linux-kernel - Re: [PATCH] tty: hvc_console: Call hvc_kick in hvc

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: <9f4136d7-e973-44ad-b966-b6993f7b9df0@kernel.org>
Date: Wed, 20 Aug 2025 07:21:27 +0200
From: Jiri Slaby <jirislaby@...nel.org>
To: Fabian Vogt <fvogt@...e.de>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] tty: hvc_console: Call hvc_kick in hvc_write
 unconditionally

On 15. 08. 25, 13:33, Fabian Vogt wrote:
> After hvc_write completes, call hvc_kick also in the case the output
> buffer has been drained, to ensure tty_wakeup gets called.
> 
> This fixes that functions which wait for a drained buffer got stuck
> occasionally.
> 
> Cc: stable@...r.kernel.org
> Closes: https://bugzilla.opensuse.org/show_bug.cgi?id=1230062
> Signed-off-by: Fabian Vogt <fvogt@...e.de>

It's hard to tell if it the right thing™ as HVC is a mess. But on the 
basic code level, LGTM. Let's see if something pops up.

Reviewed-by: Jiri Slaby <jirislaby@...nel.org>

> ---
>   drivers/tty/hvc/hvc_console.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
> index cd1f657f782d..13c663a154c4 100644
> --- a/drivers/tty/hvc/hvc_console.c
> +++ b/drivers/tty/hvc/hvc_console.c
> @@ -543,10 +543,10 @@ static ssize_t hvc_write(struct tty_struct *tty, const u8 *buf, size_t count)
>   	}
>   
>   	/*
> -	 * Racy, but harmless, kick thread if there is still pending data.
> +	 * Kick thread to flush if there's still pending data
> +	 * or to wakeup the write queue.
>   	 */
> -	if (hp->n_outbuf)
> -		hvc_kick();
> +	hvc_kick();
>   
>   	return written;
>   }


-- 
js
suse labs