xref: /linux/sound/core/control_compat.c (revision 38ea4c3d)
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 } __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_card *card = ctl->card;
83 	struct snd_ctl_elem_info *data __free(kfree) = NULL;
84 	int err;
85 
86 	data = kzalloc(sizeof(*data), GFP_KERNEL);
87 	if (! data)
88 		return -ENOMEM;
89 
90 	/* copy id */
91 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
92 		return -EFAULT;
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 		return -EFAULT;
98 
99 	err = snd_power_ref_and_wait(card);
100 	if (err < 0)
101 		return err;
102 	err = snd_ctl_elem_info(ctl, data);
103 	snd_power_unref(card);
104 	if (err < 0)
105 		return err;
106 	/* restore info to 32bit */
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 		return -EFAULT;
111 	if (put_user(data->owner, &data32->owner))
112 		return -EFAULT;
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 			return -EFAULT;
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 			return -EFAULT;
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 			return -EFAULT;
132 		break;
133 	default:
134 		break;
135 	}
136 	return 0;
137 }
138 
139 /* read / write */
140 struct snd_ctl_elem_value32 {
141 	struct snd_ctl_elem_id id;
142 	unsigned int indirect;	/* bit-field causes misalignment */
143         union {
144 		s32 integer[128];
145 		unsigned char data[512];
146 #ifndef CONFIG_X86_64
147 		s64 integer64[64];
148 #endif
149         } value;
150         unsigned char reserved[128];
151 };
152 
153 #ifdef CONFIG_X86_X32_ABI
154 /* x32 has a different alignment for 64bit values from ia32 */
155 struct snd_ctl_elem_value_x32 {
156 	struct snd_ctl_elem_id id;
157 	unsigned int indirect;	/* bit-field causes misalignment */
158 	union {
159 		s32 integer[128];
160 		unsigned char data[512];
161 		s64 integer64[64];
162 	} value;
163 	unsigned char reserved[128];
164 };
165 #endif /* CONFIG_X86_X32_ABI */
166 
167 /* get the value type and count of the control */
get_ctl_type(struct snd_card * card,struct snd_ctl_elem_id * id,int * countp)168 static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
169 			int *countp)
170 {
171 	struct snd_kcontrol *kctl;
172 	struct snd_ctl_elem_info *info __free(kfree) = NULL;
173 	int err;
174 
175 	guard(rwsem_read)(&card->controls_rwsem);
176 	kctl = snd_ctl_find_id(card, id);
177 	if (!kctl)
178 		return -ENOENT;
179 	info = kzalloc(sizeof(*info), GFP_KERNEL);
180 	if (info == NULL)
181 		return -ENOMEM;
182 	info->id = *id;
183 	err = kctl->info(kctl, info);
184 	if (err >= 0) {
185 		err = info->type;
186 		*countp = info->count;
187 	}
188 	return err;
189 }
190 
get_elem_size(snd_ctl_elem_type_t type,int count)191 static int get_elem_size(snd_ctl_elem_type_t type, int count)
192 {
193 	switch (type) {
194 	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
195 		return sizeof(s64) * count;
196 	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
197 		return sizeof(int) * count;
198 	case SNDRV_CTL_ELEM_TYPE_BYTES:
199 		return 512;
200 	case SNDRV_CTL_ELEM_TYPE_IEC958:
201 		return sizeof(struct snd_aes_iec958);
202 	default:
203 		return -1;
204 	}
205 }
206 
