write system call

src/arch/x86_64/syscall.asm

@@ -10,7 +10,8 @@ extern syscall_read
 extern syscall_lseek
 extern syscall_close
 extern syscall_isatty
-func_count equ 9
+extern syscall_write
+func_count equ 10
 
 
 func_table:
@@ -23,6 +24,7 @@ func_table:
 	dq syscall_lseek
 	dq syscall_close
 	dq syscall_isatty
+	dq syscall_write
 section .text
 global asm_syscall_entry
 

src/sys/sched/scheduler.c

@@ -327,8 +327,8 @@ void sched_runinit(){
 	}
 	
 	stdinfd->offset = stdoutfd->offset = stderrfd->offset = 0;
-	stdinfd->flags = O_RDONLY;
+	stdinfd->flags = O_RDONLY + 1;
-	stdoutfd->flags = stderrfd->flags = O_WRONLY;
+	stdoutfd->flags = stderrfd->flags = O_WRONLY + 1;
 
 	vnode_t* node;
 	ret = vfs_open(&node, vfs_root(), "sbin/init");

src/sys/syscalls/lseek.c

@@ -19,7 +19,7 @@ syscallret syscall_lseek(int ifd, off_t offset, int whence){
 
         spinlock_acquire(&proc->fdlock);
 
-        if(proc->fdcount <= ifd || fd->node == NULL || (fd->flags & FD_FLAGS_READ) == 0){
+        if(proc->fdcount <= ifd || fd->node == NULL){
                 spinlock_release(&proc->fdlock);
                 retv.errno = EBADF;
                 return retv;

src/sys/syscalls/write.c

@@ -0,0 +1,70 @@
+#include <kernel/syscalls.h>
+#include <kernel/fd.h>
+#include <kernel/alloc.h>
+#include <kernel/vfs.h>
+#include <arch/cls.h>
+#include <kernel/sched.h>
+#include <arch/spinlock.h>
+#include <kernel/vmm.h>
+#include <string.h>
+
+syscallret syscall_write(int ifd, void* buff, size_t count){
+
+	// TODO the other flags
+
+        syscallret retv;
+        retv.ret = -1;
+
+        if(buff > USER_SPACE_END){
+                retv.errno = EFAULT;
+                return retv;
+        }
+
+        proc_t* proc = arch_getcls()->thread->proc;
+
+        fd_t* fd = proc->fds + ifd;
+
+        spinlock_acquire(&proc->fdlock);
+
+        if(proc->fdcount <= ifd || fd->node == NULL || (fd->flags & FD_FLAGS_WRITE) == 0){
+                spinlock_release(&proc->fdlock);
+                retv.errno = EBADF;
+		return retv;
+        }
+
+        spinlock_acquire(&fd->lock);
+        spinlock_release(&proc->fdlock);
+
+        void* kbuff = alloc(count);
+
+        if(!kbuff){
+                spinlock_release(&fd->lock);
+                retv.errno = ENOMEM;
+                return retv;
+        }
+	
+	memcpy(kbuff, buff, count); // XXX use a more proper user copy
+	
+	if(fd->flags & O_APPEND)
+		fd->offset = fd->node->st.st_size;
+
+	int err;
+	size_t writec = vfs_write(&err, fd->node, kbuff, count, fd->offset);
+
+
+	if(err){
+		retv.errno = err;
+		goto _ret;
+	}
+
+	fd->offset += writec;
+	
+	retv.errno = 0;
+	retv.ret = writec;
+
+	_ret:
+	spinlock_release(&fd->lock);
+	free(kbuff);
+	return retv;
+}
+