On Wed 2018-06-20 19:26:19, Namit Gupta wrote:
> 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.
>
> Signed-off-by: Namit Gupta <[email protected]>
> Signed-off-by: Himanshu Maithani <[email protected]>
> ---
> kernel/printk/printk.c | 111
> ++++++++++++++++++++++++++-----------------------
> 1 file changed, 60 insertions(+), 51 deletions(-)
>
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index 512f7c2..53952ce 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -1348,71 +1348,80 @@ static int syslog_print_all(char __user *buf, int
> size, bool clear)
> {
> char *text;
> int len = 0;
> + u64 next_seq;
> + u64 seq;
> + u32 idx;
> +
> + if (!buf) {
> + if (clear) {
> + logbuf_lock_irq();
> + clear_seq = log_next_seq;
> + clear_idx = log_next_idx;
> + logbuf_unlock_irq();
I pushed a bit different version into printk.git, branch for-4.19,
see below. It removes the code duplication. Also it keeps the original
indentation. IMHO, it helped to better distinguish the code for printing
and clearing.
It is rather a cosmetic change, so I do not want you to resend
Reviewed-by tags. But feel free to disagree and ask me to use
the original variant.
This is in printk.git now:
>From 41cb6dcedd9257d51fd310bf9b2958d11d93aa2b Mon Sep 17 00:00:00 2001
From: Namit Gupta <[email protected]>
Date: Mon, 25 Jun 2018 14:58:05 +0200
Subject: [PATCH] printk: remove unnecessary kmalloc() from syslog during
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_3155531555epcas5...@epcas5p3.samsung.com
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Namit Gupta <[email protected]>
Signed-off-by: Himanshu Maithani <[email protected]>
Reviewed-by: Steven Rostedt (VMware) <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
[[email protected]: Removed code duplication.]
Signed-off-by: Petr Mladek <[email protected]>
---
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
