linux-kernel - Re: [PATCH v2 1/2] printk_ringbuffer: don't needlessly wrap data blocks around

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <d4d676a4-643d-47fb-974e-fa08009ce23b@yandex-team.ru>
Date: Thu, 11 Sep 2025 11:34:54 +0300
From: Daniil Tatianin <d-tatianin@...dex-team.ru>
To: John Ogness <john.ogness@...utronix.de>, Petr Mladek <pmladek@...e.com>
Cc: linux-kernel@...r.kernel.org, Steven Rostedt <rostedt@...dmis.org>,
 Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: Re: [PATCH v2 1/2] printk_ringbuffer: don't needlessly wrap data
 blocks around


On 9/5/25 7:10 PM, John Ogness wrote:
> On 2025-09-05, Daniil Tatianin <d-tatianin@...dex-team.ru> wrote:
>> On 9/5/25 6:27 PM, John Ogness wrote:
>>> On 2025-09-05, Daniil Tatianin <d-tatianin@...dex-team.ru> wrote:
>>>> diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
>>>> index d9fb053cff67..99989a9ce4b4 100644
>>>> --- a/kernel/printk/printk_ringbuffer.c
>>>> +++ b/kernel/printk/printk_ringbuffer.c
>>>> @@ -1234,14 +1245,14 @@ static const char *get_data(struct prb_data_ring *data_ring,
>>>>    	}
>>>>    
>>>>    	/* Regular data block: @begin less than @next and in same wrap. */
>>>> -	if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, blk_lpos->next) &&
>>>> +	if (!is_blk_wrapped(data_ring, blk_lpos->begin, blk_lpos->next) &&
>>>>    	    blk_lpos->begin < blk_lpos->next) {
>>>>    		db = to_block(data_ring, blk_lpos->begin);
>>>>    		*data_size = blk_lpos->next - blk_lpos->begin;
>>>>    
>>>>    	/* Wrapping data block: @begin is one wrap behind @next. */
>>>> -	} else if (DATA_WRAPS(data_ring, blk_lpos->begin + DATA_SIZE(data_ring)) ==
>>>> -		   DATA_WRAPS(data_ring, blk_lpos->next)) {
>>>> +	} else if (!is_blk_wrapped(data_ring,
>>>> +		   blk_lpos->begin + DATA_SIZE(data_ring), blk_lpos->next)) {
>>> It would look nicer if the arguments of the function were indented to
>>> the function parenthesis:
>>>
>>> 	} else if (!is_blk_wrapped(data_ring, blk_lpos->begin +
>>> 				   DATA_SIZE(data_ring), blk_lpos->next)) {
>> Would you like me to resend with this addressed?
> Knowing Petr, I would say "yes". :-)
>
> But wait for Petr's response before sending anything.

Friendly ping for Petr :)

>
> John