From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 685F51C5ADC; Sun, 24 Mar 2024 22:46:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711320363; cv=none; b=C/x0ZR3yCaHk+vjSWGRf61gkr0EhmpccRqgckTM0Xsl3HEokQm7y/c35dWPLrLuVeYVPvR+gF3kj5okQ2fv9+Cps2Q+IqbFbHY/1Owai32XWIMSumwzJClyRZ3EfdTx3bqDUJP53R9MD5f6irQ2alNR5SzQjcLtLVGwf+rSnJro= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711320363; c=relaxed/simple; bh=9yc9RzzNYFFCXj9TA2BrTsYbnJHVTSRf/XwLJhzcGW8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EaQU6WMAF9HAz+IL1foXaKK+dZk9maOnMS3lacRNIvcclGpiNefc3v1bHRvR7X7HhF5wuxWrNxHlN//uYO2vaGwRLmF8WdX+uobEI1eB/Up/JVMUVR8gtbjk/DBDxEb0KhdHSQlJje5GsUhgKMk70e3v5wK2l0nR1jF2ahneNkA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q6n7Eugt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Q6n7Eugt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0535C433C7; Sun, 24 Mar 2024 22:46:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711320363; bh=9yc9RzzNYFFCXj9TA2BrTsYbnJHVTSRf/XwLJhzcGW8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q6n7Eugt5MKAM/2+nDOgvMkEx3yNj+3Rtihn49xFySzgbxHwkCCOzipHclYW14RW9 dbjkcB1ca3l1lGWC7LmLR+iWP95JeAyXIwhphesMeDFPuON7h/Vj8NAMC50Ufy5aiK dElX1K4ltiG0wljo4ynLgFpPB8LX+Xn+bdQwIKAjts4RQyzmxIW+Q/Lu10ETCwFXwB c7QHB5C1cy0yOqczyPxdbaPIYhbzvRfuitalOOvAhXES6fF6kRFQdcqTB91PhiPbcJ 01eKsgPa5XhIAvPRLBVmanAW2d62xbwciY2NZ2EpDv8rT3IMAks7G2ygmbP5D3OsUh fMi31Hkg07u7w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Juergen Gross , Oleksandr Tyshchenko , Sasha Levin Subject: [PATCH 6.8 670/715] xen/events: increment refcnt only if event channel is refcounted Date: Sun, 24 Mar 2024 18:34:09 -0400 Message-ID: <20240324223455.1342824-671-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org> References: <20240324223455.1342824-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Juergen Gross [ Upstream commit d277f9d82802223f242cd9b60c988cfdda1d6be0 ] In bind_evtchn_to_irq_chip() don't increment the refcnt of the event channel blindly. In case the event channel is NOT refcounted, issue a warning instead. Add an additional safety net by doing the refcnt increment only if the caller has specified IRQF_SHARED in the irqflags parameter. Fixes: 9e90e58c11b7 ("xen: evtchn: Allow shared registration of IRQ handers") Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Link: https://lore.kernel.org/r/20240313071409.25913-3-jgross@suse.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin --- drivers/xen/events/events_base.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 3b9f080109d7e..27553673e46bc 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1190,7 +1190,7 @@ int xen_pirq_from_irq(unsigned irq) EXPORT_SYMBOL_GPL(xen_pirq_from_irq); static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, - struct xenbus_device *dev) + struct xenbus_device *dev, bool shared) { int ret = -ENOMEM; struct irq_info *info; @@ -1224,7 +1224,8 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, */ bind_evtchn_to_cpu(info, 0, false); } else if (!WARN_ON(info->type != IRQT_EVTCHN)) { - info->refcnt++; + if (shared && !WARN_ON(info->refcnt < 0)) + info->refcnt++; } ret = info->irq; @@ -1237,13 +1238,13 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, int bind_evtchn_to_irq(evtchn_port_t evtchn) { - return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL); + return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL, false); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irq); int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn) { - return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL); + return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL, false); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi); @@ -1295,7 +1296,8 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu) static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev, evtchn_port_t remote_port, - struct irq_chip *chip) + struct irq_chip *chip, + bool shared) { struct evtchn_bind_interdomain bind_interdomain; int err; @@ -1307,14 +1309,14 @@ static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev, &bind_interdomain); return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port, - chip, dev); + chip, dev, shared); } int bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device *dev, evtchn_port_t remote_port) { return bind_interdomain_evtchn_to_irq_chip(dev, remote_port, - &xen_lateeoi_chip); + &xen_lateeoi_chip, false); } EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi); @@ -1430,7 +1432,8 @@ static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn, { int irq, retval; - irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL); + irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL, + irqflags & IRQF_SHARED); if (irq < 0) return irq; retval = request_irq(irq, handler, irqflags, devname, dev_id); @@ -1471,7 +1474,8 @@ static int bind_interdomain_evtchn_to_irqhandler_chip( { int irq, retval; - irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip); + irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip, + irqflags & IRQF_SHARED); if (irq < 0) return irq; -- 2.43.0