printk: Clean up syslog_print_all()

syslog_print_all() is called twice. Once with a valid buffer
and once just to set the indexes.

Both variants are already handled separately. This patch just
makes it more obvious. It does not change the existing behavior.

Link: http://lkml.kernel.org/r/20180627150641.p56xyy6mdzvnfpig@pathway.suse.cz
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Namit Gupta <gupta.namit@samsung.com>
Cc: linux-kernel@vger.kernel.org
Cc: pankaj.m@samsung.com
Cc: a.sahrawat@samsung.com
Cc: himanshu.m@samsung.com
Signed-off-by: Petr Mladek <pmladek@suse.com>

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 16b02cc51a14cb4b5a59c3e3966d71e0409f4fe3..fcc1992c040a4ab487c225be1aaa430892b37ab2 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1356,16 +1356,6 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
        u64 seq;
        u32 idx;
 
-       if (!buf) {
-               if (clear) {
-                       logbuf_lock_irq();
-                       clear_seq = log_next_seq;
-                       clear_idx = log_next_idx;
-                       logbuf_unlock_irq();
-               }
-               return 0;
-       }
-
        text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
        if (!text)
                return -ENOMEM;
@@ -1437,6 +1427,14 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
        return len;
 }
 
+static void syslog_clear(void)
+{
+       logbuf_lock_irq();
+       clear_seq = log_next_seq;
+       clear_idx = log_next_idx;
+       logbuf_unlock_irq();
+}
+
 int do_syslog(int type, char __user *buf, int len, int source)
 {
        bool clear = false;
@@ -1481,7 +1479,7 @@ int do_syslog(int type, char __user *buf, int len, int source)
                break;
        /* Clear ring buffer */
        case SYSLOG_ACTION_CLEAR:
-               syslog_print_all(NULL, 0, true);
+               syslog_clear();
                break;
        /* Disable logging to console */
        case SYSLOG_ACTION_CONSOLE_OFF: