From: Petr Mladek <pmladek@suse.com>
To: Ryo Takakura <ryotkkr98@gmail.com>
Cc: alex@ghiti.fr, aou@eecs.berkeley.edu, bigeasy@linutronix.de,
conor.dooley@microchip.com, gregkh@linuxfoundation.org,
jirislaby@kernel.org, john.ogness@linutronix.de,
palmer@dabbelt.com, paul.walmsley@sifive.com,
samuel.holland@sifive.com, u.kleine-koenig@baylibre.com,
linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-serial@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v2] serial: sifive: lock port in startup()/shutdown() callbacks
Date: Thu, 10 Apr 2025 13:29:43 +0200 [thread overview]
Message-ID: <Z_erp2nLRKzLXuwF@pathway.suse.cz> (raw)
In-Reply-To: <20250405145354.492947-1-ryotkkr98@gmail.com>
On Sat 2025-04-05 23:53:54, Ryo Takakura wrote:
> startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS.
> The register is also accessed from write() callback.
>
> If console were printing and startup()/shutdown() callback
> gets called, its access to the register could be overwritten.
>
> Add port->lock to startup()/shutdown() callbacks to make sure
> their access to SIFIVE_SERIAL_IE_OFFS is synchronized against
> write() callback.
>
> Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
> Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
> Cc: stable@vger.kernel.org
I do not have the hardware around so I could not test it.
But the change make sense. It fixes a real race.
And the code looks reasonable:
Reviewed-by: Petr Mladek <pmladek@suse.com>
Best Regards,
Petr
next prev parent reply other threads:[~2025-04-10 11:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-05 14:53 [PATCH v2] serial: sifive: lock port in startup()/shutdown() callbacks Ryo Takakura
2025-04-10 11:29 ` Petr Mladek [this message]
2025-04-10 14:23 ` Ryo Takakura
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