xref: /linux/sound/core/control_compat.c (revision 3839a7460721b87501134697b7b90c45dcc7825d)
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 
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 __user *data;
26 	compat_caddr_t ptr;
27 	int err;
28 
29 	data = compat_alloc_user_space(sizeof(*data));
30 
31 	/* offset, space, used, count */
32 	if (copy_in_user(data, data32, 4 * sizeof(u32)))
33 		return -EFAULT;
34 	/* pids */
35 	if (get_user(ptr, &data32->pids) ||
36 	    put_user(compat_ptr(ptr), &data->pids))
37 		return -EFAULT;
38 	err = snd_ctl_elem_list(card, data);
39 	if (err < 0)
40 		return err;
41 	/* copy the result */
42 	if (copy_in_user(data32, data, 4 * sizeof(u32)))
43 		return -EFAULT;
44 	return 0;
45 }
46 
47 /*
48  * control element info
49  * it uses union, so the things are not easy..
50  */
51 
52 struct snd_ctl_elem_info32 {
53 	struct snd_ctl_elem_id id; // the size of struct is same
54 	s32 type;
55 	u32 access;
56 	u32 count;
57 	s32 owner;
58 	union {
59 		struct {
60 			s32 min;
61 			s32 max;
62 			s32 step;
63 		} integer;
64 		struct {
65 			u64 min;
66 			u64 max;
67 			u64 step;
68 		} integer64;
69 		struct {
70 			u32 items;
71 			u32 item;
72 			char name[64];
73 			u64 names_ptr;
74 			u32 names_length;
75 		} enumerated;
76 		unsigned char reserved[128];
77 	} value;
78 	unsigned char reserved[64];
79 } __attribute__((packed));
80 
81 static int snd_ctl_elem_info_compat(struct snd_ctl_file *ctl,
82 				    struct snd_ctl_elem_info32 __user *data32)
83 {
84 	struct snd_ctl_elem_info *data;
85 	int err;
86 
87 	data = kzalloc(sizeof(*data), GFP_KERNEL);
88 	if (! data)
89 		return -ENOMEM;
90 
91 	err = -EFAULT;
92 	/* copy id */
93 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
94 		goto error;
95 	/* we need to copy the item index.
96 	 * hope this doesn't break anything..
97 	 */
98 	if (get_user(data->value.enumerated.item, &data32->value.enumerated.item))
99 		goto error;
100 
101 	err = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
102 	if (err < 0)
103 		goto error;
104 	err = snd_ctl_elem_info(ctl, data);
105 	if (err < 0)
106 		goto error;
107 	/* restore info to 32bit */
108 	err = -EFAULT;
109 	/* id, type, access, count */
110 	if (copy_to_user(&data32->id, &data->id, sizeof(data->id)) ||
111 	    copy_to_user(&data32->type, &data->type, 3 * sizeof(u32)))
112 		goto error;
113 	if (put_user(data->owner, &data32->owner))
114 		goto error;
115 	switch (data->type) {
116 	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
117 	case SNDRV_CTL_ELEM_TYPE_INTEGER:
118 		if (put_user(data->value.integer.min, &data32->value.integer.min) ||
119 		    put_user(data->value.integer.max, &data32->value.integer.max) ||
120 		    put_user(data->value.integer.step, &data32->value.integer.step))
121 			goto error;
122 		break;
123 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
124 		if (copy_to_user(&data32->value.integer64,
125 				 &data->value.integer64,
126 				 sizeof(data->value.integer64)))
127 			goto error;
128 		break;
129 	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
130 		if (copy_to_user(&data32->value.enumerated,
131 				 &data->value.enumerated,
132 				 sizeof(data->value.enumerated)))
133 			goto error;
134 		break;
135 	default:
136 		break;
137 	}
138 	err = 0;
139  error:
140 	kfree(data);
141 	return err;
142 }
143 
144 /* read / write */
145 struct snd_ctl_elem_value32 {
146 	struct snd_ctl_elem_id id;
147 	unsigned int indirect;	/* bit-field causes misalignment */
148         union {
149 		s32 integer[128];
