diff options
Diffstat (limited to 'kernel/printk/nbcon.c')
| -rw-r--r-- | kernel/printk/nbcon.c | 38 |
1 files changed, 18 insertions, 20 deletions
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c index 3fa403f9831f..32fc12e53675 100644 --- a/kernel/printk/nbcon.c +++ b/kernel/printk/nbcon.c @@ -1557,18 +1557,27 @@ static int __nbcon_atomic_flush_pending_con(struct console *con, u64 stop_seq) ctxt->allow_unsafe_takeover = nbcon_allow_unsafe_takeover(); while (nbcon_seq_read(con) < stop_seq) { - if (!nbcon_context_try_acquire(ctxt, false)) - return -EPERM; - /* - * nbcon_emit_next_record() returns false when the console was - * handed over or taken over. In both cases the context is no - * longer valid. + * Atomic flushing does not use console driver synchronization + * (i.e. it does not hold the port lock for uart consoles). + * Therefore IRQs must be disabled to avoid being interrupted + * and then calling into a driver that will deadlock trying + * to acquire console ownership. */ - if (!nbcon_emit_next_record(&wctxt, true)) - return -EAGAIN; + scoped_guard(irqsave) { + if (!nbcon_context_try_acquire(ctxt, false)) + return -EPERM; - nbcon_context_release(ctxt); + /* + * nbcon_emit_next_record() returns false when + * the console was handed over or taken over. + * In both cases the context is no longer valid. + */ + if (!nbcon_emit_next_record(&wctxt, true)) + return -EAGAIN; + + nbcon_context_release(ctxt); + } if (!ctxt->backlog) { /* Are there reserved but not yet finalized records? */ @@ -1595,22 +1604,11 @@ static int __nbcon_atomic_flush_pending_con(struct console *con, u64 stop_seq) static void nbcon_atomic_flush_pending_con(struct console *con, u64 stop_seq) { struct console_flush_type ft; - unsigned long flags; int err; again: - /* - * Atomic flushing does not use console driver synchronization (i.e. - * it does not hold the port lock for uart consoles). Therefore IRQs - * must be disabled to avoid being interrupted and then calling into - * a driver that will deadlock trying to acquire console ownership. - */ - local_irq_save(flags); - err = __nbcon_atomic_flush_pending_con(con, stop_seq); - local_irq_restore(flags); - /* * If there was a new owner (-EPERM, -EAGAIN), that context is * responsible for completing. |
