xref: /openbmc/linux/sound/core/rawmidi_compat.c (revision dc6a81c3) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   32bit -> 64bit ioctl wrapper for raw MIDI API
4  *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
5  */
6 
7 /* This file included from rawmidi.c */
8 
9 #include <linux/compat.h>
10 
11 struct snd_rawmidi_params32 {
12 	s32 stream;
13 	u32 buffer_size;
14 	u32 avail_min;
15 	unsigned int no_active_sensing; /* avoid bit-field */
16 	unsigned char reserved[16];
17 } __attribute__((packed));
18 
19 static int snd_rawmidi_ioctl_params_compat(struct snd_rawmidi_file *rfile,
20 					   struct snd_rawmidi_params32 __user *src)
21 {
22 	struct snd_rawmidi_params params;
23 	unsigned int val;
24 
25 	if (get_user(params.stream, &src->stream) ||
26 	    get_user(params.buffer_size, &src->buffer_size) ||
27 	    get_user(params.avail_min, &src->avail_min) ||
28 	    get_user(val, &src->no_active_sensing))
29 		return -EFAULT;
30 	params.no_active_sensing = val;
31 	switch (params.stream) {
32 	case SNDRV_RAWMIDI_STREAM_OUTPUT:
33 		if (!rfile->output)
34 			return -EINVAL;
35 		return snd_rawmidi_output_params(rfile->output, &params);
36 	case SNDRV_RAWMIDI_STREAM_INPUT:
37 		if (!rfile->input)
38 			return -EINVAL;
39 		return snd_rawmidi_input_params(rfile->input, &params);
40 	}
41 	return -EINVAL;
42 }
43 
44 struct compat_snd_rawmidi_status64 {
45 	s32 stream;
46 	u8 rsvd[4]; /* alignment */
47 	s64 tstamp_sec;
48 	s64 tstamp_nsec;
49 	u32 avail;
50 	u32 xruns;
51 	unsigned char reserved[16];
52 } __attribute__((packed));
53 
54 static int snd_rawmidi_ioctl_status_compat64(struct snd_rawmidi_file *rfile,
55 					     struct compat_snd_rawmidi_status64 __user *src)
56 {
57 	int err;
58 	struct snd_rawmidi_status64 status;
59 	struct compat_snd_rawmidi_status64 compat_status;
60 
61 	if (get_user(status.stream, &src->stream))
62 		return -EFAULT;
63 
64 	switch (status.stream) {
65 	case SNDRV_RAWMIDI_STREAM_OUTPUT:
66 		if (!rfile->output)
67 			return -EINVAL;
68 		err = snd_rawmidi_output_status(rfile->output, &status);
69 		break;
70 	case SNDRV_RAWMIDI_STREAM_INPUT:
71 		if (!rfile->input)
72 			return -EINVAL;
73 		err = snd_rawmidi_input_status(rfile->input, &status);
74 		break;
75 	default:
76 		return -EINVAL;
77 	}
78 	if (err < 0)
79 		return err;
80 
81 	compat_status = (struct compat_snd_rawmidi_status64) {
82 		.stream = status.stream,
83 		.tstamp_sec = status.tstamp_sec,
84 		.tstamp_nsec = status.tstamp_nsec,
85 		.avail = status.avail,
86 		.xruns = status.xruns,
87 	};
88 
89 	if (copy_to_user(src, &compat_status, sizeof(*src)))
90 		return -EFAULT;
91 
92 	return 0;
93 }
94 
95 enum {
96 	SNDRV_RAWMIDI_IOCTL_PARAMS32 = _IOWR('W', 0x10, struct snd_rawmidi_params32),
97 	SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32 = _IOWR('W', 0x20, struct snd_rawmidi_status32),
98 	SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64 = _IOWR('W', 0x20, struct compat_snd_rawmidi_status64),
99 };
100 
101 static long snd_rawmidi_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
102 {
103 	struct snd_rawmidi_file *rfile;
104 	void __user *argp = compat_ptr(arg);
105 
106 	rfile = file->private_data;
107 	switch (cmd) {
108 	case SNDRV_RAWMIDI_IOCTL_PVERSION:
109 	case SNDRV_RAWMIDI_IOCTL_INFO:
110 	case SNDRV_RAWMIDI_IOCTL_DROP:
111 	case SNDRV_RAWMIDI_IOCTL_DRAIN:
112 		return snd_rawmidi_ioctl(file, cmd, (unsigned long)argp);
113 	case SNDRV_RAWMIDI_IOCTL_PARAMS32:
114 		return snd_rawmidi_ioctl_params_compat(rfile, argp);
115 	case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32:
116 		return snd_rawmidi_ioctl_status32(rfile, argp);
117 	case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64:
118 		return snd_rawmidi_ioctl_status_compat64(rfile, argp);
119 	}
120 	return -ENOIOCTLCMD;
121 }
122