From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753098AbdFLVFD (ORCPT ); Mon, 12 Jun 2017 17:05:03 -0400 Received: from mail-wr0-f180.google.com ([209.85.128.180]:34433 "EHLO mail-wr0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753066AbdFLVFA (ORCPT ); Mon, 12 Jun 2017 17:05:00 -0400 From: Rasmus Villemoes To: Andrew Morton , Matthew Wilcox , Michal Hocko , Rasmus Villemoes Cc: Alexey Dobriyan , linux-kernel@vger.kernel.org Subject: [PATCH] kernel/groups.c: use sort library function Date: Mon, 12 Jun 2017 23:02:56 +0200 Message-Id: <1497301378-22739-1-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org setgroups is not exactly a hot path, so we might as well use the library function instead of open-coding the sorting. Saves ~150 bytes. Signed-off-by: Rasmus Villemoes --- kernel/groups.c | 35 +++++++++++------------------------ 1 file changed, 11 insertions(+), 24 deletions(-) diff --git a/kernel/groups.c b/kernel/groups.c index d09727692a2a..434f6665f187 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include #include @@ -76,32 +77,18 @@ static int groups_from_user(struct group_info *group_info, return 0; } -/* a simple Shell sort */ +static int gid_cmp(const void *_a, const void *_b) +{ + kgid_t a = *(kgid_t *)_a; + kgid_t b = *(kgid_t *)_b; + + return gid_gt(a, b) - gid_lt(a, b); +} + static void groups_sort(struct group_info *group_info) { - int base, max, stride; - int gidsetsize = group_info->ngroups; - - for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1) - ; /* nothing */ - stride /= 3; - - while (stride) { - max = gidsetsize - stride; - for (base = 0; base < max; base++) { - int left = base; - int right = left + stride; - kgid_t tmp = group_info->gid[right]; - - while (left >= 0 && gid_gt(group_info->gid[left], tmp)) { - group_info->gid[right] = group_info->gid[left]; - right = left; - left -= stride; - } - group_info->gid[right] = tmp; - } - stride /= 3; - } + sort(group_info->gid, group_info->ngroups, sizeof(*group_info->gid), + gid_cmp, NULL); } /* a simple bsearch */ -- 2.1.4