From 64d0e86576ef1d33e996a926d6a02d38fb88a768 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 19 Dec 2019 10:47:10 -0500 Subject: [PATCH] improve ioctl time64 conversion fallback framework record offsets of individual slots that expand from 32- to 64-bit, rather than timespec/timeval pairs. this flexibility will be needed for some ioctls. reduce size of types in table. adjust representation of offsets to include a count rather than needing -1 padding so that the table is less ugly and doesn't need large diffs if we increase max number of slots. --- src/misc/ioctl.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/src/misc/ioctl.c b/src/misc/ioctl.c index 48613b3d..245876e2 100644 --- a/src/misc/ioctl.c +++ b/src/misc/ioctl.c @@ -14,14 +14,18 @@ #define WR 3 struct ioctl_compat_map { - int new_req, old_req, old_size; - char dir, force_align; - int offsets[4]; + int new_req, old_req; + unsigned char old_size, dir, force_align, noffs; + unsigned char offsets[8]; }; +#define NINTH(a,b,c,d,e,f,g,h,i,...) i +#define COUNT(...) NINTH(__VA_ARGS__,8,7,6,5,4,3,2,1,0) +#define OFFS(...) COUNT(__VA_ARGS__), { __VA_ARGS__ } + static const struct ioctl_compat_map compat_map[] = { - { SIOCGSTAMP, SIOCGSTAMP_OLD, 8, R, 0, { 0, -1, -1, -1 } }, - { SIOCGSTAMPNS, SIOCGSTAMPNS_OLD, 8, R, 0, { 0, -1, -1, -1 } }, + { SIOCGSTAMP, SIOCGSTAMP_OLD, 8, R, 0, OFFS(0, 4) }, + { SIOCGSTAMPNS, SIOCGSTAMPNS_OLD, 8, R, 0, OFFS(0, 4) }, }; static void convert_ioctl_struct(const struct ioctl_compat_map *map, char *old, char *new, int dir) @@ -30,28 +34,25 @@ static void convert_ioctl_struct(const struct ioctl_compat_map *map, char *old, int old_offset = 0; int old_size = map->old_size; if (!(dir & map->dir)) return; - for (int i=0; i < sizeof map->offsets / sizeof *map->offsets; i++) { + for (int i=0; i < map->noffs; i++) { int ts_offset = map->offsets[i]; - if (ts_offset < 0) break; int len = ts_offset-old_offset; if (dir==W) memcpy(old+old_offset, new+new_offset, len); else memcpy(new+new_offset, old+old_offset, len); new_offset += len; old_offset += len; - long long new_ts[2]; - long old_ts[2]; + long long new_ts; + long old_ts; int align = map->force_align ? sizeof(time_t) : alignof(time_t); new_offset += (align-1) & -new_offset; if (dir==W) { - memcpy(new_ts, new+new_offset, sizeof new_ts); - old_ts[0] = new_ts[0]; - old_ts[1] = new_ts[1]; - memcpy(old+old_offset, old_ts, sizeof old_ts); + memcpy(&new_ts, new+new_offset, sizeof new_ts); + old_ts = new_ts; + memcpy(old+old_offset, &old_ts, sizeof old_ts); } else { - memcpy(old_ts, old+old_offset, sizeof old_ts); - new_ts[0] = old_ts[0]; - new_ts[1] = old_ts[1]; - memcpy(new+new_offset, new_ts, sizeof new_ts); + memcpy(&old_ts, old+old_offset, sizeof old_ts); + new_ts = old_ts; + memcpy(new+new_offset, &new_ts, sizeof new_ts); } new_offset += sizeof new_ts; old_offset += sizeof old_ts; -- 2.25.1