ls: Show symlink target with `-l`

This patch gets rid of 2 unnecessary syscalls!

kernel/include/kernel/Process.h

@@ -102,8 +102,6 @@ namespace Kernel
 		BAN::ErrorOr<long> open_inode(VirtualFileSystem::File&&, int flags);
 
 		BAN::ErrorOr<void> create_file_or_dir(const VirtualFileSystem::File& parent, BAN::StringView path, mode_t mode) const;
-		BAN::ErrorOr<long> open_file_impl(const VirtualFileSystem::File& parent, BAN::StringView path, int oflag, mode_t = 0);
-		BAN::ErrorOr<long> sys_open(const char* path, int, mode_t);
 		BAN::ErrorOr<long> sys_openat(int, const char* path, int, mode_t);
 		BAN::ErrorOr<long> sys_close(int fd);
 		BAN::ErrorOr<long> sys_read(int fd, void* buffer, size_t count);
@@ -111,15 +109,12 @@ namespace Kernel
 		BAN::ErrorOr<long> sys_access(const char* path, int amode);
 		BAN::ErrorOr<long> sys_create_dir(const char*, mode_t);
 		BAN::ErrorOr<long> sys_unlink(const char*);
-		BAN::ErrorOr<long> readlink_impl(BAN::RefPtr<Inode>, char* buffer, size_t bufsize);
-		BAN::ErrorOr<long> sys_readlink(const char* path, char* buffer, size_t bufsize);
 		BAN::ErrorOr<long> sys_readlinkat(int fd, const char* path, char* buffer, size_t bufsize);
 
 		BAN::ErrorOr<long> sys_pread(int fd, void* buffer, size_t count, off_t offset);
 
-		BAN::ErrorOr<long> sys_chmod(const char* path, mode_t mode);
-		BAN::ErrorOr<long> sys_fchmod(int fildes, mode_t mode);
-		BAN::ErrorOr<long> sys_chown(const char* path, uid_t uid, gid_t gid);
+		BAN::ErrorOr<long> sys_fchmodat(int fd, const char* path, mode_t mode, int flag);
+		BAN::ErrorOr<long> sys_fchownat(int fd, const char* path, uid_t uid, gid_t gid, int flag);
 
 		BAN::ErrorOr<long> sys_socket(int domain, int type, int protocol);
 		BAN::ErrorOr<long> sys_getsockname(int socket, sockaddr* address, socklen_t* address_len);
@@ -148,9 +143,7 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_truncate(int fd, off_t length);
 
-		BAN::ErrorOr<long> sys_fstat(int fd, struct stat*);
 		BAN::ErrorOr<long> sys_fstatat(int fd, const char* path, struct stat* buf, int flag);
-		BAN::ErrorOr<long> sys_stat(const char* path, struct stat* buf, int flag);
 
 		BAN::ErrorOr<long> sys_realpath(const char* path, char* buffer);
 
@@ -220,6 +213,8 @@ namespace Kernel
 		Process(const Credentials&, pid_t pid, pid_t parent, pid_t sid, pid_t pgrp);
 		static Process* create_process(const Credentials&, pid_t parent, pid_t sid = 0, pid_t pgrp = 0);
 
+		BAN::ErrorOr<VirtualFileSystem::File> find_file(int fd, const char* path, int flags);
+
 		BAN::ErrorOr<void> validate_string_access(const char*);
 		BAN::ErrorOr<void> validate_pointer_access_check(const void*, size_t, bool needs_write);
 		BAN::ErrorOr<void> validate_pointer_access(const void*, size_t, bool needs_write);

kernel/kernel/Process.cpp

@@ -351,6 +351,28 @@ namespace Kernel
 		return read_from_vec_of_str(m_environ, offset, buffer);
 	}
 
+	BAN::ErrorOr<VirtualFileSystem::File> Process::find_file(int fd, const char* path, int flags)
+	{
+		ASSERT(m_process_lock.is_locked());
+
+		if (path)
+			TRY(validate_string_access(path));
+
+		VirtualFileSystem::File parent_file;
+		if (path && path[0] == '/')
+			parent_file = VirtualFileSystem::get().root_file();
+		else if (fd == AT_FDCWD)
+			parent_file = TRY(m_working_directory.clone());
+		else
+			parent_file = TRY(m_open_file_descriptors.file_of(fd));
+
+		auto file = path
+			? TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags))
+			: BAN::move(parent_file);
+
+		return file;
+	}
+
 	BAN::ErrorOr<long> Process::sys_exit(int status)
 	{
 		ASSERT(this == &Process::current());
@@ -849,14 +871,31 @@ namespace Kernel
 		return TRY(m_open_file_descriptors.open(BAN::move(file), flags));
 	}
 
-	BAN::ErrorOr<long> Process::open_file_impl(const VirtualFileSystem::File& parent, BAN::StringView path, int flags, mode_t mode)
+	BAN::ErrorOr<long> Process::sys_openat(int fd, const char* path, int flags, mode_t mode)
 	{
 		if ((flags & (O_DIRECTORY | O_CREAT)) == (O_DIRECTORY | O_CREAT))
 			return BAN::Error::from_errno(EINVAL);
 
 		LockGuard _(m_process_lock);
 
-		auto file_or_error = VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path, flags | O_NOFOLLOW);
+		TRY(validate_string_access(path));
+
+		VirtualFileSystem::File parent_file;
+		if (path[0] == '/')
+			parent_file = VirtualFileSystem::get().root_file();
+		else if (fd == AT_FDCWD)
+			parent_file = TRY(m_working_directory.clone());
+		else
+		{
+			int flags = TRY(m_open_file_descriptors.flags_of(fd));
+			if (!(flags & O_RDONLY) && !(flags & O_SEARCH))
+				return BAN::Error::from_errno(EBADF);
+			if (!TRY(m_open_file_descriptors.inode_of(fd))->mode().ifdir())
+				return BAN::Error::from_errno(ENOTDIR);
+			parent_file = TRY(m_open_file_descriptors.file_of(fd));
+		}
+
+		auto file_or_error = VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags | O_NOFOLLOW);
 
 		VirtualFileSystem::File file;
 		if (file_or_error.is_error())
@@ -865,8 +904,8 @@ namespace Kernel
 				return file_or_error.release_error();
 
 			// FIXME: There is a race condition between next two lines
-			TRY(create_file_or_dir(parent, path, (mode & 0777) | Inode::Mode::IFREG));
-			file = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path, flags));
+			TRY(create_file_or_dir(parent_file, path, (mode & 0777) | Inode::Mode::IFREG));
+			file = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags));
 		}
 		else
 		{
@@ -879,13 +918,13 @@ namespace Kernel
 			if (!file.inode->mode().ifdir() && (flags & O_DIRECTORY))
 				return BAN::Error::from_errno(ENOTDIR);
 			if (file.inode->mode().iflnk() && !(flags & O_NOFOLLOW))
-				file = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path, flags));
+				file = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags));
 		}
 
 		auto inode = file.inode;
 		ASSERT(inode);
 
-		int fd = TRY(m_open_file_descriptors.open(BAN::move(file), flags));
+		fd = TRY(m_open_file_descriptors.open(BAN::move(file), flags));
 
 		// Open controlling terminal
 		if (!(flags & O_NOCTTY) && inode->is_tty() && is_session_leader() && !m_controlling_terminal)
@@ -894,37 +933,6 @@ namespace Kernel
 		return fd;
 	}
 
-	BAN::ErrorOr<long> Process::sys_open(const char* path, int flags, mode_t mode)
-	{
-		LockGuard _(m_process_lock);
-		TRY(validate_string_access(path));
-		if (path[0] == '/')
-			return open_file_impl(VirtualFileSystem::get().root_file(), path, flags, mode);
-		return open_file_impl(m_working_directory, path, flags, mode);
-	}
-
-	BAN::ErrorOr<long> Process::sys_openat(int fd, const char* path, int flags, mode_t mode)
-	{
-		LockGuard _(m_process_lock);
-
-		TRY(validate_string_access(path));
-
-		VirtualFileSystem::File parent_file;
-		if (fd == AT_FDCWD)
-			parent_file = TRY(m_working_directory.clone());
-		else if (path[0] != '/')
-		{
-			int flags = TRY(m_open_file_descriptors.flags_of(fd));
-			if (!(flags & O_RDONLY) && !(flags & O_SEARCH))
-				return BAN::Error::from_errno(EBADF);
-			if (!TRY(m_open_file_descriptors.inode_of(fd))->mode().ifdir())
-				return BAN::Error::from_errno(ENOTDIR);
-			parent_file = TRY(m_open_file_descriptors.file_of(fd));
-		}
-
-		return open_file_impl(parent_file, path, flags, mode);
-	}
-
 	BAN::ErrorOr<long> Process::sys_close(int fd)
 	{
 		LockGuard _(m_process_lock);
@@ -1008,37 +1016,20 @@ namespace Kernel
 		return 0;
 	}
 
