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: v4.1.33~29 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=24628b51d97ff55e9a39ed87ea631af29604112f;p=linux cpuset: make sure new tasks conform to the current config of the cpuset [ Upstream commit 06f4e94898918bcad00cdd4d349313a439d6911e ] 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 Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin --- diff --git a/kernel/cpuset.c b/kernel/cpuset.c index f0acff0f66c9..388fc6f78c6f 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2042,6 +2042,20 @@ 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, @@ -2051,6 +2065,7 @@ struct cgroup_subsys cpuset_cgrp_subsys = { .cancel_attach = cpuset_cancel_attach, .attach = cpuset_attach, .bind = cpuset_bind, + .fork = cpuset_fork, .legacy_cftypes = files, .early_init = 1, };