sound/core/rawmidi_compat.c

   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 }