sys/kern/sys_memfd.c

98 	struct memfd *mfd;
105 	mfd = kmem_zalloc(sizeof(*mfd), KM_SLEEP);
106 	mfd->mfd_size = 0;
107 	mfd->mfd_uobj = uao_create(INT64_MAX - PAGE_SIZE, 0); /* same as tmpfs */
110 	strcpy(mfd->mfd_name, memfd_prefix);
112 	    &mfd->mfd_name[sizeof(memfd_prefix) - 1],
113 	    sizeof(mfd->mfd_name) - sizeof(memfd_prefix), NULL);
117 	getnanotime(&mfd->mfd_btime);
120 		mfd->mfd_seals |= F_SEAL_SEAL;
129 	fp->f_memfd = mfd;
137 	uao_detach(mfd->mfd_uobj);
138 	kmem_free(mfd, sizeof(*mfd));
148 	struct memfd *mfd = fp->f_memfd;
158 	if (*offp >= mfd->mfd_size) {
164 	todo = MIN(uio->uio_resid, mfd->mfd_size - *offp);
165 	error = ubc_uiomove(mfd->mfd_uobj, uio, todo, UVM_ADV_SEQUENTIAL,
171 	getnanotime(&mfd->mfd_atime);
185 	struct memfd *mfd = fp->f_memfd;
189 	if (mfd->mfd_seals & F_SEAL_ANY_WRITE) {
202 	if (mfd->mfd_seals & F_SEAL_GROW) {
203 		if (*offp >= mfd->mfd_size) {
209 		if (*offp + uio->uio_resid >= mfd->mfd_size)
210 			todo = mfd->mfd_size - *offp;
211 	} else if (*offp + uio->uio_resid >= mfd->mfd_size) {
218 	error = ubc_uiomove(mfd->mfd_uobj, uio, todo, UVM_ADV_SEQUENTIAL,
223 	getnanotime(&mfd->mfd_mtime);
241 	struct memfd *mfd = fp->f_memfd;
246 		strncpy(data, mfd->mfd_name, MAXPATHLEN);
252 		if (mfd->mfd_seals & F_SEAL_SEAL) {
269 		if ((mfd->mfd_seals & F_SEAL_WRITE) == 0 &&
271 		    mfd->mfd_uobj->uo_refs > 1)
277 		mfd->mfd_seals |= *(int *)data;
285 		*(int *)data = mfd->mfd_seals;
297 	struct memfd *mfd = fp->f_memfd;
304 	st->st_size = mfd->mfd_size;
307 	if ((mfd->mfd_seals & F_SEAL_ANY_WRITE) == 0)
310 	st->st_birthtimespec = mfd->mfd_btime;
311 	st->st_ctimespec = mfd->mfd_mtime;
312 	st->st_atimespec = mfd->mfd_atime;
313 	st->st_mtimespec = mfd->mfd_mtime;
323 	struct memfd *mfd = fp->f_memfd;
325 	uao_detach(mfd->mfd_uobj);
327 	kmem_free(mfd, sizeof(*mfd));
337 	struct memfd *mfd = fp->f_memfd;
351 	if (*offp + size > mfd->mfd_size) {
356 	if ((mfd->mfd_seals & F_SEAL_ANY_WRITE) &&
415 	struct memfd *mfd = fp->f_memfd;
423 	if (length == mfd->mfd_size)
426 	if ((mfd->mfd_seals & F_SEAL_SHRINK) && length < mfd->mfd_size)
428 	if ((mfd->mfd_seals & F_SEAL_GROW) && length > mfd->mfd_size)
431 	if (length > mfd->mfd_size)
432 		ubc_zerorange(mfd->mfd_uobj, mfd->mfd_size,
433 		    length - mfd->mfd_size, 0);
435 		/* length < mfd->mfd_size, so try to get rid of excess pages */
437 		end = round_page(mfd->mfd_size);
440 			rw_enter(mfd->mfd_uobj->vmobjlock, RW_WRITER);
441 			error = (*mfd->mfd_uobj->pgops->pgo_put)(mfd->mfd_uobj,
447 	getnanotime(&mfd->mfd_mtime);
448 	mfd->mfd_size = length;