Date: Tue, 15 Dec 2020 21:53:15 +0000 (UTC) From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r368681 - stable/12/sys/kern Message-ID: <202012152153.0BFLrFnj053127@repo.freebsd.org>
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Author: kevans Date: Tue Dec 15 21:53:15 2020 New Revision: 368681 URL: https://svnweb.freebsd.org/changeset/base/368681 Log: MFC r368462: cpuset_set{affinity,domain}: do not allow empty masks cpuset_modify() would not currently catch this, because it only checks that the new mask is a subset of the root set and circumvents the EDEADLK check in cpuset_testupdate(). This change both directly validates the mask coming in since we can trivially detect an empty mask, and it updates cpuset_testupdate to catch stuff like this going forward by always ensuring we don't end up with an empty mask. The check_mask argument has been renamed because the 'check' verbiage does not imply to me that it's actually doing a different operation. We're either augmenting the existing mask, or we are replacing it entirely. Modified: stable/12/sys/kern/kern_cpuset.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/kern/kern_cpuset.c ============================================================================== --- stable/12/sys/kern/kern_cpuset.c Tue Dec 15 21:52:31 2020 (r368680) +++ stable/12/sys/kern/kern_cpuset.c Tue Dec 15 21:53:15 2020 (r368681) @@ -633,7 +633,7 @@ domainset_shadow(const struct domainset *pdomain, * empty as well as RDONLY flags. */ static int -cpuset_testupdate(struct cpuset *set, cpuset_t *mask, int check_mask) +cpuset_testupdate(struct cpuset *set, cpuset_t *mask, int augment_mask) { struct cpuset *nset; cpuset_t newmask; @@ -642,13 +642,14 @@ cpuset_testupdate(struct cpuset *set, cpuset_t *mask, mtx_assert(&cpuset_lock, MA_OWNED); if (set->cs_flags & CPU_SET_RDONLY) return (EPERM); - if (check_mask) { - if (!CPU_OVERLAP(&set->cs_mask, mask)) - return (EDEADLK); + if (augment_mask) { CPU_COPY(&set->cs_mask, &newmask); CPU_AND(&newmask, mask); } else CPU_COPY(mask, &newmask); + + if (CPU_EMPTY(&newmask)) + return (EDEADLK); error = 0; LIST_FOREACH(nset, &set->cs_children, cs_siblings) if ((error = cpuset_testupdate(nset, &newmask, 1)) != 0) @@ -723,7 +724,7 @@ out: */ static int cpuset_testupdate_domain(struct cpuset *set, struct domainset *dset, - struct domainset *orig, int *count, int check_mask) + struct domainset *orig, int *count, int augment_mask __unused) { struct cpuset *nset; struct domainset *domain; @@ -1923,6 +1924,10 @@ kern_cpuset_setaffinity(struct thread *td, cpulevel_t } } + if (CPU_EMPTY(mask)) { + error = EDEADLK; + goto out; + } switch (level) { case CPU_LEVEL_ROOT: case CPU_LEVEL_CPUSET: @@ -2177,6 +2182,10 @@ kern_cpuset_setdomain(struct thread *td, cpulevel_t le goto out; } + } + if (DOMAINSET_EMPTY(mask)) { + error = EDEADLK; + goto out; } DOMAINSET_COPY(mask, &domain.ds_mask); domain.ds_policy = policy;
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