mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries

This replaces all the existing READ_ONCE() based page table accesses with
respective pxdp_get() helpers. Although these helpers m

mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries

This replaces all the existing READ_ONCE() based page table accesses with
respective pxdp_get() helpers. Although these helpers might also fallback
to READ_ONCE() as default, but they do provide an opportunity for various
platforms to override when required. This change is a step in direction to
replace all page table entry accesses with respective pxdp_get() helpers.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Ryan Roberts <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm/debug_vm_pgtable: drop RANDOM_ORVALUE trick

Macro RANDOM_ORVALUE was used to make sure the pgtable entry will be
populated with !none data in clear tests.

The RANDOM_ORVALUE tried to cover mostl

mm/debug_vm_pgtable: drop RANDOM_ORVALUE trick

Macro RANDOM_ORVALUE was used to make sure the pgtable entry will be
populated with !none data in clear tests.

The RANDOM_ORVALUE tried to cover mostly all the bits in a pgtable entry,
even if there's no discussion on whether all the bits will be vaild. Both
S390 and PPC64 have their own masks to avoid touching some bits. Now it's
the turn for x86_64.

The issue is there's a recent report from Mikhail Gavrilov showing that
this can cause a warning with the newly added pte set check in commit
8430557fc5 on writable v.s. userfaultfd-wp bit, even though the check
itself was valid, the random pte is not. We can choose to mask more bits
out.

However the need to have such random bits setup is questionable, as now
it's already guaranteed to be true on below:

- For pte level, the pgtable entry will be installed with value from
pfn_pte(), where pfn points to a valid page. Hence the pte will be
!none already if populated with pfn_pte().

- For upper-than-pte level, the pgtable entry should contain a directory
entry always, which is also !none.

All the cases look like good enough to test a pxx_clear() helper. Instead
of extending the bitmask, drop the "set random bits" trick completely. Add
some warning guards to make sure the entries will be !none before clear().

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 8430557fc584 ("mm/page_table_check: support userfault wr-protect entries")
Signed-off-by: Peter Xu <[email protected]>
Reported-by: Mikhail Gavrilov <[email protected]>
Link: https://lore.kernel.org/r/CABXGCsMB9A8-X+Np_Q+fWLURYL_0t3Y-MdoNabDM-Lzk58-DGA@mail.gmail.com
Tested-by: Mikhail Gavrilov <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Gavin Shan <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm/debug_vm_pgtable: test pmd_leaf() behavior with pmd_mkinvalid()

An invalidated pmd should still cause pmd_leaf() to return true. Let's
test for that to ensure all arches remain consistent.

Link

mm/debug_vm_pgtable: test pmd_leaf() behavior with pmd_mkinvalid()

An invalidated pmd should still cause pmd_leaf() to return true. Let's
test for that to ensure all arches remain consistent.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ryan Roberts <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

fix missing vmalloc.h includes

Patch series "Memory allocation profiling", v6.

Overview:
Low overhead [1] per-callsite memory allocation profiling. Not just for
debug kernels, overhead low enough t

fix missing vmalloc.h includes

Patch series "Memory allocation profiling", v6.

Overview:
Low overhead [1] per-callsite memory allocation profiling. Not just for
debug kernels, overhead low enough to be deployed in production.

Example output:
root@moria-kvm:~# sort -rn /proc/allocinfo
127664128 31168 mm/page_ext.c:270 func:alloc_page_ext
56373248 4737 mm/slub.c:2259 func:alloc_slab_page
14880768 3633 mm/readahead.c:247 func:page_cache_ra_unbounded
14417920 3520 mm/mm_init.c:2530 func:alloc_large_system_hash
13377536 234 block/blk-mq.c:3421 func:blk_mq_alloc_rqs
11718656 2861 mm/filemap.c:1919 func:__filemap_get_folio
9192960 2800 kernel/fork.c:307 func:alloc_thread_stack_node
4206592 4 net/netfilter/nf_conntrack_core.c:2567 func:nf_ct_alloc_hashtable
4136960 1010 drivers/staging/ctagmod/ctagmod.c:20 [ctagmod] func:ctagmod_start
3940352 962 mm/memory.c:4214 func:alloc_anon_folio
2894464 22613 fs/kernfs/dir.c:615 func:__kernfs_new_node
...

