Kernel: open() and openat() now take mode as parameter

O_CREAT now tries to create file if O_CREAT is specified

kernel/include/kernel/Process.h

@@ -77,8 +77,8 @@ namespace Kernel
 		BAN::ErrorOr<long> sys_geteuid() const { return m_credentials.euid(); }
 		BAN::ErrorOr<long> sys_getegid() const { return m_credentials.egid(); }
 
-		BAN::ErrorOr<long> sys_open(BAN::StringView, int);
+		BAN::ErrorOr<long> sys_open(BAN::StringView, int, mode_t = 0);
-		BAN::ErrorOr<long> sys_openat(int, BAN::StringView, int);
+		BAN::ErrorOr<long> sys_openat(int, BAN::StringView, int, mode_t = 0);
 		BAN::ErrorOr<long> sys_close(int fd);
 		BAN::ErrorOr<long> sys_read(int fd, void* buffer, size_t count);
 		BAN::ErrorOr<long> sys_write(int fd, const void* buffer, size_t count);

kernel/kernel/Process.cpp

@@ -490,14 +490,28 @@ namespace Kernel
 		}
 	}
 
-	BAN::ErrorOr<long> Process::sys_open(BAN::StringView path, int flags)
+	BAN::ErrorOr<long> Process::sys_open(BAN::StringView path, int flags, mode_t mode)
 	{
 		LockGuard _(m_lock);
 		BAN::String absolute_path = TRY(absolute_path_of(path));
+
+		if (flags & O_CREAT)
+		{
+			auto file_or_error = VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_WRONLY);
+			if (file_or_error.is_error())
+			{
+				if (file_or_error.error().get_error_code() == ENOENT)
+					TRY(sys_creat(path, mode));
+				else
+					return file_or_error.release_error();
+			}
+			flags &= ~O_CREAT;
+		}
+
 		return TRY(m_open_file_descriptors.open(absolute_path, flags));
 	}
 
-	BAN::ErrorOr<long> Process::sys_openat(int fd, BAN::StringView path, int flags)
+	BAN::ErrorOr<long> Process::sys_openat(int fd, BAN::StringView path, int flags, mode_t mode)
 	{
 		LockGuard _(m_lock);
 
@@ -506,7 +520,7 @@ namespace Kernel
 		TRY(absolute_path.push_back('/'));
 		TRY(absolute_path.append(path));
 
-		return sys_open(absolute_path, flags);
+		return sys_open(absolute_path, flags, mode);
 	}
 
 	BAN::ErrorOr<long> Process::sys_close(int fd)

kernel/kernel/Syscall.cpp

@@ -49,10 +49,10 @@ namespace Kernel
 			ret = Process::current().sys_close((int)arg1);
 			break;
 		case SYS_OPEN:
-			ret = Process::current().sys_open((const char*)arg1, (int)arg2);
+			ret = Process::current().sys_open((const char*)arg1, (int)arg2, (mode_t)arg3);
 			break;
 		case SYS_OPENAT:
-			ret = Process::current().sys_openat((int)arg1, (const char*)arg2, (int)arg3);
+			ret = Process::current().sys_openat((int)arg1, (const char*)arg2, (int)arg3, (mode_t)arg4);
 			break;
 		case SYS_ALLOC:
 			ret = Process::current().sys_alloc((size_t)arg1);

libc/fcntl.cpp

@@ -1,14 +1,25 @@
 #include <fcntl.h>
 #include <errno.h>
+#include <stdarg.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 
 int open(const char* path, int oflag, ...)
 {
-	return syscall(SYS_OPEN, path, oflag);
+	va_list args;
+	va_start(args, oflag);
+	mode_t mode = va_arg(args, mode_t);
+	va_end(args);
+
+	return syscall(SYS_OPEN, path, oflag, mode);
 }
 
 int openat(int fd, const char* path, int oflag, ...)
 {
-	return syscall(SYS_OPENAT, fd, path, oflag);
+	va_list args;
+	va_start(args, oflag);
+	mode_t mode = va_arg(args, mode_t);
+	va_end(args);
+
+	return syscall(SYS_OPENAT, fd, path, oflag, mode);
 }

libc/unistd.cpp

@@ -69,7 +69,8 @@ long syscall(long syscall, ...)
 		{
 			const char* path = va_arg(args, const char*);
 			int oflags = va_arg(args, int);
-			ret = Kernel::syscall(SYS_OPEN, (uintptr_t)path, oflags);
+			mode_t mode = va_arg(args, mode_t);
+			ret = Kernel::syscall(SYS_OPEN, (uintptr_t)path, oflags, mode);
 			break;
 		}
 		case SYS_OPENAT:
@@ -77,7 +78,8 @@ long syscall(long syscall, ...)
 			int fd = va_arg(args, int);
 			const char* path = va_arg(args, const char*);
 			int oflags = va_arg(args, int);
-			ret = Kernel::syscall(SYS_OPENAT, fd, (uintptr_t)path, oflags);
+			mode_t mode = va_arg(args, mode_t);
+			ret = Kernel::syscall(SYS_OPENAT, fd, (uintptr_t)path, oflags, mode);
 			break;
 		}
 		case SYS_ALLOC: