From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> mainline inclusion from mainline-v7.3-rc3 commit 815e07c8fe885a87751c2496a30ae0dcd4118210 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9956 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- rb_wake_up_waiters() is a irq_work callback which is initialized with init_irq_work(). As such it will be invoked in thread context on PREEMPT_RT. Invoking the callback in IRQ context on PREEMPT_RT is not an option due its usage of wake_up_all(). Since this callback may run in thread context, it needs to acquire ring_buffer_per_cpu::reader_lock with disabling interrupts and may not assume that they are disabled. Use raw_spinlock_irqsave() to acquire ring_buffer_per_cpu::reader_lock. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260911102152.YEtwkBj9@linutronix.de Fixes: 68282dd930ea3 ("ring-buffer: Fix resetting of shortest_full") Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- kernel/trace/ring_buffer.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 47908a826373..c1800fb607ae 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -918,14 +918,13 @@ static void rb_wake_up_waiters(struct irq_work *work) struct ring_buffer_per_cpu *cpu_buffer = container_of(rbwork, struct ring_buffer_per_cpu, irq_work); - /* Called from interrupt context */ - raw_spin_lock(&cpu_buffer->reader_lock); - rbwork->wakeup_full = false; - rbwork->full_waiters_pending = false; + scoped_guard(raw_spinlock_irqsave, &cpu_buffer->reader_lock) { + rbwork->wakeup_full = false; + rbwork->full_waiters_pending = false; - /* Waking up all waiters, they will reset the shortest full */ - cpu_buffer->shortest_full = 0; - raw_spin_unlock(&cpu_buffer->reader_lock); + /* Waking up all waiters, they will reset the shortest full */ + cpu_buffer->shortest_full = 0; + } wake_up_all(&rbwork->full_waiters); } -- 2.34.1