-	BAN::ErrorOr<long> Process::readlink_impl(BAN::RefPtr<Inode> inode, char* buffer, size_t bufsize)
-	{
-		// FIXME: no allocation needed
-		auto link_target = TRY(inode->link_target());
-
-		size_t byte_count = BAN::Math::min<size_t>(link_target.size(), bufsize);
-		memcpy(buffer, link_target.data(), byte_count);
-
-		return byte_count;
-	}
-
-	BAN::ErrorOr<long> Process::sys_readlink(const char* path, char* buffer, size_t bufsize)
-	{
-		LockGuard _(m_process_lock);
-		TRY(validate_string_access(path));
-		TRY(validate_pointer_access(buffer, bufsize, true));
-
-		auto absolute_path = TRY(absolute_path_of(path));
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_NOFOLLOW | O_RDONLY));
-		return readlink_impl(file.inode, buffer, bufsize);
-	}
-
 	BAN::ErrorOr<long> Process::sys_readlinkat(int fd, const char* path, char* buffer, size_t bufsize)
 	{
 		LockGuard _(m_process_lock);
 		TRY(validate_string_access(path));
 		TRY(validate_pointer_access(buffer, bufsize, true));
 
-		auto parent_file = TRY(m_open_file_descriptors.file_of(fd));
-		auto file = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, O_NOFOLLOW | O_RDONLY));
-		return readlink_impl(file.inode, buffer, bufsize);
+		auto inode = TRY(find_file(fd, path, O_NOFOLLOW | O_RDONLY)).inode;
+
+		// FIXME: no allocation needed
+		auto link_target = TRY(inode->link_target());
+
+		const size_t byte_count = BAN::Math::min<size_t>(link_target.size(), bufsize);
+		memcpy(buffer, link_target.data(), byte_count);
+		return byte_count;
 	}
 
 	BAN::ErrorOr<long> Process::sys_pread(int fd, void* buffer, size_t count, off_t offset)
@@ -1049,41 +1040,51 @@ namespace Kernel
 		return TRY(inode->read(offset, { (uint8_t*)buffer, count }));
 	}
 
-	BAN::ErrorOr<long> Process::sys_chmod(const char* path, mode_t mode)
+	BAN::ErrorOr<long> Process::sys_fchmodat(int fd, const char* path, mode_t mode, int flag)
 	{
 		if (mode & S_IFMASK)
 			return BAN::Error::from_errno(EINVAL);
-
-		LockGuard _(m_process_lock);
-		TRY(validate_string_access(path));
-
-		auto absolute_path = TRY(absolute_path_of(path));
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_WRONLY));
-		TRY(file.inode->chmod(mode));
-
-		return 0;
-	}
-
-	BAN::ErrorOr<long> Process::sys_fchmod(int fildes, mode_t mode)
-	{
-		if (mode & S_IFMASK)
+		if (flag & ~AT_SYMLINK_NOFOLLOW)
 			return BAN::Error::from_errno(EINVAL);
+		if (flag == AT_SYMLINK_NOFOLLOW)
+			flag = O_NOFOLLOW;
 
 		LockGuard _(m_process_lock);
-		auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
+
+		auto inode = TRY(find_file(fd, path, flag)).inode;
+
+		if (!m_credentials.is_superuser() && inode->uid() != m_credentials.euid())
+		{
+			dwarnln("cannot chmod uid {} vs {}", inode->uid(), m_credentials.euid());
+			return BAN::Error::from_errno(EPERM);
+		}
+
 		TRY(inode->chmod(mode));
 
 		return 0;
 	}
 
-	BAN::ErrorOr<long> Process::sys_chown(const char* path, uid_t uid, gid_t gid)
+	BAN::ErrorOr<long> Process::sys_fchownat(int fd, const char* path, uid_t uid, gid_t gid, int flag)
 	{
-		LockGuard _(m_process_lock);
-		TRY(validate_string_access(path));
+		if (flag & ~AT_SYMLINK_NOFOLLOW)
+			return BAN::Error::from_errno(EINVAL);
+		if (flag == AT_SYMLINK_NOFOLLOW)
+			flag = O_NOFOLLOW;
 
-		auto absolute_path = TRY(absolute_path_of(path));
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_WRONLY));
-		TRY(file.inode->chown(uid, gid));
+		LockGuard _(m_process_lock);
+
+		auto inode = TRY(find_file(fd, path, flag)).inode;
+
+		if (uid != -1 && !m_credentials.is_superuser())
+			return BAN::Error::from_errno(EPERM);
+		if (gid != -1 && !m_credentials.is_superuser() && (m_credentials.euid() != uid || !m_credentials.has_egid(gid)))
+			return BAN::Error::from_errno(EPERM);
+
+		if (uid == -1)
+			uid = inode->uid();
+		if (gid == -1)
+			gid = inode->gid();
+		TRY(inode->chown(uid, gid));
 
 		return 0;
 	}
@@ -1414,62 +1415,31 @@ namespace Kernel
 		return {};
 	}
 
-	static void read_stat_from_inode(BAN::RefPtr<Inode> inode, struct stat* out)
+	BAN::ErrorOr<long> Process::sys_fstatat(int fd, const char* path, struct stat* buf, int flag)
 	{
-		out->st_dev		= inode->dev();
-		out->st_ino		= inode->ino();
-		out->st_mode	= inode->mode().mode;
-		out->st_nlink	= inode->nlink();
-		out->st_uid		= inode->uid();
-		out->st_gid		= inode->gid();
-		out->st_rdev	= inode->rdev();
-		out->st_size	= inode->size();
-		out->st_atim	= inode->atime();
-		out->st_mtim	= inode->mtime();
-		out->st_ctim	= inode->ctime();
-		out->st_blksize	= inode->blksize();
-		out->st_blocks	= inode->blocks();
-	}
-
-	BAN::ErrorOr<long> Process::sys_fstat(int fd, struct stat* buf)
-	{
-		LockGuard _(m_process_lock);
-		TRY(validate_pointer_access(buf, sizeof(struct stat), true));
-
-		auto inode = TRY(m_open_file_descriptors.inode_of(fd));
-		read_stat_from_inode(inode, buf);
-		return 0;
-	}
-
-	BAN::ErrorOr<long> Process::sys_fstatat(int fd, const char* path, struct stat* buf, int flags)
-	{
-		if (flags & ~AT_SYMLINK_NOFOLLOW)
+		if (flag & ~AT_SYMLINK_NOFOLLOW)
 			return BAN::Error::from_errno(EINVAL);
-		if (flags == AT_SYMLINK_NOFOLLOW)
-			flags = O_NOFOLLOW;
+		if (flag == AT_SYMLINK_NOFOLLOW)
+			flag = O_NOFOLLOW;
 
 		LockGuard _(m_process_lock);
 		TRY(validate_pointer_access(buf, sizeof(struct stat), true));
 
-		auto parent_file = TRY(m_open_file_descriptors.file_of(fd));
-		auto inode = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags)).inode;
-		read_stat_from_inode(inode, buf);
-		return 0;
-	}
+		auto inode = TRY(find_file(fd, path, flag)).inode;
+		buf->st_dev		= inode->dev();
+		buf->st_ino		= inode->ino();
+		buf->st_mode	= inode->mode().mode;
+		buf->st_nlink	= inode->nlink();
+		buf->st_uid		= inode->uid();
+		buf->st_gid		= inode->gid();
+		buf->st_rdev	= inode->rdev();
+		buf->st_size	= inode->size();
+		buf->st_atim	= inode->atime();
+		buf->st_mtim	= inode->mtime();
+		buf->st_ctim	= inode->ctime();
+		buf->st_blksize	= inode->blksize();
+		buf->st_blocks	= inode->blocks();
 
