From: Dan Williams <dan.j.williams@intel.com>
To: akpm@linux-foundation.org
Cc: "Ira Weiny" <ira.weiny@intel.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Logan Gunthorpe" <logang@deltatee.com>,
"Christoph Hellwig" <hch@lst.de>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
linux-mm@kvack.org, linux-pci@vger.kernel.org,
linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org
Subject: [PATCH 0/6] mm/devm_memremap_pages: Fix page release race
Date: Fri, 29 Mar 2019 08:27:24 -0700 [thread overview]
Message-ID: <155387324370.2443841.574715745262628837.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
Logan audited the devm_memremap_pages() shutdown path and noticed that
it was possible to proceed to arch_remove_memory() before all
potential page references have been reaped.
Introduce a new ->cleanup() callback to do the work of waiting for any
straggling page references and then perform the percpu_ref_exit() in
devm_memremap_pages_release() context.
For p2pdma this involves some deeper reworks to reference count
resources on a per-instance basis rather than a per pci-device basis. A
modified genalloc api is introduced to convey a driver-private pointer
through gen_pool_{alloc,free}() interfaces. Also, a
devm_memunmap_pages() api is introduced since p2pdma does not
auto-release resources on a setup failure.
The dax and pmem changes pass the nvdimm unit tests, but the hmm and
p2pdma changes are compile-tested only.
Thoughts on the api changes?
I'm targeting to land this through Andrew's tree. 0day has chewed on
this for a day and reported no issues so far.
---
Dan Williams (6):
drivers/base/devres: Introduce devm_release_action()
mm/devm_memremap_pages: Introduce devm_memunmap_pages
pci/p2pdma: Fix the gen_pool_add_virt() failure path
lib/genalloc: Introduce chunk owners
pci/p2pdma: Track pgmap references per resource, not globally
mm/devm_memremap_pages: Fix final page put race
drivers/base/devres.c | 24 ++++++++
drivers/dax/device.c | 13 +----
drivers/nvdimm/pmem.c | 17 +++++-
drivers/pci/p2pdma.c | 105 +++++++++++++++++++++++--------------
include/linux/device.h | 1
include/linux/genalloc.h | 55 +++++++++++++++++--
include/linux/memremap.h | 8 +++
kernel/memremap.c | 23 ++++++--
lib/genalloc.c | 51 +++++++++---------
mm/hmm.c | 14 +----
tools/testing/nvdimm/test/iomap.c | 2 +
11 files changed, 209 insertions(+), 104 deletions(-)
next reply other threads:[~2019-03-29 15:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-29 15:27 Dan Williams [this message]
2019-03-29 15:27 ` [PATCH 1/6] drivers/base/devres: Introduce devm_release_action() Dan Williams
2019-03-29 15:27 ` [PATCH 2/6] mm/devm_memremap_pages: Introduce devm_memunmap_pages Dan Williams
2019-03-29 15:27 ` [PATCH 3/6] pci/p2pdma: Fix the gen_pool_add_virt() failure path Dan Williams
2019-03-29 17:24 ` Bjorn Helgaas
2019-03-29 15:27 ` [PATCH 4/6] lib/genalloc: Introduce chunk owners Dan Williams
2019-03-29 15:27 ` [PATCH 5/6] pci/p2pdma: Track pgmap references per resource, not globally Dan Williams
2019-03-29 17:50 ` Logan Gunthorpe
2019-03-29 19:32 ` Dan Williams
2019-03-29 15:27 ` [PATCH 6/6] mm/devm_memremap_pages: Fix final page put race Dan Williams
2019-03-29 9:46 ` Ira Weiny
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