33e83ffe4c
- Plug a race between pick_next_task_fair() and try_to_wake_up() where
both try to write to the same task, even though both paths hold a
runqueue lock, but obviously from different runqueues.
The problem is that the store to task::on_rq in __block_task() is
visible to try_to_wake_up() which assumes that the task is not queued.
Both sides then operate on the same task.
Cure it by rearranging __block_task() so the the store to task::on_rq is
the last operation on the task.
- Prevent a potential NULL pointer dereference in task_numa_work()
task_numa_work() iterates the VMAs of a process. A concurrent unmap of
the address space can result in a NULL pointer return from vma_next()
which is unchecked.
Add the missing NULL pointer check to prevent this.
- Operate on the correct scheduler policy in task_should_scx()
task_should_scx() returns true when a task should be handled by sched
EXT. It checks the tasks scheduling policy.
This fails when the check is done before a policy has been set.
Cure it by handing the policy into task_should_scx() so it operates
on the requested value.
- Add the missing handling of sched EXT in the delayed dequeue
mechanism. This was simply forgotten.
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Merge tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
- Plug a race between pick_next_task_fair() and try_to_wake_up() where
both try to write to the same task, even though both paths hold a
runqueue lock, but obviously from different runqueues.
The problem is that the store to task::on_rq in __block_task() is
visible to try_to_wake_up() which assumes that the task is not
queued. Both sides then operate on the same task.
Cure it by rearranging __block_task() so the the store to task::on_rq
is the last operation on the task.
- Prevent a potential NULL pointer dereference in task_numa_work()
task_numa_work() iterates the VMAs of a process. A concurrent unmap
of the address space can result in a NULL pointer return from
vma_next() which is unchecked.
Add the missing NULL pointer check to prevent this.
- Operate on the correct scheduler policy in task_should_scx()
task_should_scx() returns true when a task should be handled by sched
EXT. It checks the tasks scheduling policy.
This fails when the check is done before a policy has been set.
Cure it by handing the policy into task_should_scx() so it operates
on the requested value.
- Add the missing handling of sched EXT in the delayed dequeue
mechanism. This was simply forgotten.
* tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/ext: Fix scx vs sched_delayed
sched: Pass correct scheduling policy to __setscheduler_class
sched/numa: Fix the potential null pointer dereference in task_numa_work()
sched: Fix pick_next_task_fair() vs try_to_wake_up() race
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|---|---|---|
| .. | ||
| autogroup.c | ||
| autogroup.h | ||
| build_policy.c | ||
| build_utility.c | ||
| clock.c | ||
| completion.c | ||
| core_sched.c | ||
| core.c | ||
| cpuacct.c | ||
| cpudeadline.c | ||
| cpudeadline.h | ||
| cpufreq_schedutil.c | ||
| cpufreq.c | ||
| cpupri.c | ||
| cpupri.h | ||
| cputime.c | ||
| deadline.c | ||
| debug.c | ||
| ext.c | ||
| ext.h | ||
| fair.c | ||
| features.h | ||
| idle.c | ||
| isolation.c | ||
| loadavg.c | ||
| Makefile | ||
| 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 | ||
| syscalls.c | ||
| topology.c | ||
| wait_bit.c | ||
| wait.c | ||