From owner-dev-commits-src-all@freebsd.org Mon May 3 17:55:39 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 3DD2E638F85; Mon, 3 May 2021 17:55:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FYrHH0xDKz3JpC; Mon, 3 May 2021 17:55:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 12B5E224E5; Mon, 3 May 2021 17:55:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 143Htduj046796; Mon, 3 May 2021 17:55:39 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 143HtdH4046795; Mon, 3 May 2021 17:55:39 GMT (envelope-from git) Date: Mon, 3 May 2021 17:55:39 GMT Message-Id: <202105031755.143HtdH4046795@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: cdfcfc607acc - main - smp: Initialize arg->cpus sooner in smp_rendezvous_cpus_retry() MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: cdfcfc607acc10c8b1b2b6a427c9e1ed7e94ebb3 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 May 2021 17:55:39 -0000 The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=cdfcfc607acc10c8b1b2b6a427c9e1ed7e94ebb3 commit cdfcfc607acc10c8b1b2b6a427c9e1ed7e94ebb3 Author: Mark Johnston AuthorDate: 2021-05-03 16:43:00 +0000 Commit: Mark Johnston CommitDate: 2021-05-03 17:24:30 +0000 smp: Initialize arg->cpus sooner in smp_rendezvous_cpus_retry() Otherwise, if !smp_started is true, then smp_rendezvous_cpus_done() will harmlessly perform an atomic RMW on an uninitialized variable. Reported by: KMSAN MFC after: 1 week Sponsored by: The FreeBSD Foundation --- sys/kern/subr_smp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/sys/kern/subr_smp.c b/sys/kern/subr_smp.c index 093622d8f6aa..d4f8aac9e751 100644 --- a/sys/kern/subr_smp.c +++ b/sys/kern/subr_smp.c @@ -895,6 +895,8 @@ smp_rendezvous_cpus_retry(cpuset_t map, { int cpu; + CPU_COPY(&map, &arg->cpus); + /* * Only one CPU to execute on. */ @@ -914,7 +916,6 @@ smp_rendezvous_cpus_retry(cpuset_t map, * Execute an action on all specified CPUs while retrying until they * all acknowledge completion. */ - CPU_COPY(&map, &arg->cpus); for (;;) { smp_rendezvous_cpus( arg->cpus,