linux/mm
Peter Xu 0d206b5d2e mm/swap: add swp_offset_pfn() to fetch PFN from swap entry
We've got a bunch of special swap entries that stores PFN inside the swap
offset fields.  To fetch the PFN, normally the user just calls
swp_offset() assuming that'll be the PFN.

Add a helper swp_offset_pfn() to fetch the PFN instead, fetching only the
max possible length of a PFN on the host, meanwhile doing proper check
with MAX_PHYSMEM_BITS to make sure the swap offsets can actually store the
PFNs properly always using the BUILD_BUG_ON() in is_pfn_swap_entry().

One reason to do so is we never tried to sanitize whether swap offset can
really fit for storing PFN.  At the meantime, this patch also prepares us
with the future possibility to store more information inside the swp
offset field, so assuming "swp_offset(entry)" to be the PFN will not stand
any more very soon.

Replace many of the swp_offset() callers to use swp_offset_pfn() where
proper.  Note that many of the existing users are not candidates for the
replacement, e.g.:

  (1) When the swap entry is not a pfn swap entry at all, or,
  (2) when we wanna keep the whole swp_offset but only change the swp type.

For the latter, it can happen when fork() triggered on a write-migration
swap entry pte, we may want to only change the migration type from
write->read but keep the rest, so it's not "fetching PFN" but "changing
swap type only".  They're left aside so that when there're more
information within the swp offset they'll be carried over naturally in
those cases.

Since at it, dropping hwpoison_entry_to_pfn() because that's exactly what
the new swp_offset_pfn() is about.

