From 4cdb91b0dea7d7f59fa84a13c7753cd434fdedcf Mon Sep 17 00:00:00 2001 From: Kamalesh Babulal Date: Fri, 3 Mar 2023 15:23:10 +0530 Subject: cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers Replace mutex_[un]lock() with cgroup_[un]lock() wrappers to stay consistent across cgroup core and other subsystem code, while operating on the cgroup_mutex. Signed-off-by: Kamalesh Babulal Acked-by: Alexei Starovoitov Reviewed-by: Christian Brauner Signed-off-by: Tejun Heo --- kernel/cgroup/cgroup-v1.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel/cgroup/cgroup-v1.c') diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 52bb5a74a23b..aeef06c465ef 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -58,7 +58,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) struct cgroup_root *root; int retval = 0; - mutex_lock(&cgroup_mutex); + cgroup_lock(); cgroup_attach_lock(true); for_each_root(root) { struct cgroup *from_cgrp; @@ -72,7 +72,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) break; } cgroup_attach_unlock(true); - mutex_unlock(&cgroup_mutex); + cgroup_unlock(); return retval; } @@ -106,7 +106,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) if (ret) return ret; - mutex_lock(&cgroup_mutex); + cgroup_lock(); percpu_down_write(&cgroup_threadgroup_rwsem); @@ -145,7 +145,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) out_err: cgroup_migrate_finish(&mgctx); percpu_up_write(&cgroup_threadgroup_rwsem); - mutex_unlock(&cgroup_mutex); + cgroup_unlock(); return ret; } @@ -847,13 +847,13 @@ static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent kernfs_break_active_protection(new_parent); kernfs_break_active_protection(kn); - mutex_lock(&cgroup_mutex); + cgroup_lock(); ret = kernfs_rename(kn, new_parent, new_name_str); if (!ret) TRACE_CGROUP_PATH(rename, cgrp); - mutex_unlock(&cgroup_mutex); + cgroup_unlock(); kernfs_unbreak_active_protection(kn); kernfs_unbreak_active_protection(new_parent); @@ -1119,7 +1119,7 @@ int cgroup1_reconfigure(struct fs_context *fc) trace_cgroup_remount(root); out_unlock: - mutex_unlock(&cgroup_mutex); + cgroup_unlock(); return ret; } @@ -1246,7 +1246,7 @@ int cgroup1_get_tree(struct fs_context *fc) if (!ret && !percpu_ref_tryget_live(&ctx->root->cgrp.self.refcnt)) ret = 1; /* restart */ - mutex_unlock(&cgroup_mutex); + cgroup_unlock(); if (!ret) ret = cgroup_do_get_tree(fc); -- cgit From ab1de7ead871ebe6d12a774c3c25de0388cde082 Mon Sep 17 00:00:00 2001 From: Qi Zheng Date: Wed, 17 May 2023 07:45:45 +0000 Subject: cgroup: fix missing cpus_read_{lock,unlock}() in cgroup_transfer_tasks() The commit 4f7e7236435c ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock") fixed the deadlock between cgroup_threadgroup_rwsem and cpus_read_lock() by introducing cgroup_attach_{lock,unlock}() and removing cpus_read_{lock,unlock}() from cpuset_attach(). But cgroup_transfer_tasks() was missed and not handled, which will cause th following warning: WARNING: CPU: 0 PID: 589 at kernel/cpu.c:526 lockdep_assert_cpus_held+0x32/0x40 CPU: 0 PID: 589 Comm: kworker/1:4 Not tainted 6.4.0-rc2-next-20230517 #50 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: events cpuset_hotplug_workfn RIP: 0010:lockdep_assert_cpus_held+0x32/0x40 <...> Call Trace: cpuset_attach+0x40/0x240 cgroup_migrate_execute+0x452/0x5e0 ? _raw_spin_unlock_irq+0x28/0x40 cgroup_transfer_tasks+0x1f3/0x360 ? find_held_lock+0x32/0x90 ? cpuset_hotplug_workfn+0xc81/0xed0 cpuset_hotplug_workfn+0xcb1/0xed0 ? process_one_work+0x248/0x5b0 process_one_work+0x2b9/0x5b0 worker_thread+0x56/0x3b0 ? process_one_work+0x5b0/0x5b0 kthread+0xf1/0x120 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 So just use the cgroup_attach_{lock,unlock}() helper to fix it. Reported-by: Zhao Gongyi Signed-off-by: Qi Zheng Acked-by: Muchun Song Fixes: 05c7b7a92cc8 ("cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug") Cc: stable@vger.kernel.org # v5.17+ Signed-off-by: Tejun Heo --- kernel/cgroup/cgroup-v1.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/cgroup/cgroup-v1.c') diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index aeef06c465ef..5407241dbb45 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -108,7 +108,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) cgroup_lock(); - percpu_down_write(&cgroup_threadgroup_rwsem); + cgroup_attach_lock(true); /* all tasks in @from are being moved, all csets are source */ spin_lock_irq(&css_set_lock); @@ -144,7 +144,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) } while (task && !ret); out_err: cgroup_migrate_finish(&mgctx); - percpu_up_write(&cgroup_threadgroup_rwsem); + cgroup_attach_unlock(true); cgroup_unlock(); return ret; } -- cgit