On Thu, Aug 23, 2012 at 12:45 AM, Feng Tang <feng.tang@xxxxxxxxx> wrote: > From 57a28ee5e7662ca28ba4c793aa037d64bd082dee Mon Sep 17 00:00:00 2001 > From: Feng Tang <feng.tang@xxxxxxxxx> > Date: Wed, 22 Aug 2012 15:41:51 +0800 > Subject: [PATCH 1/2] PCI: Use local parameter pci_device_id for pci_get_subsys/class() > > 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 casue 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 suggeted by Bjorn Helgaas > > Bisected-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> > Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx> > Reviewed-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> > --- > drivers/pci/search.c | 35 +++++++++++------------------------ > 1 files changed, 11 insertions(+), 24 deletions(-) > > diff --git a/drivers/pci/search.c b/drivers/pci/search.c > index 993d4a0..78a08b1 100644 > --- 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); > } > > /** 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@xxxxxxxxx> 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@xxxxxxxxx> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> :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. Thanks Yinghai -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
