// SPDX-License-Identifier: GPL-2.0-only/* * drivers/dma-buf/sync_file.c * * Copyright (C) 2012 Google, Inc. */ #include <linux/dma-fence-unwrap.h>#include <linux/export.h>#include <linux/file.h>#include <linux/fs.h>#include <linux/kernel.h>#include <linux/poll.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/uaccess.h>#include <linux/anon_inodes.h>#include <linux/sync_file.h>#include <uapi/linux/sync_file.h> static const struct file_operations sync_file_fops; static struct sync_file *sync_file_alloc(void){	struct sync_file *sync_file; 	sync_file = kzalloc_obj(*sync_file);	if (!sync_file)		return NULL; 	sync_file->file = anon_inode_getfile("sync_file", &sync_file_fops,					     sync_file, 0);	if (IS_ERR(sync_file->file))		goto err; 	init_waitqueue_head(&sync_file->wq); 	INIT_LIST_HEAD(&sync_file->cb.node); 	return sync_file; err:	kfree(sync_file);	return NULL;} static void fence_check_cb_func(struct dma_fence *f, struct dma_fence_cb *cb){	struct sync_file *sync_file; 	sync_file = container_of(cb, struct sync_file, cb); 	wake_up_all(&sync_file->wq);} /** * sync_file_create() - creates a sync file * @fence:	fence to add to the sync_fence * * Creates a sync_file containg @fence. This function acquires and additional * reference of @fence for the newly-created &sync_file, if it succeeds. The * sync_file can be released with fput(sync_file->file). Returns the * sync_file or NULL in case of error. */struct sync_file *sync_file_create(struct dma_fence *fence){	struct sync_file *sync_file; 	sync_file = sync_file_alloc();	if (!sync_file)		return NULL; 	sync_file->fence = dma_fence_get(fence); 	return sync_file;}EXPORT_SYMBOL(sync_file_create); static struct sync_file *sync_file_fdget(int fd){	struct file *file = fget(fd); 	if (!file)		return NULL; 	if (file->f_op != &sync_file_fops)		goto err; 	return file->private_data; err:	fput(file);	return NULL;} /** * sync_file_get_fence - get the fence related to the sync_file fd * @fd:		sync_file fd to get the fence from * * Ensures @fd references a valid sync_file and returns a fence that * represents all fence in the sync_file. On error NULL is returned. */struct dma_fence *sync_file_get_fence(int fd){	struct sync_file *sync_file;	struct dma_fence *fence; 	sync_file = sync_file_fdget(fd);	if (!sync_file)		return NULL; 	fence = dma_fence_get(sync_file->fence);	fput(sync_file->file); 	return fence;}EXPORT_SYMBOL(sync_file_get_fence); /** * sync_file_get_name - get the name of the sync_file * @sync_file:		sync_file to get the fence from * @buf:		destination buffer to copy sync_file name into * @len:		available size of destination buffer. * * Each sync_file may have a name assigned either by the user (when merging * sync_files together) or created from the fence it contains. In the latter * case construction of the name is deferred until use, and so requires * sync_file_get_name(). * * Returns: a string representing the name. */char *sync_file_get_name(struct sync_file *sync_file, char *buf, int len){	if (sync_file->user_name[0]) {		strscpy(buf, sync_file->user_name, len);	} else {		struct dma_fence *fence = sync_file->fence;		const char __rcu *timeline;		const char __rcu *driver; 		rcu_read_lock();		driver = dma_fence_driver_name(fence);		timeline = dma_fence_timeline_name(fence);		snprintf(buf, len, "%s-%s%llu-%lld",			 rcu_dereference(driver),			 rcu_dereference(timeline),			 fence->context,			 fence->seqno);		rcu_read_unlock();	} 	return buf;} /** * sync_file_merge() - merge two sync_files * @name:	name of new fence * @a:		sync_file a * @b:		sync_file b * * Creates a new sync_file which contains copies of all the fences in both * @a and @b.  @a and @b remain valid, independent sync_file. Returns the * new merged sync_file or NULL in case of error. */static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,					 struct sync_file *b){	struct sync_file *sync_file;	struct dma_fence *fence; 	sync_file = sync_file_alloc();	if (!sync_file)		return NULL; 	fence = dma_fence_unwrap_merge(a->fence, b->fence);	if (!fence) {		fput(sync_file->file);		return NULL;	}	sync_file->fence = fence;	strscpy(sync_file->user_name, name, sizeof(sync_file->user_name));	return sync_file;} static int sync_file_release(struct inode *inode, struct file *file){	struct sync_file *sync_file = file->private_data; 	if (test_bit(POLL_ENABLED, &sync_file->flags))		dma_fence_remove_callback(sync_file->fence, &sync_file->cb);	dma_fence_put(sync_file->fence);	kfree(sync_file); 	return 0;} static __poll_t sync_file_poll(struct file *file, poll_table *wait){	struct sync_file *sync_file = file->private_data; 	poll_wait(file, &sync_file->wq, wait); 	if (list_empty(&sync_file->cb.node) &&	    !test_and_set_bit(POLL_ENABLED, &sync_file->flags)) {		if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,					   fence_check_cb_func) < 0)			wake_up_all(&sync_file->wq);	} 	return dma_fence_is_signaled(sync_file->fence) ? EPOLLIN : 0;} static long sync_file_ioctl_merge(struct sync_file *sync_file,				  unsigned long arg){	int fd = get_unused_fd_flags(O_CLOEXEC);	int err;	struct sync_file *fence2, *fence3;	struct sync_merge_data data; 	if (fd < 0)		return fd; 	if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {		err = -EFAULT;		goto err_put_fd;	} 	if (data.flags || data.pad) {		err = -EINVAL;		goto err_put_fd;	} 	fence2 = sync_file_fdget(data.fd2);	if (!fence2) {		err = -ENOENT;		goto err_put_fd;	} 	data.name[sizeof(data.name) - 1] = '\0';	fence3 = sync_file_merge(data.name, sync_file, fence2);	if (!fence3) {		err = -ENOMEM;		goto err_put_fence2;	} 	data.fence = fd;	if (copy_to_user((void __user *)arg, &data, sizeof(data))) {		err = -EFAULT;		goto err_put_fence3;	} 	fd_install(fd, fence3->file);	fput(fence2->file);	return 0; err_put_fence3:	fput(fence3->file); err_put_fence2:	fput(fence2->file); err_put_fd:	put_unused_fd(fd);	return err;} static int sync_fill_fence_info(struct dma_fence *fence,				 struct sync_fence_info *info){	const char __rcu *timeline;	const char __rcu *driver; 	rcu_read_lock(); 	driver = dma_fence_driver_name(fence);	timeline = dma_fence_timeline_name(fence); 	strscpy(info->obj_name, rcu_dereference(timeline),		sizeof(info->obj_name));	strscpy(info->driver_name, rcu_dereference(driver),		sizeof(info->driver_name)); 	info->status = dma_fence_get_status(fence);	info->timestamp_ns =		dma_fence_is_signaled(fence) ?			ktime_to_ns(dma_fence_timestamp(fence)) :			ktime_set(0, 0); 	rcu_read_unlock(); 	return info->status;} static long sync_file_ioctl_fence_info(struct sync_file *sync_file,				       unsigned long arg){	struct sync_fence_info *fence_info = NULL;	struct dma_fence_unwrap iter;	struct sync_file_info info;	unsigned int num_fences;	struct dma_fence *fence;	int ret;	__u32 size; 	if (copy_from_user(&info, (void __user *)arg, sizeof(info)))		return -EFAULT; 	if (info.flags || info.pad)		return -EINVAL; 	num_fences = 0;	dma_fence_unwrap_for_each(fence, &iter, sync_file->fence)		++num_fences; 	/*	 * Passing num_fences = 0 means that userspace doesn't want to	 * retrieve any sync_fence_info. If num_fences = 0 we skip filling	 * sync_fence_info and return the actual number of fences on	 * info->num_fences.	 */	if (!info.num_fences) {		info.status = dma_fence_get_status(sync_file->fence);		goto no_fences;	} else {		info.status = 1;	} 	if (info.num_fences < num_fences)		return -EINVAL; 	size = num_fences * sizeof(*fence_info);	fence_info = kzalloc(size, GFP_KERNEL);	if (!fence_info)		return -ENOMEM; 	num_fences = 0;	dma_fence_unwrap_for_each(fence, &iter, sync_file->fence) {		int status; 		status = sync_fill_fence_info(fence, &fence_info[num_fences++]);		info.status = info.status <= 0 ? info.status : status;	} 	if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,			 size)) {		ret = -EFAULT;		goto out;	} no_fences:	sync_file_get_name(sync_file, info.name, sizeof(info.name));	info.num_fences = num_fences; 	if (copy_to_user((void __user *)arg, &info, sizeof(info)))		ret = -EFAULT;	else		ret = 0; out:	kfree(fence_info); 	return ret;} static int sync_file_ioctl_set_deadline(struct sync_file *sync_file,					unsigned long arg){	struct sync_set_deadline ts; 	if (copy_from_user(&ts, (void __user *)arg, sizeof(ts)))		return -EFAULT; 	if (ts.pad)		return -EINVAL; 	dma_fence_set_deadline(sync_file->fence, ns_to_ktime(ts.deadline_ns)); 	return 0;} static long sync_file_ioctl(struct file *file, unsigned int cmd,			    unsigned long arg){	struct sync_file *sync_file = file->private_data; 	switch (cmd) {	case SYNC_IOC_MERGE:		return sync_file_ioctl_merge(sync_file, arg); 	case SYNC_IOC_FILE_INFO:		return sync_file_ioctl_fence_info(sync_file, arg); 	case SYNC_IOC_SET_DEADLINE:		return sync_file_ioctl_set_deadline(sync_file, arg); 	default:		return -ENOTTY;	}} static const struct file_operations sync_file_fops = {	.release = sync_file_release,	.poll = sync_file_poll,	.unlocked_ioctl = sync_file_ioctl,	.compat_ioctl = compat_ptr_ioctl,};