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 <redacted>
---
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
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 :-)
quoted hunk
Cc: stable@vger.kernel.org
Signed-off-by: Thadeu Lima de Souza Cascardo <redacted>
---
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" :-)
quoted hunk
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.
quoted hunk
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 :-)
quoted hunk
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