user/sven/linux.git/kernel/cgroup, branch v6.0.10

cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset

2022-10-21T10:38:59Z

[ Upstream commit ec5fbdfb99d18482619ac42605cb80fbb56068ee ] Previously, update_tasks_cpumask() is not supposed to be called with top cpuset. With cpuset partition that takes CPUs away from the top cpuset, adjusting the cpus_mask of the tasks in the top cpuset is necessary. Percpu kthreads, however, are ignored. Fixes: ee8dde0cd2ce ("cpuset: Add new v2 cpuset.sched.partition flag") Signed-off-by: Waiman Long Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin

cgroup: Honor caller's cgroup NS when resolving path

2022-10-21T10:38:58Z

[ Upstream commit 74e4b956eb1cac0e4c10c240339b1bbfbc9a4c48 ] cgroup_get_from_path() is not widely used function. Its callers presume the path is resolved under cgroup namespace. (There is one caller currently and resolving in init NS won't make harm (netfilter). However, future users may be subject to different effects when resolving globally.) Since, there's currently no use for the global resolution, modify the existing function to take cgroup NS into account. Fixes: a79a908fd2b0 ("cgroup: introduce cgroup namespaces") Signed-off-by: Michal Koutný Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin

cgroup: cgroup_get_from_id() must check the looked-up kn is a directory

2022-09-23T17:18:45Z

cgroup has to be one kernfs dir, otherwise kernel panic is caused, especially cgroup id is provide from userspace. Reported-by: Marco Patalano Fixes: 6b658c4863c1 ("scsi: cgroup: Add cgroup_get_from_id()") Cc: Muneendra Signed-off-by: Ming Lei Acked-by: Mukesh Ojha Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Tejun Heo

cgroup: Add missing cpus_read_lock() to cgroup_attach_task_all()

2022-08-25T17:36:30Z

syzbot is hitting percpu_rwsem_assert_held(&cpu_hotplug_lock) warning at cpuset_attach() [1], for commit 4f7e7236435ca0ab ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock") missed that cpuset_attach() is also called from cgroup_attach_task_all(). Add cpus_read_lock() like what cgroup_procs_write_start() does. Link: https://syzkaller.appspot.com/bug?extid=29d3a3b4d86c8136ad9e [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Fixes: 4f7e7236435ca0ab ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock") Signed-off-by: Tejun Heo

cgroup: Fix race condition at rebind_subsystems()

2022-08-23T18:11:06Z

Root cause: The rebind_subsystems() is no lock held when move css object from A list to B list,then let B's head be treated as css node at list_for_each_entry_rcu(). Solution: Add grace period before invalidating the removed rstat_css_node. Reported-by: Jing-Ting Wu Suggested-by: Michal Koutný Signed-off-by: Jing-Ting Wu Tested-by: Jing-Ting Wu Link: https://lore.kernel.org/linux-arm-kernel/d8f0bc5e2fb6ed259f9334c83279b4c011283c41.camel@mediatek.com/T/ Acked-by: Mukesh Ojha Fixes: a7df69b81aac ("cgroup: rstat: support cgroup1") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Tejun Heo

cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock

2022-08-17T17:36:05Z

Bringing up a CPU may involve creating and destroying tasks which requires read-locking threadgroup_rwsem, so threadgroup_rwsem nests inside cpus_read_lock(). However, cpuset's ->attach(), which may be called with thredagroup_rwsem write-locked, also wants to disable CPU hotplug and acquires cpus_read_lock(), leading to a deadlock. Fix it by guaranteeing that ->attach() is always called with CPU hotplug disabled and removing cpus_read_lock() call from cpuset_attach(). Signed-off-by: Tejun Heo Reviewed-and-tested-by: Imran Khan Reported-and-tested-by: Xuewen Yan Fixes: 05c7b7a92cc8 ("cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug") Cc: stable@vger.kernel.org # v5.17+

sched/psi: Remove unused parameter nbytes of psi_trigger_create()

