After copying all records to the dynamic ringbuffer, setup_log_buf() checks to see if any records were dropped during the switch. However, it needs to check before enabling interrupts since new records could arrive in an interrupt, thus causing setup_log_buf() to erroneously think that it had dropped messages.
Signed-off-by: John Ogness <[email protected]> --- kernel/printk/printk.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 1fe3d0cb2fe0..00bc1fce3299 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1181,12 +1181,12 @@ void __init setup_log_buf(int early) */ prb = &printk_rb_dynamic; + seq = prb_next_seq(&printk_rb_static) - seq; + logbuf_unlock_irqrestore(flags); - if (seq != prb_next_seq(&printk_rb_static)) { - pr_err("dropped %llu messages\n", - prb_next_seq(&printk_rb_static) - seq); - } + if (seq) + pr_err("dropped %llu messages\n", seq); pr_info("log_buf_len: %u bytes\n", log_buf_len); pr_info("early log buf free: %u(%u%%)\n", -- 2.20.1
