* [PATCH] ppc/EEH: fix crash when adding a device in a slot with DDW
@ 2012-12-27 16:34 Thadeu Lima de Souza Cascardo
[not found] ` <20121228051824.GA9975@shangw.(null)>
0 siblings, 1 reply; 4+ messages in thread
From: Thadeu Lima de Souza Cascardo @ 2012-12-27 16:34 UTC (permalink / raw)
To: linuxppc-dev
Cc: linux-kernel, benh, shangw, paulus, bhelgaas,
Thadeu Lima de Souza Cascardo, stable
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.
Cc: stable@vger.kernel.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/eeh.h | 3 +++
arch/powerpc/kernel/pci-common.c | 7 +++++--
arch/powerpc/platforms/pseries/eeh.c | 24 +++++++++++++++++++++++-
3 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index b0ef738..71aac19 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h
@@ -201,6 +201,7 @@ int eeh_dev_check_failure(struct eeh_dev *edev);
void __init eeh_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_device_tree_files(struct pci_bus *);
void eeh_remove_bus_device(struct pci_dev *, int);
/**
@@ -240,6 +241,8 @@ 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_device_tree_files(struct pci_bus *bus) { }
+
static inline void eeh_remove_bus_device(struct pci_dev *dev, int purge_pe) { }
static inline void eeh_lock(void) { }
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 7f94f76..7b1f14c 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1480,11 +1480,14 @@ 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);
+ /* Add EEH sysfs files */
+ eeh_add_device_tree_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 9a04322..a667a34 100644
--- a/arch/powerpc/platforms/pseries/eeh.c
+++ b/arch/powerpc/platforms/pseries/eeh.c
@@ -788,7 +788,6 @@ static void eeh_add_device_late(struct pci_dev *dev)
dev->dev.archdata.edev = edev;
eeh_addr_cache_insert_dev(dev);
- eeh_sysfs_add_device(dev);
}
/**
@@ -815,6 +814,29 @@ void eeh_add_device_tree_late(struct pci_bus *bus)
EXPORT_SYMBOL_GPL(eeh_add_device_tree_late);
/**
+ * eeh_add_device_tree_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_device_tree_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_device_tree_files(subbus);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(eeh_add_device_tree_files);
+
+/**
* eeh_remove_device - Undo EEH setup for the indicated pci device
* @dev: pci device to be removed
* @purge_pe: remove the PE or not
--
1.7.1
^ permalink raw reply [flat|nested] 4+ messages in thread[parent not found: <20121228051824.GA9975@shangw.(null)>]
* Re: [PATCH] ppc/EEH: fix crash when adding a device in a slot with DDW [not found] ` <20121228051824.GA9975@shangw.(null)> @ 2012-12-28 12:06 ` Thadeu Lima de Souza Cascardo 2012-12-28 19:13 ` [PATCH 1/2] EEH/OF: checking for CONFIG_EEH is not needed Thadeu Lima de Souza Cascardo 2012-12-28 19:13 ` [PATCH 2/2] ppc/EEH: fix crash when adding a device in a slot with DDW Thadeu Lima de Souza Cascardo 0 siblings, 2 replies; 4+ messages in thread From: Thadeu Lima de Souza Cascardo @ 2012-12-28 12:06 UTC (permalink / raw) To: Gavin Shan; +Cc: linuxppc-dev, linux-kernel, benh, paulus, bhelgaas, stable On Fri, Dec 28, 2012 at 01:18:24PM +0800, Gavin Shan wrote: > On Thu, Dec 27, 2012 at 02:34:00PM -0200, Thadeu Lima de Souza Cascardo wrote: > >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. > > > > Could you please explain for a bit how did you trigger the problem? I'm > not sure you got it while doing PCI hotplug or just saw the issue during > system bootup stage :-) > I did a DLPAR remove followed by a DLPAR add, using drmgr -r and drmgr -a. The reason the issue is not trigerred during bootup is that there is no driver registered yet. So no driver probe will call dma_set_mask. > >Cc: stable@vger.kernel.org > >Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> > >--- > > arch/powerpc/include/asm/eeh.h | 3 +++ > > arch/powerpc/kernel/pci-common.c | 7 +++++-- > > arch/powerpc/platforms/pseries/eeh.c | 24 +++++++++++++++++++++++- > > 3 files changed, 31 insertions(+), 3 deletions(-) > > > >diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h > >index b0ef738..71aac19 100644 > >--- a/arch/powerpc/include/asm/eeh.h > >+++ b/arch/powerpc/include/asm/eeh.h > >@@ -201,6 +201,7 @@ int eeh_dev_check_failure(struct eeh_dev *edev); > > void __init eeh_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_device_tree_files(struct pci_bus *); > > Since the function is going to add EEH specific sysfs files, its name would > be something like "eeh_add_sysfs_files" instead of "eeh_add_device_tree_files" :-) It's indeed a better name. > > > void eeh_remove_bus_device(struct pci_dev *, int); > > > > /** > >@@ -240,6 +241,8 @@ 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_device_tree_files(struct pci_bus *bus) { } > >+ > > It'd better to rename the function name to "eeh_add_sysfs_files" mentioned > as above. > > > static inline void eeh_remove_bus_device(struct pci_dev *dev, int purge_pe) { } > > > > static inline void eeh_lock(void) { } > >diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c > >index 7f94f76..7b1f14c 100644 > >--- a/arch/powerpc/kernel/pci-common.c > >+++ b/arch/powerpc/kernel/pci-common.c > >@@ -1480,11 +1480,14 @@ 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); > >+ /* Add EEH sysfs files */ > >+ eeh_add_device_tree_files(bus); > > The function name would be "eeh_add_sysfs_files" as above. > > > } > > EXPORT_SYMBOL_GPL(pcibios_finish_adding_to_bus); > > > > By the way, arch/powerpc/kernel/of_platform.c::of_pci_phb_probe is also calling > to eeh_add_device_tree_late() as well. Since you have removed part of the logic > from original eeh_add_device_tree_late(), which is add EEH specific sysfs files, > and you put that part of logic to eeh_add_device_tree_files(). So I think you > also need make the similiar change for of_pci_phb_probe() as well :-) > Good point. I will look into other call sites. However, I don't have access to other platforms to test the patch. > >diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c > >index 9a04322..a667a34 100644 > >--- a/arch/powerpc/platforms/pseries/eeh.c > >+++ b/arch/powerpc/platforms/pseries/eeh.c > >@@ -788,7 +788,6 @@ static void eeh_add_device_late(struct pci_dev *dev) > > dev->dev.archdata.edev = edev; > > > > eeh_addr_cache_insert_dev(dev); > >- eeh_sysfs_add_device(dev); > > } > > > > /** > >@@ -815,6 +814,29 @@ void eeh_add_device_tree_late(struct pci_bus *bus) > > EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); > > > > /** > >+ * eeh_add_device_tree_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_device_tree_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_device_tree_files(subbus); > >+ } > >+ } > >+} > >+EXPORT_SYMBOL_GPL(eeh_add_device_tree_files); > >+ > > The function name mentioned as above. > > >+/** > > * eeh_remove_device - Undo EEH setup for the indicated pci device > > * @dev: pci device to be removed > > * @purge_pe: remove the PE or not > > > > Thanks, > Gavin > Regards, Thadeu Cascardo. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/2] EEH/OF: checking for CONFIG_EEH is not needed 2012-12-28 12:06 ` Thadeu Lima de Souza Cascardo @ 2012-12-28 19:13 ` Thadeu Lima de Souza Cascardo 2012-12-28 19:13 ` [PATCH 2/2] ppc/EEH: fix crash when adding a device in a slot with DDW Thadeu Lima de Souza Cascardo 1 sibling, 0 replies; 4+ messages in thread From: Thadeu Lima de Souza Cascardo @ 2012-12-28 19:13 UTC (permalink / raw) To: linuxppc-dev Cc: linux-kernel, shangw, paulus, bhelgaas, Thadeu Lima de Souza Cascardo The functions used are already defined as empty inline functions for the case where EEH is disabled. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> --- arch/powerpc/kernel/of_platform.c | 4 ---- 1 files changed, 0 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/of_platform.c b/arch/powerpc/kernel/of_platform.c index 2049f2d..c5fc6b2 100644 --- a/arch/powerpc/kernel/of_platform.c +++ b/arch/powerpc/kernel/of_platform.c @@ -71,10 +71,8 @@ static int __devinit of_pci_phb_probe(struct platform_device *dev) eeh_dev_phb_init_dynamic(phb); /* Register devices with EEH */ -#ifdef CONFIG_EEH if (dev->dev.of_node->child) eeh_add_device_tree_early(dev->dev.of_node); -#endif /* CONFIG_EEH */ /* Scan the bus */ pcibios_scan_phb(phb); @@ -88,9 +86,7 @@ static int __devinit of_pci_phb_probe(struct platform_device *dev) pcibios_claim_one_bus(phb->bus); /* Finish EEH setup */ -#ifdef CONFIG_EEH eeh_add_device_tree_late(phb->bus); -#endif /* Add probed PCI devices to the device model */ pci_bus_add_devices(phb->bus); -- 1.7.1 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 2/2] ppc/EEH: fix crash when adding a device in a slot with DDW 2012-12-28 12:06 ` Thadeu Lima de Souza Cascardo 2012-12-28 19:13 ` [PATCH 1/2] EEH/OF: checking for CONFIG_EEH is not needed Thadeu Lima de Souza Cascardo @ 2012-12-28 19:13 ` Thadeu Lima de Souza Cascardo 1 sibling, 0 replies; 4+ messages in thread From: Thadeu Lima de Souza Cascardo @ 2012-12-28 19:13 UTC (permalink / raw) To: linuxppc-dev Cc: linux-kernel, shangw, paulus, bhelgaas, Thadeu Lima de Souza Cascardo, stable 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. Cc: stable@vger.kernel.org Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> --- 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(-) diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index b0ef738..0f816da 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -201,6 +201,7 @@ int eeh_dev_check_failure(struct eeh_dev *edev); void __init eeh_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 *, int); /** @@ -240,6 +241,8 @@ 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, int purge_pe) { } static inline void eeh_lock(void) { } diff --git a/arch/powerpc/kernel/of_platform.c b/arch/powerpc/kernel/of_platform.c index c5fc6b2..500dd32 100644 --- 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(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 7f94f76..4d3de7e 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1480,11 +1480,14 @@ 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 9a04322..6b73d6c 100644 --- a/arch/powerpc/platforms/pseries/eeh.c +++ b/arch/powerpc/platforms/pseries/eeh.c @@ -788,7 +788,6 @@ static void eeh_add_device_late(struct pci_dev *dev) dev->dev.archdata.edev = edev; eeh_addr_cache_insert_dev(dev); - eeh_sysfs_add_device(dev); } /** @@ -815,6 +814,29 @@ 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 * @purge_pe: remove the PE or not -- 1.7.1 ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-12-28 19:13 UTC | newest]
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2012-12-27 16:34 [PATCH] ppc/EEH: fix crash when adding a device in a slot with DDW Thadeu Lima de Souza Cascardo
[not found] ` <20121228051824.GA9975@shangw.(null)>
2012-12-28 12:06 ` Thadeu Lima de Souza Cascardo
2012-12-28 19:13 ` [PATCH 1/2] EEH/OF: checking for CONFIG_EEH is not needed Thadeu Lima de Souza Cascardo
2012-12-28 19:13 ` [PATCH 2/2] ppc/EEH: fix crash when adding a device in a slot with DDW Thadeu Lima de Souza Cascardo
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