From nobody Fri Apr 3 00:50:22 2026 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 3399FC6FA8B for ; Sun, 18 Sep 2022 13:51:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229719AbiIRNvE (ORCPT ); Sun, 18 Sep 2022 09:51:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229538AbiIRNvA (ORCPT ); Sun, 18 Sep 2022 09:51:00 -0400 Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83FBE1CB38; Sun, 18 Sep 2022 06:50:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1663509059; x=1695045059; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=JOe7XaRamQ8Iu/OfFoMs5vEKw30I5MFDyJr1Ff7z628=; b=AAxgl1c0kKr1aVJamhSY4sqMKje9yNDl6N+Wof+LJ56omNgxg3AzBW3H cXtGDlnTAYWrHDLUtWFYiNBJyjPnl3Wmi+s28mOJ52JjCXHulqMG1V5fP keXv2Je+nYlvpNfmD8pwc9XDG3PIPIqaxnIco8e4ZUByqE8M7PQGg2zjb g=; X-IronPort-AV: E=Sophos;i="5.93,325,1654560000"; d="scan'208";a="131249096" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-iad-1d-f20e0c8b.us-east-1.amazon.com) ([10.25.36.214]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Sep 2022 13:50:44 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1d-f20e0c8b.us-east-1.amazon.com (Postfix) with ESMTPS id 7A7D69FD2A; Sun, 18 Sep 2022 13:50:42 +0000 (UTC) Received: from EX19D013UWB001.ant.amazon.com (10.13.138.52) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Sun, 18 Sep 2022 13:50:37 +0000 Received: from EX13MTAUEB002.ant.amazon.com (10.43.60.12) by EX19D013UWB001.ant.amazon.com (10.13.138.52) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.12; Sun, 18 Sep 2022 13:50:37 +0000 Received: from dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (172.19.116.181) by mail-relay.amazon.com (10.43.60.234) with Microsoft SMTP Server id 15.0.1497.38 via Frontend Transport; Sun, 18 Sep 2022 13:50:36 +0000 Received: by dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (Postfix, from userid 14301484) id 927094D0F; Sun, 18 Sep 2022 13:50:36 +0000 (UTC) From: Eliav Farber To: , , , , CC: , , , Subject: [PATCH] libfs: fix negative value support in simple_attr_write() Date: Sun, 18 Sep 2022 13:50:36 +0000 Message-ID: <20220918135036.33595-1-farbere@amazon.com> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" After commit 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()"), a user trying set a negative value will get a '-EINVAL' error, because simple_attr_write() was modified to use kstrtoull() which can handle only unsigned values, instead of simple_strtoll(). This breaks all the places using DEFINE_DEBUGFS_ATTRIBUTE() with format of a signed integer. The u64 value which attr->set() receives is not an issue for negative numbers. The %lld and %llu in any case are for 64-bit value. Representing it as unsigned simplifies the generic code, but it doesn't mean we can't keep their signed value if we know that. This change basically reverts the mentioned commit, but uses kstrtoll() instead of simple_strtoll() which is obsolete. Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_att= r_write()") Signed-off-by: Eliav Farber Reviewed-by: Andy Shevchenko Reviewed-by: Yicong Yang --- fs/libfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/libfs.c b/fs/libfs.c index 31b0ddf01c31..3bccd75815db 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1016,7 +1016,7 @@ ssize_t simple_attr_write(struct file *file, const ch= ar __user *buf, goto out; =20 attr->set_buf[size] =3D '\0'; - ret =3D kstrtoull(attr->set_buf, 0, &val); + ret =3D kstrtoll(attr->set_buf, 0, &val); if (ret) goto out; ret =3D attr->set(attr->data, val); --=20 2.37.1