Link: https://lkml.kernel.org/r/20220811161331.37055-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:05 -07:00
..
damon Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
kasan - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
kfence kfence: add sysfs interface to disable kfence for selected slabs. 2022-09-11 20:25:52 -07:00
backing-dev.c mm: backing-dev: Remove the unneeded result variable 2022-09-11 20:26:02 -07:00
balloon_compaction.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-28 14:02:45 -07:00
cma_debug.c mm/cma_debug: show complete cma name in debugfs directories 2022-09-11 20:25:50 -07:00
cma_sysfs.c
cma.c Revert "mm/cma.c: remove redundant cma_mutex lock" 2022-05-13 15:11:26 -07:00
cma.h mm/cma: provide option to opt out from exposing pages on activation failure 2022-03-22 15:57:09 -07:00
compaction.c mm: fix null-ptr-deref in kswapd_is_running() 2022-09-11 20:26:04 -07:00
debug_page_ref.c
debug_vm_pgtable.c docs: rename Documentation/vm to Documentation/mm 2022-06-27 12:52:53 -07:00
debug.c mm: unexport page_init_poison 2022-03-24 19:06:45 -07:00
dmapool.c mm/dmapool.c: revert "make dma pool to use kmalloc_node" 2022-01-15 16:30:28 +02:00
early_ioremap.c mm/early_ioremap: declare early_memremap_pgprot_adjust() 2022-03-22 15:57:11 -07:00
fadvise.c riscv: compat: syscall: Add compat_sys_call_table implementation 2022-04-26 13:36:25 -07:00
failslab.c mm: fix missing handler for __GFP_NOWARN 2022-05-19 14:08:55 -07:00
filemap.c filemap: remove find_get_pages_contig() 2022-09-11 20:26:03 -07:00
folio-compat.c mm/folio-compat: Remove migration compatibility functions 2022-08-02 12:34:04 -04:00
frontswap.c frontswap: don't call ->init if no ops are registered 2022-09-26 12:14:34 -07:00
gup_test.c mm: rename is_pinnable_page() to is_longterm_pinnable_page() 2022-07-17 17:14:27 -07:00
gup_test.h
gup.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
highmem.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
hmm.c mm/swap: add swp_offset_pfn() to fetch PFN from swap entry 2022-09-26 19:46:05 -07:00
huge_memory.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
hugetlb_cgroup.c hugetlb_cgroup: use helper for_each_hstate and hstate_index 2022-09-11 20:25:53 -07:00
hugetlb_vmemmap.c mm: hugetlb_vmemmap: simplify reset_struct_pages() 2022-09-11 20:25:58 -07:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readability 2022-08-08 18:06:43 -07:00
hugetlb.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
hwpoison-inject.c mm/memory-failure: disable unpoison once hw error happens 2022-06-16 19:11:32 -07:00
init-mm.c kernel/fork: Initialize mm's PASID 2022-02-14 19:51:47 +01:00
internal.h mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage 2022-09-11 20:25:46 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: Add ioremap/iounmap_allowed() 2022-06-27 12:22:31 +01:00
Kconfig mm: remove EXPERIMENTAL flag for zswap 2022-09-11 20:26:01 -07:00
Kconfig.debug Two followon fixes for the post-5.19 series "Use pageblock_order for cma 2022-05-27 11:40:49 -07:00
khugepaged.c mm: MADV_COLLAPSE: refetch vm_end after reacquiring mmap_lock 2022-09-26 19:46:03 -07:00
kmemleak.c mm/kmemleak: make create_object return void 2022-09-11 20:26:10 -07:00
ksm.c mm: fix PageAnonExclusive clearing racing with concurrent RCU GUP-fast 2022-09-11 20:26:11 -07:00
list_lru.c mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe 2022-06-16 19:48:31 -07:00
maccess.c asm-generic updates for 5.18 2022-03-23 18:03:08 -07:00
madvise.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
Makefile mm: shrinkers: introduce debugfs interface for memory shrinkers 2022-07-03 18:08:40 -07:00
mapping_dirty_helpers.c mm: move tlb_flush_pending inline helpers to mm_inline.h 2022-01-15 16:30:27 +02:00
memblock.c memblock updates for v5.20 2022-08-09 09:48:30 -07:00
memcontrol.c mm: memcg: export workingset refault stats for cgroup v1 2022-09-11 20:25:59 -07:00
memfd.c memfd: fix F_SEAL_WRITE after shmem huge page allocated 2022-03-05 11:08:32 -08:00
memory_hotplug.c mm: fix null-ptr-deref in kswapd_is_running() 2022-09-11 20:26:04 -07:00
memory-failure.c mm/swap: add swp_offset_pfn() to fetch PFN from swap entry 2022-09-26 19:46:05 -07:00
memory.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
mempolicy.c mm/hugetlb: add dedicated func to get 'allowed' nodemask for current process 2022-09-11 20:25:50 -07:00
mempool.c mm/mempool: use might_alloc() 2022-06-16 19:48:30 -07:00
memremap.c mm/mremap_pages: save a few cycles in get_dev_pagemap() 2022-09-11 20:26:11 -07:00
memtest.c
migrate_device.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
migrate.c memory tiering: hot page selection with hint page fault latency 2022-09-11 20:25:54 -07:00
mincore.c mm: teach core mm about pte markers 2022-05-13 07:20:09 -07:00
mlock.c mm: handling Non-LRU pages returned by vm_normal_pages 2022-07-17 17:14:28 -07:00
mm_init.c
mmap_lock.c
mmap.c mm: align larger anonymous mappings on THP boundaries 2022-09-11 20:25:47 -07:00
mmu_gather.c mm/mmu_gather: limit free batch count and add schedule point in tlb_batch_pages_flush 2022-04-28 23:16:12 -07:00
mmu_notifier.c mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove() 2022-04-21 20:01:10 -07:00
mmzone.c Folio changes for 5.18 2022-03-22 17:03:12 -07:00
mprotect.c memory tiering: hot page selection with hint page fault latency 2022-09-11 20:25:54 -07:00
mremap.c Yang Shi has improved the behaviour of khugepaged collapsing of readonly 2022-05-26 12:32:41 -07:00
msync.c
nommu.c mm: nommu: pass a pointer to virt_to_page() 2022-07-17 17:14:37 -07:00
oom_kill.c mm/oom_kill.c: fix vm_oom_kill_table[] ifdeffery 2022-06-01 15:57:16 -07:00
page_alloc.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
page_counter.c mm: page_counter: remove unneeded atomic ops for low/min 2022-09-11 20:26:01 -07:00
page_ext.c page_ext: introduce boot parameter 'early_page_ext' 2022-09-11 20:26:02 -07:00
page_idle.c mm: don't be stuck to rmap lock on reclaim path 2022-05-19 14:08:54 -07:00
page_io.c mm/swap: remove the end_write_func argument to __swap_writepage 2022-09-11 20:25:50 -07:00
page_isolation.c mm/page_isolation: fix isolate_single_pageblock() isolation behavior 2022-09-26 12:14:34 -07:00
page_owner.c mm/page_owner.c: add llseek for page_owner 2022-09-11 20:25:59 -07:00
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c mm: fix use-after free of page_ext after race with memory-offline 2022-09-11 20:25:57 -07:00
page_vma_mapped.c mm/swap: add swp_offset_pfn() to fetch PFN from swap entry 2022-09-26 19:46:05 -07:00
page-writeback.c writeback: avoid use-after-free after removing device 2022-08-28 14:02:43 -07:00
pagewalk.c mm: pagewalk: add api documentation for walk_page_range_novma() 2022-09-11 20:26:00 -07:00
percpu-internal.h percpu: improve percpu_alloc_percpu event trace 2022-05-13 07:20:18 -07:00
percpu-km.c
percpu-stats.c mm: use vmalloc_array and vcalloc for array allocations 2022-03-08 09:30:46 -05:00
percpu-vm.c
percpu.c mm: percpu: use kmemleak_ignore_phys() instead of kmemleak_free() 2022-07-17 17:14:47 -07:00
pgalloc-track.h
pgtable-generic.c mm: avoid unnecessary flush on change_huge_pmd() 2022-05-13 07:20:05 -07:00
process_vm_access.c
ptdump.c mm: sparsemem: use page table lock to protect kernel pmd operations 2022-03-22 15:57:08 -07:00
readahead.c filemap: Fix serialization adding transparent huge pages to page cache 2022-06-23 12:22:00 -04:00
rmap.c mm: fix PageAnonExclusive clearing racing with concurrent RCU GUP-fast 2022-09-11 20:26:11 -07:00
rodata_test.c
secretmem.c mm: fix dereferencing possible ERR_PTR 2022-09-11 16:22:31 -07:00
shmem.c shmem: update folio if shmem_replace_page() updates the page 2022-08-28 14:02:43 -07:00
shrinker_debug.c mm: shrinkers: fix double kfree on shrinker name 2022-07-29 18:07:13 -07:00
shuffle.c
shuffle.h
slab_common.c mm/slab_common: move generic bulk alloc/free functions to SLOB 2022-07-20 13:30:12 +02:00
slab.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
slab.h mm/slab_common: move generic bulk alloc/free functions to SLOB 2022-07-20 13:30:12 +02:00
slob.c mm/slab_common: move generic bulk alloc/free functions to SLOB 2022-07-20 13:30:12 +02:00
slub.c kfence: add sysfs interface to disable kfence for selected slabs. 2022-09-11 20:25:52 -07:00
sparse-vmemmap.c mm: hugetlb_vmemmap: move vmemmap code related to HugeTLB to hugetlb_vmemmap.c 2022-08-08 18:06:42 -07:00
sparse.c mm: memory_hotplug: enumerate all supported section flags 2022-07-03 18:08:49 -07:00
swap_cgroup.c mm: use vmalloc_array and vcalloc for array allocations 2022-03-08 09:30:46 -05:00
swap_slots.c arm64: enable THP_SWAP for arm64 2022-07-20 10:52:40 +01:00
swap_state.c mm: fix VM_BUG_ON in __delete_from_swap_cache() 2022-09-11 16:22:31 -07:00
swap.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
swap.h mm/swap: remove the end_write_func argument to __swap_writepage 2022-09-11 20:25:50 -07:00
swapfile.c mm/swap: convert delete_from_swap_cache() to take a folio 2022-07-03 18:08:48 -07:00
truncate.c mm: Remove __delete_from_page_cache() 2022-06-29 08:51:05 -04:00
usercopy.c usercopy: use unsigned long instead of uintptr_t 2022-07-01 17:03:38 -07:00
userfaultfd.c mm/uffd: reset write protection when unregister with wp-mode 2022-08-20 15:17:45 -07:00
util.c mm/util.c: add warning if __vm_enough_memory fails 2022-09-11 20:25:54 -07:00
vmacache.c
vmalloc.c mm/vmalloc: extend find_vmap_lowest_match_check with extra arguments 2022-09-11 20:26:05 -07:00
vmpressure.c
vmscan.c Merge branch 'mm-hotfixes-stable' into mm-stable 2022-09-26 13:13:15 -07:00
vmstat.c memory tiering: rate limit NUMA migration throughput 2022-09-11 20:25:54 -07:00
workingset.c mm: shrinkers: provide shrinkers with names 2022-07-03 18:08:40 -07:00
z3fold.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
zbud.c
zpool.c zpool: remove the list of pools_head 2022-01-15 16:30:31 +02:00
zsmalloc.c zsmalloc: zs_object_copy: replace email link to doc 2022-09-11 20:25:56 -07:00
zswap.c mm/swap: remove the end_write_func argument to __swap_writepage 2022-09-11 20:25:50 -07:00