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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
	linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Carsten Emde <C.Emde@osadl.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	John Kacur <jkacur@redhat.com>, Julia Cartwright <julia@ni.com>,
	Daniel Wagner <wagi@monom.org>, Tom Zanussi <zanussi@kernel.org>,
	Scott Wood <swood@redhat.com>
Subject: [PATCH RT 16/32] sched: migrate disable: Protect cpus_ptr with lock
Date: Fri, 17 Jan 2020 12:41:27 -0500	[thread overview]
Message-ID: <20200117174129.785425698@goodmis.org> (raw)
In-Reply-To: 20200117174111.282847363@goodmis.org

4.19.94-rt39-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Scott Wood <swood@redhat.com>

[ Upstream commit 27ee52a891ed2c7e2e2c8332ccae0de7c2674b09 ]

Various places assume that cpus_ptr is protected by rq/pi locks,
so don't change it before grabbing those locks.

Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/sched/core.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a29f33e776d0..d9a3f88508ee 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7250,9 +7250,8 @@ migrate_disable_update_cpus_allowed(struct task_struct *p)
 	struct rq *rq;
 	struct rq_flags rf;
 
-	p->cpus_ptr = cpumask_of(smp_processor_id());
-
 	rq = task_rq_lock(p, &rf);
+	p->cpus_ptr = cpumask_of(smp_processor_id());
 	update_nr_migratory(p, -1);
 	p->nr_cpus_allowed = 1;
 	task_rq_unlock(rq, p, &rf);
@@ -7264,9 +7263,8 @@ migrate_enable_update_cpus_allowed(struct task_struct *p)
 	struct rq *rq;
 	struct rq_flags rf;
 
-	p->cpus_ptr = &p->cpus_mask;
-
 	rq = task_rq_lock(p, &rf);
+	p->cpus_ptr = &p->cpus_mask;
 	p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask);
 	update_nr_migratory(p, 1);
 	task_rq_unlock(rq, p, &rf);
-- 
2.24.1



  parent reply	other threads:[~2020-01-17 17:41 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-17 17:41 [PATCH RT 00/32] Linux 4.19.94-rt39-rc1 Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 01/32] i2c: exynos5: Remove IRQF_ONESHOT Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 02/32] i2c: hix5hd2: " Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 03/32] sched/deadline: Ensure inactive_timer runs in hardirq context Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 04/32] thermal/x86_pkg_temp: make pkg_temp_lock a raw spinlock Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 05/32] dma-buf: Use seqlock_t instread disabling preemption Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 06/32] KVM: arm/arm64: Let the timer expire in hardirq context on RT Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 07/32] x86: preempt: Check preemption level before looking at lazy-preempt Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 08/32] hrtimer: Use READ_ONCE to access timer->base in hrimer_grab_expiry_lock() Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 09/32] hrtimer: Dont grab the expiry lock for non-soft hrtimer Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 10/32] hrtimer: Prevent using hrtimer_grab_expiry_lock() on migration_base Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 11/32] hrtimer: Add a missing bracket and hide `migration_base on !SMP Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 12/32] posix-timers: Unlock expiry lock in the early return Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 14/32] sched: __set_cpus_allowed_ptr: Check cpus_mask, not cpus_ptr Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 15/32] sched: Remove dead __migrate_disabled() check Steven Rostedt
2020-01-17 17:41 ` Steven Rostedt [this message]
2020-01-17 17:41 ` [PATCH RT 17/32] lib/smp_processor_id: Dont use cpumask_equal() Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 18/32] futex: Make the futex_hash_bucket spinlock_t again and bring back its old state Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 19/32] locking/rtmutex: Clean ->pi_blocked_on in the error case Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 20/32] lib/ubsan: Dont seralize UBSAN report Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 21/32] kmemleak: Change the lock of kmemleak_object to raw_spinlock_t Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 22/32] sched: migrate_enable: Use select_fallback_rq() Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 23/32] sched: Lazy migrate_disable processing Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 24/32] sched: migrate_enable: Use stop_one_cpu_nowait() Steven Rostedt
2020-01-22  8:31   ` Sebastian Andrzej Siewior
2020-01-22 11:33     ` Steven Rostedt
2020-01-22 18:39       ` Scott Wood
2020-01-22 19:07         ` Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 25/32] Revert "cpufreq: drop K8s driver from beeing selected" Steven Rostedt
2020-01-22  8:38   ` Sebastian Andrzej Siewior
2020-01-22 11:34     ` Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 26/32] Revert "ARM: Initialize split page table locks for vector page" Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 28/32] locking: Make spinlock_t and rwlock_t a RCU section on RT Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 29/32] sched/core: migrate_enable() must access takedown_cpu_task on !HOTPLUG_CPU Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 30/32] lib/smp_processor_id: Adjust check_preemption_disabled() Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 31/32] sched: migrate_enable: Busy loop until the migration request is completed Steven Rostedt
2020-01-17 17:41 ` [PATCH RT 32/32] Linux 4.19.94-rt39-rc1 Steven Rostedt
     [not found] ` <20200117174131.455165326@goodmis.org>
2020-01-22  8:43   ` [PATCH RT 27/32] x86/fpu: Dont cache access to fpu_fpregs_owner_ctx Sebastian Andrzej Siewior
2020-01-22 11:34     ` Steven Rostedt

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