Usage:
kconfig options:
- CONFIG_MEM_ALLOC_PROFILING
- CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
- CONFIG_MEM_ALLOC_PROFILING_DEBUG
adds warnings for allocations that weren't accounted because of a
missing annotation

sysctl:
/proc/sys/vm/mem_profiling

Runtime info:
/proc/allocinfo

Notes:

[1]: Overhead
To measure the overhead we are comparing the following configurations:
(1) Baseline with CONFIG_MEMCG_KMEM=n
(2) Disabled by default (CONFIG_MEM_ALLOC_PROFILING=y &&
CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=n)
(3) Enabled by default (CONFIG_MEM_ALLOC_PROFILING=y &&
CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=y)
(4) Enabled at runtime (CONFIG_MEM_ALLOC_PROFILING=y &&
CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=n && /proc/sys/vm/mem_profiling=1)
(5) Baseline with CONFIG_MEMCG_KMEM=y && allocating with __GFP_ACCOUNT
(6) Disabled by default (CONFIG_MEM_ALLOC_PROFILING=y &&
CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=n) && CONFIG_MEMCG_KMEM=y
(7) Enabled by default (CONFIG_MEM_ALLOC_PROFILING=y &&
CONFIG_MEM_ALLOC_PROFILING_BY_DEFAULT=y) && CONFIG_MEMCG_KMEM=y

Performance overhead:
To evaluate performance we implemented an in-kernel test executing
multiple get_free_page/free_page and kmalloc/kfree calls with allocation
sizes growing from 8 to 240 bytes with CPU frequency set to max and CPU
affinity set to a specific CPU to minimize the noise. Below are results
from running the test on Ubuntu 22.04.2 LTS with 6.8.0-rc1 kernel on
56 core Intel Xeon:

kmalloc pgalloc
(1 baseline) 6.764s 16.902s
(2 default disabled) 6.793s (+0.43%) 17.007s (+0.62%)
(3 default enabled) 7.197s (+6.40%) 23.666s (+40.02%)
(4 runtime enabled) 7.405s (+9.48%) 23.901s (+41.41%)
(5 memcg) 13.388s (+97.94%) 48.460s (+186.71%)
(6 def disabled+memcg) 13.332s (+97.10%) 48.105s (+184.61%)
(7 def enabled+memcg) 13.446s (+98.78%) 54.963s (+225.18%)

Memory overhead:
Kernel size:

text data bss dec diff
(1) 26515311 18890222 17018880 62424413
(2) 26524728 19423818 16740352 62688898 264485
(3) 26524724 19423818 16740352 62688894 264481
(4) 26524728 19423818 16740352 62688898 264485
(5) 26541782 18964374 16957440 62463596 39183

Memory consumption on a 56 core Intel CPU with 125GB of memory:
Code tags: 192 kB
PageExts: 262144 kB (256MB)
SlabExts: 9876 kB (9.6MB)
PcpuExts: 512 kB (0.5MB)

Total overhead is 0.2% of total memory.

Benchmarks:

Hackbench tests run 100 times:
hackbench -s 512 -l 200 -g 15 -f 25 -P
baseline disabled profiling enabled profiling
avg 0.3543 0.3559 (+0.0016) 0.3566 (+0.0023)
stdev 0.0137 0.0188 0.0077


hackbench -l 10000
baseline disabled profiling enabled profiling
avg 6.4218 6.4306 (+0.0088) 6.5077 (+0.0859)
stdev 0.0933 0.0286 0.0489

stress-ng tests:
stress-ng --class memory --seq 4 -t 60
stress-ng --class cpu --seq 4 -t 60
Results posted at: https://evilpiepirate.org/~kent/memalloc_prof_v4_stress-ng/

[2] https://lore.kernel.org/all/[email protected]/


This patch (of 37):

The next patch drops vmalloc.h from a system header in order to fix a
circular dependency; this adds it to all the files that were pulling it in
implicitly.

[[email protected]: fix arch/alpha/lib/memcpy.c]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix arch/x86/mm/numa_32.c]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: a few places were depending on sizes.h]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix mm/kasan/hw_tags.c]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix arc build]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kent Overstreet <[email protected]>
Signed-off-by: Suren Baghdasaryan <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
Tested-by: Kees Cook <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Alice Ryhl <[email protected]>
Cc: Andreas Hindborg <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: "Björn Roy Baron" <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Gary Guo <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Wedson Almeida Filho <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm/debug_vm_pgtable: fix BUG_ON with pud advanced test

Architectures like powerpc add debug checks to ensure we find only devmap
PUD pte entries. These debug checks are only done with CONFIG_DEBUG_

mm/debug_vm_pgtable: fix BUG_ON with pud advanced test

Architectures like powerpc add debug checks to ensure we find only devmap
PUD pte entries. These debug checks are only done with CONFIG_DEBUG_VM.
This patch marks the ptes used for PUD advanced test devmap pte entries so
that we don't hit on debug checks on architecture like ppc64 as below.

WARNING: CPU: 2 PID: 1 at arch/powerpc/mm/book3s64/radix_pgtable.c:1382 radix__pud_hugepage_update+0x38/0x138
....
NIP [c0000000000a7004] radix__pud_hugepage_update+0x38/0x138
LR [c0000000000a77a8] radix__pudp_huge_get_and_clear+0x28/0x60
Call Trace:
[c000000004a2f950] [c000000004a2f9a0] 0xc000000004a2f9a0 (unreliable)
[c000000004a2f980] [000d34c100000000] 0xd34c100000000
[c000000004a2f9a0] [c00000000206ba98] pud_advanced_tests+0x118/0x334
[c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48
[c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388

Also

kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202!
....

NIP [c000000000096510] pudp_huge_get_and_clear_full+0x98/0x174
LR [c00000000206bb34] pud_advanced_tests+0x1b4/0x334
Call Trace:
[c000000004a2f950] [000d34c100000000] 0xd34c100000000 (unreliable)
[c000000004a2f9a0] [c00000000206bb34] pud_advanced_tests+0x1b4/0x334
[c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48
[c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 27af67f35631 ("powerpc/book3s64/mm: enable transparent pud hugepage")
Signed-off-by: Aneesh Kumar K.V (IBM) <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER

commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive. This has caused
issues with

mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER

commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive. This has caused
issues with code that was not yet upstream and depended on the previous
definition.

To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: fix multiple typos in multiple files

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Muhammad Muzammil <[email protected]>
Reviewed-by

mm: fix multiple typos in multiple files

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Muhammad Muzammil <[email protected]>
Reviewed-by: Randy Dunlap <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Muhammad Muzammil <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: change pudp_huge_get_and_clear_full take vm_area_struct as arg

We will use this in a later patch to do tlb flush when clearing pud
entries on powerpc. This is similar to commit 93a98695f2f9 ("m

mm: change pudp_huge_get_and_clear_full take vm_area_struct as arg

We will use this in a later patch to do tlb flush when clearing pud
entries on powerpc. This is similar to commit 93a98695f2f9 ("mm: change
pmdp_huge_get_and_clear_full take vm_area_struct as arg")

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Joao Martins <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm/hugepage pud: allow arch-specific helper function to check huge page pud support

Patch series "Add support for DAX vmemmap optimization for ppc64", v6.

This patch series implements changes requi

mm/hugepage pud: allow arch-specific helper function to check huge page pud support

Patch series "Add support for DAX vmemmap optimization for ppc64", v6.

This patch series implements changes required to support DAX vmemmap
optimization for ppc64. The vmemmap optimization is only enabled with
radix MMU translation and 1GB PUD mapping with 64K page size.

The patch series also splits the hugetlb vmemmap optimization as a
separate Kconfig variable so that architectures can enable DAX vmemmap
optimization without enabling hugetlb vmemmap optimization. This should
enable architectures like arm64 to enable DAX vmemmap optimization while
they can't enable hugetlb vmemmap optimization. More details of the same
are in patch "mm/vmemmap optimization: Split hugetlb and devdax vmemmap
optimization".

With 64K page size for 16384 pages added (1G) we save 14 pages
With 4K page size for 262144 pages added (1G) we save 4094 pages
With 4K page size for 512 pages added (2M) we save 6 pages


This patch (of 13):

Architectures like powerpc would like to enable transparent huge page pud
support only with radix translation. To support that add
has_transparent_pud_hugepage() helper that architectures can override.

[[email protected]: use the new has_transparent_pud_hugepage()]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Joao Martins <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: Make pte_mkwrite() take a VMA

The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm ch

mm: Make pte_mkwrite() take a VMA

The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.

One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). Future patches will make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.

But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.

So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.

Previous work pte_mkwrite() renamed pte_mkwrite_novma() and converted
callers that don't have a VMA were to use pte_mkwrite_novma(). So now
change pte_mkwrite() to take a VMA and change the remaining callers to
pass a VMA. Apply the same changes for pmd_mkwrite().

No functional change.

Suggested-by: David Hildenbrand <[email protected]>
Signed-off-by: Rick Edgecombe <[email protected]>
Signed-off-by: Dave Hansen <[email protected]>
Reviewed-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Link: https://lore.kernel.org/all/20230613001108.3040476-4-rick.p.edgecombe%40intel.com

show more ...

mm/debug_vm_pgtable,page_table_check: warn pte map fails

Failures here would be surprising: pte_advanced_tests() and
pte_clear_tests() and __page_table_check_pte_clear_range() each issue a
warning i

mm/debug_vm_pgtable,page_table_check: warn pte map fails

Failures here would be surprising: pte_advanced_tests() and
pte_clear_tests() and __page_table_check_pte_clear_range() each issue a
warning if pte_offset_map() or pte_offset_map_lock() fails.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Hugh Dickins <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Qi Zheng <[email protected]>
Cc: Ralph Campbell <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Steven Price <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Thomas Hellström <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Yu Zhao <[email protected]>
Cc: Zack Rusin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm, treewide: redefine MAX_ORDER sanely

MAX_ORDER currently defined as number of orders page allocator supports:
user can ask buddy allocator for page order between 0 and MAX_ORDER-1.

This definiti

mm, treewide: redefine MAX_ORDER sanely

MAX_ORDER currently defined as number of orders page allocator supports:
user can ask buddy allocator for page order between 0 and MAX_ORDER-1.

This definition is counter-intuitive and lead to number of bugs all over
the kernel.

Change the definition of MAX_ORDER to be inclusive: the range of orders
user can ask from buddy allocator is 0..MAX_ORDER now.

[[email protected]: fix min() warning]
Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box
[[email protected]: fix another min_t warning]
[[email protected]: fixups per Zi Yan]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix underlining in docs]
Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kirill A. Shutemov <[email protected]>
Reviewed-by: Michael Ellerman <[email protected]> [powerpc]
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: prefer xxx_page() alloc/free functions for order-0 pages

Update instances of alloc_pages(..., 0), __get_free_pages(..., 0) and
__free_pages(..., 0) to use alloc_page(), __get_free_page() and
__f

mm: prefer xxx_page() alloc/free functions for order-0 pages

Update instances of alloc_pages(..., 0), __get_free_pages(..., 0) and
__free_pages(..., 0) to use alloc_page(), __get_free_page() and
__free_page() respectively in core code.

Link: https://lkml.kernel.org/r/50c48ca4789f1da2a65795f2346f5ae3eff7d665.1678710232.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Uladzislau Rezki (Sony) <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm/debug_vm_pgtable: replace pte_mkhuge() with arch_make_huge_pte()

Since the following commit arch_make_huge_pte() should be used directly in
generic memory subsystem as a platform provided page ta

mm/debug_vm_pgtable: replace pte_mkhuge() with arch_make_huge_pte()

Since the following commit arch_make_huge_pte() should be used directly in
generic memory subsystem as a platform provided page table helper, instead
of pte_mkhuge(). Change hugetlb_basic_tests() to call
arch_make_huge_pte() directly, and update its relevant documentation entry
as required.

'commit 16785bd77431 ("mm: merge pte_mkhuge() call into arch_make_huge_pte()")'

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Reported-by: Christophe Leroy <[email protected]>
Link: https://lore.kernel.org/all/[email protected]/
Cc: Jonathan Corbet <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE

__HAVE_ARCH_PTE_SWP_EXCLUSIVE is now supported by all architectures that
support swp PTEs, so let's drop it.

Link: https://lkml.kernel.org/r/20230113171026.

mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE

__HAVE_ARCH_PTE_SWP_EXCLUSIVE is now supported by all architectures that
support swp PTEs, so let's drop it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks

Patch series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all
architectures with swap PTEs".

This is the follow-up on [1]:
[PATCH v2 0/

mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks

Patch series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all
architectures with swap PTEs".

This is the follow-up on [1]:
[PATCH v2 0/8] mm: COW fixes part 3: reliable GUP R/W FOLL_GET of
anonymous pages

After we implemented __HAVE_ARCH_PTE_SWP_EXCLUSIVE on most prominent
enterprise architectures, implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all
remaining architectures that support swap PTEs.

