Waiman Long 9a5418bc48 sched/core: Use kfree_rcu() in do_set_cpus_allowed() ... Commit 851a723e45 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") may call kfree() if user_cpus_ptr was previously set. Unfortunately, some of the callers of do_set_cpus_allowed() may have pi_lock held when calling it. So the following splats may be printed especially when running with a PREEMPT_RT kernel: WARNING: possible circular locking dependency detected BUG: sleeping function called from invalid context To avoid these problems, kfree_rcu() is used instead. An internal cpumask_rcuhead union is created for the sole purpose of facilitating the use of kfree_rcu() to free the cpumask. Since user_cpus_ptr is not being used in non-SMP configs, the newly introduced alloc_user_cpus_ptr() helper will return NULL in this case and sched_setaffinity() is modified to handle this special case. Fixes: 851a723e45 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20221231041120.440785-3-longman@redhat.com		2023-01-09 11:43:23 +01:00
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Makefile	…
autogroup.c	…
autogroup.h	…
build_policy.c	…
build_utility.c	…
clock.c	…
completion.c	…
core.c	sched/core: Use kfree_rcu() in do_set_cpus_allowed()	2023-01-09 11:43:23 +01:00
core_sched.c	…
cpuacct.c	…
cpudeadline.c	…
cpudeadline.h	…
cpufreq.c	…
cpufreq_schedutil.c	…
cpupri.c	…
cpupri.h	…
cputime.c	…
deadline.c	…
debug.c	…
fair.c	…
features.h	…
idle.c	…
isolation.c	…
loadavg.c	…
membarrier.c	…
pelt.c	…
pelt.h	…
psi.c	…
rt.c	…
sched-pelt.h	…
sched.h	…
smp.h	…
stats.c	…
stats.h	…
stop_task.c	…
swait.c	…
topology.c	…
wait.c	…
wait_bit.c	…