52f4fe9db
Denys Vlasenko
2011-06-22
Subject
id: correct getgroups usage
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No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
coreutils/id.c+15 -16
| @@ -117,7 +117,7 @@ static int print_user(uid_t id, const char *prefix) | |
| /* On error set *n < 0 and return >= 0 | |
| * If *n is too small, update it and return < 0 | |
| - | * (ok to trash groups[] in both cases) |
| + | * (ok to trash groups[] in both cases) |
| * Otherwise fill in groups[] and return >= 0 | |
| */ | |
| static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n) | |
| @@ -131,20 +131,19 @@ static int get_groups(const char *username, gid_t rgid, gid_t *groups, int *n) | |
| m = getgrouplist(username, rgid, groups, n); | |
| /* I guess *n < 0 might indicate error. Anyway, | |
| * malloc'ing -1 bytes won't be good, so: */ | |
| - | //if (*n < 0) |
| - | // return 0; |
| - | //return m; |
| - | //commented out here, happens below anyway |
| - | } else { |
| - | /* On error -1 is returned, which ends up in *n */ |
| - | int nn = getgroups(*n, groups); |
| - | /* 0: nn <= *n, groups[] was big enough; -1 otherwise */ |
| - | m = - (nn > *n); |
| - | *n = nn; |
| + | if (*n < 0) |
| + | return 0; |
| + | return m; |
| } | |
| - | if (*n < 0) |
| - | return 0; /* error, don't return < 0! */ |
| - | return m; |
| + | |
| + | *n = getgroups(*n, groups); |
| + | if (*n >= 0) |
| + | return *n; |
| + | /* Error */ |
| + | if (errno == EINVAL) /* *n is too small? */ |
| + | *n = getgroups(0, groups); /* get needed *n */ |
| + | /* if *n >= 0, return -1 (got new *n), else return 0 (error): */ |
| + | return -(*n >= 0); |
| } | |
| int id_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; | |
| @@ -214,11 +213,11 @@ int id_main(int argc UNUSED_PARAM, char **argv) | |
| /* We are supplying largish buffer, trying | |
| * to not run get_groups() twice. That might be slow | |
| * ("user database in remote SQL server" case) */ | |
| - | groups = xmalloc(64 * sizeof(gid_t)); |
| + | groups = xmalloc(64 * sizeof(groups[0])); |
| n = 64; | |
| if (get_groups(username, rgid, groups, &n) < 0) { | |
| /* Need bigger buffer after all */ | |
| - | groups = xrealloc(groups, n * sizeof(gid_t)); |
| + | groups = xrealloc(groups, n * sizeof(groups[0])); |
| get_groups(username, rgid, groups, &n); | |
| } | |
| if (n > 0) { | |