linux_dsm_epyc7002/drivers/pci
Dan Williams 50f44ee724 mm/devm_memremap_pages: fix final page put race
Logan noticed that devm_memremap_pages_release() kills the percpu_ref
drops all the page references that were acquired at init and then
immediately proceeds to unplug, arch_remove_memory(), the backing pages
for the pagemap.  If for some reason device shutdown actually collides
with a busy / elevated-ref-count page then arch_remove_memory() should
be deferred until after that reference is dropped.

As it stands the "wait for last page ref drop" happens *after*
devm_memremap_pages_release() returns, which is obviously too late and
can lead to crashes.

Fix this situation by assigning the responsibility to wait for the
percpu_ref to go idle to devm_memremap_pages() with a new ->cleanup()
callback.  Implement the new cleanup callback for all
devm_memremap_pages() users: pmem, devdax, hmm, and p2pdma.

Link: http://lkml.kernel.org/r/155727339156.292046.5432007428235387859.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 41e94a8513 ("add devm_memremap_pages")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-13 17:34:56 -10:00
..
controller pci-v5.2-changes 2019-05-14 10:30:10 -07:00
endpoint Merge branch 'remotes/lorenzo/pci/misc' 2019-05-13 18:34:44 -05:00
hotplug pci-v5.2-changes 2019-05-14 10:30:10 -07:00
pcie pci-v5.2-changes 2019-05-14 10:30:10 -07:00
switch pci-v5.2-changes 2019-05-14 10:30:10 -07:00
access.c PCI: Uninline PCI bus accessors for better ftracing 2018-10-04 16:37:37 -05:00
ats.c PCI/ATS: Add pci_ats_page_aligned() interface 2019-02-26 11:08:07 +01:00
bus.c PCI: Replace dev_printk(KERN_DEBUG) with dev_info(), etc 2019-05-09 07:49:58 -05:00
ecam.c
host-bridge.c
iov.c PCI/IOV: Add flag so platforms can skip VF scanning 2019-01-01 19:04:37 -06:00
irq.c
Kconfig PCI: Fix PCI kconfig menu organization 2019-01-14 17:01:20 -06:00
Makefile PCI: OF: Allow of_pci_get_max_link_speed() to be used by PCI Endpoint drivers 2019-04-15 13:24:02 +01:00
mmap.c
msi.c PCI: Add pci_dev_id() helper 2019-04-29 16:12:05 -05:00
of.c Merge branch 'remotes/lorenzo/pci/keystone' 2019-05-13 18:34:41 -05:00
p2pdma.c mm/devm_memremap_pages: fix final page put race 2019-06-13 17:34:56 -10:00
pci-acpi.c ACPI/PCI: PM: Add missing wakeup.flags.valid checks 2019-05-27 10:51:06 +02:00
pci-bridge-emul.c PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flags 2019-02-22 10:51:14 +00:00
pci-bridge-emul.h PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flags 2019-02-22 10:51:14 +00:00
pci-driver.c PCI: PM: Avoid possible suspend-to-idle issue 2019-05-27 10:55:08 +02:00
pci-label.c
pci-mid.c x86/cpu: Sanitize FAM6_ATOM naming 2018-10-02 10:14:32 +02:00
pci-pf-stub.c
pci-stub.c PCI: Replace printk(KERN_INFO) with pr_info(), etc 2019-05-09 07:49:54 -05:00
pci-sysfs.c PCI: Use dev_printk() when possible 2019-05-09 07:49:49 -05:00
pci.c pci-v5.2-changes 2019-05-14 10:30:10 -07:00
pci.h pci-v5.2-changes 2019-05-14 10:30:10 -07:00
probe.c pci-v5.2-changes 2019-05-14 10:30:10 -07:00
proc.c PCI: Mark expected switch fall-throughs 2019-03-20 15:11:11 -05:00
quirks.c pci-v5.2-changes 2019-05-14 10:30:10 -07:00
remove.c PCI/ASPM: Fix link_state teardown on device removal 2018-09-17 16:32:23 -05:00
rom.c
search.c PCI: Add pci_dev_id() helper 2019-04-29 16:12:05 -05:00
setup-bus.c Merge branch 'pci/trivial' 2019-05-13 18:34:48 -05:00
setup-irq.c
setup-res.c
slot.c PCI: Replace printk(KERN_INFO) with pr_info(), etc 2019-05-09 07:49:54 -05:00
syscall.c
vc.c
vpd.c PCI/VPD: Check for VPD access completion before checking for timeout 2018-08-14 16:04:46 -05:00
xen-pcifront.c Merge branch 'pci/printk' 2019-05-13 18:34:46 -05:00