From 834bf33e5717c01fe250c677fa854e7e3ee5fdcf Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Mon, 31 Jul 2023 22:24:11 +0300
Subject: [PATCH] LibC: we don't parse syscall arguments in unistd

We just call Kernel::syscall() with 5 arguments from the variadic function.

This was a necessary addition since the syscall() function
used over 2 KiB of stack space.
---
 libc/unistd.cpp | 288 ++----------------------------------------------
 1 file changed, 8 insertions(+), 280 deletions(-)

diff --git a/libc/unistd.cpp b/libc/unistd.cpp
index a13cb02c..4f6dd6ef 100644
--- a/libc/unistd.cpp
+++ b/libc/unistd.cpp
@@ -27,287 +27,15 @@ long syscall(long syscall, ...)
 	va_list args;
 	va_start(args, syscall);
 
-	long ret = -1;
-
-	switch (syscall)
-	{
-		case SYS_EXIT:
-		{
-			int exit_code = va_arg(args, int);
-			ret = Kernel::syscall(SYS_EXIT, exit_code);
-			break;
-		}
-		case SYS_READ:
-		{
-			int fd = va_arg(args, int);
-			void* buffer = va_arg(args, void*);
-			size_t bytes = va_arg(args, size_t);
-			ret = Kernel::syscall(SYS_READ, fd, (uintptr_t)buffer, bytes);
-			break;
-		}
-		case SYS_WRITE:
-		{
-			int fd = va_arg(args, int);
-			const void* buffer = va_arg(args, const void*);
-			size_t bytes = va_arg(args, size_t);
-			ret = Kernel::syscall(SYS_WRITE, fd, (uintptr_t)buffer, bytes);
-			break;
-		}
-		case SYS_TERMID:
-		{
-			char* buffer = va_arg(args, char*);
-			ret = Kernel::syscall(SYS_TERMID, (uintptr_t)buffer);
-			break;
-		}
-		case SYS_CLOSE:
-		{
-			int fd = va_arg(args, int);
-			ret = Kernel::syscall(SYS_CLOSE, fd);
-			break;
-		}
-		case SYS_OPEN:
-		{
-			const char* path = va_arg(args, const char*);
-			int oflags = va_arg(args, int);
-			mode_t mode = va_arg(args, mode_t);
-			ret = Kernel::syscall(SYS_OPEN, (uintptr_t)path, oflags, mode);
-			break;
-		}
-		case SYS_OPENAT:
-		{
-			int fd = va_arg(args, int);
-			const char* path = va_arg(args, const char*);
-			int oflags = va_arg(args, int);
-			mode_t mode = va_arg(args, mode_t);
-			ret = Kernel::syscall(SYS_OPENAT, fd, (uintptr_t)path, oflags, mode);
-			break;
-		}
-		case SYS_ALLOC:
-		{
-			size_t bytes = va_arg(args, size_t);
-			ret = Kernel::syscall(SYS_ALLOC, bytes);
-			break;
-		}
-		case SYS_REALLOC:
-		{
-			void* ptr = va_arg(args, void*);
-			size_t size = va_arg(args, size_t);
-			ret = Kernel::syscall(SYS_REALLOC, (uintptr_t)ptr, size);
-			break;
-		}
-		case SYS_FREE:
-		{
-			void* ptr = va_arg(args, void*);
-			ret = Kernel::syscall(SYS_FREE, (uintptr_t)ptr);
-			break;
-		}
-		case SYS_SEEK:
-		{
-			int fd = va_arg(args, int);
-			off_t offset = va_arg(args, off_t);
-			int whence = va_arg(args, int);
-			ret = Kernel::syscall(SYS_SEEK, fd, offset, whence);
-			break;
-		}
-		case SYS_TELL:
-		{
-			int fd = va_arg(args, int);
-			ret = Kernel::syscall(SYS_TELL, fd);
-			break;
-		}
-		case SYS_GET_TERMIOS:
-		{
-			struct termios* termios = va_arg(args, struct termios*);
-			ret = Kernel::syscall(SYS_GET_TERMIOS, (uintptr_t)termios);
-			break;
-		}
-		case SYS_SET_TERMIOS:
-		{
-			const struct termios* termios = va_arg(args, const struct termios*);
-			ret = Kernel::syscall(SYS_SET_TERMIOS, (uintptr_t)termios);
-			break;
-		}
-		case SYS_FORK:
-		{
-			ret = Kernel::syscall(SYS_FORK);
-			break;
-		}
-		case SYS_EXEC:
-		{
-			const char* pathname = va_arg(args, const char*);
-			const char* const* argv = va_arg(args, const char* const*);
-			const char* const* envp = va_arg(args, const char* const*);
-			ret = Kernel::syscall(SYS_EXEC, (uintptr_t)pathname, (uintptr_t)argv, (uintptr_t)envp);
-			break;
-		}
-		case SYS_SLEEP:
-		{
-			unsigned int seconds = va_arg(args, unsigned int);
-			ret = Kernel::syscall(SYS_SLEEP, seconds);
-			break;
-		}
-		case SYS_WAIT:
-		{
-			pid_t pid = va_arg(args, pid_t);
-			int* stat_loc = va_arg(args, int*);
-			int options = va_arg(args, int);
-			ret = Kernel::syscall(SYS_WAIT, pid, (uintptr_t)stat_loc, options);
-			break;
-		}
-		case SYS_FSTAT:
-		{
-			int fd = va_arg(args, int);
-			struct stat* buf = va_arg(args, struct stat*);
-			ret = Kernel::syscall(SYS_FSTAT, (uintptr_t)fd, (uintptr_t)buf);
-			break;
-		}
-		case SYS_SETENVP:
-		{
-			char** envp = va_arg(args, char**);
-			ret = Kernel::syscall(SYS_SETENVP, (uintptr_t)envp);
-			break;
-		}
-		case SYS_READ_DIR_ENTRIES:
-		{
-			int fd = va_arg(args, int);
-			void* buffer = va_arg(args, void*);
-			size_t buffer_size = va_arg(args, size_t);
-			ret = Kernel::syscall(SYS_READ_DIR_ENTRIES, fd, (uintptr_t)buffer, buffer_size);
-			break;
-		}
-		case SYS_SET_UID:
-		{
-			uid_t uid = va_arg(args, uid_t);
-			ret = Kernel::syscall(SYS_SET_UID, uid);
-			break;
-		}
-		case SYS_SET_GID:
-		{
-			gid_t gid = va_arg(args, gid_t);
-			ret = Kernel::syscall(SYS_SET_GID, gid);
-			break;
-		}
-		case SYS_SET_EUID:
-		{
-			uid_t uid = va_arg(args, uid_t);
-			ret = Kernel::syscall(SYS_SET_EUID, uid);
-			break;
-		}
-		case SYS_SET_EGID:
-		{
-			gid_t gid = va_arg(args, gid_t);
-			ret = Kernel::syscall(SYS_SET_EGID, gid);
-			break;
-		}
-		case SYS_SET_REUID:
-		{
-			uid_t ruid = va_arg(args, uid_t);
-			uid_t euid = va_arg(args, uid_t);
-			ret = Kernel::syscall(SYS_SET_REUID, ruid, euid);
-			break;
-		}
-		case SYS_SET_REGID:
-		{
-			gid_t rgid = va_arg(args, gid_t);
-			gid_t egid = va_arg(args, gid_t);
-			ret = Kernel::syscall(SYS_SET_REGID, rgid, egid);
-			break;
-		}
-		case SYS_GET_UID:
-		{
-			ret = Kernel::syscall(SYS_GET_UID);
-			break;
-		}
-		case SYS_GET_GID:
-		{
-			ret = Kernel::syscall(SYS_GET_GID);
-			break;
-		}
-		case SYS_GET_EUID:
-		{
-			ret = Kernel::syscall(SYS_GET_EUID);
-			break;
-		}
-		case SYS_GET_EGID:
-		{
-			ret = Kernel::syscall(SYS_GET_EGID);
-			break;
-		}
-		case SYS_GET_PWD:
-		{
-			char* buffer = va_arg(args, char*);
-			size_t size = va_arg(args, size_t);
-			ret = Kernel::syscall(SYS_GET_PWD, (uintptr_t)buffer, size);
-			break;
-		}
-		case SYS_SET_PWD:
-		{
-			const char* path = va_arg(args, const char*);
-			ret = Kernel::syscall(SYS_SET_PWD, (uintptr_t)path);
-			break;
-		}
-		case SYS_CLOCK_GETTIME:
-		{
-			clockid_t clock_id = va_arg(args, clockid_t);
-			timespec* tp = va_arg(args, timespec*);
-			ret = Kernel::syscall(SYS_CLOCK_GETTIME, clock_id, (uintptr_t)tp);
-			break;
-		}
-		case SYS_PIPE:
-		{
-			int* fildes = va_arg(args, int*);
-			ret = Kernel::syscall(SYS_PIPE, (uintptr_t)fildes);
-			break;
-		}
-		case SYS_DUP2:
-		{
-			int fildes = va_arg(args, int);
-			int fildes2 = va_arg(args, int);
-			ret = Kernel::syscall(SYS_DUP2, fildes, fildes2);
-			break;
-		}
-		case SYS_RAISE:
-		{
-			int signal = va_arg(args, int);
-			ret = Kernel::syscall(SYS_RAISE, signal);
-			break;
-		}
-		case SYS_KILL:
-		{
-			pid_t pid = va_arg(args, pid_t);
-			int signal = va_arg(args, int);
-			ret = Kernel::syscall(SYS_KILL, pid, signal);
-			break;
-		}
-		case SYS_SIGNAL:
-		{
-			int signal = va_arg(args, int);
-			void (*handler)(int) = va_arg(args, void(*)(int));
-			ret = Kernel::syscall(SYS_SIGNAL, signal, (uintptr_t)handler);
-			break;
-		}
-		case SYS_TCSETPGRP:
-		{
-			int fd = va_arg(args, int);
-			pid_t pgrp = va_arg(args, pid_t);
-			ret = Kernel::syscall(SYS_TCSETPGRP, fd, pgrp);
-			break;
-		}
-		case SYS_GET_PID:
-		{
-			ret = Kernel::syscall(SYS_GET_PID);
-			break;
-		}
-		case SYS_SIGNAL_DONE:
-			// Should not be called by an user
-			// fall through
-		default:
-			puts("LibC: Unhandeled syscall");
-			ret = -ENOSYS;
-			break;
-	}
-
+	uintptr_t arg1 = va_arg(args, uintptr_t);
+	uintptr_t arg2 = va_arg(args, uintptr_t);
+	uintptr_t arg3 = va_arg(args, uintptr_t);
+	uintptr_t arg4 = va_arg(args, uintptr_t);
+	uintptr_t arg5 = va_arg(args, uintptr_t);
+	
 	va_end(args);
+
+	long ret = Kernel::syscall(syscall, arg1, arg2, arg3, arg4, arg5);
 	
 	if (ret < 0)
 	{