_page_at(cache.paddr, 0, PageTable::Flags::Present);
-			memcpy(buffer, (void*)(page_cache_offset * m_sector_size), m_sector_size);
+			memcpy(buffer.data(), (void*)(page_cache_offset * m_sector_size), m_sector_size);
 			page_table.unmap_page(0);
 
 			return true;
@@ -55,8 +57,9 @@ namespace Kernel
 		return false;
 	};
 
-	BAN::ErrorOr<void> DiskCache::write_to_cache(uint64_t sector, const uint8_t* buffer, bool dirty)
+	BAN::ErrorOr<void> DiskCache::write_to_cache(uint64_t sector, BAN::ConstByteSpan buffer, bool dirty)
 	{
+		ASSERT(buffer.size() >= m_sector_size);
 		uint64_t sectors_per_page = PAGE_SIZE / m_sector_size;
 		uint64_t page_cache_offset = sector % sectors_per_page;
 		uint64_t page_cache_start = sector - page_cache_offset;
@@ -80,7 +83,7 @@ namespace Kernel
 			{
 				CriticalScope _;
 				page_table.map_page_at(cache.paddr, 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
-				memcpy((void*)(page_cache_offset * m_sector_size), buffer, m_sector_size);
+				memcpy((void*)(page_cache_offset * m_sector_size), buffer.data(), m_sector_size);
 				page_table.unmap_page(0);
 			}
 
@@ -110,8 +113,8 @@ namespace Kernel
 
 		{
 			CriticalScope _;
-			page_table.map_page_at(cache.paddr, 0, PageTable::Flags::Present);
+			page_table.map_page_at(cache.paddr, 0, PageTable::Flags::ReadWrite | PageTable::Flags::Present);
-			memcpy((void*)(page_cache_offset * m_sector_size), buffer, m_sector_size);
+			memcpy((void*)(page_cache_offset * m_sector_size), buffer.data(), m_sector_size);
 			page_table.unmap_page(0);
 		}
 
@@ -149,7 +152,8 @@ namespace Kernel
 				else
 				{
 					dprintln_if(DEBUG_SYNC, "syncing {}->{}", cache.first_sector + sector_start, cache.first_sector + sector_start + sector_count);
-					TRY(m_device.write_sectors_impl(cache.first_sector + sector_start, sector_count, m_sync_cache.data() + sector_start * m_sector_size));
+					auto data_slice = m_sync_cache.span().slice(sector_start * m_sector_size, sector_count * m_sector_size);
+					TRY(m_device.write_sectors_impl(cache.first_sector + sector_start, sector_count, data_slice));
 					sector_start += sector_count + 1;
 					sector_count = 0;
 				}
@@ -158,7 +162,8 @@ namespace Kernel
 			if (sector_count > 0)
 			{
 				dprintln_if(DEBUG_SYNC, "syncing {}->{}", cache.first_sector + sector_start, cache.first_sector + sector_start + sector_count);
-				TRY(m_device.write_sectors_impl(cache.first_sector + sector_start, sector_count, m_sync_cache.data() + sector_start * m_sector_size));
+				auto data_slice = m_sync_cache.span().slice(sector_start * m_sector_size, sector_count * m_sector_size);
+				TRY(m_device.write_sectors_impl(cache.first_sector + sector_start, sector_count, data_slice));
 			}
 
 			cache.dirty_mask = 0;

kernel/kernel/Storage/StorageDevice.cpp

@@ -153,8 +153,10 @@ namespace Kernel
 		if (total_size() < sizeof(GPTHeader))
 			return BAN::Error::from_error_code(ErrorCode::Storage_GPTHeader);
 
-		BAN::Vector<uint8_t> lba1(sector_size());
+		BAN::Vector<uint8_t> lba1;
-		TRY(read_sectors(1, 1, lba1.data()));
+		TRY(lba1.resize(sector_size()));
+
+		TRY(read_sectors(1, 1, lba1.span()));
 
 		const GPTHeader& header = *(const GPTHeader*)lba1.data();
 		if (!is_valid_gpt_header(header, sector_size()))
@@ -169,7 +171,7 @@ namespace Kernel
 