This makes sure that exclusive anonymous pages will stay exclusive, even
after they were swapped out -- for example, making GUP R/W FOLL_GET of
anonymous pages reliable. Details can be found in [1].

This primarily fixes remaining known O_DIRECT memory corruptions that can
happen on concurrent swapout, whereby we can lose DMA reads to a page
(modifying the user page by writing to it).

To verify, there are two test cases (requiring swap space, obviously):
(1) The O_DIRECT+swapout test case [2] from Andrea. This test case tries
triggering a race condition.
(2) My vmsplice() test case [3] that tries to detect if the exclusive
marker was lost during swapout, not relying on a race condition.


For example, on 32bit x86 (with and without PAE), my test case fails
without these patches:
$ ./test_swp_exclusive
FAIL: page was replaced during COW
But succeeds with these patches:
$ ./test_swp_exclusive
PASS: page was not replaced during COW


Why implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE for all architectures, even
the ones where swap support might be in a questionable state? This is the
first step towards removing "readable_exclusive" migration entries, and
instead using pte_swp_exclusive() also with (readable) migration entries
instead (as suggested by Peter). The only missing piece for that is
supporting pmd_swp_exclusive() on relevant architectures with THP
migration support.

As all relevant architectures now implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE,,
we can drop __HAVE_ARCH_PTE_SWP_EXCLUSIVE in the last patch.

I tried cross-compiling all relevant setups and tested on x86 and sparc64
so far.

CCing arch maintainers only on this cover letter and on the respective
patch(es).

[1] https://lkml.kernel.org/r/[email protected]
[2] https://gitlab.com/aarcange/kernel-testcases-for-v5.11/-/blob/main/page_count_do_wp_page-swap.c
[3] https://gitlab.com/davidhildenbrand/scratchspace/-/blob/main/test_swp_exclusive.c


This patch (of 26):

We want to implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures.
Let's extend our sanity checks, especially testing that our PTE bit does
not affect:

* is_swap_pte() -> pte_present() and pte_none()
* the swap entry + type
* pte_swp_soft_dirty()

Especially, the pfn_pte() is dodgy when the swap PTE layout differs
heavily from ordinary PTEs. Let's properly construct a swap PTE from swap
type+offset.

[[email protected]: fix build]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Anton Ivanov <[email protected]>
Cc: <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Brian Cain <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: H. Peter Anvin (Intel) <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: Stefan Kristiansson <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xuerui Wang <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm/debug: use valid physical memory for pmd/pud tests

The page table debug tests need a physical address to validate low-level
page table manipulation with. The memory at this address is not actual

mm/debug: use valid physical memory for pmd/pud tests

The page table debug tests need a physical address to validate low-level
page table manipulation with. The memory at this address is not actually
touched, it just encoded in the page table entries at various levels
during the tests only.

Since the memory is not used, the code just picks the physical address of
the start_kernel symbol. This value is then truncated to get a properly
aligned address that is to be used for various tests. Because of the
truncation, the address might not actually exist, or might not describe a
complete huge page. That's not a problem for most tests, but the
arch-specific code may check for attribute validity and consistency. The
x86 version of {pud,pmd}_set_huge actually validates the MTRRs for the
PMD/PUD range. This may fail with an address derived from start_kernel,
depending on where the kernel was loaded and what the physical memory
layout of the system is. This then leads to false negatives for the
{pud,pmd}_set_huge tests.

Avoid this by finding a properly aligned memory range that exists and is
usable. If such a range is not found, skip the tests that needed it.

[[email protected]: v3]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 399145f9eb6c ("mm/debug: add tests validating architecture page table helpers")
Signed-off-by: Frank van der Linden <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm: remove unused savedwrite infrastructure

NUMA hinting no longer uses savedwrite, let's rip it out.

... and while at it, drop __pte_write() and __pmd_write() on ppc64.

Link: https://lkml.kernel.

mm: remove unused savedwrite infrastructure

NUMA hinting no longer uses savedwrite, let's rip it out.

... and while at it, drop __pte_write() and __pmd_write() on ppc64.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm: debug_vm_pgtable: use VM_ACCESS_FLAGS

Directly use VM_ACCESS_FLAGS instead VMFLAGS.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kefeng Wang

mm: debug_vm_pgtable: use VM_ACCESS_FLAGS

Directly use VM_ACCESS_FLAGS instead VMFLAGS.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kefeng Wang <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Jarkko Sakkinen <[email protected]>
Cc: "Pan, Xinhui" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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docs: rename Documentation/vm to Documentation/mm

so it will be consistent with code mm directory and with
Documentation/admin-guide/mm and won't be confused with virtual machines.

