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printk: always use deferred printk when flush printk_safe lines

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Always use printk_deferred() in printk_safe_flush_line().
Flushing can be done from NMI or printk_safe contexts (when
we are in panic), so we can't call console drivers, yet still
want to store the messages in the logbuf buffer. Therefore we
use a deferred printk version.

Link: http://lkml.kernel.org/r/20170206164253.GA463@tigerII.localdomain
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Calvin Owens <calvinowens@fb.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Sergey Senozhatsky 2017-02-07 01:42:53 +09:00 committed by Petr Mladek
parent 099f1c84c0
commit 7acac3445a
1 changed files with 6 additions and 8 deletions
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14
kernel/printk/printk_safe.c
View File

@ -110,17 +110,15 @@ again:
return add;
}
static void printk_safe_flush_line(const char *text, int len)
static inline void printk_safe_flush_line(const char *text, int len)
{
/*
* The buffers are flushed in NMI only on panic. The messages must
* go only into the ring buffer at this stage. Consoles will get
* explicitly called later when a crashdump is not generated.
* Avoid any console drivers calls from here, because we may be
* in NMI or printk_safe context (when in panic). The messages
* must go only into the ring buffer at this stage. Consoles will
* get explicitly called later when a crashdump is not generated.
*/
if (in_nmi())
printk_deferred("%.*s", len, text);
else
printk("%.*s", len, text);
printk_deferred("%.*s", len, text);
}
/* printk part of the temporary buffer line by line */