linux/mm
Peter Xu 0b1ef4fde7 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/20240523132139.289719-1-peterx@redhat.com
Fixes: 8430557fc5 ("mm/page_table_check: support userfault wr-protect entries")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Link: https://lore.kernel.org/r/CABXGCsMB9A8-X+Np_Q+fWLURYL_0t3Y-MdoNabDM-Lzk58-DGA@mail.gmail.com
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-15 10:43:08 -07:00
..
damon mm/damon/core: fix return value from damos_wmark_metric_value 2024-05-11 15:41:36 -07:00
kasan fix missing vmalloc.h includes 2024-04-25 20:55:49 -07:00
kfence mm: introduce slabobj_ext to support slab object extensions 2024-04-25 20:55:51 -07:00
kmsan kmsan: do not wipe out origin when doing partial unpoisoning 2024-06-05 19:19:25 -07:00
backing-dev.c writeback: support retrieving per group debug writeback stats of bdi 2024-05-05 17:53:51 -07:00
balloon_compaction.c
bootmem_info.c bootmem: use kmemleak_free_part_phys in put_page_bootmem 2023-10-25 16:47:13 -07:00
cma.c mm/cma: drop incorrect alignment check in cma_init_reserved_mem 2024-04-25 20:56:42 -07:00
cma.h mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
cma_debug.c
cma_sysfs.c mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
compaction.c memory: remove the now superfluous sentinel element from ctl_table array 2024-04-25 20:56:32 -07:00
debug.c mm/debug: print only page mapcount (excluding folio entire mapcount) in __dump_folio() 2024-05-05 17:53:31 -07:00
debug_page_alloc.c mm: page_alloc: consolidate free page accounting 2024-04-25 20:56:04 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: drop RANDOM_ORVALUE trick 2024-06-15 10:43:08 -07:00
dmapool.c mm/mempool/dmapool: remove CONFIG_DEBUG_SLAB ifdefs 2023-12-05 11:17:58 +01:00
dmapool_test.c
early_ioremap.c
execmem.c mm/execmem, arch: convert remaining overrides of module_alloc to execmem 2024-05-14 00:31:43 -07:00
fadvise.c
fail_page_alloc.c
failslab.c
filemap.c mm: fix xyz_noprof functions calling profiled functions 2024-06-05 19:19:26 -07:00
folio-compat.c mm: remove __set_page_dirty_nobuffers() 2024-04-25 20:56:25 -07:00
gup.c mm/gup: fix hugepd handling in hugetlb rework 2024-05-07 10:37:01 -07:00
gup_test.c
gup_test.h
highmem.c x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs 2023-12-29 12:22:28 -08:00
hmm.c mm/treewide: replace pXd_huge() with pXd_leaf() 2024-04-25 20:55:46 -07:00
huge_memory.c mm: huge_memory: fix misused mapping_large_folio_support() for anon folios 2024-06-15 10:43:06 -07:00
hugetlb.c mm/hugetlb: do not call vma_add_reservation upon ENOMEM 2024-06-05 19:19:26 -07:00
hugetlb_cgroup.c mm/hugetlb: assert hugetlb_lock in __hugetlb_cgroup_commit_charge 2024-05-05 17:53:41 -07:00
hugetlb_vmemmap.c memory: remove the now superfluous sentinel element from ctl_table array 2024-04-25 20:56:32 -07:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: fix reference to nonexistent file 2023-10-25 16:47:14 -07:00
hwpoison-inject.c mm/memory-failure: convert shake_page() to shake_folio() 2024-05-05 17:53:45 -07:00
init-mm.c mm: Deprecate pasid field 2023-12-12 10:11:32 +01:00
internal.h Revert "mm: init_mlocked_on_free_v3" 2024-06-15 10:43:05 -07:00
interval_tree.c
io-mapping.c
ioremap.c
Kconfig The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
Kconfig.debug mm/slub: unify all sl[au]b parameters with "slab_$param" 2024-01-22 10:31:08 +01:00
khugepaged.c mm: simplify thp_vma_allowable_order 2024-05-05 17:53:53 -07:00
kmemleak.c mm: lift gfp_kmemleak_mask() to gfp.h 2024-05-19 14:40:44 -07:00
ksm.c mm/ksm: fix ksm_zero_pages accounting 2024-06-05 19:19:26 -07:00
list_lru.c mm/zswap: stop lru list shrinking when encounter warm region 2024-02-22 10:24:54 -08:00
maccess.c
madvise.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
Makefile mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mapping_dirty_helpers.c mm: fix clean_record_shared_mapping_range kernel-doc 2023-08-24 16:20:30 -07:00
memblock.c cxl fixes for 6.8-rc6 2024-02-24 15:53:40 -08:00
memcontrol.c memcg: remove the lockdep assert from __mod_objcg_mlstate() 2024-06-05 19:19:24 -07:00
memfd.c mm/memfd: refactor memfd_tag_pins() and memfd_wait_for_pins() 2024-03-04 17:01:21 -08:00
memory-failure.c mm/memory-failure: fix handling of dissolved but not taken off from buddy pages 2024-05-24 11:55:08 -07:00
memory-tiers.c memory tier: create CPUless memory tiers after obtaining HMAT info 2024-05-05 17:53:26 -07:00
memory.c mm: fix possible OOB in numa_rebuild_large_mapping() 2024-06-15 10:43:07 -07:00
memory_hotplug.c mm/hugetlb: rename dissolve_free_huge_pages() to dissolve_free_hugetlb_folios() 2024-05-05 17:53:35 -07:00
mempolicy.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mempool.c mm: fix xyz_noprof functions calling profiled functions 2024-06-05 19:19:26 -07:00
memremap.c mm: convert put_devmap_managed_page_refs() to put_devmap_managed_folio_refs() 2024-05-05 17:53:49 -07:00
memtest.c memtest: use {READ,WRITE}_ONCE in memory scanning 2024-03-13 12:12:21 -07:00
migrate.c mm/migrate: fix kernel BUG at mm/compaction.c:2761! 2024-06-15 10:43:07 -07:00
