WSL2-Linux-Kernel/mm
Jan Kara 2820005eda Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again"
commit 30139c702048f1097342a31302cbd3d478f50c63 upstream.

Patch series "mm: Avoid possible overflows in dirty throttling".

Dirty throttling logic assumes dirty limits in page units fit into
32-bits.  This patch series makes sure this is true (see patch 2/2 for
more details).


This patch (of 2):

This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78.

The commit is broken in several ways.  Firstly, the removed (u64) cast
from the multiplication will introduce a multiplication overflow on 32-bit
archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the
default settings with 4GB of RAM will trigger this).  Secondly, the
div64_u64() is unnecessarily expensive on 32-bit archs.  We have
div64_ul() in case we want to be safe & cheap.  Thirdly, if dirty
thresholds are larger than 1<<32 pages, then dirty balancing is going to
blow up in many other spectacular ways anyway so trying to fix one
possible overflow is just moot.

Link: https://lkml.kernel.org/r/20240621144017.30993-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240621144246.11148-1-jack@suse.cz
Fixes: 9319b647902c ("mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-By: Zach O'Keefe <zokeefe@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18 13:07:33 +02:00
..
damon mm/damon/ops-common: atomically test and clear young on ptes and pmds 2023-07-23 13:47:47 +02:00
kasan kasan: disable kasan_non_canonical_hook() for HW tags 2023-12-23 10:42:00 +01:00
kfence mm: kfence: fix using kfence_metadata without initialization in show_object() 2023-03-30 12:48:01 +02:00
Kconfig kmap_local: don't assume kmap PTEs are linear arrays in memory 2021-11-25 09:48:43 +01:00
Kconfig.debug
Makefile mm: introduce Data Access MONitor (DAMON) 2021-09-08 11:50:24 -07:00
backing-dev.c writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs 2023-05-11 23:00:18 +09:00
balloon_compaction.c
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-31 17:16:48 +02:00
cleancache.c
cma.c mm/cma: drop incorrect alignment check in cma_init_reserved_mem 2024-07-05 09:14:13 +02:00
cma.h
cma_debug.c
cma_sysfs.c
compaction.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-10 16:19:37 +02:00
debug.c mm/debug: sync up latest migrate_reason to migrate_reason_names 2021-09-24 16:13:35 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: remove pte entry from the page table 2022-02-08 18:34:05 +01:00
dmapool.c
early_ioremap.c mm/early_ioremap.c: remove redundant early_ioremap_shutdown() 2021-09-08 11:50:24 -07:00
fadvise.c
failslab.c
filemap.c mm/filemap: avoid buffered read/write race to read inconsistent data 2024-01-05 15:13:39 +01:00
frontswap.c
gup.c mm/migration: return errno when isolate_huge_page failed 2023-02-14 19:17:56 +01:00
gup_test.c
gup_test.h
highmem.c highmem: fix checks in __kmap_local_sched_{in,out} 2022-04-13 20:59:21 +02:00
hmm.c mm/hmm: fault non-owner device private entries 2022-08-03 12:03:54 +02:00
huge_memory.c mm/userfaultfd: propagate uffd-wp bit when PTE-mapping the huge zeropage 2023-03-22 13:31:35 +01:00
hugetlb.c mm/migration: return errno when isolate_huge_page failed 2023-02-14 19:17:56 +01:00
hugetlb_cgroup.c
hugetlb_vmemmap.c
hugetlb_vmemmap.h
hwpoison-inject.c mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler 2022-07-12 16:35:05 +02:00
init-mm.c
internal.h mm/numa: automatically generate node migration order 2021-09-03 09:58:16 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: move ioremap_page_range to vmalloc.c 2021-09-08 11:50:24 -07:00
khugepaged.c mm/khugepaged: check again on anon uffd-wp during isolation 2023-04-26 13:51:52 +02:00
kmemleak.c Revert "mm: kmemleak: take a full lowmem check in kmemleak_*_phys()" 2022-09-15 11:30:00 +02:00
ksm.c mm/ksm: remove old GCC 4.9+ check 2021-09-13 10:18:28 -07:00
list_lru.c
maccess.c maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault() 2022-11-26 09:24:47 +01:00
madvise.c mm: fix madivse_pageout mishandling on non-LRU page 2022-10-05 10:39:39 +02:00
mapping_dirty_helpers.c
