[PATCH RFC 01/11] PCI: sysfs: Nullify freed pointers

[Sergey Miroshnichenko]

After hotplugging a bridge the PCI topology will be changed: buses may have
their numbers changed. In this case all the affected sysfs entries/symlinks
must be recreated, because they have BDF address in their names.

Set the freed pointers to NULL, so the !NULL checks will be satisfied when
its time to recreate the sysfs entries.

Signed-off-by: Sergey Miroshnichenko <s.miroshniche...@yadro.com>
---
 drivers/pci/pci-sysfs.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 793412954529..a238935c1193 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1129,12 +1129,14 @@ static void pci_remove_resource_files(struct pci_dev 
*pdev)
                if (res_attr) {
                        sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
                        kfree(res_attr);
+                       pdev->res_attr[i] = NULL;
                }
 
                res_attr = pdev->res_attr_wc[i];
                if (res_attr) {
                        sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
                        kfree(res_attr);
+                       pdev->res_attr_wc[i] = NULL;
                }
        }
 }
@@ -1175,8 +1177,11 @@ static int pci_create_attr(struct pci_dev *pdev, int 
num, int write_combine)
        res_attr->size = pci_resource_len(pdev, num);
        res_attr->private = (void *)(unsigned long)num;
        retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
-       if (retval)
+       if (retval) {
                kfree(res_attr);
+               if (pdev->res_attr[num] == res_attr)
+                       pdev->res_attr[num] = NULL;
+       }
 
        return retval;
 }
-- 
2.23.0