From: Will Deacon <will@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Marc Zyngier <maz@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Peter Zijlstra <peterz@infradead.org>, Morten Rasmussen <morten.rasmussen@arm.com>, Qais Yousef <qais.yousef@arm.com>, Suren Baghdasaryan <surenb@google.com>, Quentin Perret <qperret@google.com>, Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>, Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@redhat.com>, Vincent Guittot <vincent.guittot@linaro.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, Dietmar Eggemann <dietmar.eggemann@arm.com>, Daniel Bristot de Oliveira <bristot@redhat.com>, Valentin Schneider <valentin.schneider@arm.com>, Mark Rutland <mark.rutland@arm.com>, kernel-team@android.com, Valentin Schneider <Valentin.Schneider@arm.com> Subject: [PATCH v11 05/16] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Date: Fri, 30 Jul 2021 12:24:32 +0100 [thread overview] Message-ID: <20210730112443.23245-6-will@kernel.org> (raw) In-Reply-To: <20210730112443.23245-1-will@kernel.org> Reject explicit requests to change the affinity mask of a task via set_cpus_allowed_ptr() if the requested mask is not a subset of the mask returned by task_cpu_possible_mask(). This ensures that the 'cpus_mask' for a given task cannot contain CPUs which are incapable of executing it, except in cases where the affinity is forced. Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Reviewed-by: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> --- kernel/sched/core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9fd598b8dac5..dbce9cd83a53 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2700,15 +2700,17 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, u32 flags) { const struct cpumask *cpu_valid_mask = cpu_active_mask; + const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p); unsigned int dest_cpu; struct rq_flags rf; struct rq *rq; int ret = 0; + bool kthread = p->flags & PF_KTHREAD; rq = task_rq_lock(p, &rf); update_rq_clock(rq); - if (p->flags & PF_KTHREAD || is_migration_disabled(p)) { + if (kthread || is_migration_disabled(p)) { /* * Kernel threads are allowed on online && !active CPUs, * however, during cpu-hot-unplug, even these might get pushed @@ -2722,6 +2724,11 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, cpu_valid_mask = cpu_online_mask; } + if (!kthread && !cpumask_subset(new_mask, cpu_allowed_mask)) { + ret = -EINVAL; + goto out; + } + /* * Must re-check here, to close a race against __kthread_bind(), * sched_setaffinity() is not guaranteed to observe the flag. -- 2.32.0.402.g57bb445576-goog
WARNING: multiple messages have this Message-ID
From: Will Deacon <will@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Marc Zyngier <maz@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Peter Zijlstra <peterz@infradead.org>, Morten Rasmussen <morten.rasmussen@arm.com>, Qais Yousef <qais.yousef@arm.com>, Suren Baghdasaryan <surenb@google.com>, Quentin Perret <qperret@google.com>, Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>, Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@redhat.com>, Vincent Guittot <vincent.guittot@linaro.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, Dietmar Eggemann <dietmar.eggemann@arm.com>, Daniel Bristot de Oliveira <bristot@redhat.com>, Valentin Schneider <valentin.schneider@arm.com>, Mark Rutland <mark.rutland@arm.com>, kernel-team@android.com, Valentin Schneider <Valentin.Schneider@arm.com> Subject: [PATCH v11 05/16] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Date: Fri, 30 Jul 2021 12:24:32 +0100 [thread overview] Message-ID: <20210730112443.23245-6-will@kernel.org> (raw) In-Reply-To: <20210730112443.23245-1-will@kernel.org> Reject explicit requests to change the affinity mask of a task via set_cpus_allowed_ptr() if the requested mask is not a subset of the mask returned by task_cpu_possible_mask(). This ensures that the 'cpus_mask' for a given task cannot contain CPUs which are incapable of executing it, except in cases where the affinity is forced. Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com> Reviewed-by: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> --- kernel/sched/core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9fd598b8dac5..dbce9cd83a53 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2700,15 +2700,17 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, u32 flags) { const struct cpumask *cpu_valid_mask = cpu_active_mask; + const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p); unsigned int dest_cpu; struct rq_flags rf; struct rq *rq; int ret = 0; + bool kthread = p->flags & PF_KTHREAD; rq = task_rq_lock(p, &rf); update_rq_clock(rq); - if (p->flags & PF_KTHREAD || is_migration_disabled(p)) { + if (kthread || is_migration_disabled(p)) { /* * Kernel threads are allowed on online && !active CPUs, * however, during cpu-hot-unplug, even these might get pushed @@ -2722,6 +2724,11 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, cpu_valid_mask = cpu_online_mask; } + if (!kthread && !cpumask_subset(new_mask, cpu_allowed_mask)) { + ret = -EINVAL; + goto out; + } + /* * Must re-check here, to close a race against __kthread_bind(), * sched_setaffinity() is not guaranteed to observe the flag. -- 2.32.0.402.g57bb445576-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-07-30 11:25 UTC|newest] Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-30 11:24 [PATCH v11 00/16] Add support for 32-bit tasks on asymmetric AArch32 systems Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-07-30 11:24 ` [PATCH v11 01/16] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 02/16] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 03/16] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 04/16] cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq() Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` Will Deacon [this message] 2021-07-30 11:24 ` [PATCH v11 05/16] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 06/16] sched: Introduce task_struct::user_cpus_ptr to track requested affinity Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 07/16] sched: Split the guts of sched_setaffinity() into a helper function Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-17 15:40 ` Peter Zijlstra 2021-08-17 15:40 ` Peter Zijlstra 2021-08-18 10:50 ` Will Deacon 2021-08-18 10:50 ` Will Deacon 2021-08-18 10:56 ` Peter Zijlstra 2021-08-18 10:56 ` Peter Zijlstra 2021-08-18 11:11 ` Will Deacon 2021-08-18 11:11 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 08/16] sched: Allow task CPU affinity to be restricted on asymmetric systems Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-17 15:10 ` Peter Zijlstra 2021-08-17 15:10 ` Peter Zijlstra 2021-08-18 10:42 ` Will Deacon 2021-08-18 10:42 ` Will Deacon 2021-08-18 10:56 ` Peter Zijlstra 2021-08-18 10:56 ` Peter Zijlstra 2021-08-18 11:53 ` Peter Zijlstra 2021-08-18 11:53 ` Peter Zijlstra 2021-08-18 12:19 ` Will Deacon 2021-08-18 12:19 ` Will Deacon 2021-08-18 11:06 ` Peter Zijlstra 2021-08-18 11:06 ` Peter Zijlstra 2021-08-17 15:41 ` Peter Zijlstra 2021-08-17 15:41 ` Peter Zijlstra 2021-08-18 10:43 ` Will Deacon 2021-08-18 10:43 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 09/16] sched: Introduce dl_task_check_affinity() to check proposed affinity Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon 2021-07-30 11:24 ` [PATCH v11 10/16] arm64: Implement task_cpu_possible_mask() Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-07-30 11:24 ` [PATCH v11 11/16] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-07-30 11:24 ` [PATCH v11 12/16] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-07-30 11:24 ` [PATCH v11 13/16] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-07-30 11:24 ` [PATCH v11 14/16] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-07-30 11:24 ` [PATCH v11 15/16] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon 2021-07-30 11:24 ` Will Deacon 2021-07-30 11:24 ` [PATCH v11 16/16] Documentation: arm64: describe asymmetric 32-bit support Will Deacon 2021-07-30 11:24 ` Will Deacon
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