ash: cache more of uid/gid syscalls

Testcase:
setuidgid 1:1 strace ash -c 'test -x TODO; test -x TODO; echo $?'
should show that second "test -x" does not query ids again.

function                                             old     new   delta
ash_main                                            1236    1256     +20
get_cached_euid                                        -      19     +19
get_cached_egid                                        -      19     +19
test_main                                             56      72     +16
test_exec                                            119     135     +16
is_in_supplementary_groups                            52      57      +5
nexpr                                                718     702     -16
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 4/1 up/down: 95/-16)             Total: 79 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 8748464ed..f5f8e1635 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1206,11 +1206,13 @@ gid_t *bb_getgroups(int *ngroups, gid_t *group_array) FAST_FUNC;
  * getgroups() is cached in supplementary_array[], to make successive calls faster.
  */
 struct cached_groupinfo {
-        //TODO? gid_t egid;
+        uid_t euid;
+        gid_t egid;
         int ngroups;
         gid_t *supplementary_array;
 };
-//TODO? int FAST_FUNC get_cached_egid(gid_t *egid);
+uid_t FAST_FUNC get_cached_euid(uid_t *euid);
+gid_t FAST_FUNC get_cached_egid(gid_t *egid);
 int FAST_FUNC is_in_supplementary_groups(struct cached_groupinfo *groupinfo, gid_t gid);
 
 #if ENABLE_FEATURE_UTMP