Dan Williams 20bd0198be cxl/mem: Fix shutdown order ... [ Upstream commit 88d3917f82 ] Ira reports that removing cxl_mock_mem causes a crash with the following trace: BUG: kernel NULL pointer dereference, address: 0000000000000044 [..] RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core] [..] Call Trace: <TASK> cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x29/0x40 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 device_unregister+0x13/0x60 devm_release_action+0x4d/0x90 ? __pfx_unregister_port+0x10/0x10 [cxl_core] delete_endpoint+0x121/0x130 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 ? lock_release+0x142/0x290 cdev_device_del+0x15/0x50 cxl_memdev_unregister+0x54/0x70 [cxl_core] This crash is due to the clearing out the cxl_memdev's driver context (@cxlds) before the subsystem is done with it. This is ultimately due to the region(s), that this memdev is a member, being torn down and expecting to be able to de-reference @cxlds, like here: static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) ... if (cxlds->rcd) goto endpoint_reset; ... Fix it by keeping the driver context valid until memdev-device unregistration, and subsequently the entire stack of related dependencies, unwinds. Fixes: 9cc238c7a5 ("cxl/pci: Introduce cdevm_file_operations") Reported-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-11-20 11:08:27 +01:00
..
core	cxl/mem: Fix shutdown order	2023-11-20 11:08:27 +01:00
acpi.c	cxl/acpi: Do not add DSDT disabled ACPI0016 host bridge ports	2021-09-07 11:39:01 -07:00
cxl.h	cxl/pci: Simplify register setup	2021-08-06 08:27:02 -07:00
cxlmem.h	cxl/mem: Account for partitionable space in ram/pmem ranges	2021-08-10 11:57:59 -07:00
Kconfig	cxl/pmem: Add initial infrastructure for pmem support	2021-06-15 16:47:14 -07:00
Makefile	cxl: Move cxl_core to new directory	2021-08-06 08:22:53 -07:00
pci.c	cxl/pci: Fix NULL vs ERR_PTR confusion	2021-11-18 19:16:04 +01:00
pci.h	cxl/pci: Simplify register setup	2021-08-06 08:27:02 -07:00
pmem.c	cxl/pmem: Fix reference counting for delayed work	2022-01-27 11:02:58 +01:00