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| author | Karl Mehltretter <kmehltretter@gmail.com> | 2026-05-23 21:51:22 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-06-03 12:38:47 +0300 |
| commit | d8c897b20bf4d4cbb1e935a8ceb666bcc0f82580 (patch) | |
| tree | c21738200b49eb097fccc2103491e61d1ccaab50 /include/linux/timerqueue.h | |
| parent | cb19b8a9add2ed3774c1276e0a3906e52e8cf39a (diff) | |
| download | linux-d8c897b20bf4d4cbb1e935a8ceb666bcc0f82580.tar.xz | |
lockdep/selftests: Restore migrate_disable() state on PREEMPT_RT
The lockdep selftests deliberately run unbalanced locking patterns.
dotest() restores the task state they leave behind before running the
next testcase.
On PREEMPT_RT, spin_lock() uses migrate_disable() instead of disabling
preemption. dotest() cleans up the resulting migration-disabled state, but
that cleanup is still guarded by CONFIG_SMP.
That used to match the scheduler data model, where migration_disabled was
also CONFIG_SMP-only. The commit referenced below made SMP scheduler state
unconditional, so CONFIG_SMP=n PREEMPT_RT kernels with
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y report success from the selftests and
then trip over stale current->migration_disabled state:
releasing a pinned lock
bad: scheduling from the idle thread!
Kernel panic - not syncing: Fatal exception
Save and restore current->migration_disabled for every PREEMPT_RT build.
Fixes: cac5cefbade9 ("sched/smp: Make SMP unconditional")
Assisted-by: Codex:gpt-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20260523185123.17482-2-kmehltretter@gmail.com
Diffstat (limited to 'include/linux/timerqueue.h')
0 files changed, 0 insertions, 0 deletions