 		BAN::Vector<uint8_t> entry_array;
 		TRY(entry_array.resize(size));
-		TRY(read_sectors(header.partition_entry_lba, size / sector_size(), entry_array.data()));
+		TRY(read_sectors(header.partition_entry_lba, size / sector_size(), entry_array.span()));
 
 		if (!is_valid_gpt_crc32(header, lba1, entry_array))
 			return BAN::Error::from_error_code(ErrorCode::Storage_GPTHeader);
@@ -226,8 +228,9 @@ namespace Kernel
 		memcpy(m_label, label, sizeof(m_label));
 	}
 
-	BAN::ErrorOr<void> Partition::read_sectors(uint64_t lba, uint8_t sector_count, uint8_t* buffer)
+	BAN::ErrorOr<void> Partition::read_sectors(uint64_t lba, uint8_t sector_count, BAN::ByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= sector_count * m_device.sector_size());
 		const uint32_t sectors_in_partition = m_lba_end - m_lba_start;
 		if (lba + sector_count > sectors_in_partition)
 			return BAN::Error::from_error_code(ErrorCode::Storage_Boundaries);
@@ -235,8 +238,9 @@ namespace Kernel
 		return {};
 	}
 
-	BAN::ErrorOr<void> Partition::write_sectors(uint64_t lba, uint8_t sector_count, const uint8_t* buffer)
+	BAN::ErrorOr<void> Partition::write_sectors(uint64_t lba, uint8_t sector_count, BAN::ConstByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= sector_count * m_device.sector_size());
 		const uint32_t sectors_in_partition = m_lba_end - m_lba_start;
 		if (lba + sector_count > sectors_in_partition)
 			return BAN::Error::from_error_code(ErrorCode::Storage_Boundaries);
@@ -244,23 +248,23 @@ namespace Kernel
 		return {};
 	}
 
-	BAN::ErrorOr<size_t> Partition::read_impl(off_t offset, void* buffer, size_t bytes)
+	BAN::ErrorOr<size_t> Partition::read_impl(off_t offset, BAN::ByteSpan buffer)
 	{
 		ASSERT(offset >= 0);
 
-		if (offset % m_device.sector_size() || bytes % m_device.sector_size())
+		if (offset % m_device.sector_size() || buffer.size() % m_device.sector_size())
 			return BAN::Error::from_errno(ENOTSUP);
 
 		const uint32_t sectors_in_partition = m_lba_end - m_lba_start;
 		uint32_t lba = offset / m_device.sector_size();
-		uint32_t sector_count = bytes / m_device.sector_size();
+		uint32_t sector_count = buffer.size() / m_device.sector_size();
 
 		if (lba == sectors_in_partition)
 			return 0;
 		if (lba + sector_count > sectors_in_partition)
 			sector_count = sectors_in_partition - lba;
 
-		TRY(read_sectors(lba, sector_count, (uint8_t*)buffer));
+		TRY(read_sectors(lba, sector_count, buffer));
 		return sector_count * m_device.sector_size();
 	}
 
@@ -283,36 +287,51 @@ namespace Kernel
 		return {};
 	}
 
-	BAN::ErrorOr<void> StorageDevice::read_sectors(uint64_t lba, uint64_t sector_count, uint8_t* buffer)
+	BAN::ErrorOr<void> StorageDevice::read_sectors(uint64_t lba, uint64_t sector_count, BAN::ByteSpan buffer)
 	{
+		ASSERT(buffer.size() >= sector_count * sector_size());
+
+		{
+			LockGuard _(m_lock);
+			Thread::TerminateBlocker blocker(Thread::current());
+			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_lock);
 			Thread::TerminateBlocker blocker(Thread::current());
 
