diff options
Diffstat (limited to 'kernel/user_namespace.c')
| -rw-r--r-- | kernel/user_namespace.c | 132 |
1 files changed, 58 insertions, 74 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index c9904ee084c4..563a2981d7c7 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -256,28 +256,17 @@ static int cmp_map_id(const void *k, const void *e) * map_id_range_down_max - Find idmap via binary search in ordered idmap array. * Can only be called if number of mappings exceeds UID_GID_MAP_MAX_BASE_EXTENTS. */ -static u32 map_id_range_down_max(struct uid_gid_map *map, u32 id, u32 count) +static struct uid_gid_extent * +map_id_range_down_max(unsigned extents, struct uid_gid_map *map, u32 id, u32 count) { - u32 extents; - struct uid_gid_extent *extent; struct idmap_key key; key.map_up = false; key.count = count; key.id = id; - extents = map->nr_extents; - smp_rmb(); - - extent = bsearch(&key, map->forward, extents, - sizeof(struct uid_gid_extent), cmp_map_id); - /* Map the id or note failure */ - if (extent) - id = (id - extent->first) + extent->lower_first; - else - id = (u32) -1; - - return id; + return bsearch(&key, map->forward, extents, + sizeof(struct uid_gid_extent), cmp_map_id); } /** @@ -285,41 +274,43 @@ static u32 map_id_range_down_max(struct uid_gid_map *map, u32 id, u32 count) * Can only be called if number of mappings is equal or less than * UID_GID_MAP_MAX_BASE_EXTENTS. */ -static u32 map_id_range_down_base(struct uid_gid_map *map, u32 id, u32 count) +static struct uid_gid_extent * +map_id_range_down_base(unsigned extents, struct uid_gid_map *map, u32 id, u32 count) { - unsigned idx, extents; + unsigned idx; u32 first, last, id2; id2 = id + count - 1; /* Find the matching extent */ - extents = map->nr_extents; - smp_rmb(); for (idx = 0; idx < extents; idx++) { first = map->extent[idx].first; last = first + map->extent[idx].count - 1; if (id >= first && id <= last && (id2 >= first && id2 <= last)) - break; + return &map->extent[idx]; } - /* Map the id or note failure */ - if (idx < extents) - id = (id - first) + map->extent[idx].lower_first; - else - id = (u32) -1; - - return id; + return NULL; } static u32 map_id_range_down(struct uid_gid_map *map, u32 id, u32 count) { - u32 extents = map->nr_extents; + struct uid_gid_extent *extent; + unsigned extents = map->nr_extents; smp_rmb(); if (extents <= UID_GID_MAP_MAX_BASE_EXTENTS) - return map_id_range_down_base(map, id, count); + extent = map_id_range_down_base(extents, map, id, count); + else + extent = map_id_range_down_max(extents, map, id, count); - return map_id_range_down_max(map, id, count); + /* Map the id or note failure */ + if (extent) + id = (id - extent->first) + extent->lower_first; + else + id = (u32) -1; + + return id; } /** @@ -327,38 +318,40 @@ static u32 map_id_range_down(struct uid_gid_map *map, u32 id, u32 count) * Can only be called if number of mappings is equal or less than * UID_GID_MAP_MAX_BASE_EXTENTS. */ -static u32 map_id_down_base(struct uid_gid_map *map, u32 id) +static struct uid_gid_extent * +map_id_down_base(unsigned extents, struct uid_gid_map *map, u32 id) { - unsigned idx, extents; + unsigned idx; u32 first, last; /* Find the matching extent */ - extents = map->nr_extents; - smp_rmb(); for (idx = 0; idx < extents; idx++) { first = map->extent[idx].first; last = first + map->extent[idx].count - 1; if (id >= first && id <= last) - break; + return &map->extent[idx]; } - /* Map the id or note failure */ - if (idx < extents) - id = (id - first) + map->extent[idx].lower_first; - else - id = (u32) -1; - - return id; + return NULL; } static u32 map_id_down(struct uid_gid_map *map, u32 id) { - u32 extents = map->nr_extents; + struct uid_gid_extent *extent; + unsigned extents = map->nr_extents; smp_rmb(); if (extents <= UID_GID_MAP_MAX_BASE_EXTENTS) - return map_id_down_base(map, id); + extent = map_id_down_base(extents, map, id); + else + extent = map_id_range_down_max(extents, map, id, 1); - return map_id_range_down_max(map, id, 1); + /* Map the id or note failure */ + if (extent) + id = (id - extent->first) + extent->lower_first; + else + id = (u32) -1; + + return id; } /** @@ -366,48 +359,50 @@ static u32 map_id_down(struct uid_gid_map *map, u32 id) * Can only be called if number of mappings is equal or less than * UID_GID_MAP_MAX_BASE_EXTENTS. */ -static u32 map_id_up_base(struct uid_gid_map *map, u32 id) +static struct uid_gid_extent * +map_id_up_base(unsigned extents, struct uid_gid_map *map, u32 id) { - unsigned idx, extents; + unsigned idx; u32 first, last; /* Find the matching extent */ - extents = map->nr_extents; - smp_rmb(); for (idx = 0; idx < extents; idx++) { first = map->extent[idx].lower_first; last = first + map->extent[idx].count - 1; if (id >= first && id <= last) - break; + return &map->extent[idx]; } - /* Map the id or note failure */ - if (idx < extents) - id = (id - first) + map->extent[idx].first; - else - id = (u32) -1; - - return id; + return NULL; } /** * map_id_up_max - Find idmap via binary search in ordered idmap array. * Can only be called if number of mappings exceeds UID_GID_MAP_MAX_BASE_EXTENTS. */ -static u32 map_id_up_max(struct uid_gid_map *map, u32 id) +static struct uid_gid_extent * +map_id_up_max(unsigned extents, struct uid_gid_map *map, u32 id) { - u32 extents; - struct uid_gid_extent *extent; struct idmap_key key; key.map_up = true; key.count = 1; key.id = id; - extents = map->nr_extents; + return bsearch(&key, map->reverse, extents, + sizeof(struct uid_gid_extent), cmp_map_id); +} + +static u32 map_id_up(struct uid_gid_map *map, u32 id) +{ + struct uid_gid_extent *extent; + unsigned extents = map->nr_extents; smp_rmb(); - extent = bsearch(&key, map->reverse, extents, - sizeof(struct uid_gid_extent), cmp_map_id); + if (extents <= UID_GID_MAP_MAX_BASE_EXTENTS) + extent = map_id_up_base(extents, map, id); + else + extent = map_id_up_max(extents, map, id); + /* Map the id or note failure */ if (extent) id = (id - extent->lower_first) + extent->first; @@ -417,17 +412,6 @@ static u32 map_id_up_max(struct uid_gid_map *map, u32 id) return id; } -static u32 map_id_up(struct uid_gid_map *map, u32 id) -{ - u32 extents = map->nr_extents; - smp_rmb(); - - if (extents <= UID_GID_MAP_MAX_BASE_EXTENTS) - return map_id_up_base(map, id); - - return map_id_up_max(map, id); -} - /** * make_kuid - Map a user-namespace uid pair into a kuid. * @ns: User namespace that the uid is in |