Signed-off-by: M

docs: rename Documentation/vm to Documentation/mm

so it will be consistent with code mm directory and with
Documentation/admin-guide/mm and won't be confused with virtual machines.

Signed-off-by: Mike Rapoport <[email protected]>
Suggested-by: Matthew Wilcox <[email protected]>
Tested-by: Ira Weiny <[email protected]>
Acked-by: Jonathan Corbet <[email protected]>
Acked-by: Wu XiangCheng <[email protected]>

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mm/debug_vm_pgtable: add tests for __HAVE_ARCH_PTE_SWP_EXCLUSIVE

Let's test that __HAVE_ARCH_PTE_SWP_EXCLUSIVE works as expected.

Link: https://lkml.kernel.org/r/20220329164329.208407-3-david@redha

mm/debug_vm_pgtable: add tests for __HAVE_ARCH_PTE_SWP_EXCLUSIVE

Let's test that __HAVE_ARCH_PTE_SWP_EXCLUSIVE works as expected.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Don Dutile <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Liang Zhang <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Oded Gabbay <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Pedro Demarchi Gomes <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm/debug_vm_pgtable: drop protection_map[] usage

Patch series "mm: protection_map[] cleanups".


This patch (of 2):

Although protection_map[] contains the platform defined page protection
map for a

mm/debug_vm_pgtable: drop protection_map[] usage

Patch series "mm: protection_map[] cleanups".


This patch (of 2):

Although protection_map[] contains the platform defined page protection
map for a given vm_flags combination, vm_get_page_prot() is the right
interface to use. This will also reduce dependency on protection_map[]
which is going to be dropped off completely later on.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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mm/debug_vm_pgtable: remove pte entry from the page table

Patch series "page table check fixes and cleanups", v5.

This patch (of 4):

The pte entry that is used in pte_advanced_tests() is never rem

mm/debug_vm_pgtable: remove pte entry from the page table

Patch series "page table check fixes and cleanups", v5.

This patch (of 4):

The pte entry that is used in pte_advanced_tests() is never removed from
the page table at the end of the test.

The issue is detected by page_table_check, to repro compile kernel with
the following configs:

CONFIG_DEBUG_VM_PGTABLE=y
CONFIG_PAGE_TABLE_CHECK=y
CONFIG_PAGE_TABLE_CHECK_ENFORCED=y

During the boot the following BUG is printed:

debug_vm_pgtable: [debug_vm_pgtable ]: Validating architecture page table helpers
------------[ cut here ]------------
kernel BUG at mm/page_table_check.c:162!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-11413-g2c271fe77d52 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
...

The entry should be properly removed from the page table before the page
is released to the free list.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: a5c3b9ffb0f4 ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers")
Signed-off-by: Pasha Tatashin <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Tested-by: Zi Yan <[email protected]>
Acked-by: David Rientjes <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Wei Xu <[email protected]>
Cc: Greg Thelen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: <[email protected]> [5.9+]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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mm: ptep_clear() page table helper

We have ptep_get_and_clear() and ptep_get_and_clear_full() helpers to
clear PTE from user page tables, but there is no variant for simple
clear of a present PTE fr

mm: ptep_clear() page table helper

We have ptep_get_and_clear() and ptep_get_and_clear_full() helpers to
clear PTE from user page tables, but there is no variant for simple
clear of a present PTE from user page tables without using a low level
pte_clear() which can be either native or para-virtualised.

Add a new ptep_clear() that can be used in common code to clear PTEs
from page table. We will need this call later in order to add a hook
for page table check.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Pasha Tatashin <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Greg Thelen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sami Tolvanen <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Wei Xu <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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mm/debug_vm_pgtable: update comments regarding migration swap entries

Commit 4dd845b5a3e5 ("mm/swapops: rework swap entry manipulation code")
had changed migtation entry related helpers. Just updat

mm/debug_vm_pgtable: update comments regarding migration swap entries

Commit 4dd845b5a3e5 ("mm/swapops: rework swap entry manipulation code")
had changed migtation entry related helpers. Just update
debug_vm_pgatble() synced documentation to reflect those changes.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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