From: Nicolai Buchwitz <nb@tipi-net.de>
To: Dan Carpenter <dan@cryspen.com>
Cc: "Russell King" <linux@armlinux.org.uk>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Jiri Slaby" <jirislaby@kernel.org>,
"Kartik Rajput" <kkartik@nvidia.com>,
"Fan Wu" <fanwu01@zju.edu.cn>, "Frank Li" <Frank.Li@nxp.com>,
"Karl Mehltretter" <kmehltretter@gmail.com>,
"Stefan Dösinger" <stefandoesinger@gmail.com>,
linux-serial@vger.kernel.org
Subject: Re: [PATCH] serial: amba-pl011: Fix divide by zero in pl011_console_get_options()
Date: Thu, 12 Nov 2026 09:08:00 +0100 [thread overview]
Message-ID: <3726053453c5abac97e4fe90bf40d205@tipi-net.de> (raw)
In-Reply-To: <6fdea544b2fb8f4226e296a952331cd42684474d.1794315353.git.dan@cryspen.com>
Hi Dan
On 11.11.2026 10:23, Dan Carpenter wrote:
> When you boot QEMU with -kernel and don't set a baud rate the ibrd and
> fbrd values are zero and so clkdiv is also zero. It results in a
> divide
> by zero. Most of the time people don't notice because on
> qemu-system-arm64 when you divide by zero the result is zero and
> everything works. However, if you enable UBSAN, then the divide by
> zero
> leads to a crash and the boot fails.
>
> Return early when clkdev is zero. This leaves the baud rate set to its
nit: clkdiv
> default value of 38400.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Cc: stable@vger.kernel.org
> Signed-off-by: Dan Carpenter <dan@cryspen.com>
> [...]
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Thanks,
Nicolai
prev parent reply other threads:[~2026-11-12 8:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-11 9:23 [PATCH] serial: amba-pl011: Fix divide by zero in pl011_console_get_options() Dan Carpenter
2026-11-11 9:29 ` sashiko-bot
2026-11-12 8:08 ` Nicolai Buchwitz [this message]
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