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)207 static int copy_ctl_value_from_user(struct snd_card *card,
208 				    struct snd_ctl_elem_value *data,
209 				    void __user *userdata,
210 				    void __user *valuep,
211 				    int *typep, int *countp)
212 {
213 	struct snd_ctl_elem_value32 __user *data32 = userdata;
214 	int i, type, size;
215 	int count;
216 	unsigned int indirect;
217 
218 	if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
219 		return -EFAULT;
220 	if (get_user(indirect, &data32->indirect))
221 		return -EFAULT;
222 	if (indirect)
223 		return -EINVAL;
224 	type = get_ctl_type(card, &data->id, &count);
225 	if (type < 0)
226 		return type;
227 
228 	if (type == (__force int)SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
229 	    type == (__force int)SNDRV_CTL_ELEM_TYPE_INTEGER) {
230 		for (i = 0; i < count; i++) {
231 			s32 __user *intp = valuep;
232 			int val;
233 			if (get_user(val, &intp[i]))
234 				return -EFAULT;
235 			data->value.integer.value[i] = val;
236 		}
237 	} else {
238 		size = get_elem_size((__force snd_ctl_elem_type_t)type, count);
239 		if (size < 0) {
240 			dev_err(card->dev, "snd_ioctl32_ctl_elem_value: unknown type %d\n", type);
241 			return -EINVAL;
242 		}
243 		if (copy_from_user(data->value.bytes.data, valuep, size))
244 			return -EFAULT;
245 	}
246 
247 	*typep = type;
248 	*countp = count;
249 	return 0;
250 }
251 
252 /* 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)253 static int copy_ctl_value_to_user(void __user *userdata,
254 				  void __user *valuep,
255 				  struct snd_ctl_elem_value *data,
256 				  int type, int count)
257 {
258 	struct snd_ctl_elem_value32 __user *data32 = userdata;
259 	int i, size;
260 
261 	if (type == (__force int)SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
262 	    type == (__force int)SNDRV_CTL_ELEM_TYPE_INTEGER) {
263 		for (i = 0; i < count; i++) {
264 			s32 __user *intp = valuep;
265 			int val;
266 			val = data->value.integer.value[i];
267 			if (put_user(val, &intp[i]))
268 				return -EFAULT;
269 		}
270 	} else {
271 		size = get_elem_size((__force snd_ctl_elem_type_t)type, count);
272 		if (copy_to_user(valuep, data->value.bytes.data, size))
273 			return -EFAULT;
274 	}
275 	if (copy_to_user(&data32->id, &data->id, sizeof(data32->id)))
276 		return -EFAULT;
277 	return 0;
278 }
279 
__ctl_elem_read_user(struct snd_card * card,void __user * userdata,void __user * valuep)280 static int __ctl_elem_read_user(struct snd_card *card,
281 				void __user *userdata, void __user *valuep)
282 {
283 	struct snd_ctl_elem_value *data __free(kfree) = NULL;
284 	int err, type, count;
285 
286 	data = kzalloc(sizeof(*data), GFP_KERNEL);
287 	if (data == NULL)
288 		return -ENOMEM;
289 
290 	err = copy_ctl_value_from_user(card, data, userdata, valuep,
291 				       &type, &count);
292 	if (err < 0)
293 		return err;
294 
295 	err = snd_ctl_elem_read(card, data);
296 	if (err < 0)
297 		return err;
298 	return copy_ctl_value_to_user(userdata, valuep, data, type, count);
299 }
300 
ctl_elem_read_user(struct snd_card * card,void __user * userdata,void __user * valuep)301 static int ctl_elem_read_user(struct snd_card *card,
302 			      void __user *userdata, void __user *valuep)
303 {
