PCI: Use pci_device_id on stack for pci_get_subsys/class() to avoid kmalloc

This fixes a kernel warning https://lkml.org/lkml/2012/7/31/682

pci_get_subsys() may get called in late system reboot stage, using
a sleepable kmalloc() sounds fragile and will cause a kernel warning
with my recent commmit 55c844a "x86/reboot: Fix a warning message
triggered by stop_other_cpus()" which disable local interrupt in
late system shutdown/reboot phase. Using a local parameter instead
will fix it and make it eligible for calling forom atomic context.

Do the same change for the pci_get_class() as suggested by Bjorn Helgaas

[bhelgaas: changelog]
Bisected-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Fengguang Wu <fengguang.wu@intel.com>

diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 993d4a0a24699661bc2adfef5125a6be07f50a64..78a08b1a0454f30dad95f8e9bb01fe247623edf9 100644 (file)
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -245,8 +245,7 @@ struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
                               unsigned int ss_vendor, unsigned int ss_device,
                               struct pci_dev *from)
 {
-       struct pci_dev *pdev;
-       struct pci_device_id *id;
+       struct pci_device_id id;
 
        /*
         * pci_find_subsys() can be called on the ide_setup() path,
@@ -257,18 +256,12 @@ struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
        if (unlikely(no_pci_devices()))
                return NULL;
 
-       id = kzalloc(sizeof(*id), GFP_KERNEL);
-       if (!id)
-               return NULL;
-       id->vendor = vendor;
-       id->device = device;
-       id->subvendor = ss_vendor;
-       id->subdevice = ss_device;
-
-       pdev = pci_get_dev_by_id(id, from);
-       kfree(id);
+       id.vendor = vendor;
+       id.device = device;
+       id.subvendor = ss_vendor;
+       id.subdevice = ss_device;
 
-       return pdev;
+       return pci_get_dev_by_id(&id, from);
 }
 
 /**
@@ -307,19 +300,13 @@ pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
  */
 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
 {
-       struct pci_dev *dev;
-       struct pci_device_id *id;
+       struct pci_device_id id;
 
-       id = kzalloc(sizeof(*id), GFP_KERNEL);
-       if (!id)
-               return NULL;
-       id->vendor = id->device = id->subvendor = id->subdevice = PCI_ANY_ID;
-       id->class_mask = PCI_ANY_ID;
-       id->class = class;
+       id.vendor = id.device = id.subvendor = id.subdevice = PCI_ANY_ID;
+       id.class_mask = PCI_ANY_ID;
+       id.class = class;
 
-       dev = pci_get_dev_by_id(id, from);
-       kfree(id);
-       return dev;
+       return pci_get_dev_by_id(&id, from);
 }
 
 /**