From 18bea63d1c6b93a279db0f9ca658716308f7043a Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Sat, 13 May 2023 21:12:09 -0300
Subject: [PATCH] kernel: write syscall

---
 kernel-src/arch/x86-64/syscall.asm     |  4 ++-
 kernel-src/sys/syscalls/write.c        | 43 ++++++++++++++++++++++++++
 patches/mlibc/jinx-working-patch.patch | 16 ++++++----
 3 files changed, 56 insertions(+), 7 deletions(-)
 create mode 100644 kernel-src/sys/syscalls/write.c

diff --git a/kernel-src/arch/x86-64/syscall.asm b/kernel-src/arch/x86-64/syscall.asm
index 1046d6a6..d06319f8 100644
--- a/kernel-src/arch/x86-64/syscall.asm
+++ b/kernel-src/arch/x86-64/syscall.asm
@@ -6,6 +6,7 @@ extern syscall_read
 extern syscall_seek
 extern syscall_close
 extern syscall_archctl
+extern syscall_write
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -14,7 +15,8 @@ dq syscall_read
 dq syscall_seek
 dq syscall_close
 dq syscall_archctl
-syscallcount equ 7
+dq syscall_write
+syscallcount equ 8
 section .text
 global arch_syscall_entry
 ; on entry:
diff --git a/kernel-src/sys/syscalls/write.c b/kernel-src/sys/syscalls/write.c
new file mode 100644
index 00000000..b970d243
--- /dev/null
+++ b/kernel-src/sys/syscalls/write.c
@@ -0,0 +1,43 @@
+#include <kernel/syscalls.h>
+#include <kernel/vfs.h>
+#include <kernel/file.h>
+#include <errno.h>
+
+syscallret_t syscall_write(context_t *context, int fd, void *buffer, size_t size) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	void *kernelbuff = vmm_map(NULL, size, VMM_FLAGS_ALLOCATE, ARCH_MMU_FLAGS_READ | ARCH_MMU_FLAGS_WRITE | ARCH_MMU_FLAGS_NOEXEC, NULL);
+	if (kernelbuff == NULL) {
+		ret.errno = ENOMEM;
+		return ret;
+	}
+
+	file_t *file = fd_get(fd);
+
+	if (file == NULL || (file->flags & FILE_WRITE) == 0) {
+		ret.errno = EBADF;
+		goto cleanup;
+	}
+
+	// TODO safe memcpy
+	memcpy(kernelbuff, buffer, size);
+
+	// TODO pass flags
+	size_t byteswritten;
+	ret.errno = vfs_write(file->vnode, kernelbuff, size, file->offset, &byteswritten, 0);
+
+	if (ret.errno)
+		goto cleanup;
+
+	file->offset += byteswritten;
+	ret.ret = byteswritten;
+	ret.errno = 0;
+cleanup:
+	if (file)
+		fd_release(file);
+
+	vmm_unmap(kernelbuff, size, 0);
+	return ret;
+}
diff --git a/patches/mlibc/jinx-working-patch.patch b/patches/mlibc/jinx-working-patch.patch
index fce6eb03..45015c4f 100644
--- a/patches/mlibc/jinx-working-patch.patch
+++ b/patches/mlibc/jinx-working-patch.patch
@@ -133,10 +133,10 @@ index 0000000..e5b087a
 +
 diff --git mlibc-workdir/sysdeps/astral/generic/generic.cpp mlibc-workdir/sysdeps/astral/generic/generic.cpp
 new file mode 100644
-index 0000000..1bf8c55
+index 0000000..30fd3b0
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/generic/generic.cpp
-@@ -0,0 +1,154 @@
+@@ -0,0 +1,157 @@
 +#include <bits/ensure.h>
 +#include <mlibc/debug.hpp>
 +#include <mlibc/all-sysdeps.hpp>
@@ -255,7 +255,10 @@ index 0000000..1bf8c55
 +	}
 +
 +	int sys_write(int fd, const void *buff, size_t count, ssize_t *bytes_written) {
-+		return ENOSYS;
++		long writec;
++		long error = syscall(SYSCALL_WRITE, &writec, fd, (uint64_t)buff, count);
++		*bytes_written = writec;
++		return error;
 +	}
 +
 +	int sys_seek(int fd, off_t offset, int whence, off_t *new_offset) {
@@ -282,7 +285,7 @@ index 0000000..1bf8c55
 +	}
 +	
 +	int sys_isatty(int fd) {
-+		return ENOSYS;
++		return 0;
 +	}
 +
 +	int sys_clock_get(int clock, time_t *secs, long *nanos) {
@@ -310,10 +313,10 @@ index 0000000..990eca0
 +#endif
 diff --git mlibc-workdir/sysdeps/astral/include/astral/syscall.h mlibc-workdir/sysdeps/astral/include/astral/syscall.h
 new file mode 100644
-index 0000000..2d4b960
+index 0000000..ce00d62
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/include/astral/syscall.h
-@@ -0,0 +1,30 @@
+@@ -0,0 +1,31 @@
 +#ifndef _SYSCALL_H_INCLUDE
 +#define _SYSCALL_H_INCLUDE
 +
@@ -324,6 +327,7 @@ index 0000000..2d4b960
 +#define SYSCALL_SEEK 4
 +#define SYSCALL_CLOSE 5
 +#define SYSCALL_ARCHCTL 6
++#define SYSCALL_WRITE 7
 +
 +#include <stddef.h>
 +#include <stdint.h>