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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * compat ioctls for control API
4  *
5  *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
6  */
7 
8 /* this file included from control.c */
9 
10 #include <linux/compat.h>
11 #include <linux/slab.h>
12 
13 struct snd_ctl_elem_list32 {
14 	u32 offset;
15 	u32 space;
16 	u32 used;
17 	u32 count;
18 	u32 pids;
19 	unsigned char reserved[50];
20 } /* don't set packed attribute here */;
21 
snd_ctl_elem_list_compat(struct snd_card * card,struct snd_ctl_elem_list32 __user * data32)22 static int snd_ctl_elem_list_compat(struct snd_card *card,
23 				    struct snd_ctl_elem_list32 __user *data32)
24 {
25 	struct snd_ctl_elem_list data = {};
26 	compat_caddr_t ptr;
27 	int err;
28 
29 	/* offset, space, used, count */
30 	if (copy_from_user(&data, data32, 4 * sizeof(u32)))
31 		return -EFAULT;
32 	/* pids */
33 	if (get_user(ptr, &data32->pids))
34 		return -EFAULT;
35 	data.pids = compat_ptr(ptr);
36 	err = snd_ctl_elem_list(card, &data);
37 	if (err < 0)
38 		return err;
39 	/* copy the result */
40 	if (copy_to_user(data32, &data, 4 * sizeof(u32)))
41 		return -EFAULT;
42 	return 0;
43 }
44 
45 /*
46  * control element info
47  * it uses union, so the things are not easy..
48  */
49 
50 struct snd_ctl_elem_info32 {
51 	struct snd_ctl_elem_id id; // the size of struct is same
52 	s32 type;
53 	u32 access;
54 	u32 count;
55 	s32 owner;
56 	union {
57 		struct {
58 			s32 min;
59 			s32 max;
60 			s32 step;
61 		} integer;
62 		struct {
63 			u64 min;
64 			u64 max;
65 			u64 step;
66 		} integer64;
67 		struct {
68 			u32 items;
69 			u32 item;
70 			char name[64];
71 			u64 names_ptr;
72 			u32 names_length;
73 		} enumerated;
74 		unsigned char reserved[128];
75 	} value;
76 	unsigned char reserved[64];
77 } __attribute__((packed));
78 
snd_ctl_elem_info_compat(struct snd_ctl_file * ctl,struct snd_ctl_elem_info32 __user * data32)79 static int snd_ctl_elem_info_compat(struct snd_ctl_file *ctl,
80 				    struct snd_ctl_elem_info32 __user *data32)
81 {
82 	struct snd_ctl_elem_info *data;
83 	int err;
84 
85 	data = kzalloc(sizeof(*data), GFP_KERNEL);
86 	if (! data)
87 		return -ENOMEM;
88 
89 	err = -EFAULT;
90 	/* copy id */
91 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
92 		goto error;
93 	/* we need to copy the item index.
94 	 * hope this doesn't break anything..
95 	 */
96 	if (get_user(data->value.enumerated.item, &data32->value.enumerated.item))
97 		goto error;
98 
99 	err = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
100 	if (err < 0)
101 		goto error;
102 	err = snd_ctl_elem_info(ctl, data);
103 	if (err < 0)
104 		goto error;
105 	/* restore info to 32bit */
106 	err = -EFAULT;
107 	/* id, type, access, count */
108 	if (copy_to_user(&data32->id, &data->id, sizeof(data->id)) ||
109 	    copy_to_user(&data32->type, &data->type, 3 * sizeof(u32)))
110 		goto error;
111 	if (put_user(data->owner, &data32->owner))
112 		goto error;
113 	switch (data->type) {
114 	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
115 	case SNDRV_CTL_ELEM_TYPE_INTEGER:
116 		if (put_user(data->value.integer.min, &data32->value.integer.min) ||
117 		    put_user(data->value.integer.max, &data32->value.integer.max) ||
118 		    put_user(data->value.integer.step, &data32->value.integer.step))
119 			goto error;
120 		break;
121 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
122 		if (copy_to_user(&data32->value.integer64,
123 				 &data->value.integer64,
124 				 sizeof(data->value.integer64)))
125 			goto error;
126 		break;
127 	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
128 		if (copy_to_user(&data32->value.enumerated,
129 				 &data->value.enumerated,
130 				 sizeof(data->value.enumerated)))
131 			goto error;
132 		break;
133 	default:
134 		break;
135 	}
136 	err = 0;
137  error:
138 	kfree(data);
139 	return err;
140 }
141 
142 /* read / write */
143 struct snd_ctl_elem_value32 {
144 	struct snd_ctl_elem_id id;
145 	unsigned int indirect;	/* bit-field causes misalignment */
146         union {
147 		s32 integer[128];
148 		unsigned char data[512];
149 #ifndef CONFIG_X86_64
150 		s64 integer64[64];
151 #endif
152         } value;
153         unsigned char reserved[128];
154 };
155 
156 #ifdef CONFIG_X86_X32
157 /* x32 has a different alignment for 64bit values from ia32 */
158 struct snd_ctl_elem_value_x32 {
159 	struct snd_ctl_elem_id id;
160 	unsigned int indirect;	/* bit-field causes misalignment */
161 	union {
162 		s32 integer[128];
163 		unsigned char data[512];
164 		s64 integer64[64];
165 	} value;
166 	unsigned char reserved[128];
167 };
168 #endif /* CONFIG_X86_X32 */
169 
170 /* get the value type and count of the control */
get_ctl_type(struct snd_card * card,struct snd_ctl_elem_id * id,int * countp)171 static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
172 			int *countp)
173 {
174 	struct snd_kcontrol *kctl;
175 	struct snd_ctl_elem_info *info;
176 	int err;
177 
178 	down_read(&card->controls_rwsem);
179 	kctl = snd_ctl_find_id(card, id);
180 	if (! kctl) {
181 		up_read(&card->controls_rwsem);
182 		return -ENOENT;
183 	}
184 	info = kzalloc(sizeof(*info), GFP_KERNEL);
185 	if (info == NULL) {
186 		up_read(&card->controls_rwsem);
187 		return -ENOMEM;
188 	}
189 	info->id = *id;
190 	err = kctl->info(kctl, info);
191 	up_read(&card->controls_rwsem);
192 	if (err >= 0) {
193 		err = info->type;
194 		*countp = info->count;
195 	}
196 	kfree(info);
197 	return err;
198 }
199 
get_elem_size(int type,int count)200 static int get_elem_size(int type, int count)
201 {
202 	switch (type) {
203 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
204 		return sizeof(s64) * count;
205 	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
206 		return sizeof(int) * count;
207 	case SNDRV_CTL_ELEM_TYPE_BYTES:
