printk: Split the code for storing a message into the log buffer

It is just a preparation step. The patch does not change
the existing behavior.

Link: http://lkml.kernel.org/r/20180627140817.27764-2-pmladek@suse.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 247808333ba430f75c0ac7382bc08d6f219685cf..a844c611b17c19eeddb68e1c1c18cb9ab63a101b 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1824,28 +1824,16 @@ static size_t log_output(int facility, int level, enum log_flags lflags, const c
        return log_store(facility, level, lflags, 0, dict, dictlen, text, text_len);
 }
 
-asmlinkage int vprintk_emit(int facility, int level,
-                           const char *dict, size_t dictlen,
-                           const char *fmt, va_list args)
+/* Must be called under logbuf_lock. */
+int vprintk_store(int facility, int level,
+                 const char *dict, size_t dictlen,
+                 const char *fmt, va_list args)
 {
        static char textbuf[LOG_LINE_MAX];
        char *text = textbuf;
        size_t text_len;
        enum log_flags lflags = 0;
-       unsigned long flags;
-       int printed_len;
-       bool in_sched = false;
-
-       if (level == LOGLEVEL_SCHED) {
-               level = LOGLEVEL_DEFAULT;
-               in_sched = true;
-       }
-
-       boot_delay_msec(level);
-       printk_delay();
 
-       /* This stops the holder of console_sem just where we want him */
-       logbuf_lock_irqsave(flags);
        /*
         * The printf needs to come first; we need the syslog
         * prefix which might be passed-in as a parameter.
@@ -1886,8 +1874,29 @@ asmlinkage int vprintk_emit(int facility, int level,
        if (dict)
                lflags |= LOG_PREFIX|LOG_NEWLINE;
 
-       printed_len = log_output(facility, level, lflags, dict, dictlen, text, text_len);
+       return log_output(facility, level, lflags,
+                         dict, dictlen, text, text_len);
+}
 
+asmlinkage int vprintk_emit(int facility, int level,
+                           const char *dict, size_t dictlen,
+                           const char *fmt, va_list args)
+{
+       int printed_len;
+       bool in_sched = false;
+       unsigned long flags;
+
+       if (level == LOGLEVEL_SCHED) {
+               level = LOGLEVEL_DEFAULT;
+               in_sched = true;
+       }
+
+       boot_delay_msec(level);
+       printk_delay();
+
+       /* This stops the holder of console_sem just where we want him */
+       logbuf_lock_irqsave(flags);
+       printed_len = vprintk_store(facility, level, dict, dictlen, fmt, args);
        logbuf_unlock_irqrestore(flags);
 
        /* If called from the scheduler, we can not call up(). */