[PATCH v4 11/14] sched: Reject CPU affinity changes based on arch_task_cpu_possible_mask()
From: Will Deacon <will@kernel.org>
Date: 2020-11-24 15:51:44
Also in:
linux-arch, lkml
Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
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 arch_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. Signed-off-by: Will Deacon <will@kernel.org> --- kernel/sched/core.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 99992d0beb65..095deda50643 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c@@ -1877,6 +1877,7 @@ static int __set_cpus_allowed_ptr_locked(struct task_struct *p, struct rq_flags *rf) { const struct cpumask *cpu_valid_mask = cpu_active_mask; + const struct cpumask *cpu_allowed_mask = arch_task_cpu_possible_mask(p); unsigned int dest_cpu; int ret = 0;
@@ -1887,6 +1888,9 @@ static int __set_cpus_allowed_ptr_locked(struct task_struct *p, * Kernel threads are allowed on online && !active CPUs */ cpu_valid_mask = cpu_online_mask; + } else if (!cpumask_subset(new_mask, cpu_allowed_mask)) { + ret = -EINVAL; + goto out; } /*
--
2.29.2.454.gaff20da3a2-goog
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