PCI: fix memleak for pci dev removing during hotplug

unreferenced object 0xffff880276d17700 (size 64):
  comm "swapper/0", pid 1, jiffies 4294897182 (age 3976.028s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 18 f9 de 76 02 88 ff ff  ...........v....
    10 00 00 00 0e 00 00 00 0f 28 40 00 00 00 00 00  .........(@.....
  backtrace:
    [<ffffffff81c8aede>] kmemleak_alloc+0x26/0x43
    [<ffffffff811385f0>] __kmalloc+0x121/0x183
    [<ffffffff813cf821>] pci_add_cap_save_buffer+0x35/0x7c
    [<ffffffff813d12b7>] pci_allocate_cap_save_buffers+0x1d/0x65
    [<ffffffff813cdb52>] pci_device_add+0x92/0xf1
    [<ffffffff81c8afe6>] pci_scan_single_device+0x9f/0xa1
    [<ffffffff813cdbd2>] pci_scan_slot.part.20+0x21/0x106
    [<ffffffff813cdce2>] pci_scan_slot+0x2b/0x35
    [<ffffffff81c8dae4>] __pci_scan_child_bus+0x51/0x107
    [<ffffffff81c8d75b>] pci_scan_bridge+0x376/0x6ae
    [<ffffffff81c8db60>] __pci_scan_child_bus+0xcd/0x107
    [<ffffffff81c8dbab>] pci_scan_child_bus+0x11/0x2a
    [<ffffffff81cca58c>] pci_acpi_scan_root+0x18b/0x21c
    [<ffffffff81c916be>] acpi_pci_root_add+0x1e1/0x42a
    [<ffffffff81406210>] acpi_device_probe+0x50/0x190
    [<ffffffff814a0227>] really_probe+0x99/0x126

Need to free saved_buffer for capabilities.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/pci.c

@@ -1916,6 +1916,15 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev)
 			"unable to preallocate PCI-X save buffer\n");
 }
 
+void pci_free_cap_save_buffers(struct pci_dev *dev)
+{
+	struct pci_cap_saved_state *tmp;
+	struct hlist_node *pos, *n;
+
+	hlist_for_each_entry_safe(tmp, pos, n, &dev->saved_cap_space, next)
+		kfree(tmp);
+}
+
 /**
  * pci_enable_ari - enable ARI forwarding if hardware support it
  * @dev: the PCI device

drivers/pci/pci.h

@@ -73,6 +73,7 @@ extern int __pci_pme_wakeup(struct pci_dev *dev, void *ign);
 extern void pci_pm_init(struct pci_dev *dev);
 extern void platform_pci_wakeup_init(struct pci_dev *dev);
 extern void pci_allocate_cap_save_buffers(struct pci_dev *dev);
+void pci_free_cap_save_buffers(struct pci_dev *dev);
 
 static inline void pci_wakeup_event(struct pci_dev *dev)
 {

drivers/pci/probe.c

@@ -1024,6 +1024,7 @@ static void pci_release_capabilities(struct pci_dev *dev)
 {
 	pci_vpd_release(dev);
 	pci_iov_release(dev);
+	pci_free_cap_save_buffers(dev);
 }
 
 /**