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 int mode;
  17         unsigned char reserved[12];
  18 } __attribute__((packed));
  19
  20 static int snd_rawmidi_ioctl_params_compat(struct snd_rawmidi_file *rfile,
  21                                            struct snd_rawmidi_params32 __user *src)
  22 {
  23         struct snd_rawmidi_params params;
  24         unsigned int val;
  25
  26         if (get_user(params.stream, &src->stream) ||
  27             get_user(params.buffer_size, &src->buffer_size) ||
  28             get_user(params.avail_min, &src->avail_min) ||
  29             get_user(params.mode, &src->mode) ||
  30             get_user(val, &src->no_active_sensing))
  31                 return -EFAULT;
  32         params.no_active_sensing = val;
  33         switch (params.stream) {
  34         case SNDRV_RAWMIDI_STREAM_OUTPUT:
  35                 if (!rfile->output)
  36                         return -EINVAL;
  37                 return snd_rawmidi_output_params(rfile->output, &params);
  38         case SNDRV_RAWMIDI_STREAM_INPUT:
  39                 if (!rfile->input)
  40                         return -EINVAL;
  41                 return snd_rawmidi_input_params(rfile->input, &params);
  42         }
  43         return -EINVAL;
  44 }
  45
  46 struct compat_snd_rawmidi_status64 {
  47         s32 stream;
  48         u8 rsvd[4]; /* alignment */
  49         s64 tstamp_sec;
  50         s64 tstamp_nsec;
  51         u32 avail;
  52         u32 xruns;
  53         unsigned char reserved[16];
  54 } __attribute__((packed));
  55
  56 static int snd_rawmidi_ioctl_status_compat64(struct snd_rawmidi_file *rfile,
  57                                              struct compat_snd_rawmidi_status64 __user *src)
  58 {
  59         int err;
  60         struct snd_rawmidi_status64 status;
  61         struct compat_snd_rawmidi_status64 compat_status;
  62
  63         if (get_user(status.stream, &src->stream))
  64                 return -EFAULT;
  65
  66         switch (status.stream) {
  67         case SNDRV_RAWMIDI_STREAM_OUTPUT:
  68                 if (!rfile->output)
  69                         return -EINVAL;
  70                 err = snd_rawmidi_output_status(rfile->output, &status);
  71                 break;
  72         case SNDRV_RAWMIDI_STREAM_INPUT:
  73                 if (!rfile->input)
  74                         return -EINVAL;
  75                 err = snd_rawmidi_input_status(rfile->input, &status);
  76                 break;
  77         default:
  78                 return -EINVAL;
  79         }
  80         if (err < 0)
  81                 return err;
  82
  83         compat_status = (struct compat_snd_rawmidi_status64) {
  84                 .stream = status.stream,
  85                 .tstamp_sec = status.tstamp_sec,
  86                 .tstamp_nsec = status.tstamp_nsec,
  87                 .avail = status.avail,
  88                 .xruns = status.xruns,
  89         };
  90
  91         if (copy_to_user(src, &compat_status, sizeof(*src)))
  92                 return -EFAULT;
  93
  94         return 0;
  95 }
  96
  97 enum {
  98         SNDRV_RAWMIDI_IOCTL_PARAMS32 = _IOWR('W', 0x10, struct snd_rawmidi_params32),
  99         SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32 = _IOWR('W', 0x20, struct snd_rawmidi_status32),
 100         SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64 = _IOWR('W', 0x20, struct compat_snd_rawmidi_status64),
 101 };
 102
 103 static long snd_rawmidi_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
 104 {
 105         struct snd_rawmidi_file *rfile;
 106         void __user *argp = compat_ptr(arg);
 107
 108         rfile = file->private_data;
 109         switch (cmd) {
 110         case SNDRV_RAWMIDI_IOCTL_PVERSION:
 111         case SNDRV_RAWMIDI_IOCTL_INFO:
 112         case SNDRV_RAWMIDI_IOCTL_DROP:
 113         case SNDRV_RAWMIDI_IOCTL_DRAIN:
 114                 return snd_rawmidi_ioctl(file, cmd, (unsigned long)argp);
 115         case SNDRV_RAWMIDI_IOCTL_PARAMS32:
 116                 return snd_rawmidi_ioctl_params_compat(rfile, argp);
 117         case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT32:
 118                 return snd_rawmidi_ioctl_status32(rfile, argp);
 119         case SNDRV_RAWMIDI_IOCTL_STATUS_COMPAT64:
 120                 return snd_rawmidi_ioctl_status_compat64(rfile, argp);
 121         }
 122         return -ENOIOCTLCMD;
 123 }