vmmcache: initial implementation

kernel-src/sys/syscalls/mmap.c

@@ -57,11 +57,18 @@ syscallret_t syscall_mmap(context_t *context, void *hint, size_t len, int prot,
 	vmmfiledesc_t vfd;
 	file_t *file = NULL;
 	if (isfile) {
+		// make sure offset is page aligned
+		if (offset % PAGE_SIZE) {
+			ret.errno = EINVAL;
+			return ret;
+		}
+
 		file = fd_get(fd);
 		if (file == NULL) {
 			ret.errno = EBADF;
 			return ret;
 		}
+
 		vfd.node = file->vnode;
 		vfd.offset = offset;
 	}

kernel-src/sys/syscalls/open.c

@@ -61,7 +61,9 @@ syscallret_t syscall_openat(context_t *context, int dirfd, const char *path, int
 		goto cleanup;
 
 	if (vnode->type == V_TYPE_REGULAR && (flags & O_TRUNC)) {
+		MUTEX_ACQUIRE(&vnode->sizelock, false);
 		ret.errno = VOP_RESIZE(vnode, 0, &_cpu()->thread->proc->cred);
+		MUTEX_RELEASE(&vnode->sizelock);
 		if (ret.errno)
 			goto cleanup;
 	}

kernel-src/sys/syscalls/truncate.c

@@ -1,4 +1,5 @@
 #include <kernel/syscalls.h>
+#include <mutex.h>
 
 syscallret_t syscall_ftruncate(int fd, size_t size) {
 	syscallret_t ret = {
@@ -16,7 +17,9 @@ syscallret_t syscall_ftruncate(int fd, size_t size) {
 		goto cleanup;
 	}
 
+	MUTEX_ACQUIRE(&file->vnode->sizelock, false);
 	ret.errno = VOP_RESIZE(file->vnode, size, &_cpu()->thread->proc->cred);
+	MUTEX_RELEASE(&file->vnode->sizelock);
 	ret.ret = ret.errno ? -1 : 0;
 
 	cleanup: