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From: Christoph Hellwig <hch@lst.de>
To: bhelgaas@google.com
Cc: arjan@linux.intel.com, keith.busch@linux.intel.com,
	jthumshirn@suse.de, ming.lei@redhat.com,
	linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org
Subject: [PATCH] PCI/sysfs: do not allow enabling/disabling a device with a driver
Date: Fri, 18 May 2018 18:56:24 +0200	[thread overview]
Message-ID: <20180518165624.13993-1-hch@lst.de> (raw)

Manpulating the enable_cnt behind the back of the driver will wreck
complete havok with the kernel state, so disallow it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/pci/pci-sysfs.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 366d93af051d..788a200fb2dc 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -288,13 +288,16 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (!val) {
-		if (pci_is_enabled(pdev))
-			pci_disable_device(pdev);
-		else
-			result = -EIO;
-	} else
+	device_lock(dev);
+	if (dev->driver)
+		result = -EBUSY;
+	else if (val)
 		result = pci_enable_device(pdev);
+	else if (pci_is_enabled(pdev))
+		pci_disable_device(pdev);
+	else
+		result = -EIO;
+	device_unlock(dev);
 
 	return result < 0 ? result : count;
 }
-- 
2.17.0

WARNING: multiple messages have this Message-ID (diff)
From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH] PCI/sysfs: do not allow enabling/disabling a device with a driver
Date: Fri, 18 May 2018 18:56:24 +0200	[thread overview]
Message-ID: <20180518165624.13993-1-hch@lst.de> (raw)

Manpulating the enable_cnt behind the back of the driver will wreck
complete havok with the kernel state, so disallow it.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/pci/pci-sysfs.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 366d93af051d..788a200fb2dc 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -288,13 +288,16 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (!val) {
-		if (pci_is_enabled(pdev))
-			pci_disable_device(pdev);
-		else
-			result = -EIO;
-	} else
+	device_lock(dev);
+	if (dev->driver)
+		result = -EBUSY;
+	else if (val)
 		result = pci_enable_device(pdev);
+	else if (pci_is_enabled(pdev))
+		pci_disable_device(pdev);
+	else
+		result = -EIO;
+	device_unlock(dev);
 
 	return result < 0 ? result : count;
 }
-- 
2.17.0

             reply	other threads:[~2018-05-18 16:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-18 16:56 Christoph Hellwig [this message]
2018-05-18 16:56 ` [PATCH] PCI/sysfs: do not allow enabling/disabling a device with a driver Christoph Hellwig
2018-05-18 17:23 ` Keith Busch
2018-05-18 17:23   ` Keith Busch
2018-05-22  7:36 ` Johannes Thumshirn
2018-05-22  7:36   ` Johannes Thumshirn
2018-05-25 22:30 ` Bjorn Helgaas
2018-05-25 22:30   ` Bjorn Helgaas

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