-	BAN::ErrorOr<long> Process::sys_stat(const char* path, struct stat* buf, int flags)
-	{
-		if (flags & ~AT_SYMLINK_NOFOLLOW)
-			return BAN::Error::from_errno(EINVAL);
-		if (flags == AT_SYMLINK_NOFOLLOW)
-			flags = O_NOFOLLOW;
-
-		LockGuard _(m_process_lock);
-		TRY(validate_pointer_access(buf, sizeof(struct stat), true));
-
-		auto absolute_path = TRY(absolute_path_of(path));
-		auto inode = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, flags)).inode;
-		read_stat_from_inode(inode, buf);
 		return 0;
 	}
 
@@ -1481,7 +1451,7 @@ namespace Kernel
 
 		auto absolute_path = TRY(absolute_path_of(path));
 
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_SEARCH));
+		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_RDONLY));
 		if (file.canonical_path.size() >= PATH_MAX)
 			return BAN::Error::from_errno(ENAMETOOLONG);
 

userspace/libraries/LibC/fcntl.cpp

@@ -15,7 +15,7 @@ int open(const char* path, int oflag, ...)
 	mode_t mode = va_arg(args, mode_t);
 	va_end(args);
 
-	return syscall(SYS_OPEN, path, oflag, __UMASKED_MODE(mode));
+	return openat(AT_FDCWD, path, oflag, mode);
 }
 
 int openat(int fd, const char* path, int oflag, ...)

userspace/libraries/LibC/include/sys/syscall.h

@@ -11,7 +11,6 @@ __BEGIN_DECLS
 	O(SYS_WRITE,			write)			\
 	O(SYS_TERMID,			termid)			\
 	O(SYS_CLOSE,			close)			\
-	O(SYS_OPEN,				open)			\
 	O(SYS_OPENAT,			openat)			\
 	O(SYS_SEEK,				seek)			\
 	O(SYS_TELL,				tell)			\
@@ -21,7 +20,6 @@ __BEGIN_DECLS
 	O(SYS_EXEC,				exec)			\
 	O(SYS_SLEEP,			sleep)			\
 	O(SYS_WAIT,				wait)			\
-	O(SYS_FSTAT,			fstat)			\
 	O(SYS_READ_DIR,			readdir)		\
 	O(SYS_SET_UID,			setuid)			\
 	O(SYS_SET_GID,			setgid)			\
@@ -48,21 +46,18 @@ __BEGIN_DECLS
 	O(SYS_FCNTL,			fcntl)			\
 	O(SYS_NANOSLEEP,		nanosleep)		\
 	O(SYS_FSTATAT,			fstatat)		\
-	O(SYS_STAT,				stat)			\
 	O(SYS_SYNC,				sync)			\
 	O(SYS_MMAP,				mmap)			\
 	O(SYS_MUNMAP,			munmap) 		\
 	O(SYS_TTY_CTRL,			tty_ctrl)		\
 	O(SYS_POWEROFF,			poweroff)		\
-	O(SYS_CHMOD,			chmod)			\
-	O(SYS_FCHMOD,			fchmod)			\
+	O(SYS_FCHMODAT,			fchmodat)		\
 	O(SYS_CREATE_DIR,		create_dir)		\
 	O(SYS_UNLINK,			unlink) 		\
-	O(SYS_READLINK,			readlink)		\
 	O(SYS_READLINKAT,		readlinkat)		\
 	O(SYS_MSYNC,			msync)			\
 	O(SYS_PREAD,			pread)			\
-	O(SYS_CHOWN,			chown)			\
+	O(SYS_FCHOWNAT,			fchownat)		\
 	O(SYS_LOAD_KEYMAP,		load_keymap)	\
 	O(SYS_SOCKET,			socket)			\
 	O(SYS_BIND,				bind)			\

userspace/libraries/LibC/sys/stat.cpp

@@ -1,6 +1,5 @@
 #include <BAN/Assert.h>
 
-#include <errno.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
@@ -10,17 +9,22 @@ mode_t __umask = 0;
 
 int chmod(const char* path, mode_t mode)
 {
-	return syscall(SYS_CHMOD, path, mode);
+	return fchmodat(AT_FDCWD, path, mode, 0);
 }
 
 int fchmod(int fildes, mode_t mode)
 {
-	return syscall(SYS_FCHMOD, fildes, mode);
+	return fchmodat(fildes, nullptr, mode, 0);
+}
+
+int fchmodat(int fildes, const char* path, mode_t mode, int flag)
+{
+	return syscall(SYS_FCHMODAT, fildes, path, mode, flag);
 }
 
 int fstat(int fildes, struct stat* buf)
 {
-	return syscall(SYS_FSTAT, fildes, buf);
+	return fstatat(fildes, nullptr, buf, 0);
 }
 
 int fstatat(int fd, const char* __restrict path, struct stat* __restrict buf, int flag)
@@ -30,12 +34,12 @@ int fstatat(int fd, const char* __restrict path, struct stat* __restrict buf, in
 
 int lstat(const char* __restrict path, struct stat* __restrict buf)
 {
-	return syscall(SYS_STAT, path, buf, AT_SYMLINK_NOFOLLOW);
+	return fstatat(AT_FDCWD, path, buf, AT_SYMLINK_NOFOLLOW);
 }
 
 int stat(const char* __restrict path, struct stat* __restrict buf)
 {
-	return syscall(SYS_STAT, path, buf, 0);
+	return fstatat(AT_FDCWD, path, buf, 0);
 }
 
 mode_t umask(mode_t cmask)

userspace/libraries/LibC/unistd.cpp

@@ -3,6 +3,7 @@
 #include <kernel/Syscall.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <pwd.h>
 #include <stdarg.h>
 #include <stdio.h>
@@ -86,7 +87,7 @@ ssize_t write(int fildes, const void* buf, size_t nbyte)
 
 ssize_t readlink(const char* __restrict path, char* __restrict buf, size_t bufsize)
 {
-	return syscall(SYS_READLINK, path, buf, bufsize);
+	return readlinkat(AT_FDCWD, path, buf, bufsize);
 }
 
 ssize_t readlinkat(int fd, const char* __restrict path, char* __restrict buf, size_t bufsize)
@@ -314,7 +315,22 @@ int chdir(const char* path)
 
 int chown(const char* path, uid_t owner, gid_t group)
 {
-	return syscall(SYS_CHOWN, path, owner, group);
+	return fchownat(AT_FDCWD, path, owner, group, 0);
+}
+
+int lchown(const char* path, uid_t owner, gid_t group)
+{
+	return fchownat(AT_FDCWD, path, owner, group, AT_SYMLINK_NOFOLLOW);
+}
+
+int fchown(int fildes, uid_t owner, gid_t group)
+{
+	return fchownat(fildes, nullptr, owner, group, 0);
+}
+
+int fchownat(int fd, const char* path, uid_t owner, gid_t group, int flag)
+{
+	return syscall(SYS_FCHOWNAT, fd, path, owner, group, flag);
 }
 
 void sync(void)

userspace/programs/DynamicLoader/main.cpp

@@ -557,7 +557,7 @@ static void handle_dynamic(LoadedElf& elf)
 		if (auto ret = syscall(SYS_REALPATH, path_buffer, realpath); ret < 0)
 			print_error_and_exit("realpath", ret);
 
-		int library_fd = syscall(SYS_OPEN, realpath, O_RDONLY);
+		int library_fd = syscall(SYS_OPENAT, AT_FDCWD, realpath, O_RDONLY);
 		if (library_fd < 0)
 			print_error_and_exit("could not open library", library_fd);
 
@@ -882,7 +882,7 @@ int _entry(int argc, char** argv, char** envp, int fd)
 		argc--;
 		argv++;
 
-		fd = syscall(SYS_OPEN, argv[0], O_RDONLY);
+		fd = syscall(SYS_OPENAT, AT_FDCWD, argv[0], O_RDONLY);
 		if (fd < 0)
 			print_error_and_exit("could not open program", fd);
 	}

userspace/programs/DynamicLoader/utils.cpp

@@ -68,7 +68,7 @@ static int s_random_fd;
 
 void init_random()
 {
-	s_random_fd = syscall(SYS_OPEN, "/dev/random", O_RDONLY);
+	s_random_fd = syscall(SYS_OPENAT, AT_FDCWD, "/dev/random", O_RDONLY);
 	if (s_random_fd < 0)
 		print_error_and_exit("could not open /dev/random", s_random_fd);
 }

