[PATCH 0/2] printk: always report dropped messages

From: Sergey Senozhatsky
Date: Sat Dec 24 2016 - 09:10:44 EST


Two patches: trivial clean up and console_unlock() "fix".

The `printk messages dropped' report is printed as part of actual
kernel message, that's why we do 'text + len, sizeof(text) - len'
later in msg_print_text().

The problem here is that we may eventually skip the message, and
thus lose the 'printk messages dropped' report, if `console_loglevel'
check tells us to do so. Missing kernel messages in serial log
together with the missing 'printk messages dropped' can be quite

There are two options to address it:
a) forbid suppress_message_printing() if we know that we must print
`printk messages dropped'

b) print `printk messages dropped' as a standalone message.

Sergey Senozhatsky (2):
printk: drop call_console_drivers() unused param
printk: always report lost messages on serial console

kernel/printk/printk.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)