From 1d3fa370346d9d96ab0efb84e3312aed3aeb35ea Mon Sep 17 00:00:00 2001 From: Arun KS Date: Thu, 23 Jan 2014 15:54:19 -0800 Subject: [PATCH] printk: flush conflicting continuation line An earlier newline was missing and current print is from different task. In this scenario flush the continuation line and store this line seperatly. This patch fix the below scenario of timestamp interleaving, [ 28.154370 ] read_word_reg : reg[0x 3], reg[0x 4] data [0x 642] [ 28.155428 ] uart disconnect [ 31.947341 ] dvfs[cpufreq.c<275>]:plug-in cpu<1> done [ 28.155445 ] UART detached : send switch state 201 [ 32.014112 ] read_reg : reg[0x 3] data[0x21] [akpm@linux-foundation.org: simplify and condense the code] Signed-off-by: Arun KS Signed-off-by: Arun KS Cc: Joe Perches Cc: Tejun Heo Cc: Frederic Weisbecker Cc: Paul Gortmaker Cc: Kay Sievers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/printk/printk.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index f8b41bddc6dc..b1d255f04135 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1595,10 +1595,13 @@ asmlinkage int vprintk_emit(int facility, int level, * either merge it with the current buffer and flush, or if * there was a race with interrupts (prefix == true) then just * flush it out and store this line separately. + * If the preceding printk was from a different task and missed + * a newline, flush and append the newline. */ - if (cont.len && cont.owner == current) { - if (!(lflags & LOG_PREFIX)) - stored = cont_add(facility, level, text, text_len); + if (cont.len) { + if (cont.owner == current && !(lflags & LOG_PREFIX)) + stored = cont_add(facility, level, text, + text_len); cont_flush(LOG_NEWLINE); }