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 static const struct ioctl_compat_map compat_map[] = {
27 { SIOCGSTAMP, SIOCGSTAMP_OLD, 8, R, 0, OFFS(0, 4) },
28 { SIOCGSTAMPNS, SIOCGSTAMPNS_OLD, 8, R, 0, OFFS(0, 4) },
31 static void convert_ioctl_struct(const struct ioctl_compat_map *map, char *old, char *new, int dir)
35 int old_size = map->old_size;
36 if (!(dir & map->dir)) return;
37 for (int i=0; i < map->noffs; i++) {
38 int ts_offset = map->offsets[i];
39 int len = ts_offset-old_offset;
40 if (dir==W) memcpy(old+old_offset, new+new_offset, len);
41 else memcpy(new+new_offset, old+old_offset, len);
46 int align = map->force_align ? sizeof(time_t) : alignof(time_t);
47 new_offset += (align-1) & -new_offset;
49 memcpy(&new_ts, new+new_offset, sizeof new_ts);
51 memcpy(old+old_offset, &old_ts, sizeof old_ts);
53 memcpy(&old_ts, old+old_offset, sizeof old_ts);
55 memcpy(new+new_offset, &new_ts, sizeof new_ts);
57 new_offset += sizeof new_ts;
58 old_offset += sizeof old_ts;
60 if (dir==W) memcpy(old+old_offset, new+new_offset, old_size-old_offset);
61 else memcpy(new+new_offset, old+old_offset, old_size-old_offset);
64 int ioctl(int fd, int req, ...)
69 arg = va_arg(ap, void *);
71 int r = __syscall(SYS_ioctl, fd, req, arg);
73 for (int i=0; i<sizeof compat_map/sizeof *compat_map; i++) {
74 if (compat_map[i].new_req != req) continue;
79 convert_ioctl_struct(&compat_map[i], u.buf, arg, W);
80 r = __syscall(SYS_ioctl, fd, compat_map[i].old_req, u.buf);
82 convert_ioctl_struct(&compat_map[i], u.buf, arg, R);
85 return __syscall_ret(r);