hwdep.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * HWDEP Interface for HD-audio codec
  4 *
  5 * Copyright (c) 2007 Takashi Iwai <tiwai@suse.de>
  6 */
  7
  8#include <linux/init.h>
  9#include <linux/slab.h>
 10#include <linux/compat.h>
 11#include <linux/nospec.h>
 12#include <sound/core.h>
 13#include <sound/hda_codec.h>
 14#include "hda_local.h"
 15#include <sound/hda_hwdep.h>
 16#include <sound/minors.h>
 17
 18/*
 19 * write/read an out-of-bound verb
 20 */
 21static int verb_write_ioctl(struct hda_codec *codec,
 22			    struct hda_verb_ioctl __user *arg)
 23{
 24	u32 verb, res;
 25
 26	if (get_user(verb, &arg->verb))
 27		return -EFAULT;
 28	res = snd_hda_codec_read(codec, verb >> 24, 0,
 29				 (verb >> 8) & 0xffff, verb & 0xff);
 30	if (put_user(res, &arg->res))
 31		return -EFAULT;
 32	return 0;
 33}
 34
 35static int get_wcap_ioctl(struct hda_codec *codec,
 36			  struct hda_verb_ioctl __user *arg)
 37{
 38	u32 verb, res;
 39	
 40	if (get_user(verb, &arg->verb))
 41		return -EFAULT;
 42	/* open-code get_wcaps(verb>>24) with nospec */
 43	verb >>= 24;
 44	if (verb < codec->core.start_nid ||
 45	    verb >= codec->core.start_nid + codec->core.num_nodes) {
 46		res = 0;
 47	} else {
 48		verb -= codec->core.start_nid;
 49		verb = array_index_nospec(verb, codec->core.num_nodes);
 50		res = codec->wcaps[verb];
 51	}
 52	if (put_user(res, &arg->res))
 53		return -EFAULT;
 54	return 0;
 55}
 56
 57
 58/*
 59 */
 60static int hda_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
 61			   unsigned int cmd, unsigned long arg)
 62{
 63	struct hda_codec *codec = hw->private_data;
 64	void __user *argp = (void __user *)arg;
 65
 66	switch (cmd) {
 67	case HDA_IOCTL_PVERSION:
 68		return put_user(HDA_HWDEP_VERSION, (int __user *)argp);
 69	case HDA_IOCTL_VERB_WRITE:
 70		return verb_write_ioctl(codec, argp);
 71	case HDA_IOCTL_GET_WCAP:
 72		return get_wcap_ioctl(codec, argp);
 73	}
 74	return -ENOIOCTLCMD;
 75}
 76
 77#ifdef CONFIG_COMPAT
 78static int hda_hwdep_ioctl_compat(struct snd_hwdep *hw, struct file *file,
 79				  unsigned int cmd, unsigned long arg)
 80{
 81	return hda_hwdep_ioctl(hw, file, cmd, (unsigned long)compat_ptr(arg));
 82}
 83#endif
 84
 85static int hda_hwdep_open(struct snd_hwdep *hw, struct file *file)
 86{
 87	if (!capable(CAP_SYS_RAWIO))
 88		return -EACCES;
 89	return 0;
 90}
 91
 92int snd_hda_create_hwdep(struct hda_codec *codec)
 93{
 94	char hwname[16];
 95	struct snd_hwdep *hwdep;
 96	int err;
 97
 98	sprintf(hwname, "HDA Codec %d", codec->addr);
 99	err = snd_hwdep_new(codec->card, hwname, codec->addr, &hwdep);
100	if (err < 0)
101		return err;
102	codec->hwdep = hwdep;
103	sprintf(hwdep->name, "HDA Codec %d", codec->addr);
104	hwdep->iface = SNDRV_HWDEP_IFACE_HDA;
105	hwdep->private_data = codec;
106	hwdep->exclusive = 1;
107
108	hwdep->ops.open = hda_hwdep_open;
109	hwdep->ops.ioctl = hda_hwdep_ioctl;
110#ifdef CONFIG_COMPAT
111	hwdep->ops.ioctl_compat = hda_hwdep_ioctl_compat;
112#endif
113
114	/* for sysfs */
115	hwdep->dev->groups = snd_hda_dev_attr_groups;
116	dev_set_drvdata(hwdep->dev, codec);
117
118	return 0;
119}