From nobody Tue Dec 16 23:43:32 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 EC0CBC2FC3C for ; Thu, 17 Aug 2023 14:18:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351779AbjHQORm (ORCPT ); Thu, 17 Aug 2023 10:17:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60636 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351783AbjHQORP (ORCPT ); Thu, 17 Aug 2023 10:17:15 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DE512D5F for ; Thu, 17 Aug 2023 07:17:13 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RRRsJ0Vv8z4f3q2y for ; Thu, 17 Aug 2023 22:17:08 +0800 (CST) Received: from ubuntu20.huawei.com (unknown [10.67.174.33]) by APP1 (Coremail) with SMTP id cCh0CgB38S3OK95kF+6GAw--.40006S2; Thu, 17 Aug 2023 22:17:08 +0800 (CST) From: "GONG, Ruiqi" To: Kees Cook , Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: gongruiqi1@huawei.com Subject: [PATCH] lkdtm: use the return value of strim() Date: Thu, 17 Aug 2023 22:21:17 +0800 Message-Id: <20230817142117.972418-1-gongruiqi@huaweicloud.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: cCh0CgB38S3OK95kF+6GAw--.40006S2 X-Coremail-Antispam: 1UD129KBjvdXoW7Xw48JF17Jr4kCryDKFyfZwb_yoWktrX_Cw 4Yqr18CFsxu3WfAw1q93WUZr45ua1DWFsY9r4aqrW3ZFy7Wrs5JFyFgrn5Xw43Cr4Dur9r Kr95W3yIqw42kjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUboxYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwV A0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x02 67AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxV AFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2 j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7x kEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s 1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnI WIevJa73UjIFyTuYvjxUzsqWUUUUU X-CM-SenderInfo: pjrqw2pxltxq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "GONG, Ruiqi" Make use of the return value of strim() to achieve left-trim as well as right-trim, which prevents the following unusual fail case: # echo " EXCEPTION" > /sys/kernel/debug/provoke-crash/DIRECT sh: write error: Invalid argument Link: https://github.com/KSPP/linux/issues/337 Signed-off-by: GONG, Ruiqi --- drivers/misc/lkdtm/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index 0772e4a4757e..812c96461ab2 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -242,7 +242,7 @@ static ssize_t lkdtm_debugfs_entry(struct file *f, } /* NULL-terminate and remove enter */ buf[count] =3D '\0'; - strim(buf); + buf =3D strim(buf); =20 crashtype =3D find_crashtype(buf); free_page((unsigned long)buf); @@ -318,7 +318,7 @@ static ssize_t direct_entry(struct file *f, const char = __user *user_buf, } /* NULL-terminate and remove enter */ buf[count] =3D '\0'; - strim(buf); + buf =3D strim(buf); =20 crashtype =3D find_crashtype(buf); free_page((unsigned long) buf); --=20 2.25.1