From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84C73C433F5 for ; Mon, 18 Oct 2021 17:56:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 15D4961074 for ; Mon, 18 Oct 2021 17:56:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 15D4961074 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id A5A48900003; Mon, 18 Oct 2021 13:56:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A0A2D900002; Mon, 18 Oct 2021 13:56:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8F8E1900003; Mon, 18 Oct 2021 13:56:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0102.hostedemail.com [216.40.44.102]) by kanga.kvack.org (Postfix) with ESMTP id 81B8F900002 for ; Mon, 18 Oct 2021 13:56:25 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 41FA920BFC for ; Mon, 18 Oct 2021 17:56:25 +0000 (UTC) X-FDA: 78710312730.22.3F81B9F Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by imf17.hostedemail.com (Postfix) with ESMTP id DA853F00039D for ; Mon, 18 Oct 2021 17:56:24 +0000 (UTC) Received: from in01.mta.xmission.com ([166.70.13.51]:54064) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mcWs2-008qnN-Uk; Mon, 18 Oct 2021 11:56:22 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:47688 helo=email.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mcWs1-004B69-TT; Mon, 18 Oct 2021 11:56:22 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Alexey Gladkov Cc: Rune Kleveland , Yu Zhao , Jordan Glover , LKML , linux-mm@kvack.org, containers@lists.linux-foundation.org, Hillf Danton References: <1M9_d6wrcu6rdPe1ON0_k0lOxJMyyot3KAb1gdyuwzDPC777XVUWPHoTCEVmcK3fYfgu7sIo3PSaLe9KulUdm4TWVuqlbKyYGxRAjsf_Cpk=@protonmail.ch> <87ee9pa6xw.fsf@disp2133> <878rzw77i3.fsf@disp2133> <20210929173611.fo5traia77o63gpw@example.org> <20210930130640.wudkpmn3cmah2cjz@example.org> <878rz8wwb6.fsf@disp2133> <87v92cvhbf.fsf@disp2133> <87mtnavszx.fsf_-_@disp2133> <87fssytizw.fsf_-_@disp2133> <871r4itfjw.fsf_-_@disp2133> <877dearzfo.fsf_-_@disp2133> Date: Mon, 18 Oct 2021 12:56:15 -0500 In-Reply-To: <877dearzfo.fsf_-_@disp2133> (Eric W. Biederman's message of "Mon, 18 Oct 2021 12:54:35 -0500") Message-ID: <87v91uqksg.fsf_-_@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1mcWs1-004B69-TT;;;mid=<87v91uqksg.fsf_-_@disp2133>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+x/oKEKjfMZ4oFtprE1q52ZoFCksH/iBo= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 2/4] ucounts: Remove unnecessary test for NULL ucount in get_ucounts X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: DA853F00039D X-Stat-Signature: mh37i1k9b63n9wrwuiw9x9ti1gmfh6yx Authentication-Results: imf17.hostedemail.com; dkim=none; spf=pass (imf17.hostedemail.com: domain of ebiederm@xmission.com designates 166.70.13.231 as permitted sender) smtp.mailfrom=ebiederm@xmission.com; dmarc=pass (policy=none) header.from=xmission.com X-HE-Tag: 1634579784-671267 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: All of the callers of get_ucounts are passeds a non-NULL value so stop handling a NULL ucounts pointer in get_ucounts. It is guaranteed that ever valid fully formed cred that is passed to commit_cred contains a non-NULL ucounts pointer. This in turn gurantees that current_ucounts() never returns NULL. The call of get_ucounts in user_shm_lock is always passed current_ucounts(). The call of get_ucounts in mqueue_get_inode is always passed current_ucounts(). The call of get_ucounts in inc_rlmit_get_ucounts is always passed iter, after iter has been verified to be non-NULL. The call of get_ucounts in key_change_session_keyring is always passed current_ucounts(). The call of get_ucounts in prepare_cred is always passed current_ucounts(). The call of get_ucounts in prepare_kernel_cred is always passed task->cred->ucounts or init_cred->ucounts which being on tasks are guaranteed to have a non-NULL ucounts field. Signed-off-by: "Eric W. Biederman" --- kernel/ucount.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/ucount.c b/kernel/ucount.c index eb03f3c68375..708d05164a7d 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -152,7 +152,7 @@ static void hlist_add_ucounts(struct ucounts *ucounts) struct ucounts *get_ucounts(struct ucounts *ucounts) { - if (ucounts && atomic_add_negative(1, &ucounts->count)) { + if (atomic_add_negative(1, &ucounts->count)) { put_ucounts(ucounts); ucounts = NULL; } -- 2.20.1