Oscar Salvador f5c12105c1 mm,page_owner: fix refcount imbalance ...

Current code does not contemplate scenarios were an allocation and free
operation on the same pages do not handle it in the same amount at once. 
To give an example, page_alloc_exact(), where we will allocate a page of
enough order to stafisfy the size request, but we will free the remainings
right away.

In the above example, we will increment the stack_record refcount only
once, but we will decrease it the same number of times as number of unused
pages we have to free.  This will lead to a warning because of refcount
imbalance.

Fix this by recording the number of base pages in the refcount field.

Link: https://lkml.kernel.org/r/20240404070702.2744-3-osalvador@suse.de
Reported-by: syzbot+41bbfdb8d41003d12c0f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/00000000000090e8ff0613eda0e5@google.com
Fixes: 217b2119b9 ("mm,page_owner: implement the tracking of the stacks count")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2024-04-16 15:39:49 -07:00

..

damon

Docs/mm/damon/design: remove the details for pageout as paddr doesn't use MADV_PAGEOUT

2024-03-04 17:01:17 -08:00

active_mm.rst

lazy tlb: allow lazy tlb mm refcounting to be configurable

2023-03-28 16:20:08 -07:00

arch_pgtable_helpers.rst

Documentation/mm: drop pte_bad() descriptions from arch page table helpers

2023-12-10 16:51:40 -08:00

balance.rst

Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-02-23 17:09:35 -08:00

bootmem.rst

…

free_page_reporting.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

highmem.rst

Merge tag 'docs-6.6' of git://git.lwn.net/linux

2023-08-30 20:05:42 -07:00

hmm.rst

docs/mm: remove references to hmm_mirror ops and clean typos

2023-08-28 12:41:17 -06:00

hugetlbfs_reserv.rst

mm: convert free_huge_page() to free_huge_folio()

2023-08-21 14:28:43 -07:00

hwpoison.rst

Documentation: Fix typos

2023-08-18 11:29:03 -06:00

index.rst

mm: kill frontswap

2023-08-21 13:37:26 -07:00

ksm.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

memory-model.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

mmu_notifier.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

multigen_lru.rst

mm: multi-gen LRU: improve design doc

2023-03-28 16:20:07 -07:00

numa.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

oom.rst

…

overcommit-accounting.rst

docs: mm: fix vm overcommit documentation for OVERCOMMIT_GUESS

2023-10-10 13:35:55 -06:00

page_allocation.rst

…

page_cache.rst

ubifs: Convert ubifs_vm_page_mkwrite() to use a folio

2024-02-25 21:08:00 +01:00

page_frags.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

page_migration.rst

Documentation: Fix typos

2023-08-18 11:29:03 -06:00

page_owner.rst

mm,page_owner: fix refcount imbalance

2024-04-16 15:39:49 -07:00

page_reclaim.rst

docs/mm: Physical Memory: remove useless markup

2023-02-02 10:18:04 -07:00

page_table_check.rst

mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM

2023-05-29 16:14:28 +01:00

page_tables.rst

Documentation/page_tables: Add info about MMU/TLB and Page Faults

2023-10-10 13:35:55 -06:00

physical_memory.rst

docs/mm: Physical Memory: Fix grammar

2023-04-11 16:16:50 -06:00

process_addrs.rst

…

remap_file_pages.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

shmfs.rst

…

slab.rst

…

slub.rst

mm/slub: make the description of slab_min_objects helpful in doc

2024-01-22 10:31:08 +01:00

split_page_table_lock.rst

mm: remove pgtable_{pmd, pte}_page_{ctor, dtor}() wrappers

2023-08-21 13:37:58 -07:00

swap.rst

…

transhuge.rst

mm/rmap: rename COMPOUND_MAPPED to ENTIRELY_MAPPED

2023-12-29 11:58:56 -08:00

unevictable-lru.rst

Documentation: stop referring to page_remove_rmap()

2023-12-29 11:58:54 -08:00

vmalloc.rst

…

vmalloced-kernel-stacks.rst

…

vmemmap_dedup.rst

docs: update link to powerpc/vmemmap_dedup.rst

2023-10-10 13:35:55 -06:00

z3fold.rst

docs/mm: remove useless markup

2023-02-02 10:18:05 -07:00

zsmalloc.rst

mm: add orphaned kernel-doc to the rst files.

2023-08-24 16:20:31 -07:00