From: Zefan Li Date: Tue, 9 Aug 2016 03:25:01 +0000 (+0800) Subject: cpuset: make sure new tasks conform to the current config of the cpuset X-Git-Tag: firefly_0821_release~176^2~4^2~28^2~73 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=06ec7a1d7646;p=firefly-linux-kernel-4.4.55.git cpuset: make sure new tasks conform to the current config of the cpuset commit 06f4e94898918bcad00cdd4d349313a439d6911e upstream. A new task inherits cpus_allowed and mems_allowed masks from its parent, but if someone changes cpuset's config by writing to cpuset.cpus/cpuset.mems before this new task is inserted into the cgroup's task list, the new task won't be updated accordingly. Signed-off-by: Zefan Li Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 11eaf14b52c2..e120bd983ad0 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2074,6 +2074,20 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css) mutex_unlock(&cpuset_mutex); } +/* + * Make sure the new task conform to the current state of its parent, + * which could have been changed by cpuset just after it inherits the + * state from the parent and before it sits on the cgroup's task list. + */ +void cpuset_fork(struct task_struct *task) +{ + if (task_css_is_root(task, cpuset_cgrp_id)) + return; + + set_cpus_allowed_ptr(task, ¤t->cpus_allowed); + task->mems_allowed = current->mems_allowed; +} + struct cgroup_subsys cpuset_cgrp_subsys = { .css_alloc = cpuset_css_alloc, .css_online = cpuset_css_online, @@ -2084,6 +2098,7 @@ struct cgroup_subsys cpuset_cgrp_subsys = { .attach = cpuset_attach, .post_attach = cpuset_post_attach, .bind = cpuset_bind, + .fork = cpuset_fork, .legacy_cftypes = files, .early_init = 1, };