bec8b6e944
6 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Aneesh Kumar K.V
|
77e080e768 |
mm/memunmap: don't access uninitialized memmap in memunmap_pages()
Patch series "mm/memory_hotplug: Shrink zones before removing memory",
v6.
This series fixes the access of uninitialized memmaps when shrinking
zones/nodes and when removing memory. Also, it contains all fixes for
crashes that can be triggered when removing certain namespace using
memunmap_pages() - ZONE_DEVICE, reported by Aneesh.
We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be
more involved (we don't have SECTION_IS_ONLINE as an indicator), and
shrinking is only of limited use (set_zone_contiguous() cannot detect
the ZONE_DEVICE as contiguous).
We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount
of code to a minimum. Shrinking is especially necessary to keep
zone->contiguous set where possible, especially, on memory unplug of
DIMMs at zone boundaries.
--------------------------------------------------------------------------
Zones are now properly shrunk when offlining memory blocks or when
onlining failed. This allows to properly shrink zones on memory unplug
even if the separate memory blocks of a DIMM were onlined to different
zones or re-onlined to a different zone after offlining.
Example:
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 0
present 0
managed 0
:/# echo "online_movable" > /sys/devices/system/memory/memory41/state
:/# echo "online_movable" > /sys/devices/system/memory/memory43/state
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 98304
present 65536
managed 65536
:/# echo 0 > /sys/devices/system/memory/memory43/online
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 32768
present 32768
managed 32768
:/# echo 0 > /sys/devices/system/memory/memory41/online
:/# cat /proc/zoneinfo
Node 1, zone Movable
spanned 0
present 0
managed 0
This patch (of 10):
With an altmap, the memmap falling into the reserved altmap space are not
initialized and, therefore, contain a garbage NID and a garbage zone.
Make sure to read the NID/zone from a memmap that was initialized.
This fixes a kernel crash that is observed when destroying a namespace:
kernel BUG at include/linux/mm.h:1107!
cpu 0x1: Vector: 700 (Program Check) at [c000000274087890]
pc: c0000000004b9728: memunmap_pages+0x238/0x340
lr: c0000000004b9724: memunmap_pages+0x234/0x340
...
pid = 3669, comm = ndctl
kernel BUG at include/linux/mm.h:1107!
devm_action_release+0x30/0x50
release_nodes+0x268/0x2d0
device_release_driver_internal+0x174/0x240
unbind_store+0x13c/0x190
drv_attr_store+0x44/0x60
sysfs_kf_write+0x70/0xa0
kernfs_fop_write+0x1ac/0x290
__vfs_write+0x3c/0x70
vfs_write+0xe4/0x200
ksys_write+0x7c/0x140
system_call+0x5c/0x68
The "page_zone(pfn_to_page(pfn)" was introduced by
|
||
Anshuman Khandual
|
6d0e984941 |
mm/memremap: drop unused SECTION_SIZE and SECTION_MASK
SECTION_SIZE and SECTION_MASK macros are not getting used anymore. But they do conflict with existing definitions on arm64 platform causing following warning during build. Lets drop these unused macros. mm/memremap.c:16: warning: "SECTION_MASK" redefined #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) arch/arm64/include/asm/pgtable-hwdef.h:79: note: this is the location of the previous definition #define SECTION_MASK (~(SECTION_SIZE-1)) mm/memremap.c:17: warning: "SECTION_SIZE" redefined #define SECTION_SIZE (1UL << PA_SECTION_SHIFT) arch/arm64/include/asm/pgtable-hwdef.h:78: note: this is the location of the previous definition #define SECTION_SIZE (_AC(1, UL) << SECTION_SHIFT) Link: http://lkml.kernel.org/r/1569312010-31313-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Jason Gunthorpe
|
daa138a58c |
Merge branch 'odp_fixes' into hmm.git
From rdma.git Jason Gunthorpe says: ==================== This is a collection of general cleanups for ODP to clarify some of the flows around umem creation and use of the interval tree. ==================== The branch is based on v5.3-rc5 due to dependencies, and is being taken into hmm.git due to dependencies in the next patches. * odp_fixes: RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr RDMA/mlx5: Use ib_umem_start instead of umem.address RDMA/core: Make invalidate_range a device operation RDMA/odp: Use kvcalloc for the dma_list and page_list RDMA/odp: Check for overflow when computing the umem_odp end RDMA/odp: Provide ib_umem_odp_release() to undo the allocs RDMA/odp: Split creating a umem_odp from ib_umem_get RDMA/odp: Make the three ways to create a umem_odp clear RMDA/odp: Consolidate umem_odp initialization RDMA/odp: Make it clearer when a umem is an implicit ODP umem RDMA/odp: Iterate over the whole rbtree directly RDMA/odp: Use the common interval tree library instead of generic RDMA/mlx5: Fix MR npages calculation for IB_ACCESS_HUGETLB Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
||
Ralph Campbell
|
7ab0ad0e74 |
mm/hmm: fix ZONE_DEVICE anon page mapping reuse
When a ZONE_DEVICE private page is freed, the page->mapping field can be
set. If this page is reused as an anonymous page, the previous value
can prevent the page from being inserted into the CPU's anon rmap table.
For example, when migrating a pte_none() page to device memory:
migrate_vma(ops, vma, start, end, src, dst, private)
migrate_vma_collect()
src[] = MIGRATE_PFN_MIGRATE
migrate_vma_prepare()
/* no page to lock or isolate so OK */
migrate_vma_unmap()
/* no page to unmap so OK */
ops->alloc_and_copy()
/* driver allocates ZONE_DEVICE page for dst[] */
migrate_vma_pages()
migrate_vma_insert_page()
page_add_new_anon_rmap()
__page_set_anon_rmap()
/* This check sees the page's stale mapping field */
if (PageAnon(page))
return
/* page->mapping is not updated */
The result is that the migration appears to succeed but a subsequent CPU
fault will be unable to migrate the page back to system memory or worse.
Clear the page->mapping field when freeing the ZONE_DEVICE page so stale
pointer data doesn't affect future page use.
Link: http://lkml.kernel.org/r/20190719192955.30462-3-rcampbell@nvidia.com
Fixes:
|
||
Dan Williams
|
06282373ff |
mm/memremap: Fix reuse of pgmap instances with internal references
Currently, attempts to shutdown and re-enable a device-dax instance
trigger:
Missing reference count teardown definition
WARNING: CPU: 37 PID: 1608 at mm/memremap.c:211 devm_memremap_pages+0x234/0x850
[..]
RIP: 0010:devm_memremap_pages+0x234/0x850
[..]
Call Trace:
dev_dax_probe+0x66/0x190 [device_dax]
really_probe+0xef/0x390
driver_probe_device+0xb4/0x100
device_driver_attach+0x4f/0x60
Given that the setup path initializes pgmap->ref, arrange for it to be
also torn down so devm_memremap_pages() is ready to be called again and
not be mistaken for the 3rd-party per-cpu-ref case.
Fixes:
|
||
Christoph Hellwig
|
14c5cebad5 |
memremap: move from kernel/ to mm/
memremap.c implements MM functionality for ZONE_DEVICE, so it really should be in the mm/ directory, not the kernel/ one. Link: http://lkml.kernel.org/r/20190722094143.18387-1-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |