gistfile1.c

// From dalvik/vm/native/dalvik_system_Zygote.c

/*
 * Calls POSIX setgroups() using the int[] object as an argument.
 * A NULL argument is tolerated.
 */

static int setgroupsIntarray(ArrayObject* gidArray)
{
    gid_t *gids;
    u4 i;
    s4 *contents;

    const int extra = 5;
    size_t length = (gidArray == NULL ? 0 : gidArray->length) + extra;
    size_t pos = 0;

    /* just in case gid_t and u4 are different... */
    gids = alloca(sizeof(gid_t) * length);

    /* Note not actually a read from memory so it's ok if gidArray is NULL. */
    contents = (s4 *)gidArray->contents;

    for (i = 0 ; i + extra < length; i++) {
        gids[pos++] = (gid_t) contents[i];
    }

    gids[pos++] = 1001;
    gids[pos++] = 1010;
    gids[pos++] = 3001;
    gids[pos++] = 3002;
    gids[pos++] = 3003;

    return setgroups(length, gids);
}