10 #define alignof(t) offsetof(struct { char c; t x; }, x)
16 struct ioctl_compat_map {
18 unsigned char old_size, dir, force_align, noffs;
19 unsigned char offsets[8];
22 #define NINTH(a,b,c,d,e,f,g,h,i,...) i
23 #define COUNT(...) NINTH(__VA_ARGS__,8,7,6,5,4,3,2,1,0)
24 #define OFFS(...) COUNT(__VA_ARGS__), { __VA_ARGS__ }
26 /* yields a type for a struct with original size n, with a misaligned
27 * timeval/timespec expanded from 32- to 64-bit. for use with ioctl
28 * number producing macros; only size of result is meaningful. */
29 #define new_misaligned(n) struct { int i; time_t t; char c[(n)-4]; }
31 static const struct ioctl_compat_map compat_map[] = {
32 { SIOCGSTAMP, SIOCGSTAMP_OLD, 8, R, 0, OFFS(0, 4) },
33 { SIOCGSTAMPNS, SIOCGSTAMPNS_OLD, 8, R, 0, OFFS(0, 4) },
35 /* SNDRV_TIMER_IOCTL_STATUS */
36 { _IOR('T', 0x14, char[96]), _IOR('T', 0x14, 88), 88, R, 0, OFFS(0,4) },
38 /* SNDRV_PCM_IOCTL_STATUS[_EXT] */
39 { _IOR('A', 0x20, char[128]), _IOR('A', 0x20, char[108]), 108, R, 1, OFFS(4,8,12,16,52,56,60,64) },
40 { _IOWR('A', 0x24, char[128]), _IOWR('A', 0x24, char[108]), 108, WR, 1, OFFS(4,8,12,16,52,56,60,64) },
42 /* SNDRV_RAWMIDI_IOCTL_STATUS */
43 { _IOWR('W', 0x20, char[48]), _IOWR('W', 0x20, char[36]), 36, WR, 1, OFFS(4,8) },
45 /* SNDRV_PCM_IOCTL_SYNC_PTR - with 3 subtables */
46 { _IOWR('A', 0x23, char[136]), _IOWR('A', 0x23, char[132]), 0, WR, 1, 0 },
47 { 0, 0, 4, WR, 1, 0 }, /* snd_pcm_sync_ptr (flags only) */
48 { 0, 0, 32, WR, 1, OFFS(8,12,16,24,28) }, /* snd_pcm_mmap_status */
49 { 0, 0, 8, WR, 1, OFFS(0,4) }, /* snd_pcm_mmap_control */
51 /* VIDIOC_QUERYBUF, VIDIOC_QBUF, VIDIOC_DQBUF, VIDIOC_PREPARE_BUF */
52 { _IOWR('V', 9, new_misaligned(72)), _IOWR('V', 9, char[72]), 72, WR, 0, OFFS(20) },
53 { _IOWR('V', 15, new_misaligned(72)), _IOWR('V', 15, char[72]), 72, WR, 0, OFFS(20) },
54 { _IOWR('V', 17, new_misaligned(72)), _IOWR('V', 17, char[72]), 72, WR, 0, OFFS(20) },
55 { _IOWR('V', 93, new_misaligned(72)), _IOWR('V', 93, char[72]), 72, WR, 0, OFFS(20) },
58 { _IOR('V', 89, new_misaligned(96)), _IOR('V', 89, char[96]), 96, R, 0, OFFS(76,80) },
61 { _IOR('t', 63, char[16]), _IOR('t', 63, char[8]), 8, R, 0, OFFS(0,4) },
63 /* PPGETTIME, PPSETTIME */
64 { _IOR('p', 0x95, char[16]), _IOR('p', 0x95, char[8]), 8, R, 0, OFFS(0,4) },
65 { _IOW('p', 0x96, char[16]), _IOW('p', 0x96, char[8]), 8, W, 0, OFFS(0,4) },
68 { _IOW(0x6, 0xf, char[16]), 0x060f, 8, W, 0, OFFS(0,4) },
71 static void convert_ioctl_struct(const struct ioctl_compat_map *map, char *old, char *new, int dir)
75 int old_size = map->old_size;
76 if (!(dir & map->dir)) return;
78 /* offsets hard-coded for SNDRV_PCM_IOCTL_SYNC_PTR;
79 * if another exception appears this needs changing. */
80 convert_ioctl_struct(map+1, old, new, dir);
81 convert_ioctl_struct(map+2, old+4, new+8, dir);
82 convert_ioctl_struct(map+3, old+68, new+72, dir);
85 for (int i=0; i < map->noffs; i++) {
86 int ts_offset = map->offsets[i];
87 int len = ts_offset-old_offset;
88 if (dir==W) memcpy(old+old_offset, new+new_offset, len);
89 else memcpy(new+new_offset, old+old_offset, len);
94 int align = map->force_align ? sizeof(time_t) : alignof(time_t);
95 new_offset += (align-1) & -new_offset;
97 memcpy(&new_ts, new+new_offset, sizeof new_ts);
99 memcpy(old+old_offset, &old_ts, sizeof old_ts);
101 memcpy(&old_ts, old+old_offset, sizeof old_ts);
103 memcpy(new+new_offset, &new_ts, sizeof new_ts);
105 new_offset += sizeof new_ts;
106 old_offset += sizeof old_ts;
108 if (dir==W) memcpy(old+old_offset, new+new_offset, old_size-old_offset);
109 else memcpy(new+new_offset, old+old_offset, old_size-old_offset);
112 int ioctl(int fd, int req, ...)
117 arg = va_arg(ap, void *);
119 int r = __syscall(SYS_ioctl, fd, req, arg);
120 if (req && r==-ENOTTY) {
121 for (int i=0; i<sizeof compat_map/sizeof *compat_map; i++) {
122 if (compat_map[i].new_req != req) continue;
127 convert_ioctl_struct(&compat_map[i], u.buf, arg, W);
128 r = __syscall(SYS_ioctl, fd, compat_map[i].old_req, u.buf);
130 convert_ioctl_struct(&compat_map[i], u.buf, arg, R);
133 return __syscall_ret(r);