[PATCH] printk: remove unnecessary kmalloc() from syslog during

[Namit Gupta]

When the request is only for clearing logs, there is no need for
allocation/deallocation. Only the indexes need to be reset and returned.
Rest of the patch is mostly made up of changes because of indention.

Link: http://lkml.kernel.org/r/20180620135951epcas5p3bd2a8f25ec689ca333bce861b527dba2~54wyKcT0_3155531555epcas5p3y@xxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: pankaj.m@xxxxxxxxxxx
Cc: a.sahrawat@xxxxxxxxxxx
Signed-off-by: Namit Gupta <gupta.namit@xxxxxxxxxxx>
Signed-off-by: Himanshu Maithani <himanshu.m@xxxxxxxxxxx>
Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
[pmladek@xxxxxxxx: Removed code duplication.]
Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
---
 kernel/printk/printk.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 247808333ba4..0fa2ca6fd8f9 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1350,12 +1350,14 @@ static int syslog_print(char __user *buf, int size)
 
 static int syslog_print_all(char __user *buf, int size, bool clear)
 {
-	char *text;
+	char *text = NULL;
 	int len = 0;
 
-	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
-	if (!text)
-		return -ENOMEM;
+	if (buf) {
+		text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+		if (!text)
+			return -ENOMEM;
+	}
 
 	logbuf_lock_irq();
 	if (buf) {
@@ -1426,7 +1428,8 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 	}
 	logbuf_unlock_irq();
 
-	kfree(text);
+	if (text)
+		kfree(text);
 	return len;
 }
 
-- 
2.13.7