linux-kernel - [PATCH AUTOSEL 6.10 5/9] soc: qcom: icc-bwmon: Allow for interrupts to be shared across instances

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240728004934.1706375-5-sashal@kernel.org>
Date: Sat, 27 Jul 2024 20:49:25 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Sibi Sankar <quic_sibis@...cinc.com>,
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
	Bjorn Andersson <andersson@...nel.org>,
	Sasha Levin <sashal@...nel.org>,
	krzysztof.kozlowski@...aro.org,
	konrad.dybcio@...aro.org,
	linux-arm-msm@...r.kernel.org
Subject: [PATCH AUTOSEL 6.10 5/9] soc: qcom: icc-bwmon: Allow for interrupts to be shared across instances

From: Sibi Sankar <quic_sibis@...cinc.com>

[ Upstream commit dc18836435e7f8dda019db2c618c69194933157f ]

The multiple BWMONv4 instances available on the X1E80100 SoC use the
same interrupt number. Mark them are shared to allow for re-use across
instances.

Using IRQF_SHARED coupled with devm_request_threaded_irq implies that
the irq can still trigger during/after bwmon_remove due to other active
bwmon instances. Handle this race by relying on bwmon_disable to disable
the interrupt and coupled with explicit request/free irqs.

Signed-off-by: Sibi Sankar <quic_sibis@...cinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Link: https://lore.kernel.org/r/20240624092214.146935-4-quic_sibis@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/soc/qcom/icc-bwmon.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/soc/qcom/icc-bwmon.c b/drivers/soc/qcom/icc-bwmon.c
index fb323b3364db4..e1ffd453ecdf0 100644
--- a/drivers/soc/qcom/icc-bwmon.c
+++ b/drivers/soc/qcom/icc-bwmon.c
@@ -781,9 +781,14 @@ static int bwmon_probe(struct platform_device *pdev)
 	bwmon->dev = dev;
 
 	bwmon_disable(bwmon);
-	ret = devm_request_threaded_irq(dev, bwmon->irq, bwmon_intr,
-					bwmon_intr_thread,
-					IRQF_ONESHOT, dev_name(dev), bwmon);
+
+	/*
+	 * SoCs with multiple cpu-bwmon instances can end up using a shared interrupt
+	 * line. Using the devm_ variant might result in the IRQ handler being executed
+	 * after bwmon_disable in bwmon_remove()
+	 */
+	ret = request_threaded_irq(bwmon->irq, bwmon_intr, bwmon_intr_thread,
+				   IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), bwmon);
 	if (ret)
 		return dev_err_probe(dev, ret, "failed to request IRQ\n");
 
@@ -798,6 +803,7 @@ static void bwmon_remove(struct platform_device *pdev)
 	struct icc_bwmon *bwmon = platform_get_drvdata(pdev);
 
 	bwmon_disable(bwmon);
+	free_irq(bwmon->irq, bwmon);
 }
 
 static const struct icc_bwmon_data msm8998_bwmon_data = {
-- 
2.43.0