From patchwork Tue Feb 26 16:12:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3.5.y.z, extended, stable] Patch "powerpc/eeh: Fix crash when adding a device in a slot with" has been added to staging queue Date: Tue, 26 Feb 2013 06:12:40 -0000 From: Luis Henriques X-Patchwork-Id: 223267 Message-Id: <1361895160-26573-1-git-send-email-luis.henriques@canonical.com> To: Thadeu Lima de Souza Cascardo Cc: Benjamin Herrenschmidt , kernel-team@lists.ubuntu.com, Gavin Shan This is a note to let you know that I have just added a patch titled powerpc/eeh: Fix crash when adding a device in a slot with to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ >From f5e56b84c4d3d953f80c2452dc4f8a44d9750968 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Fri, 28 Dec 2012 09:13:19 +0000 Subject: [PATCH] powerpc/eeh: Fix crash when adding a device in a slot with DDW 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 [ luis: adjust context ] Signed-off-by: Luis Henriques --- arch/powerpc/include/asm/eeh.h | 4 ++++ arch/powerpc/kernel/of_platform.c | 3 +++ arch/powerpc/kernel/pci-common.c | 7 +++++-- arch/powerpc/platforms/pseries/eeh.c | 24 +++++++++++++++++++++++- 4 files changed, 35 insertions(+), 3 deletions(-) -- 1.8.1.2 diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index d60f998..c487556 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -130,6 +130,7 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev); 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 *); void eeh_remove_bus_device(struct pci_dev *); /** @@ -183,7 +184,10 @@ static inline void eeh_add_device_tree_early(struct device_node *dn) { } 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) #endif /* CONFIG_EEH */ diff --git a/arch/powerpc/kernel/of_platform.c b/arch/powerpc/kernel/of_platform.c index 2049f2d..2089fbd 100644 --- a/arch/powerpc/kernel/of_platform.c +++ b/arch/powerpc/kernel/of_platform.c @@ -95,6 +95,9 @@ static int __devinit of_pci_phb_probe(struct platform_device *dev) /* 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; } diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 8e78e93..41d69fc 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1458,11 +1458,14 @@ void pcibios_finish_adding_to_bus(struct pci_bus *bus) 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); diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c index 9a0b5f5..b1d91b5 100644 --- a/arch/powerpc/platforms/pseries/eeh.c +++ b/arch/powerpc/platforms/pseries/eeh.c @@ -1088,7 +1088,6 @@ static void eeh_add_device_late(struct pci_dev *dev) dev->dev.archdata.edev = edev; pci_addr_cache_insert_device(dev); - eeh_sysfs_add_device(dev); } /** @@ -1115,6 +1114,29 @@ void eeh_add_device_tree_late(struct pci_bus *bus) 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 *