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Dan Williams 4d5c42a80b cxl/hdm: Fix DPA reservation vs cxl_endpoint_decoder lifetime
After adding support for emulating platform firmware established DPA
reservations, the cxl-topology.sh [1] unit test started crashing with
the following signature:

 general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bc3: 0000 [#1] PREEMPT SMP
 [..]
 RIP: 0010:to_cxl_port+0x8/0x60 [cxl_core]
 [..]
 Call Trace:
  <TASK>
  __cxl_dpa_release+0x1b/0xd0 [cxl_core]
  cxl_dpa_release+0x1d/0x30 [cxl_core]
  release_nodes+0x63/0x90
  devres_release_all+0x88/0xc0

...i.e. a use after free of a 'struct cxl_endpoint_decoder' object. This
results from the ordering of init_hdm_decoder() before add_hdm_decoder()
where, at release time, the decoder is unregistered and released before
the DPA reservation.

Fix this by extending the life of the object until all DPA reservations
have been released which also preserves platform decoder settings being
settled by the time the decoder is published in sysfs (KOBJ_ADD time).

Note that the @len == 0 case in __cxl_dpa_reserve() is avoided in
practice as this function is only called for committed decoders and new
non-zero DPA allocations.

Link: https://github.com/pmem/ndctl/blob/pending/test/cxl-topology.sh [1]
Fixes: 9c57cde0dc ("cxl/hdm: Enumerate allocated DPA")
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/165896020625.3546860.12390103413706292760.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-08-01 15:36:33 -07:00
arch powerpc/mm: Export memory_add_physaddr_to_nid() for modules 2022-07-29 07:37:49 -07:00
block block/bfq: Enable I/O statistics 2022-06-16 16:59:28 -06:00
certs certs: fix and refactor CONFIG_SYSTEM_BLACKLIST_HASH_LIST build 2022-06-15 21:52:32 +03:00
crypto crypto: memneq - move into lib/ 2022-06-12 14:51:51 +08:00
Documentation cxl/hdm: Commit decoder state to hardware 2022-07-25 12:18:07 -07:00
drivers cxl/hdm: Fix DPA reservation vs cxl_endpoint_decoder lifetime 2022-08-01 15:36:33 -07:00
fs Fixes for 5.19-rc3: 2022-06-19 09:24:49 -05:00
include cxl/region: Introduce cxl_pmem_region objects 2022-07-26 12:23:01 -07:00
init gcc-12: disable '-Warray-bounds' universally for now 2022-06-09 10:11:12 -07:00
ipc These changes update the ipc sysctls so that they are fundamentally 2022-06-03 15:54:57 -07:00
kernel resource: Introduce alloc_free_mem_region() 2022-07-21 17:19:25 -07:00
lib Build tool updates: 2022-06-19 09:54:16 -05:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm resource: Introduce alloc_free_mem_region() 2022-07-21 17:19:25 -07:00
net NFS Client Fixes for Linux 5.19-rc 2022-06-17 15:17:57 -05:00
samples drm for 5.19-rc1 2022-05-25 16:18:27 -07:00
scripts Build tool updates: 2022-06-19 09:54:16 -05:00
security selinux: free contexts previously transferred in selinux_add_opt() 2022-06-15 21:20:45 -04:00
sound sound fixes for 5.19-rc2 2022-06-10 10:20:57 -07:00
tools cxl/hdm: Commit decoder state to hardware 2022-07-25 12:18:07 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: x86: disable preemption around the call to kvm_arch_vcpu_{un|}blocking 2022-06-09 10:52:20 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap MAINTAINERS: Update Ben's email address 2022-06-21 12:59:51 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Update Ben's email address 2022-06-21 12:59:51 -07:00
Makefile Linux 5.19-rc3 2022-06-19 15:06:47 -05:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.