| Message ID | 20120908134220.GA24831@localhost (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
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); > } -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, 8 Sep 2012 21:42:20 +0800 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. Yes, thanks for the quick root cause and fix to the bug in my code. - Feng -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Sep 8, 2012 at 8:34 AM, Feng Tang <feng.tang@intel.com> wrote: >> 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. > > Yes, thanks for the quick root cause and fix to the bug in my code. Can you resubmit your patch with two extra "memset" line? Thanks Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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; - 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); }