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: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 21 insertions, 40 deletions

diff --git a/drivers/spi/pxa2xx_spi_pci.c b/drivers/spi/pxa2xx_spi_pci.c
index 351d8a375b57..19752b09e155 100644
--- a/drivers/spi/pxa2xx_spi_pci.c
+++ b/drivers/spi/pxa2xx_spi_pci.c
@@ -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 @@ err_dev_add:
         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) },
         { },
 };