lkml.org 
[lkml]   [2012]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH 1/2] PCI: Use local parameter pci_device_id for pci_get_subsys/class()
    From
    On Sat, Sep 8, 2012 at 6:42 AM, Fengguang Wu <fengguang.wu@intel.com> wrote:
    > On Fri, Sep 07, 2012 at 06:32:48PM -0700, Yinghai Lu wrote:
    >
    >> > with this one in pci/next pci config in /sys are not created.
    >> >
    >> > 10:~ # lspci -tv
    >> > pcilib: Cannot open /sys/bus/pci/devices/0000:00:03.0/config
    >> > lspci: Unable to read the standard configuration space header of
    >> > device 0000:00:03.0
    >> > pcilib: Cannot open /sys/bus/pci/devices/0000:00:02.0/config
    >> > lspci: Unable to read the standard configuration space header of
    >> > device 0000:00:02.0
    >> > pcilib: Cannot open /sys/bus/pci/devices/0000:00:01.3/config
    >> > lspci: Unable to read the standard configuration space header of
    >> > device 0000:00:01.3
    >> > pcilib: Cannot open /sys/bus/pci/devices/0000:00:01.1/config
    >> > lspci: Unable to read the standard configuration space header of
    >> > device 0000:00:01.1
    >> > pcilib: Cannot open /sys/bus/pci/devices/0000:00:01.0/config
    >> > lspci: Unable to read the standard configuration space header of
    >> > device 0000:00:01.0
    >> > pcilib: Cannot open /sys/bus/pci/devices/0000:00:00.0/config
    >> > lspci: Unable to read the standard configuration space header of
    >> > device 0000:00:00.0
    >> > -[0000:00]-
    >> >
    >> > bisected to this commit
    >> >
    >> > ccee7d23102f5e5765ec24779c5b77472af8f79e is the first bad commit
    >> > commit ccee7d23102f5e5765ec24779c5b77472af8f79e
    >> > Author: Feng Tang <feng.tang@intel.com>
    >> > Date: Thu Aug 23 15:45:03 2012 +0800
    >> >
    >> > 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>
    >> >
    >> > :040000 040000 dee62a035816b73abc68e40de8f21c7349efc4cb
    >> > 70b2a6258bffa1ab963bd650d8f5d02da774fbce M drivers
    >> >
    >> > so the stack get overrun ?
    >> >
    >> > Bjorn, I think it is this one that cause lspci broken that I mentioned
    >> > during meeting at San Diego.
    >
    > This makes lspci work again on my side. The caveat is, kzalloc() will
    > zero out all data while the new local variable leaves some data
    > uninitialized.
    >
    > diff --git a/drivers/pci/search.c b/drivers/pci/search.c
    > index 78a08b1..9148b6e 100644
    > --- a/drivers/pci/search.c
    > +++ b/drivers/pci/search.c
    > @@ -245,7 +245,12 @@ 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_device_id id;
    > + struct pci_device_id id = {
    > + .vendor = vendor,
    > + .device = device,
    > + .subvendor = ss_vendor,
    > + .subdevice = ss_device,
    > + };
    >
    > /*
    > * pci_find_subsys() can be called on the ide_setup() path,
    > @@ -256,11 +261,6 @@ struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
    > if (unlikely(no_pci_devices()))
    > return NULL;
    >
    > - id.vendor = vendor;
    > - id.device = device;
    > - id.subvendor = ss_vendor;
    > - id.subdevice = ss_device;
    > -

    yes, here forget to clear .class and .class_mask

    > return pci_get_dev_by_id(&id, from);
    > }
    >
    > @@ -300,11 +300,14 @@ 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_device_id id;
    > -
    > - id.vendor = id.device = id.subvendor = id.subdevice = PCI_ANY_ID;
    > - id.class_mask = PCI_ANY_ID;
    > - id.class = class;
    > + struct pci_device_id id = {
    > + .vendor = PCI_ANY_ID,
    > + .device = PCI_ANY_ID,
    > + .subvendor = PCI_ANY_ID,
    > + .subdevice = PCI_ANY_ID,
    > + .class_mask = PCI_ANY_ID,
    > + .class = class,
    > + };
    >
    > return pci_get_dev_by_id(&id, from);
    > }


    \
     
     \ /
      Last update: 2012-09-08 18:21    [W:0.040 / U:0.112 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site