From nobody Mon Sep 15 18:11:24 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42B6FC5479D for ; Wed, 11 Jan 2023 03:58:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231939AbjAKD56 (ORCPT ); Tue, 10 Jan 2023 22:57:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231828AbjAKD5w (ORCPT ); Tue, 10 Jan 2023 22:57:52 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0A711260B for ; Tue, 10 Jan 2023 19:57:50 -0800 (PST) Received: from dggpemm100011.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NsDKn6zN2zqV3Q; Wed, 11 Jan 2023 11:53:01 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpemm100011.china.huawei.com (7.185.36.112) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Wed, 11 Jan 2023 11:57:47 +0800 From: Li Lingfeng To: CC: , , , , , , , , , , Subject: [PATCH-next RESEND v2] lib: parser: optimize match_NUMER apis to use local array Date: Wed, 11 Jan 2023 12:22:15 +0800 Message-ID: <20230111042215.4120156-1-lilingfeng3@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm100011.china.huawei.com (7.185.36.112) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Memory will be allocated to store substring_t in match_strdup(), which means the caller of match_strdup() may need to be scheduled out to wait for recla= iming memory. Using local array to store substring_t to remove the restriction. Link: https://lore.kernel.org/all/20221104023938.2346986-5-yukuai1@huaweicl= oud.com/ Signed-off-by: Li Lingfeng Acked-by: Tejun Heo --- lib/parser.c | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-) diff --git a/lib/parser.c b/lib/parser.c index bcb23484100e..0d00f0adb063 100644 --- a/lib/parser.c +++ b/lib/parser.c @@ -11,6 +11,15 @@ #include #include =20 +/* + * max size needed by diffrent bases to express U64 + * HEX: "0xFFFFFFFFFFFFFFFF" --> 18 + * DEC: "18446744073709551615" --> 20 + * OCT: "01777777777777777777777" --> 23 + * pick the max one to define NUMBER_BUF_LEN + */ +#define NUMBER_BUF_LEN 24 + /** * match_one - Determines if a string matches a simple pattern * @s: the string to examine for presence of the pattern @@ -129,14 +138,13 @@ EXPORT_SYMBOL(match_token); static int match_number(substring_t *s, int *result, int base) { char *endp; - char *buf; + char buf[NUMBER_BUF_LEN]; int ret; long val; =20 - buf =3D match_strdup(s); - if (!buf) - return -ENOMEM; - + if ((s->to - s->from) >=3D NUMBER_BUF_LEN) + return -ERANGE; + match_strlcpy(buf, s, NUMBER_BUF_LEN); ret =3D 0; val =3D simple_strtol(buf, &endp, base); if (endp =3D=3D buf) @@ -145,7 +153,6 @@ static int match_number(substring_t *s, int *result, in= t base) ret =3D -ERANGE; else *result =3D (int) val; - kfree(buf); return ret; } =20 @@ -163,18 +170,16 @@ static int match_number(substring_t *s, int *result, = int base) */ static int match_u64int(substring_t *s, u64 *result, int base) { - char *buf; + char buf[NUMBER_BUF_LEN]; int ret; u64 val; =20 - buf =3D match_strdup(s); - if (!buf) - return -ENOMEM; - + if ((s->to - s->from) >=3D NUMBER_BUF_LEN) + return -ERANGE; + match_strlcpy(buf, s, NUMBER_BUF_LEN); ret =3D kstrtoull(buf, base, &val); if (!ret) *result =3D val; - kfree(buf); return ret; } =20 @@ -206,14 +211,13 @@ EXPORT_SYMBOL(match_int); */ int match_uint(substring_t *s, unsigned int *result) { - int err =3D -ENOMEM; - char *buf =3D match_strdup(s); + char buf[NUMBER_BUF_LEN]; =20 - if (buf) { - err =3D kstrtouint(buf, 10, result); - kfree(buf); - } - return err; + if ((s->to - s->from) >=3D NUMBER_BUF_LEN) + return -ERANGE; + match_strlcpy(buf, s, NUMBER_BUF_LEN); + + return kstrtouint(buf, 10, result); } EXPORT_SYMBOL(match_uint); =20 --=20 2.31.1