304 	int err;
305 
306 	err = snd_power_ref_and_wait(card);
307 	if (err < 0)
308 		return err;
309 	err = __ctl_elem_read_user(card, userdata, valuep);
310 	snd_power_unref(card);
311 	return err;
312 }
313 
__ctl_elem_write_user(struct snd_ctl_file * file,void __user * userdata,void __user * valuep)314 static int __ctl_elem_write_user(struct snd_ctl_file *file,
315 				 void __user *userdata, void __user *valuep)
316 {
317 	struct snd_ctl_elem_value *data __free(kfree) = NULL;
318 	struct snd_card *card = file->card;
319 	int err, type, count;
320 
321 	data = kzalloc(sizeof(*data), GFP_KERNEL);
322 	if (data == NULL)
323 		return -ENOMEM;
324 
325 	err = copy_ctl_value_from_user(card, data, userdata, valuep,
326 				       &type, &count);
327 	if (err < 0)
328 		return err;
329 
330 	err = snd_ctl_elem_write(card, file, data);
331 	if (err < 0)
332 		return err;
333 	return copy_ctl_value_to_user(userdata, valuep, data, type, count);
334 }
335 
ctl_elem_write_user(struct snd_ctl_file * file,void __user * userdata,void __user * valuep)336 static int ctl_elem_write_user(struct snd_ctl_file *file,
337 			       void __user *userdata, void __user *valuep)
338 {
339 	struct snd_card *card = file->card;
340 	int err;
341 
342 	err = snd_power_ref_and_wait(card);
343 	if (err < 0)
344 		return err;
345 	err = __ctl_elem_write_user(file, userdata, valuep);
346 	snd_power_unref(card);
347 	return err;
348 }
349 
snd_ctl_elem_read_user_compat(struct snd_card * card,struct snd_ctl_elem_value32 __user * data32)350 static int snd_ctl_elem_read_user_compat(struct snd_card *card,
351 					 struct snd_ctl_elem_value32 __user *data32)
352 {
353 	return ctl_elem_read_user(card, data32, &data32->value);
354 }
355 
snd_ctl_elem_write_user_compat(struct snd_ctl_file * file,struct snd_ctl_elem_value32 __user * data32)356 static int snd_ctl_elem_write_user_compat(struct snd_ctl_file *file,
357 					  struct snd_ctl_elem_value32 __user *data32)
358 {
359 	return ctl_elem_write_user(file, data32, &data32->value);
360 }
361 
362 #ifdef CONFIG_X86_X32_ABI
snd_ctl_elem_read_user_x32(struct snd_card * card,struct snd_ctl_elem_value_x32 __user * data32)363 static int snd_ctl_elem_read_user_x32(struct snd_card *card,
364 				      struct snd_ctl_elem_value_x32 __user *data32)
365 {
366 	return ctl_elem_read_user(card, data32, &data32->value);
367 }
368 
snd_ctl_elem_write_user_x32(struct snd_ctl_file * file,struct snd_ctl_elem_value_x32 __user * data32)369 static int snd_ctl_elem_write_user_x32(struct snd_ctl_file *file,
370 				       struct snd_ctl_elem_value_x32 __user *data32)
371 {
372 	return ctl_elem_write_user(file, data32, &data32->value);
373 }
374 #endif /* CONFIG_X86_X32_ABI */
375 
376 /* 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)377 static int snd_ctl_elem_add_compat(struct snd_ctl_file *file,
378 				   struct snd_ctl_elem_info32 __user *data32,
379 				   int replace)
380 {
381 	struct snd_ctl_elem_info *data __free(kfree) = NULL;
382 
383 	data = kzalloc(sizeof(*data), GFP_KERNEL);
384 	if (! data)
385 		return -ENOMEM;
386 
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 		return -EFAULT;
391 	if (get_user(data->owner, &data32->owner))
392 		return -EFAULT;
