Date: Mon, 10 May 2021 13:49:31 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 44d26e9e781f - stable/13 - smp: Initialize arg->cpus sooner in smp_rendezvous_cpus_retry() Message-ID: <202105101349.14ADnV1C026451@gitrepo.freebsd.org>
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The branch stable/13 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=44d26e9e781fdf47fe0e1e6c987d519a751b14fa commit 44d26e9e781fdf47fe0e1e6c987d519a751b14fa Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2021-05-03 16:43:00 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2021-05-10 13:35:53 +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 Sponsored by: The FreeBSD Foundation (cherry picked from commit cdfcfc607acc10c8b1b2b6a427c9e1ed7e94ebb3) --- 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,
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