From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Qing Wang <wangqing@vivo.com>
Cc: Jiri Slaby <jirislaby@kernel.org>, Joel Stanley <joel@jms.id.au>,
Andrew Jeffery <andrew@aj.id.au>,
linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tty: 8250: replace snprintf in show functions with sysfs_emit
Date: Fri, 15 Oct 2021 08:57:56 +0200 [thread overview]
Message-ID: <YWkmdELuWa6ITIIR@kroah.com> (raw)
In-Reply-To: <1634280682-5002-1-git-send-email-wangqing@vivo.com>
On Thu, Oct 14, 2021 at 11:51:22PM -0700, Qing Wang wrote:
> show() must not use snprintf() when formatting the value to be
> returned to user space.
Why must it not? What is broken in the existing code?
>
> Fix the coccicheck warnings:
> WARNING: use scnprintf or sprintf.
>
> Signed-off-by: Qing Wang <wangqing@vivo.com>
> ---
> drivers/tty/serial/8250/8250_aspeed_vuart.c | 6 +++---
> drivers/tty/serial/8250/8250_port.c | 2 +-
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
> index 2350fb3..082b9bd 100644
> --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
> +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
> @@ -82,7 +82,7 @@ static ssize_t lpc_address_show(struct device *dev,
> addr = (aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRH) << 8) |
> (aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRL));
>
> - return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr);
> + return sysfs_emit(buf - 1, "0x%x\n", addr);
what is the buf-1 thing here for?
Doing a tree-wide change for this type of thing might not be wanted by
many maintainers, especially if you introduce bugs like this :(
greg k-h
next prev parent reply other threads:[~2021-10-15 6:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-15 6:51 [PATCH] tty: 8250: replace snprintf in show functions with sysfs_emit Qing Wang
2021-10-15 6:57 ` Greg Kroah-Hartman [this message]
[not found] ` <AOQACwDzEi5UM3m3ezm-D4o5.9.1634281082401.Hmail.wangqing@vivo.com>
2021-10-15 7:13 ` 回复: " 王擎
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