Qais Yousef ab6e10de9d ANDROID: cgroup/cpuset: Fix suspicous RCU usage WARNING ... task_cs() is called from cpuset_cpus_allowed_fallback() without holding the read_rcu_lock() causing the below splat. Fix by holding the rcu_read_lock(). [ 0.090199] ============================= [ 0.090399] WARNING: suspicious RCU usage [ 0.090600] 5.10.19-00939-gc3bf09a68b63-dirty #368 Not tainted [ 0.090837] ----------------------------- [ 0.091000] include/linux/cgroup.h:494 suspicious rcu_dereference_check() usage! [ 0.091246] [ 0.091246] other info that might help us debug this: [ 0.091246] [ 0.091499] [ 0.091499] rcu_scheduler_active = 1, debug_locks = 1 [ 0.091738] 4 locks held by swapper/0/1: [ 0.091902] #0: ffff800014e3f510 (cpu_add_remove_lock){+.+.}-{3:3}, at: cpu_up+0x100/0x190 [ 0.092726] #1: ffff800014e3f6b0 (cpu_hotplug_lock){++++}-{0:0}, at: _cpu_up+0x4c/0x1c8 [ 0.093540] #2: ffff800014e47478 (smpboot_threads_lock){+.+.}-{3:3}, at: smpboot_create_threads+0x34/0xc0 [ 0.094399] #3: ffff0008001d0878 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x58/0x828 [ 0.095199] [ 0.095199] stack backtrace: [ 0.095425] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.19-00939-gc3bf09a68b63-dirty #368 [ 0.095670] Hardware name: Foundation-v8A (DT) [ 0.095834] Call trace: [ 0.096099] dump_backtrace+0x0/0x1a8 [ 0.096353] show_stack+0x18/0x68 [ 0.096571] dump_stack+0xf8/0x168 [ 0.096817] lockdep_rcu_suspicious+0xe4/0xf8 [ 0.097063] cpuset_cpus_allowed_fallback+0x184/0x1f8 [ 0.097299] select_fallback_rq+0x24c/0x2c0 [ 0.097526] try_to_wake_up+0x1e4/0x828 [ 0.097740] wake_up_process+0x18/0x28 [ 0.097999] kthread_park+0x74/0xc8 [ 0.098209] __smpboot_create_thread.part.0+0x90/0x168 [ 0.098486] smpboot_create_threads+0x84/0xc0 [ 0.098699] cpuhp_invoke_callback+0xe8/0xe50 [ 0.098947] _cpu_up+0xe0/0x1c8 [ 0.099126] cpu_up+0x120/0x190 [ 0.099399] bringup_nonboot_cpus+0x94/0xd0 [ 0.099659] smp_init+0x30/0x8c [ 0.099873] kernel_init_freeable+0x1d4/0x328 [ 0.100099] kernel_init+0x14/0x118 [ 0.100339] ret_from_fork+0x10/0x34 Bug: 178507149 Fixes: 210463b39c ("FROMLIST: cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1") Signed-off-by: Qais Yousef <qais.yousef@arm.com> Change-Id: Ib7688e7d0c37cbf119d806ce79157a467b9e35f6		2021-03-03 09:02:19 +00:00
..
cgroup-internal.h	fs_parse: fold fs_parameter_desc/fs_parameter_spec	2020-02-07 14:48:37 -05:00
cgroup-v1.c	Merge 5.10.17 into android12-5.10	2021-02-18 11:21:01 +01:00
cgroup.c	Merge 5.10.17 into android12-5.10	2021-02-18 11:21:01 +01:00
cpuset.c	ANDROID: cgroup/cpuset: Fix suspicous RCU usage WARNING	2021-03-03 09:02:19 +00:00
debug.c	kernel: cgroup: fix misuse of %x	2019-05-06 08:47:48 -07:00
freezer.c	cgroup: freezer: don't change task and cgroups status unnecessarily	2019-11-07 07:38:41 -08:00
legacy_freezer.c	cgroup: rename freezer.c into legacy_freezer.c	2019-04-19 11:26:48 -07:00
Makefile	cgroup: cgroup v2 freezer	2019-04-19 11:26:48 -07:00
namespace.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
pids.c	clone3: allow spawning processes into cgroups	2020-02-12 17:57:51 -05:00
rdma.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 451	2019-06-19 17:09:08 +02:00
rstat.c	cgroup: unexport cgroup_rstat_updated	2020-06-29 09:09:08 -06:00