Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760253Ab3CHCvy (ORCPT ); Thu, 7 Mar 2013 21:51:54 -0500 Received: from mail-oa0-f51.google.com ([209.85.219.51]:40737 "EHLO mail-oa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753474Ab3CHCvx (ORCPT ); Thu, 7 Mar 2013 21:51:53 -0500 MIME-Version: 1.0 In-Reply-To: <20130304033708.479195432@decadent.org.uk> References: <20130304033707.648729212@decadent.org.uk> <20130304033708.479195432@decadent.org.uk> Date: Fri, 8 Mar 2013 13:51:52 +1100 X-Google-Sender-Auth: 4FPUhDvvhr6DdYqSuXGBHS6LuOA Message-ID: Subject: Re: [ 008/153] powerpc/eeh: Fix crash when adding a device in a slot with DDW From: Michael Neuling To: Ben Hutchings Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, akpm@linux-foundation.org, Thadeu Lima de Souza Cascardo , Gavin Shan , Benjamin Herrenschmidt Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5575 Lines: 146 This patch is breaking the celleb_defconfig on powerpc with: arch/powerpc/kernel/of_platform.c: In function 'of_pci_phb_probe': arch/powerpc/kernel/of_platform.c:95:2: error: implicit declaration of function 'eeh_add_sysfs_files' [-Werror=implicit-function-declaration] Mikey On Mon, Mar 4, 2013 at 2:37 PM, Ben Hutchings wrote: > 3.2-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Thadeu Lima de Souza Cascardo > > commit 6a040ce72598159a74969a2d01ab0ba5ee6536b3 upstream. > > The DDW code uses a eeh_dev struct from the pci_dev. However, this is > not set until eeh_add_device_late is called. > > Since pci_bus_add_devices is called before eeh_add_device_late, the PCI > devices are added to the bus, making drivers' probe hooks to be called. > These will call set_dma_mask, which will call the DDW code, which will > require the eeh_dev struct from pci_dev. This would result in a crash, > due to a NULL dereference. > > Calling eeh_add_device_late after pci_bus_add_devices would make the > system BUG, because device files shouldn't be added to devices there > were not added to the system. So, a new function is needed to add such > files only after pci_bus_add_devices have been called. > > Signed-off-by: Thadeu Lima de Souza Cascardo > Acked-by: Gavin Shan > Signed-off-by: Benjamin Herrenschmidt > [bwh: Backported to 3.2: adjust context] > Signed-off-by: Ben Hutchings > --- > arch/powerpc/include/asm/eeh.h | 3 +++ > arch/powerpc/kernel/of_platform.c | 3 +++ > arch/powerpc/kernel/pci-common.c | 7 +++++-- > arch/powerpc/platforms/pseries/eeh.c | 24 +++++++++++++++++++++++- > 4 files changed, 34 insertions(+), 3 deletions(-) > > --- a/arch/powerpc/include/asm/eeh.h > +++ b/arch/powerpc/include/asm/eeh.h > @@ -61,6 +61,7 @@ void __init pci_addr_cache_build(void); > */ > void eeh_add_device_tree_early(struct device_node *); > void eeh_add_device_tree_late(struct pci_bus *); > +void eeh_add_sysfs_files(struct pci_bus *); > > /** > * eeh_remove_device_recursive - undo EEH for device & children. > @@ -105,6 +106,8 @@ static inline void eeh_add_device_tree_e > > static inline void eeh_add_device_tree_late(struct pci_bus *bus) { } > > +static inline void eeh_add_sysfs_files(struct pci_bus *bus) { } > + > static inline void eeh_remove_bus_device(struct pci_dev *dev) { } > #define EEH_POSSIBLE_ERROR(val, type) (0) > #define EEH_IO_ERROR_VALUE(size) (-1UL) > --- a/arch/powerpc/kernel/of_platform.c > +++ b/arch/powerpc/kernel/of_platform.c > @@ -91,6 +91,9 @@ static int __devinit of_pci_phb_probe(st > /* Add probed PCI devices to the device model */ > pci_bus_add_devices(phb->bus); > > + /* sysfs files should only be added after devices are added */ > + eeh_add_sysfs_files(phb->bus); > + > return 0; > } > > --- a/arch/powerpc/kernel/pci-common.c > +++ b/arch/powerpc/kernel/pci-common.c > @@ -1536,11 +1536,14 @@ void pcibios_finish_adding_to_bus(struct > pcibios_allocate_bus_resources(bus); > pcibios_claim_one_bus(bus); > > + /* Fixup EEH */ > + eeh_add_device_tree_late(bus); > + > /* Add new devices to global lists. Register in proc, sysfs. */ > pci_bus_add_devices(bus); > > - /* Fixup EEH */ > - eeh_add_device_tree_late(bus); > + /* sysfs files should only be added after devices are added */ > + eeh_add_sysfs_files(bus); > } > EXPORT_SYMBOL_GPL(pcibios_finish_adding_to_bus); > > --- a/arch/powerpc/platforms/pseries/eeh.c > +++ b/arch/powerpc/platforms/pseries/eeh.c > @@ -1238,7 +1238,6 @@ static void eeh_add_device_late(struct p > pdn->pcidev = dev; > > pci_addr_cache_insert_device(dev); > - eeh_sysfs_add_device(dev); > } > > void eeh_add_device_tree_late(struct pci_bus *bus) > @@ -1257,6 +1256,29 @@ void eeh_add_device_tree_late(struct pci > EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); > > /** > + * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus > + * @bus: PCI bus > + * > + * This routine must be used to add EEH sysfs files for PCI > + * devices which are attached to the indicated PCI bus. The PCI bus > + * is added after system boot through hotplug or dlpar. > + */ > +void eeh_add_sysfs_files(struct pci_bus *bus) > +{ > + struct pci_dev *dev; > + > + list_for_each_entry(dev, &bus->devices, bus_list) { > + eeh_sysfs_add_device(dev); > + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { > + struct pci_bus *subbus = dev->subordinate; > + if (subbus) > + eeh_add_sysfs_files(subbus); > + } > + } > +} > +EXPORT_SYMBOL_GPL(eeh_add_sysfs_files); > + > +/** > * eeh_remove_device - undo EEH setup for the indicated pci device > * @dev: pci device to be removed > * > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/