208 		return 512;
209 	case SNDRV_CTL_ELEM_TYPE_IEC958:
210 		return sizeof(struct snd_aes_iec958);
211 	default:
212 		return -1;
213 	}
214 }
215 
copy_ctl_value_from_user(struct snd_card * card,struct snd_ctl_elem_value * data,void __user * userdata,void __user * valuep,int * typep,int * countp)216 static int copy_ctl_value_from_user(struct snd_card *card,
217 				    struct snd_ctl_elem_value *data,
218 				    void __user *userdata,
219 				    void __user *valuep,
220 				    int *typep, int *countp)
221 {
222 	struct snd_ctl_elem_value32 __user *data32 = userdata;
223 	int i, type, size;
224 	int count;
225 	unsigned int indirect;
226 
227 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
228 		return -EFAULT;
229 	if (get_user(indirect, &data32->indirect))
230 		return -EFAULT;
231 	if (indirect)
232 		return -EINVAL;
233 	type = get_ctl_type(card, &data->id, &count);
234 	if (type < 0)
235 		return type;
236 
237 	if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
238 	    type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
239 		for (i = 0; i < count; i++) {
240 			s32 __user *intp = valuep;
241 			int val;
242 			if (get_user(val, &intp[i]))
243 				return -EFAULT;
244 			data->value.integer.value[i] = val;
245 		}
246 	} else {
247 		size = get_elem_size(type, count);
248 		if (size < 0) {
249 			dev_err(card->dev, "snd_ioctl32_ctl_elem_value: unknown type %d\n", type);
250 			return -EINVAL;
251 		}
252 		if (copy_from_user(data->value.bytes.data, valuep, size))
253 			return -EFAULT;
254 	}
255 
256 	*typep = type;
257 	*countp = count;
258 	return 0;
259 }
260 
261 /* restore the value to 32bit */
copy_ctl_value_to_user(void __user * userdata,void __user * valuep,struct snd_ctl_elem_value * data,int type,int count)262 static int copy_ctl_value_to_user(void __user *userdata,
263 				  void __user *valuep,
264 				  struct snd_ctl_elem_value *data,
265 				  int type, int count)
266 {
267 	struct snd_ctl_elem_value32 __user *data32 = userdata;
268 	int i, size;
269 
270 	if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
271 	    type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
272 		for (i = 0; i < count; i++) {
273 			s32 __user *intp = valuep;
274 			int val;
275 			val = data->value.integer.value[i];
276 			if (put_user(val, &intp[i]))
277 				return -EFAULT;
278 		}
279 	} else {
280 		size = get_elem_size(type, count);
281 		if (copy_to_user(valuep, data->value.bytes.data, size))
282 			return -EFAULT;
283 	}
284 	if (copy_to_user(&data32->id, &data->id, sizeof(data32->id)))
285 		return -EFAULT;
286 	return 0;
287 }
288 
ctl_elem_read_user(struct snd_card * card,void __user * userdata,void __user * valuep)289 static int ctl_elem_read_user(struct snd_card *card,
290 			      void __user *userdata, void __user *valuep)
291 {
292 	struct snd_ctl_elem_value *data;
293 	int err, type, count;
294 
295 	data = kzalloc(sizeof(*data), GFP_KERNEL);
296 	if (data == NULL)
297 		return -ENOMEM;
298 
299 	err = copy_ctl_value_from_user(card, data, userdata, valuep,
300 				       &type, &count);
301 	if (err < 0)
302 		goto error;
303 
304 	err = snd_power_wait(card, SNDRV_CTL_POWER_D0);
305 	if (err < 0)
306 		goto error;
307 	down_read(&card->controls_rwsem);
308 	err = snd_ctl_elem_read(card, data);
309 	up_read(&card->controls_rwsem);
310 	if (err < 0)
311 		goto error;
312 	err = copy_ctl_value_to_user(userdata, valuep, data, type, count);
313  error:
314 	kfree(data);
315 	return err;
316 }
317 
ctl_elem_write_user(struct snd_ctl_file * file,void __user * userdata,void __user * valuep)318 static int ctl_elem_write_user(struct snd_ctl_file *file,
319 			       void __user *userdata, void __user *valuep)
320 {
321 	struct snd_ctl_elem_value *data;
322 	struct snd_card *card = file->card;
323 	int err, type, count;
324 
325 	data = kzalloc(sizeof(*data), GFP_KERNEL);
326 	if (data == NULL)
327 		return -ENOMEM;
328 
329 	err = copy_ctl_value_from_user(card, data, userdata, valuep,
330 				       &type, &count);
331 	if (err < 0)
332 		goto error;
333 
334 	err = snd_power_wait(card, SNDRV_CTL_POWER_D0);
335 	if (err < 0)
336 		goto error;
337 	down_write(&card->controls_rwsem);
338 	err = snd_ctl_elem_write(card, file, data);
339 	up_write(&card->controls_rwsem);
340 	if (err < 0)
341 		goto error;
342 	err = copy_ctl_value_to_user(userdata, valuep, data, type, count);
343  error:
344 	kfree(data);
345 	return err;
346 }
347 
snd_ctl_elem_read_user_compat(struct snd_card * card,struct snd_ctl_elem_value32 __user * data32)348 static int snd_ctl_elem_read_user_compat(struct snd_card *card,
349 					 struct snd_ctl_elem_value32 __user *data32)
350 {
351 	return ctl_elem_read_user(card, data32, &data32->value);
352 }
353 
snd_ctl_elem_write_user_compat(struct snd_ctl_file * file,struct snd_ctl_elem_value32 __user * data32)354 static int snd_ctl_elem_write_user_compat(struct snd_ctl_file *file,
355 					  struct snd_ctl_elem_value32 __user *data32)
356 {
357 	return ctl_elem_write_user(file, data32, &data32->value);
358 }
359 
360 #ifdef CONFIG_X86_X32
snd_ctl_elem_read_user_x32(struct snd_card * card,struct snd_ctl_elem_value_x32 __user * data32)361 static int snd_ctl_elem_read_user_x32(struct snd_card *card,
362 				      struct snd_ctl_elem_value_x32 __user *data32)
363 {
364 	return ctl_elem_read_user(card, data32, &data32->value);
365 }
366 
snd_ctl_elem_write_user_x32(struct snd_ctl_file * file,struct snd_ctl_elem_value_x32 __user * data32)367 static int snd_ctl_elem_write_user_x32(struct snd_ctl_file *file,
368 				       struct snd_ctl_elem_value_x32 __user *data32)
369 {
370 	return ctl_elem_write_user(file, data32, &data32->value);
371 }
372 #endif /* CONFIG_X86_X32 */
373 
374 /* add or replace a user control */
snd_ctl_elem_add_compat(struct snd_ctl_file * file,struct snd_ctl_elem_info32 __user * data32,int replace)375 static int snd_ctl_elem_add_compat(struct snd_ctl_file *file,
376 				   struct snd_ctl_elem_info32 __user *data32,
377 				   int replace)
378 {
379 	struct snd_ctl_elem_info *data;
380 	int err;
381 
382 	data = kzalloc(sizeof(*data), GFP_KERNEL);
383 	if (! data)
384 		return -ENOMEM;
385 
386 	err = -EFAULT;
387 	/* id, type, access, count */ \
388 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)) ||
389 	    copy_from_user(&data->type, &data32->type, 3 * sizeof(u32)))
390 		goto error;
391 	if (get_user(data->owner, &data32->owner))
392 		goto error;
393 	switch (data->type) {
394 	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
395 	case SNDRV_CTL_ELEM_TYPE_INTEGER:
396 		if (get_user(data->value.integer.min, &data32->value.integer.min) ||
397 		    get_user(data->value.integer.max, &data32->value.integer.max) ||
398 		    get_user(data->value.integer.step, &data32->value.integer.step))
399 			goto error;
400 		break;
401 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
402 		if (copy_from_user(&data->value.integer64,
403 				   &data32->value.integer64,
404 				   sizeof(data->value.integer64)))
405 			goto error;
406 		break;
407 	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
408 		if (copy_from_user(&data->value.enumerated,
409 				   &data32->value.enumerated,
410 				   sizeof(data->value.enumerated)))
411 			goto error;
412 		data->value.enumerated.names_ptr =
413 			(uintptr_t)compat_ptr(data->value.enumerated.names_ptr);
414 		break;
415 	default:
416 		break;
417 	}
418 	err = snd_ctl_elem_add(file, data, replace);
419  error:
420 	kfree(data);
421 	return err;
422 }
423 
424 enum {
425 	SNDRV_CTL_IOCTL_ELEM_LIST32 = _IOWR('U', 0x10, struct snd_ctl_elem_list32),
426 	SNDRV_CTL_IOCTL_ELEM_INFO32 = _IOWR('U', 0x11, struct snd_ctl_elem_info32),
427 	SNDRV_CTL_IOCTL_ELEM_READ32 = _IOWR('U', 0x12, struct snd_ctl_elem_value32),
428 	SNDRV_CTL_IOCTL_ELEM_WRITE32 = _IOWR('U', 0x13, struct snd_ctl_elem_value32),
429 	SNDRV_CTL_IOCTL_ELEM_ADD32 = _IOWR('U', 0x17, struct snd_ctl_elem_info32),
430 	SNDRV_CTL_IOCTL_ELEM_REPLACE32 = _IOWR('U', 0x18, struct snd_ctl_elem_info32),
431 #ifdef CONFIG_X86_X32
432 	SNDRV_CTL_IOCTL_ELEM_READ_X32 = _IOWR('U', 0x12, struct snd_ctl_elem_value_x32),
433 	SNDRV_CTL_IOCTL_ELEM_WRITE_X32 = _IOWR('U', 0x13, struct snd_ctl_elem_value_x32),
434 #endif /* CONFIG_X86_X32 */
435 };
436 
snd_ctl_ioctl_compat(struct file * file,unsigned int cmd,unsigned long arg)437 static inline long snd_ctl_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
438 {
439 	struct snd_ctl_file *ctl;
440 	struct snd_kctl_ioctl *p;
441 	void __user *argp = compat_ptr(arg);
442 	int err;
443 
444 	ctl = file->private_data;
445 	if (snd_BUG_ON(!ctl || !ctl->card))
446 		return -ENXIO;
447 
448 	switch (cmd) {
449 	case SNDRV_CTL_IOCTL_PVERSION:
450 	case SNDRV_CTL_IOCTL_CARD_INFO:
451 	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
452 	case SNDRV_CTL_IOCTL_POWER:
453 	case SNDRV_CTL_IOCTL_POWER_STATE:
454 	case SNDRV_CTL_IOCTL_ELEM_LOCK:
455 	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
456 	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
457 	case SNDRV_CTL_IOCTL_TLV_READ:
458 	case SNDRV_CTL_IOCTL_TLV_WRITE:
459 	case SNDRV_CTL_IOCTL_TLV_COMMAND:
460 		return snd_ctl_ioctl(file, cmd, (unsigned long)argp);
461 	case SNDRV_CTL_IOCTL_ELEM_LIST32:
462 		return snd_ctl_elem_list_compat(ctl->card, argp);
463 	case SNDRV_CTL_IOCTL_ELEM_INFO32:
464 		return snd_ctl_elem_info_compat(ctl, argp);
465 	case SNDRV_CTL_IOCTL_ELEM_READ32:
466 		return snd_ctl_elem_read_user_compat(ctl->card, argp);
467 	case SNDRV_CTL_IOCTL_ELEM_WRITE32:
468 		return snd_ctl_elem_write_user_compat(ctl, argp);
469 	case SNDRV_CTL_IOCTL_ELEM_ADD32:
470 		return snd_ctl_elem_add_compat(ctl, argp, 0);
471 	case SNDRV_CTL_IOCTL_ELEM_REPLACE32:
472 		return snd_ctl_elem_add_compat(ctl, argp, 1);
473 #ifdef CONFIG_X86_X32
474 	case SNDRV_CTL_IOCTL_ELEM_READ_X32:
475 		return snd_ctl_elem_read_user_x32(ctl->card, argp);
476 	case SNDRV_CTL_IOCTL_ELEM_WRITE_X32:
477 		return snd_ctl_elem_write_user_x32(ctl, argp);
478 #endif /* CONFIG_X86_X32 */
479 	}
480 
481 	down_read(&snd_ioctl_rwsem);
482 	list_for_each_entry(p, &snd_control_compat_ioctls, list) {
483 		if (p->fioctl) {
484 			err = p->fioctl(ctl->card, ctl, cmd, arg);
485 			if (err != -ENOIOCTLCMD) {
486 				up_read(&snd_ioctl_rwsem);
487 				return err;
488 			}
489 		}
490 	}
491 	up_read(&snd_ioctl_rwsem);
492 	return -ENOIOCTLCMD;
493 }
494