150 		unsigned char data[512];
151 #ifndef CONFIG_X86_64
152 		s64 integer64[64];
153 #endif
154         } value;
155         unsigned char reserved[128];
156 };
157 
158 #ifdef CONFIG_X86_X32
159 /* x32 has a different alignment for 64bit values from ia32 */
160 struct snd_ctl_elem_value_x32 {
161 	struct snd_ctl_elem_id id;
162 	unsigned int indirect;	/* bit-field causes misalignment */
163 	union {
164 		s32 integer[128];
165 		unsigned char data[512];
166 		s64 integer64[64];
167 	} value;
168 	unsigned char reserved[128];
169 };
170 #endif /* CONFIG_X86_X32 */
171 
172 /* get the value type and count of the control */
173 static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
174 			int *countp)
175 {
176 	struct snd_kcontrol *kctl;
177 	struct snd_ctl_elem_info *info;
178 	int err;
179 
180 	down_read(&card->controls_rwsem);
181 	kctl = snd_ctl_find_id(card, id);
182 	if (! kctl) {
183 		up_read(&card->controls_rwsem);
184 		return -ENOENT;
185 	}
186 	info = kzalloc(sizeof(*info), GFP_KERNEL);
187 	if (info == NULL) {
188 		up_read(&card->controls_rwsem);
189 		return -ENOMEM;
190 	}
191 	info->id = *id;
192 	err = kctl->info(kctl, info);
193 	up_read(&card->controls_rwsem);
194 	if (err >= 0) {
195 		err = info->type;
196 		*countp = info->count;
197 	}
198 	kfree(info);
199 	return err;
200 }
201 
202 static int get_elem_size(int type, int count)
203 {
204 	switch (type) {
205 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
206 		return sizeof(s64) * count;
207 	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
208 		return sizeof(int) * count;
209 	case SNDRV_CTL_ELEM_TYPE_BYTES:
210 		return 512;
211 	case SNDRV_CTL_ELEM_TYPE_IEC958:
212 		return sizeof(struct snd_aes_iec958);
213 	default:
214 		return -1;
215 	}
216 }
217 
218 static int copy_ctl_value_from_user(struct snd_card *card,
219 				    struct snd_ctl_elem_value *data,
220 				    void __user *userdata,
221 				    void __user *valuep,
222 				    int *typep, int *countp)
223 {
224 	struct snd_ctl_elem_value32 __user *data32 = userdata;
225 	int i, type, size;
226 	int uninitialized_var(count);
227 	unsigned int indirect;
228 
229 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
230 		return -EFAULT;
231 	if (get_user(indirect, &data32->indirect))
232 		return -EFAULT;
233 	if (indirect)
234 		return -EINVAL;
235 	type = get_ctl_type(card, &data->id, &count);
236 	if (type < 0)
237 		return type;
238 
239 	if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
240 	    type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
241 		for (i = 0; i < count; i++) {
242 			s32 __user *intp = valuep;
243 			int val;
244 			if (get_user(val, &intp[i]))
245 				return -EFAULT;
246 			data->value.integer.value[i] = val;
247 		}
248 	} else {
249 		size = get_elem_size(type, count);
250 		if (size < 0) {
251 			dev_err(card->dev, "snd_ioctl32_ctl_elem_value: unknown type %d\n", type);
252 			return -EINVAL;
253 		}
254 		if (copy_from_user(data->value.bytes.data, valuep, size))
255 			return -EFAULT;
256 	}
257 
258 	*typep = type;
259 	*countp = count;
260 	return 0;
261 }
262 
263 /* restore the value to 32bit */
264 static int copy_ctl_value_to_user(void __user *userdata,
265 				  void __user *valuep,
266 				  struct snd_ctl_elem_value *data,
267 				  int type, int count)
268 {
269 	int i, size;
270 
271 	if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
272 	    type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
273 		for (i = 0; i < count; i++) {
274 			s32 __user *intp = valuep;
275 			int val;
