1 based on https://github.com/dankamongmen/libdank/blob/master/libdank/compat-FreeBSD.c
2 --- usb_stream/pcm_usb_stream.c.orig	2024-06-10 09:18:39 UTC
3 +++ usb_stream/pcm_usb_stream.c
4 @@ -77,6 +77,69 @@ static pthread_mutex_t uus_mutex = PTHREAD_MUTEX_INITI
5  static struct user_usb_stream *uus;
6  static pthread_mutex_t uus_mutex = PTHREAD_MUTEX_INITIALIZER;
7 
8 +#ifndef __linux__
9 +/*
10 + * Copyright (c) 2000-2011, Nick Black et al
11 + * All rights reserved.
12 + *
13 + * Redistribution and use in source and binary forms, with or without
14 + * modification, are permitted provided that the following conditions are met:
15 + *     * Redistributions of source code must retain the above copyright
16 + *       notice, this list of conditions and the following disclaimer.
17 + *     * Redistributions in binary form must reproduce the above copyright
18 + *       notice, this list of conditions and the following disclaimer in the
19 + *       documentation and/or other materials provided with the distribution.
20 + *     * Neither the name of Nick Black nor the names of other contributors may
21 + * be used to endorse or promote products derived from this software
22 + * without specific prior written permission.
23 + *
24 + * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
25 + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
26 + * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL <copyright
27 + * holder> BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
28 + * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 + * POSSIBILITY OF SUCH DAMAGE.
34 + */
35 +
36 +// This is suitable really only for use with libdank's mremap_and_ftruncate(),
37 +// due to assumptions it makes about the flags to pass to mmap(2). The only
38 +// mremap(2) use case addressed is that of MREMAP_MAYMOVE. oldaddr must be a
39 +// valid previous return from mmap(); NULL is not acceptable (ala Linux's
40 +// mremap(2)), resulting in undefined behavior, despite realloc(3) semantics.
41 +// Similarly, oldlen and newlen must be non-zero (and page-aligned).
42 +void *mremap_compat(int fd,void *oldaddr,size_t oldlen,
43 +               size_t newlen,int prot,int flags){
44 +   void *ret;
45 +
46 +   // From mmap(2) on freebsd 6.3: A successful FIXED mmap deletes any
47 +   // previous mapping in the allocated address range. This means:
48 +   // remapping over a current map will blow it away (unless FIXED isn't
49 +   // provided, in which case it can't overlap an old mapping. See bug
50 +   // 733 for extensive discussion of this issue for Linux and FreeBSD).
51 +   if((ret = mmap((char *)oldaddr + oldlen,newlen - oldlen,prot,flags,fd,oldlen)) == MAP_FAILED){
52 +       // We couldn't get the memory whatsoever (or we were a fresh
53 +       // allocation that succeeded). Return the immediate result...
54 +       return ret;
55 +   } // ret != MAP_FAILED. Did we squash?
56 +   if(ret != (char *)oldaddr + oldlen){
57 +       // We got the memory, but not where we wanted it. Copy over the
58 +       // old map, and then free it up...
59 +       munmap(ret,newlen - oldlen);
60 +       if((ret = mmap(NULL,newlen,prot,flags,fd,0)) == MAP_FAILED){
61 +           return ret;
62 +       }
63 +       memcpy(ret,oldaddr,oldlen);
64 +       munmap(oldaddr,oldlen); // Free the old mapping
65 +       return ret;
66 +   } // We successfully squashed. Return a pointer to the first buf.
67 +   return oldaddr;
68 +}
69 +#endif
70 +
71  static struct user_usb_stream *get_uus(int card)
72  {
73  	pthread_mutex_lock(&uus_mutex);
74 @@ -217,7 +280,11 @@ static int snd_pcm_us_prepare(snd_pcm_ioplug_t *io)
75  		}
76 
77 
78 +#ifdef __linux__
79  		uus->s = mremap(uus->s, sizeof(struct usb_stream), uus->s->read_size, MREMAP_MAYMOVE);
80 +#else
81 +		uus->s = mremap_compat(us->pfd.fd, uus->s, sizeof(struct usb_stream), uus->s->read_size, PROT_READ, MAP_SHARED);
82 +#endif
83  		if (MAP_FAILED == uus->s) {
84  			perror("ALSA/USX2Y: mmap");
85  			return -EPERM;
86