Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934003Ab3CLXRZ (ORCPT ); Tue, 12 Mar 2013 19:17:25 -0400 Received: from ozlabs.org ([203.10.76.45]:48626 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933449Ab3CLXRV (ORCPT ); Tue, 12 Mar 2013 19:17:21 -0400 From: Michael Neuling To: Thadeu Lima de Souza Cascardo cc: Ben Hutchings , linux-kernel@vger.kernel.org, stable@vger.kernel.org, akpm@linux-foundation.org, Gavin Shan , Benjamin Herrenschmidt Subject: Re: [ 008/153] powerpc/eeh: Fix crash when adding a device in a slot with DDW In-reply-to: <20130312181457.GA24837@oc0268524204.ibm.com> References: <20130304033707.648729212@decadent.org.uk> <20130304033708.479195432@decadent.org.uk> <1362713395.3768.466.camel@deadeye.wl.decadent.org.uk> <20130312181457.GA24837@oc0268524204.ibm.com> Comments: In-reply-to Thadeu Lima de Souza Cascardo message dated "Tue, 12 Mar 2013 15:14:57 -0300." X-Mailer: MH-E 8.2; nmh 1.5; GNU Emacs 23.4.1 Date: Wed, 13 Mar 2013 10:17:18 +1100 Message-ID: <5857.1363130238@ale.ozlabs.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7348 Lines: 180 Thadeu Lima de Souza Cascardo wrote: > On Fri, Mar 08, 2013 at 03:29:55AM +0000, Ben Hutchings wrote: > > On Fri, 2013-03-08 at 13:51 +1100, Michael Neuling wrote: > > > 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] > > > > In 3.2 this file doesn't (directly) include which is where > > the definition was added. In mainline it does. > > > > Assuming that this change is actually required for 3.2 (which I'm not > > sure about), I suppose we just need to add the #include. > > > > Ben. > > > > This is not required for 3.2. The patch that *may* have broken DLPAR > (39baadbf36cee3ede5fdb8a34006d9109e5e2570) was introduced between 3.3 > and 3.4. Reverting 066f289835f09a3f744d6bac96f25e25d20b3ded (from 3.2.40) fixes the problem for me so I'm ok if we do that instead. Mikey > > Regards. > Cascardo. > > > > 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/ > > > > > > > > > > > -- > > Ben Hutchings > > Always try to do things in chronological order; > > it's less confusing that way. > > -- 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/