mk-rootfs.sh

hc

2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376

 kernel/drivers/uio/uio_pci_generic.c
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@@ -39,6 +39,22 @@
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 	return container_of(info, struct uio_pci_generic_dev, info);
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 }
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+static int release(struct uio_info *info, struct inode *inode)
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+{
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+	struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info);
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+
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+	/*
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+	 * This driver is insecure when used with devices doing DMA, but some
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+	 * people (mis)use it with such devices.
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+	 * Let's at least make sure DMA isn't left enabled after the userspace
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+	 * driver closes the fd.
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+	 * Note that there's a non-zero chance doing this will wedge the device
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+	 * at least until reset.
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+	 */
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+	pci_clear_master(gdev->pdev);
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+	return 0;
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+}
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+
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 /* Interrupt handler. Read/modify/write the command register to disable
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  * the interrupt. */
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 static irqreturn_t irqhandler(int irq, struct uio_info *info)
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@@ -78,6 +94,7 @@
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 	gdev->info.name = "uio_pci_generic";
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 	gdev->info.version = DRIVER_VERSION;
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+	gdev->info.release = release;
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 	gdev->pdev = pdev;
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 	if (pdev->irq) {
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 		gdev->info.irq = pdev->irq;