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-rw-r--r--kernel/printk/printk_safe.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 3cdaeaef9ce1..724d9292d4b9 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -39,7 +39,7 @@
* There are situations when we want to make sure that all buffers
* were handled or when IRQs are blocked.
*/
-static int printk_safe_irq_ready;
+static int printk_safe_irq_ready __read_mostly;
#define SAFE_LOG_BUF_LEN ((1 << CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT) - \
sizeof(atomic_t) - \
@@ -63,11 +63,8 @@ static DEFINE_PER_CPU(struct printk_safe_seq_buf, nmi_print_seq);
/* Get flushed in a more safe context. */
static void queue_flush_work(struct printk_safe_seq_buf *s)
{
- if (printk_safe_irq_ready) {
- /* Make sure that IRQ work is really initialized. */
- smp_rmb();
+ if (printk_safe_irq_ready)
irq_work_queue(&s->work);
- }
}
/*
@@ -398,8 +395,12 @@ void __init printk_safe_init(void)
#endif
}
- /* Make sure that IRQ works are initialized before enabling. */
- smp_wmb();
+ /*
+ * In the highly unlikely event that a NMI were to trigger at
+ * this moment. Make sure IRQ work is set up before this
+ * variable is set.
+ */
+ barrier();
printk_safe_irq_ready = 1;
/* Flush pending messages that did not have scheduled IRQ works. */