From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F987376469 for ; Mon, 5 Oct 2026 21:47:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791236830; cv=none; b=jAmR8MxP8q1PaDwPN+ljSlu4KUKn+it3v50GIfet4vsSMWJFmIK4F/t3PWL00qmZJAR4UwrUCujj8CxWrmYEzh9lPpf9gl4aCfX1Dv/eUlv7tNKLNfjWTJ89tFdiklXroW690bzdRIEMCOhpXDlk8t9j2V3M5Rd20MmSrdwymDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791236830; c=relaxed/simple; bh=3huf1cMk7VjwDGpQhhdcr75G9zOWNaq48fAd8CG7xOA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mc3HOAwWz/xQcfSIc551UtOezDPir00Uzm+hGa+K/jG5/pfc9dTAs1HjmBSgfCvjvx8Zf2ZUoN/0lKSjkF8+/az9WN5u2aQP+YEgxqGg2cM0TjgTman/xMPFD257btqXHawXMUx7dGTiQjGi3MTLT8/hP0rj1ARWU1IHVUJ854s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cbHvLWZE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cbHvLWZE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C5A71F000FF; Mon, 5 Oct 2026 21:47:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791236828; bh=+nVrxM7shDPgvOfx9PlI5GimBDjSZFWsmPK1ehEo6bg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cbHvLWZE1qZtbvf6sB7/G2is+gWPXrXFanXikHbipYzJGu4sUvInxDgyYkte2MIFH rYJQk6uK4S3uwU0J3HqrXKq7xb4WTxsG+vZklC3xbAXcsOceA/s36Ajv/+/IBxApWm ymI5jYLnXE8SuAuHD3LSAHnW0M9MaozeXHkXwsRelP6kxfI96uWseAXhjt13lW9wW+ heUl8ydBAZpe7g2SQeg28s6t+Zm+EHYOMizoj5nmCmOp36CSmE60xH7x9jD3yJWkqJ 8TRczix2xQMWi0lYbhj6SXW2oY4Lsjbk0ZabPYFXf6QbKje0aeJFerV3f3vxQ/XuJa SvVAx7VhViUoA== From: Sasha Levin To: stable@vger.kernel.org Cc: "Jiri Slaby (SUSE)" , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.18.y 1/2] serial: serial_core: simplify uart_ioctl() returns Date: Mon, 5 Oct 2026 17:47:03 -0400 Message-ID: <20261005214655.3401887-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026100554-renewable-overpower-2a0c@gregkh> References: <2026100554-renewable-overpower-2a0c@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Jiri Slaby (SUSE)" [ Upstream commit f374a33e90e6cc17b05629636e68a012dc8347ed ] Neither uart_do_autoconfig(), nor uart_wait_modem_status() can return -ENOIOCTLCMD. The ENOIOCTLCMD checks are there to check if 'cmd' matched against TIOCSERCONFIG, and TIOCMIWAIT respectively. (With 0 or error in 'ret', it does not matter.) Therefore, the code can simply return from the TIOCSERCONFIG and TIOCMIWAIT spots immediately. To be more explicit, use 'if' instead of switch-case for those single values. And return without jumping to the 'out' label -- it can be removed too. Signed-off-by: Jiri Slaby (SUSE) Link: https://patch.msgid.link/20251119100140.830761-10-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 8ca59f7baee7 ("serial: fix ioctl hangup race") Signed-off-by: Sasha Levin --- drivers/tty/serial/serial_core.c | 35 ++++++++------------------------ 1 file changed, 9 insertions(+), 26 deletions(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 32cdfc59a9ad9..3dc109ab0a7e2 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1564,37 +1564,20 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) void __user *uarg = (void __user *)arg; int ret = -ENOIOCTLCMD; - - /* - * These ioctls don't rely on the hardware to be present. - */ - switch (cmd) { - case TIOCSERCONFIG: + /* This ioctl doesn't rely on the hardware to be present. */ + if (cmd == TIOCSERCONFIG) { down_write(&tty->termios_rwsem); ret = uart_do_autoconfig(tty, state); up_write(&tty->termios_rwsem); - break; - } - - if (ret != -ENOIOCTLCMD) - goto out; - - if (tty_io_error(tty)) { - ret = -EIO; - goto out; + return ret; } - /* - * The following should only be used when hardware is present. - */ - switch (cmd) { - case TIOCMIWAIT: - ret = uart_wait_modem_status(state, arg); - break; - } + if (tty_io_error(tty)) + return -EIO; - if (ret != -ENOIOCTLCMD) - goto out; + /* This should only be used when the hardware is present. */ + if (cmd == TIOCMIWAIT) + return uart_wait_modem_status(state, arg); /* rs485_config requires more locking than others */ if (cmd == TIOCSRS485) @@ -1642,7 +1625,7 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) mutex_unlock(&port->mutex); if (cmd == TIOCSRS485) up_write(&tty->termios_rwsem); -out: + return ret; } -- 2.53.0