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Commit 0f3e1d27 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Grant Likely
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spi/pxa2xx pci: fix the release - remove race 



Right now the platform device and its platform data is included in one big
struct which requires its custom ->release function. The problem with the
release function within the driver is that it might be called after the
driver was removed because someone was holding a reference to it and it
was not called right after platform_device_unregister(). So we also free
the platform device memory to which one might hold a reference.

This patch uses the normal pdev functions so this kind of race does not
occur.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent c170093d

drivers/spi/pxa2xx_spi_pci.c

+21 −40
Original line number Diff line number Diff line
@@ -7,10 +7,9 @@ 
#include <linux/of_device.h>

#include <linux/spi/pxa2xx_spi.h>



struct awesome_struct {

struct ce4100_info {

	struct ssp_device ssp;

	struct platform_device spi_pdev;

	struct pxa2xx_spi_master spi_pdata;

	struct platform_device *spi_pdev;

};



static DEFINE_MUTEX(ssp_lock);
@@ -51,23 +50,15 @@ void pxa_ssp_free(struct ssp_device *ssp) 
}

EXPORT_SYMBOL_GPL(pxa_ssp_free);



static void plat_dev_release(struct device *dev)

{

	struct awesome_struct *as = container_of(dev,

			struct awesome_struct, spi_pdev.dev);



	of_device_node_put(&as->spi_pdev.dev);

}



static int __devinit ce4100_spi_probe(struct pci_dev *dev,

		const struct pci_device_id *ent)

{

	int ret;

	resource_size_t phys_beg;

	resource_size_t phys_len;

	struct awesome_struct *spi_info;

	struct ce4100_info *spi_info;

	struct platform_device *pdev;

	struct pxa2xx_spi_master *spi_pdata;

	struct pxa2xx_spi_master spi_pdata;

	struct ssp_device *ssp;



	ret = pci_enable_device(dev);
@@ -84,33 +75,30 @@ static int __devinit ce4100_spi_probe(struct pci_dev *dev, 
		return ret;

	}



	pdev = platform_device_alloc("pxa2xx-spi", dev->devfn);

	spi_info = kzalloc(sizeof(*spi_info), GFP_KERNEL);

	if (!spi_info) {

	if (!pdev || !spi_info ) {

		ret = -ENOMEM;

		goto err_kz;

		goto err_nomem;

	}

	ssp = &spi_info->ssp;

	pdev = &spi_info->spi_pdev;

	spi_pdata =  &spi_info->spi_pdata;

	memset(&spi_pdata, 0, sizeof(spi_pdata));

	spi_pdata.num_chipselect = dev->devfn;



	pdev->name = "pxa2xx-spi";

	pdev->id = dev->devfn;

	pdev->dev.parent = &dev->dev;

	pdev->dev.platform_data = &spi_info->spi_pdata;

	ret = platform_device_add_data(pdev, &spi_pdata, sizeof(spi_pdata));

	if (ret)

		goto err_nomem;



	pdev->dev.parent = &dev->dev;

#ifdef CONFIG_OF

	pdev->dev.of_node = dev->dev.of_node;

#endif

	pdev->dev.release = plat_dev_release;



	spi_pdata->num_chipselect = dev->devfn;



	ssp = &spi_info->ssp;

	ssp->phys_base = pci_resource_start(dev, 0);

	ssp->mmio_base = ioremap(phys_beg, phys_len);

	if (!ssp->mmio_base) {

		dev_err(&pdev->dev, "failed to ioremap() registers\n");

		ret = -EIO;

		goto err_remap;

		goto err_nomem;

	}

	ssp->irq = dev->irq;

	ssp->port_id = pdev->id;
@@ -122,7 +110,7 @@ static int __devinit ce4100_spi_probe(struct pci_dev *dev, 


	pci_set_drvdata(dev, spi_info);



	ret = platform_device_register(pdev);

	ret = platform_device_add(pdev);

	if (ret)

		goto err_dev_add;
@@ -135,27 +123,21 @@ static int __devinit ce4100_spi_probe(struct pci_dev *dev, 
	mutex_unlock(&ssp_lock);

	iounmap(ssp->mmio_base);



err_remap:

	kfree(spi_info);



err_kz:

err_nomem:

	release_mem_region(phys_beg, phys_len);



	platform_device_put(pdev);

	kfree(spi_info);

	return ret;

}



static void __devexit ce4100_spi_remove(struct pci_dev *dev)

{

	struct awesome_struct *spi_info;

	struct platform_device *pdev;

	struct ce4100_info *spi_info;

	struct ssp_device *ssp;



	spi_info = pci_get_drvdata(dev);



	ssp = &spi_info->ssp;

	pdev = &spi_info->spi_pdev;



	platform_device_unregister(pdev);

	platform_device_unregister(spi_info->spi_pdev);



	iounmap(ssp->mmio_base);

	release_mem_region(pci_resource_start(dev, 0),
@@ -171,7 +153,6 @@ static void __devexit ce4100_spi_remove(struct pci_dev *dev) 
}



static struct pci_device_id ce4100_spi_devices[] __devinitdata = {



	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2e6a) },

	{ },

};