Searched hist:19398821 (Results 1 – 3 of 3) sorted by relevance
| /openbmc/linux/drivers/cxl/core/ |
| H A D | pmem.c | 19398821 Fri Jan 20 18:26:12 CST 2023 Dan Williams <dan.j.williams@intel.com> cxl/pmem: Fix nvdimm unregistration when cxl_pmem driver is absent
The cxl_pmem.ko module houses the driver for both cxl_nvdimm_bridge
objects and cxl_nvdimm objects. When the core creates a cxl_nvdimm it
arranges for it to be autoremoved when the bridge goes down. However, if
the bridge never initialized because the cxl_pmem.ko module never
loaded, it sets up a the following crash scenario:
BUG: kernel NULL pointer dereference, address: 0000000000000478
[..]
RIP: 0010:cxl_nvdimm_probe+0x99/0x140 [cxl_pmem]
[..]
Call Trace:
<TASK>
cxl_bus_probe+0x17/0x50 [cxl_core]
really_probe+0xde/0x380
__driver_probe_device+0x78/0x170
driver_probe_device+0x1f/0x90
__driver_attach+0xd2/0x1c0
bus_for_each_dev+0x79/0xc0
bus_add_driver+0x1b1/0x200
driver_register+0x89/0xe0
cxl_pmem_init+0x50/0xff0 [cxl_pmem]
It turns out the recent rework to simplify nvdimm probing obviated the
need to unregister cxl_nvdimm objects at cxl_nvdimm_bridge ->remove()
time. Leave the cxl_nvdimm device registered until the hosting
cxl_memdev departs. The alternative is that the cxl_memdev needs to be
reattached whenever the cxl_nvdimm_bridge attach state cycles, which is
awkward and unnecessary.
The only requirement is to make sure that when the cxl_nvdimm_bridge
goes away any dependent cxl_nvdimm objects are shutdown. Handle that in
unregister_nvdimm_bus().
With these registration entanglements removed there is no longer a need
to pre-load the cxl_pmem module in cxl_acpi.
Fixes: cb9cfff82f6a ("cxl/acpi: Simplify cxl_nvdimm_bridge probing")
Reported-by: Gregory Price <gregory.price@memverge.com>
Debugged-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/167426077263.3955046.9695309346988027311.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
|
| /openbmc/linux/drivers/cxl/ |
| H A D | pmem.c | 19398821 Fri Jan 20 18:26:12 CST 2023 Dan Williams <dan.j.williams@intel.com> cxl/pmem: Fix nvdimm unregistration when cxl_pmem driver is absent
The cxl_pmem.ko module houses the driver for both cxl_nvdimm_bridge
objects and cxl_nvdimm objects. When the core creates a cxl_nvdimm it
arranges for it to be autoremoved when the bridge goes down. However, if
the bridge never initialized because the cxl_pmem.ko module never
loaded, it sets up a the following crash scenario:
BUG: kernel NULL pointer dereference, address: 0000000000000478
[..]
RIP: 0010:cxl_nvdimm_probe+0x99/0x140 [cxl_pmem]
[..]
Call Trace:
<TASK>
cxl_bus_probe+0x17/0x50 [cxl_core]
really_probe+0xde/0x380
__driver_probe_device+0x78/0x170
driver_probe_device+0x1f/0x90
__driver_attach+0xd2/0x1c0
bus_for_each_dev+0x79/0xc0
bus_add_driver+0x1b1/0x200
driver_register+0x89/0xe0
cxl_pmem_init+0x50/0xff0 [cxl_pmem]
It turns out the recent rework to simplify nvdimm probing obviated the
need to unregister cxl_nvdimm objects at cxl_nvdimm_bridge ->remove()
time. Leave the cxl_nvdimm device registered until the hosting
cxl_memdev departs. The alternative is that the cxl_memdev needs to be
reattached whenever the cxl_nvdimm_bridge attach state cycles, which is
awkward and unnecessary.
The only requirement is to make sure that when the cxl_nvdimm_bridge
goes away any dependent cxl_nvdimm objects are shutdown. Handle that in
unregister_nvdimm_bus().
With these registration entanglements removed there is no longer a need
to pre-load the cxl_pmem module in cxl_acpi.
Fixes: cb9cfff82f6a ("cxl/acpi: Simplify cxl_nvdimm_bridge probing")
Reported-by: Gregory Price <gregory.price@memverge.com>
Debugged-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/167426077263.3955046.9695309346988027311.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
|
| H A D | acpi.c | 19398821 Fri Jan 20 18:26:12 CST 2023 Dan Williams <dan.j.williams@intel.com> cxl/pmem: Fix nvdimm unregistration when cxl_pmem driver is absent
The cxl_pmem.ko module houses the driver for both cxl_nvdimm_bridge
objects and cxl_nvdimm objects. When the core creates a cxl_nvdimm it
arranges for it to be autoremoved when the bridge goes down. However, if
the bridge never initialized because the cxl_pmem.ko module never
loaded, it sets up a the following crash scenario:
BUG: kernel NULL pointer dereference, address: 0000000000000478
[..]
RIP: 0010:cxl_nvdimm_probe+0x99/0x140 [cxl_pmem]
[..]
Call Trace:
<TASK>
cxl_bus_probe+0x17/0x50 [cxl_core]
really_probe+0xde/0x380
__driver_probe_device+0x78/0x170
driver_probe_device+0x1f/0x90
__driver_attach+0xd2/0x1c0
bus_for_each_dev+0x79/0xc0
bus_add_driver+0x1b1/0x200
driver_register+0x89/0xe0
cxl_pmem_init+0x50/0xff0 [cxl_pmem]
It turns out the recent rework to simplify nvdimm probing obviated the
need to unregister cxl_nvdimm objects at cxl_nvdimm_bridge ->remove()
time. Leave the cxl_nvdimm device registered until the hosting
cxl_memdev departs. The alternative is that the cxl_memdev needs to be
reattached whenever the cxl_nvdimm_bridge attach state cycles, which is
awkward and unnecessary.
The only requirement is to make sure that when the cxl_nvdimm_bridge
goes away any dependent cxl_nvdimm objects are shutdown. Handle that in
unregister_nvdimm_bus().
With these registration entanglements removed there is no longer a need
to pre-load the cxl_pmem module in cxl_acpi.
Fixes: cb9cfff82f6a ("cxl/acpi: Simplify cxl_nvdimm_bridge probing")
Reported-by: Gregory Price <gregory.price@memverge.com>
Debugged-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/167426077263.3955046.9695309346988027311.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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