userspace/programs/Shell/main.cpp

@@ -342,6 +342,54 @@ BAN::Optional<int> execute_builtin(BAN::Vector<BAN::String>& args, int fd_in, in
 		while (*current)
 			fprintf(fout, "%s\n", *current++);
 	}
+	else if (args.front() == "cd"_sv)
+	{
+		if (args.size() > 2)
+		{
+			fprintf(fout, "cd: too many arguments\n");
+			return 1;
+		}
+
+		BAN::StringView path;
+
+		if (args.size() == 1)
+		{
+			if (const char* path_env = getenv("HOME"))
+				path = path_env;
+			else
+				return 0;
+		}
+		else
+			path = args[1];
+
+		if (chdir(path.data()) == -1)
+			ERROR_RETURN("chdir", 1);
+	}
+	else if (args.front() == "time"_sv)
+	{
+		args.remove(0);
+
+		timespec start, end;
+
+		if (clock_gettime(CLOCK_MONOTONIC, &start) == -1)
+			ERROR_RETURN("clock_gettime", 1);
+
+		int ret = execute_command(args, fd_in, fd_out);
+
+		if (clock_gettime(CLOCK_MONOTONIC, &end) == -1)
+			ERROR_RETURN("clock_gettime", 1);
+
+		uint64_t total_ns = 0;
+		total_ns += (end.tv_sec - start.tv_sec) * 1'000'000'000;
+		total_ns += end.tv_nsec - start.tv_nsec;
+
+		int secs  =  total_ns / 1'000'000'000;
+		int msecs = (total_ns % 1'000'000'000) / 1'000'000;
+
+		fprintf(fout, "took %d.%03d s\n", secs, msecs);
+
+		return ret;
+	}
 	else if (args.front() == "start-gui"_sv)
 	{
 		pid_t pid = fork();

userspace/programs/WindowServer/main.cpp

@@ -130,7 +130,7 @@ int open_server_fd()
 		exit(1);
 	}
 
-	if (chmod("/tmp/resolver.sock", 0777) == -1)
+	if (chmod(LibGUI::s_window_server_socket.data(), 0777) == -1)
 	{
 		perror("chmod");
 		exit(1);

userspace/programs/ls/main.cpp

@@ -21,6 +21,7 @@ struct simple_entry_t
 {
 	BAN::String name;
 	struct stat st;
+	BAN::String link;
 };
 
 struct full_entry_t
@@ -117,6 +118,8 @@ BAN::String build_time_string(BAN::Time time)
 
 int list_directory(const BAN::String& path, config_t config)
 {
+	static char link_buffer[PATH_MAX];
+
 	BAN::Vector<simple_entry_t> entries;
 
 	struct stat st;
@@ -131,7 +134,16 @@ int list_directory(const BAN::String& path, config_t config)
 	int ret = 0;
 
 	if (!S_ISDIR(st.st_mode))
+	{
 		MUST(entries.emplace_back(path, st));
+		if (S_ISLNK(st.st_mode))
+		{
+			if (readlink(path.data(), link_buffer, sizeof(link_buffer)) == -1)
+				perror("readlink");
+			else
+				MUST(entries.back().link.append(link_buffer));
+		}
+	}
 	else
 	{
 		DIR* dirp = opendir(path.data());
@@ -155,6 +167,13 @@ int list_directory(const BAN::String& path, config_t config)
 			}
 
 			MUST(entries.emplace_back(BAN::StringView(dirent->d_name), st));
+			if (S_ISLNK(st.st_mode))
+			{
+				if (readlinkat(dirfd(dirp), dirent->d_name, link_buffer, sizeof(link_buffer)) == -1)
+					perror("readlink");
+				else
+					MUST(entries.back().link.append(link_buffer));
+			}
 		}
 
 		closedir(dirp);
@@ -214,6 +233,11 @@ int list_directory(const BAN::String& path, config_t config)
 		GET_ENTRY_STRING(time,	time);
 
 		full_entry.full_name = MUST(BAN::String::formatted("{}{}\e[m", entry_color(entry.st.st_mode), entry.name));
+		if (S_ISLNK(entry.st.st_mode))
+		{
+			MUST(full_entry.full_name.append(" -> "_sv));
+			MUST(full_entry.full_name.append(entry.link));
+		}
 
 		MUST(full_entries.push_back(BAN::move(full_entry)));
 	}