276 			val = data->value.integer.value[i];
277 			if (put_user(val, &intp[i]))
278 				return -EFAULT;
279 		}
280 	} else {
281 		size = get_elem_size(type, count);
282 		if (copy_to_user(valuep, data->value.bytes.data, size))
283 			return -EFAULT;
284 	}
285 	return 0;
286 }
287 
288 static int ctl_elem_read_user(struct snd_card *card,
289 			      void __user *userdata, void __user *valuep)
290 {
291 	struct snd_ctl_elem_value *data;
292 	int err, type, count;
293 
294 	data = kzalloc(sizeof(*data), GFP_KERNEL);
295 	if (data == NULL)
296 		return -ENOMEM;
297 
298 	err = copy_ctl_value_from_user(card, data, userdata, valuep,
299 				       &type, &count);
300 	if (err < 0)
301 		goto error;
302 
303 	err = snd_power_wait(card, SNDRV_CTL_POWER_D0);
304 	if (err < 0)
305 		goto error;
306 	err = snd_ctl_elem_read(card, data);
307 	if (err < 0)
308 		goto error;
309 	err = copy_ctl_value_to_user(userdata, valuep, data, type, count);
310  error:
311 	kfree(data);
312 	return err;
313 }
314 
315 static int ctl_elem_write_user(struct snd_ctl_file *file,
316 			       void __user *userdata, void __user *valuep)
317 {
318 	struct snd_ctl_elem_value *data;
319 	struct snd_card *card = file->card;
320 	int err, type, count;
321 
322 	data = kzalloc(sizeof(*data), GFP_KERNEL);
323 	if (data == NULL)
324 		return -ENOMEM;
325 
326 	err = copy_ctl_value_from_user(card, data, userdata, valuep,
327 				       &type, &count);
328 	if (err < 0)
329 		goto error;
330 
331 	err = snd_power_wait(card, SNDRV_CTL_POWER_D0);
332 	if (err < 0)
333 		goto error;
334 	err = snd_ctl_elem_write(card, file, data);
335 	if (err < 0)
336 		goto error;
337 	err = copy_ctl_value_to_user(userdata, valuep, data, type, count);
338  error:
339 	kfree(data);
340 	return err;
341 }
342 
343 static int snd_ctl_elem_read_user_compat(struct snd_card *card,
344 					 struct snd_ctl_elem_value32 __user *data32)
345 {
346 	return ctl_elem_read_user(card, data32, &data32->value);
347 }
348 
349 static int snd_ctl_elem_write_user_compat(struct snd_ctl_file *file,
350 					  struct snd_ctl_elem_value32 __user *data32)
351 {
352 	return ctl_elem_write_user(file, data32, &data32->value);
353 }
354 
355 #ifdef CONFIG_X86_X32
356 static int snd_ctl_elem_read_user_x32(struct snd_card *card,
357 				      struct snd_ctl_elem_value_x32 __user *data32)
358 {
359 	return ctl_elem_read_user(card, data32, &data32->value);
360 }
361 
362 static int snd_ctl_elem_write_user_x32(struct snd_ctl_file *file,
363 				       struct snd_ctl_elem_value_x32 __user *data32)
364 {
365 	return ctl_elem_write_user(file, data32, &data32->value);
366 }
367 #endif /* CONFIG_X86_X32 */
368 
369 /* add or replace a user control */
370 static int snd_ctl_elem_add_compat(struct snd_ctl_file *file,
371 				   struct snd_ctl_elem_info32 __user *data32,
372 				   int replace)
373 {
374 	struct snd_ctl_elem_info *data;
375 	int err;
376 
377 	data = kzalloc(sizeof(*data), GFP_KERNEL);
378 	if (! data)
379 		return -ENOMEM;
380 
381 	err = -EFAULT;
382 	/* id, type, access, count */ \
383 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)) ||
384 	    copy_from_user(&data->type, &data32->type, 3 * sizeof(u32)))
385 		goto error;
386 	if (get_user(data->owner, &data32->owner))
387 		goto error;
388 	switch (data->type) {
389 	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
390 	case SNDRV_CTL_ELEM_TYPE_INTEGER:
391 		if (get_user(data->value.integer.min, &data32->value.integer.min) ||
392 		    get_user(data->value.integer.max, &data32->value.integer.max) ||