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 			return -EFAULT;
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 			return -EFAULT;
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 			return -EFAULT;
412 		data->value.enumerated.names_ptr =
413 			(uintptr_t)compat_ptr(data->value.enumerated.names_ptr);
414 		break;
415 	default:
416 		break;
417 	}
418 	return snd_ctl_elem_add(file, data, replace);
419 }
420 
421 enum {
422 	SNDRV_CTL_IOCTL_ELEM_LIST32 = _IOWR('U', 0x10, struct snd_ctl_elem_list32),
423 	SNDRV_CTL_IOCTL_ELEM_INFO32 = _IOWR('U', 0x11, struct snd_ctl_elem_info32),
424 	SNDRV_CTL_IOCTL_ELEM_READ32 = _IOWR('U', 0x12, struct snd_ctl_elem_value32),
425 	SNDRV_CTL_IOCTL_ELEM_WRITE32 = _IOWR('U', 0x13, struct snd_ctl_elem_value32),
426 	SNDRV_CTL_IOCTL_ELEM_ADD32 = _IOWR('U', 0x17, struct snd_ctl_elem_info32),
427 	SNDRV_CTL_IOCTL_ELEM_REPLACE32 = _IOWR('U', 0x18, struct snd_ctl_elem_info32),
428 #ifdef CONFIG_X86_X32_ABI
429 	SNDRV_CTL_IOCTL_ELEM_READ_X32 = _IOWR('U', 0x12, struct snd_ctl_elem_value_x32),
430 	SNDRV_CTL_IOCTL_ELEM_WRITE_X32 = _IOWR('U', 0x13, struct snd_ctl_elem_value_x32),
431 #endif /* CONFIG_X86_X32_ABI */
432 };
433 
snd_ctl_ioctl_compat(struct file * file,unsigned int cmd,unsigned long arg)434 static inline long snd_ctl_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
435 {
436 	struct snd_ctl_file *ctl;
437 	struct snd_kctl_ioctl *p;
438 	void __user *argp = compat_ptr(arg);
439 	int err;
440 
441 	ctl = file->private_data;
442 	if (snd_BUG_ON(!ctl || !ctl->card))
443 		return -ENXIO;
444 
445 	switch (cmd) {
446 	case SNDRV_CTL_IOCTL_PVERSION:
447 	case SNDRV_CTL_IOCTL_CARD_INFO:
448 	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
449 	case SNDRV_CTL_IOCTL_POWER:
450 	case SNDRV_CTL_IOCTL_POWER_STATE:
451 	case SNDRV_CTL_IOCTL_ELEM_LOCK:
452 	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
453 	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
454 	case SNDRV_CTL_IOCTL_TLV_READ:
455 	case SNDRV_CTL_IOCTL_TLV_WRITE:
456 	case SNDRV_CTL_IOCTL_TLV_COMMAND:
457 		return snd_ctl_ioctl(file, cmd, (unsigned long)argp);
458 	case SNDRV_CTL_IOCTL_ELEM_LIST32:
459 		return snd_ctl_elem_list_compat(ctl->card, argp);
460 	case SNDRV_CTL_IOCTL_ELEM_INFO32:
461 		return snd_ctl_elem_info_compat(ctl, argp);
462 	case SNDRV_CTL_IOCTL_ELEM_READ32:
463 		return snd_ctl_elem_read_user_compat(ctl->card, argp);
464 	case SNDRV_CTL_IOCTL_ELEM_WRITE32:
465 		return snd_ctl_elem_write_user_compat(ctl, argp);
466 	case SNDRV_CTL_IOCTL_ELEM_ADD32:
467 		return snd_ctl_elem_add_compat(ctl, argp, 0);
468 	case SNDRV_CTL_IOCTL_ELEM_REPLACE32:
469 		return snd_ctl_elem_add_compat(ctl, argp, 1);
470 #ifdef CONFIG_X86_X32_ABI
471 	case SNDRV_CTL_IOCTL_ELEM_READ_X32:
472 		return snd_ctl_elem_read_user_x32(ctl->card, argp);
473 	case SNDRV_CTL_IOCTL_ELEM_WRITE_X32:
474 		return snd_ctl_elem_write_user_x32(ctl, argp);
475 #endif /* CONFIG_X86_X32_ABI */
476 	}
477 
478 	guard(rwsem_read)(&snd_ioctl_rwsem);
479 	list_for_each_entry(p, &snd_control_compat_ioctls, list) {
480 		if (p->fioctl) {
481 			err = p->fioctl(ctl->card, ctl, cmd, arg);
482 			if (err != -ENOIOCTLCMD)
483 				return err;
484 		}
485 	}
486 	return -ENOIOCTLCMD;
487 }
488