migrate_device.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
mincore.c
mlock.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mm_init.c Revert "mm: init_mlocked_on_free_v3" 2024-06-15 10:43:05 -07:00
mm_slot.h
mmap.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mmap_lock.c
mmu_gather.c mm/mmu_gather: improve cond_resched() handling with large folios and expensive page freeing 2024-02-22 15:27:17 -08:00
mmu_notifier.c mmu_notifier: remove the .change_pte() callback 2024-04-11 13:18:36 -04:00
mmzone.c zswap: shrink zswap pool based on memory pressure 2023-12-12 10:57:02 -08:00
mprotect.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mremap.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mseal.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
msync.c
nommu.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
oom_kill.c memory: remove the now superfluous sentinel element from ctl_table array 2024-04-25 20:56:32 -07:00
page-writeback.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
page_alloc.c Revert "mm: init_mlocked_on_free_v3" 2024-06-15 10:43:05 -07:00
page_counter.c
page_ext.c mm: make page_ext_get() take a const argument 2024-04-25 20:56:14 -07:00
page_idle.c
page_io.c mm: drop the 'anon_' prefix for swap-out mTHP counters 2024-06-05 19:19:23 -07:00
page_isolation.c mm: page_isolation: prepare for hygienic freelists 2024-04-25 20:56:04 -07:00
page_owner.c mm/page-owner: use gfp_nested_mask() instead of open coded masking 2024-05-19 14:40:44 -07:00
page_poison.c mm/page_poison: replace kmap_atomic() with kmap_local_page() 2023-12-10 16:51:50 -08:00
page_reporting.c mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
page_reporting.h
page_table_check.c mm/page_table_check: fix crash on ZONE_DEVICE 2024-06-15 10:43:04 -07:00
page_vma_mapped.c mm: make page_mapped_in_vma conditional on CONFIG_MEMORY_FAILURE 2024-05-05 17:53:45 -07:00
pagewalk.c mm: pagewalk: assert write mmap lock only for walking the user page tables 2023-12-10 16:51:53 -08:00
percpu-internal.h mm: percpu: add codetag reference into pcpuobj_ext 2024-04-25 20:55:56 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c percpu: clean up all mappings when pcpu_map_pages() fails 2024-04-25 20:55:49 -07:00
percpu.c mm: percpu: enable per-cpu allocation tagging 2024-04-25 20:55:56 -07:00
pgalloc-track.h
pgtable-generic.c mm: fix race between __split_huge_pmd_locked() and GUP-fast 2024-05-07 10:37:00 -07:00
process_vm_access.c mm: fix process_vm_rw page counts 2023-12-10 16:51:39 -08:00
ptdump.c mm: ptdump: add check_wx_pages debugfs attribute 2024-02-22 10:24:47 -08:00
readahead.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
rmap.c mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED 2024-05-11 15:41:35 -07:00
rodata_test.c
secretmem.c mm/secretmem: use a folio in secretmem_fault() 2023-08-21 13:38:02 -07:00
shmem.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
shmem_quota.c tmpfs: fix race on handling dquot rbtree 2024-03-26 11:07:23 -07:00
show_mem.c lib: add memory allocations report in show_mem() 2024-04-25 20:55:57 -07:00
shrinker.c mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info() 2024-01-05 09:58:32 -08:00
shrinker_debug.c mm: shrinker: convert shrinker_rwsem to mutex 2023-10-04 10:32:26 -07:00
shuffle.c
shuffle.h mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
slab.h The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
slab_common.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
slub.c codetag: avoid race at alloc_slab_obj_exts 2024-06-05 19:19:26 -07:00
sparse-vmemmap.c
sparse.c mm/sparse: guard the size of mem_section is power of 2 2024-05-05 17:53:40 -07:00
swap.c mm: add kernel-doc for folio_mark_accessed() 2024-05-05 17:53:50 -07:00
swap.h mm/swap: fix race when skipping swapcache 2024-02-20 14:20:48 -08:00
swap_cgroup.c
swap_slots.c mm: swap: update get_swap_pages() to take folio order 2024-04-25 20:56:37 -07:00
swap_state.c mm: remove struct page from get_shadow_from_swap_cache 2024-04-25 20:56:40 -07:00
swapfile.c getting rid of bogus set_blocksize() uses, switching it 2024-05-21 08:34:51 -07:00
truncate.c mm: convert pagecache_isize_extended to use a folio 2024-04-25 20:56:43 -07:00
usercopy.c
userfaultfd.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
util.c mm: fix xyz_noprof functions calling profiled functions 2024-06-05 19:19:26 -07:00
vmalloc.c vmalloc: check CONFIG_EXECMEM in is_vmalloc_or_module_addr() 2024-06-05 19:19:25 -07:00
vmpressure.c eventfd: simplify eventfd_signal() 2023-11-28 14:08:38 +01:00
vmscan.c mm: drop the 'anon_' prefix for swap-out mTHP counters 2024-06-05 19:19:23 -07:00
vmstat.c iommu: observability of the IOMMU allocations 2024-04-15 14:31:47 +02:00
workingset.c mm: cleanup WORKINGSET_NODES in workingset 2024-05-07 10:36:59 -07:00
z3fold.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zbud.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zpool.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zsmalloc.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zswap.c mm: zswap: remove same_filled module params 2024-05-05 17:53:38 -07:00