393 		    get_user(data->value.integer.step, &data32->value.integer.step))
394 			goto error;
395 		break;
396 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
397 		if (copy_from_user(&data->value.integer64,
398 				   &data32->value.integer64,
399 				   sizeof(data->value.integer64)))
400 			goto error;
401 		break;
402 	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
403 		if (copy_from_user(&data->value.enumerated,
404 				   &data32->value.enumerated,
405 				   sizeof(data->value.enumerated)))
406 			goto error;
407 		data->value.enumerated.names_ptr =
408 			(uintptr_t)compat_ptr(data->value.enumerated.names_ptr);
409 		break;
410 	default:
411 		break;
412 	}
413 	err = snd_ctl_elem_add(file, data, replace);
414  error:
415 	kfree(data);
416 	return err;
417 }
418 
419 enum {
420 	SNDRV_CTL_IOCTL_ELEM_LIST32 = _IOWR('U', 0x10, struct snd_ctl_elem_list32),
421 	SNDRV_CTL_IOCTL_ELEM_INFO32 = _IOWR('U', 0x11, struct snd_ctl_elem_info32),
422 	SNDRV_CTL_IOCTL_ELEM_READ32 = _IOWR('U', 0x12, struct snd_ctl_elem_value32),
423 	SNDRV_CTL_IOCTL_ELEM_WRITE32 = _IOWR('U', 0x13, struct snd_ctl_elem_value32),
424 	SNDRV_CTL_IOCTL_ELEM_ADD32 = _IOWR('U', 0x17, struct snd_ctl_elem_info32),
425 	SNDRV_CTL_IOCTL_ELEM_REPLACE32 = _IOWR('U', 0x18, struct snd_ctl_elem_info32),
426 #ifdef CONFIG_X86_X32
427 	SNDRV_CTL_IOCTL_ELEM_READ_X32 = _IOWR('U', 0x12, struct snd_ctl_elem_value_x32),
428 	SNDRV_CTL_IOCTL_ELEM_WRITE_X32 = _IOWR('U', 0x13, struct snd_ctl_elem_value_x32),
429 #endif /* CONFIG_X86_X32 */
430 };
431 
432 static inline long snd_ctl_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
433 {
434 	struct snd_ctl_file *ctl;
435 	struct snd_kctl_ioctl *p;
436 	void __user *argp = compat_ptr(arg);
437 	int err;
438 
439 	ctl = file->private_data;
440 	if (snd_BUG_ON(!ctl || !ctl->card))
441 		return -ENXIO;
442 
443 	switch (cmd) {
444 	case SNDRV_CTL_IOCTL_PVERSION:
445 	case SNDRV_CTL_IOCTL_CARD_INFO:
446 	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
447 	case SNDRV_CTL_IOCTL_POWER:
448 	case SNDRV_CTL_IOCTL_POWER_STATE:
449 	case SNDRV_CTL_IOCTL_ELEM_LOCK:
450 	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
451 	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
452 	case SNDRV_CTL_IOCTL_TLV_READ:
453 	case SNDRV_CTL_IOCTL_TLV_WRITE:
454 	case SNDRV_CTL_IOCTL_TLV_COMMAND:
455 		return snd_ctl_ioctl(file, cmd, (unsigned long)argp);
456 	case SNDRV_CTL_IOCTL_ELEM_LIST32:
457 		return snd_ctl_elem_list_compat(ctl->card, argp);
458 	case SNDRV_CTL_IOCTL_ELEM_INFO32:
459 		return snd_ctl_elem_info_compat(ctl, argp);
460 	case SNDRV_CTL_IOCTL_ELEM_READ32:
461 		return snd_ctl_elem_read_user_compat(ctl->card, argp);
462 	case SNDRV_CTL_IOCTL_ELEM_WRITE32:
463 		return snd_ctl_elem_write_user_compat(ctl, argp);
464 	case SNDRV_CTL_IOCTL_ELEM_ADD32:
465 		return snd_ctl_elem_add_compat(ctl, argp, 0);
466 	case SNDRV_CTL_IOCTL_ELEM_REPLACE32:
467 		return snd_ctl_elem_add_compat(ctl, argp, 1);
468 #ifdef CONFIG_X86_X32
469 	case SNDRV_CTL_IOCTL_ELEM_READ_X32:
470 		return snd_ctl_elem_read_user_x32(ctl->card, argp);
471 	case SNDRV_CTL_IOCTL_ELEM_WRITE_X32:
472 		return snd_ctl_elem_write_user_x32(ctl, argp);
473 #endif /* CONFIG_X86_X32 */
474 	}
475 
476 	down_read(&snd_ioctl_rwsem);
477 	list_for_each_entry(p, &snd_control_compat_ioctls, list) {
478 		if (p->fioctl) {
479 			err = p->fioctl(ctl->card, ctl, cmd, arg);
480 			if (err != -ENOIOCTLCMD) {
481 				up_read(&snd_ioctl_rwsem);
482 				return err;
483 			}
484 		}
485 	}
486 	up_read(&snd_ioctl_rwsem);
487 	return -ENOIOCTLCMD;
488 }
489