2022-08-15T22:35:25Z

psi_trigger_create()'s 'nbytes' parameter is not used, so we can remove it. Signed-off-by: Hao Jia Reviewed-by: Ingo Molnar Acked-by: Johannes Weiner Signed-off-by: Tejun Heo

Merge tag 'sched-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-08-07T00:34:06Z

Pull scheduler fixes from Ingo Molnar: "Various fixes: a deadline scheduler fix, a migration fix, a Sparse fix and a comment fix" * tag 'sched-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Do not requeue task on CPU excluded from cpus_mask sched/rt: Fix Sparse warnings due to undefined rt.c declarations exit: Fix typo in comment: s/sub-theads/sub-threads sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed

Merge tag 'cgroup-for-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2022-08-03T16:45:08Z

Pull cgroup updates from Tejun Heo: "Several core optimizations: - threadgroup_rwsem write locking is skipped when configuring controllers in empty subtrees. Combined with CLONE_INTO_CGROUP, this allows the common static usage pattern to not grab threadgroup_rwsem at all (glibc still doesn't seem ready for CLONE_INTO_CGROUP unfortunately). - threadgroup_rwsem used to be put into non-percpu mode by default due to latency concerns in specific use cases. There's no reason for everyone else to pay for it. Make the behavior optional. - psi no longer allocates memory when disabled. ... along with some code cleanups" * tag 'cgroup-for-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: Skip subtree root in cgroup_update_dfl_csses() cgroup: remove "no" prefixed mount options cgroup: Make !percpu threadgroup_rwsem operations optional cgroup: Add "no" prefixed mount options cgroup: Elide write-locking threadgroup_rwsem when updating csses on an empty subtree cgroup.c: remove redundant check for mixable cgroup in cgroup_migrate_vet_dst cgroup.c: add helper __cset_cgroup_from_root to cleanup duplicated codes psi: dont alloc memory for psi by default

sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed

2022-08-03T08:34:26Z

With cgroup v2, the cpuset's cpus_allowed mask can be empty indicating that the cpuset will just use the effective CPUs of its parent. So cpuset_can_attach() can call task_can_attach() with an empty mask. This can lead to cpumask_any_and() returns nr_cpu_ids causing the call to dl_bw_of() to crash due to percpu value access of an out of bound CPU value. For example: [80468.182258] BUG: unable to handle page fault for address: ffffffff8b6648b0 : [80468.191019] RIP: 0010:dl_cpu_busy+0x30/0x2b0 : [80468.207946] Call Trace: [80468.208947] cpuset_can_attach+0xa0/0x140 [80468.209953] cgroup_migrate_execute+0x8c/0x490 [80468.210931] cgroup_update_dfl_csses+0x254/0x270 [80468.211898] cgroup_subtree_control_write+0x322/0x400 [80468.212854] kernfs_fop_write_iter+0x11c/0x1b0 [80468.213777] new_sync_write+0x11f/0x1b0 [80468.214689] vfs_write+0x1eb/0x280 [80468.215592] ksys_write+0x5f/0xe0 [80468.216463] do_syscall_64+0x5c/0x80 [80468.224287] entry_SYSCALL_64_after_hwframe+0x44/0xae Fix that by using effective_cpus instead. For cgroup v1, effective_cpus is the same as cpus_allowed. For v2, effective_cpus is the real cpumask to be used by tasks within the cpuset anyway. Also update task_can_attach()'s 2nd argument name to cs_effective_cpus to reflect the change. In addition, a check is added to task_can_attach() to guard against the possibility that cpumask_any_and() may return a value >= nr_cpu_ids. Fixes: 7f51412a415d ("sched/deadline: Fix bandwidth check/update when migrating tasks between exclusive cpusets") Signed-off-by: Waiman Long Signed-off-by: Ingo Molnar Acked-by: Juri Lelli Link: https://lore.kernel.org/r/20220803015451.2219567-1-longman@redhat.com