-			uint8_t* buffer_ptr = buffer + offset * sector_size();
+			auto sector_buffer = buffer.slice(offset * sector_size(), sector_size());
-			if (m_disk_cache.has_value())
+			if (m_disk_cache->read_from_cache(lba + offset, sector_buffer))
-				if (m_disk_cache->read_from_cache(lba + offset, buffer_ptr))
+				continue;
-					continue;
+			TRY(read_sectors_impl(lba + offset, 1, sector_buffer));
-			TRY(read_sectors_impl(lba + offset, 1, buffer_ptr));
+			(void)m_disk_cache->write_to_cache(lba + offset, sector_buffer, false);
-			if (m_disk_cache.has_value())
-				(void)m_disk_cache->write_to_cache(lba + offset, buffer_ptr, false);
 		}
 		
 		return {};
 	}
 
-	BAN::ErrorOr<void> StorageDevice::write_sectors(uint64_t lba, uint64_t sector_count, const uint8_t* buffer)
+	BAN::ErrorOr<void> StorageDevice::write_sectors(uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan buffer)
 	{
-		// TODO: use disk cache for dirty pages. I don't wanna think about how to do it safely now
+		ASSERT(buffer.size() >= sector_count * sector_size());
+
+		{
+			LockGuard _(m_lock);
+			Thread::TerminateBlocker blocker(Thread::current());
+			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_lock);
 			Thread::TerminateBlocker blocker(Thread::current());
 
-			const uint8_t* buffer_ptr = buffer + offset * sector_size();
+			auto sector_buffer = buffer.slice(offset * sector_size(), sector_size());
-			if (!m_disk_cache.has_value() || m_disk_cache->write_to_cache(lba + offset, buffer_ptr, true).is_error())
+			if (m_disk_cache->write_to_cache(lba + offset, sector_buffer, true).is_error())
-				TRY(write_sectors_impl(lba + offset, 1, buffer_ptr));
+				TRY(write_sectors_impl(lba + offset, 1, sector_buffer));
 		}
 
 		return {};

kernel/kernel/Terminal/TTY.cpp

@@ -95,7 +95,7 @@ namespace Kernel
 						TTY::current()->m_tty_ctrl.semaphore.block();
 
 					Input::KeyEvent event;
-					size_t read = MUST(inode->read(0, &event, sizeof(event)));
+					size_t read = MUST(inode->read(0, BAN::ByteSpan::from(event)));
 					ASSERT(read == sizeof(event));
 					TTY::current()->on_key_event(event);
 				}
@@ -298,7 +298,7 @@ namespace Kernel
 			putchar_impl(ch);
 	}
 
-	BAN::ErrorOr<size_t> TTY::read_impl(off_t, void* buffer, size_t count)
+	BAN::ErrorOr<size_t> TTY::read_impl(off_t, BAN::ByteSpan buffer)
 	{
 		LockGuard _(m_lock);
 		while (!m_output.flush)
@@ -314,8 +314,8 @@ namespace Kernel
 			return 0;
 		}
 
-		size_t to_copy = BAN::Math::min<size_t>(count, m_output.bytes);
+		size_t to_copy = BAN::Math::min<size_t>(buffer.size(), m_output.bytes);
-		memcpy(buffer, m_output.buffer.data(), to_copy);
+		memcpy(buffer.data(), m_output.buffer.data(), to_copy);
 
 		memmove(m_output.buffer.data(), m_output.buffer.data() + to_copy, m_output.bytes - to_copy);
 		m_output.bytes -= to_copy;
@@ -328,12 +328,12 @@ namespace Kernel
 		return to_copy;
 	}
 
-	BAN::ErrorOr<size_t> TTY::write_impl(off_t, const void* buffer, size_t count)
+	BAN::ErrorOr<size_t> TTY::write_impl(off_t, BAN::ConstByteSpan buffer)
 	{
 		LockGuard _(m_lock);
-		for (size_t i = 0; i < count; i++)
+		for (size_t i = 0; i < buffer.size(); i++)
-			putchar(((uint8_t*)buffer)[i]);
+			putchar(buffer[i]);
-		return count;
+		return buffer.size();
 	}
 
 	bool TTY::has_data_impl() const