memblock.c memblock: allow to specify flags with memblock_add_node() 2023-12-20 15:17:33 +01:00
memcontrol.c mm: kmem: drop __GFP_NOFAIL when allocating objcg vectors 2023-11-28 16:56:35 +00:00
memfd.c memfd: check for non-NULL file_seals in memfd_create() syscall 2023-06-28 10:29:45 +02:00
memory-failure.c mm/huge_memory: don't unpoison huge_zero_folio 2024-07-05 09:14:22 +02:00
memory.c x86/mm/pat: fix VM_PAT handling in COW mappings 2024-04-13 13:01:47 +02:00
memory_hotplug.c memblock: allow to specify flags with memblock_add_node() 2023-12-20 15:17:33 +01:00
mempolicy.c migrate: hugetlb: check for hugetlb shared PMD in node migration 2023-02-14 19:17:56 +01:00
mempool.c
memremap.c mm/memremap.c: map FS_DAX device memory as decrypted 2022-11-16 09:58:27 +01:00
memtest.c memtest: use {READ,WRITE}_ONCE in memory scanning 2024-04-10 16:18:42 +02:00
migrate.c mm/migrate: set swap entry values of THP tail pages properly. 2024-04-10 16:19:31 +02:00
mincore.c
mlock.c mm/mlock: fix potential imbalanced rlimit ucounts adjustment 2022-05-15 20:18:53 +02:00
mm_init.c
mmap.c mm/mmap: undo ->mmap() when arch_validate_flags() fails 2022-10-26 12:34:24 +02:00
mmap_lock.c
mmu_gather.c mm/khugepaged: fix GUP-fast interaction by sending IPI 2022-12-14 11:37:17 +01:00
mmu_notifier.c mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove() 2022-04-27 14:38:58 +02:00
mmzone.c
mprotect.c mm: don't try to NUMA-migrate COW pages that have other uses 2022-02-23 12:03:03 +01:00
mremap.c mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0) 2022-04-13 20:59:22 +02:00
msync.c
nommu.c Merge tag 'denywrite-for-5.15' of git://github.com/davidhildenbrand/linux 2021-09-04 11:35:47 -07:00
oom_kill.c oom_kill.c: futex: delay the OOM reaper to allow time for proper futex cleanup 2022-04-27 14:38:58 +02:00
page-writeback.c Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" 2024-07-18 13:07:33 +02:00
page_alloc.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-10 16:19:37 +02:00
page_counter.c
page_ext.c mm/migrate: add CPU hotplug to demotion #ifdef 2021-10-18 20:22:02 -10:00
page_idle.c mm/idle_page_tracking: make PG_idle reusable 2021-09-08 11:50:24 -07:00
page_io.c mm: fix unexpected zeroed page mapping with zram swap 2022-04-20 09:34:18 +02:00
page_isolation.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
page_owner.c mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE 2021-09-08 11:50:22 -07:00
page_poison.c
page_reporting.c
page_reporting.h
page_vma_mapped.c
pagewalk.c mm: pagewalk: Fix race between unmap and page walker 2022-09-08 12:28:05 +02:00
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
pgalloc-track.h
pgtable-generic.c
process_vm_access.c
ptdump.c mm: pagewalk: Fix race between unmap and page walker 2022-09-08 12:28:05 +02:00
readahead.c vfs: fix readahead(2) on block devices 2023-11-20 11:08:13 +01:00
rmap.c mm/rmap: Fix anon_vma->degree ambiguity leading to double-reuse 2022-09-05 10:30:07 +02:00
rodata_test.c
secretmem.c mm: fix dereferencing possible ERR_PTR 2022-10-05 10:39:39 +02:00
shmem.c tmpfs: verify {g,u}id mount options correctly 2023-09-19 12:22:30 +02:00
shuffle.c
shuffle.h
slab.c mm/slab: Fix undefined init_cache_node_node() for NUMA and !SMP 2023-03-30 12:47:56 +02:00
slab.h mm, kfence: support kmem_dump_obj() for KFENCE objects 2022-04-27 14:38:51 +02:00
slab_common.c mm, kfence: support kmem_dump_obj() for KFENCE objects 2022-04-27 14:38:51 +02:00
slob.c mm, kfence: support kmem_dump_obj() for KFENCE objects 2022-04-27 14:38:51 +02:00
slub.c mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context. 2022-09-28 11:11:44 +02:00
sparse-vmemmap.c
sparse.c mm/sparsemem: fix race in accessing memory_section->usage 2024-02-23 08:54:34 +01:00
swap.c mm: fs: invalidate bh_lrus for only cold path 2021-09-24 16:13:35 -07:00
swap_cgroup.c
swap_slots.c
swap_state.c mm: swap: get rid of livelock in swapin readahead 2022-03-23 09:16:41 +01:00
swapfile.c mm: swap: fix race between free_swap_and_cache() and swapoff() 2024-04-10 16:18:39 +02:00
truncate.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
usercopy.c mm/usercopy: return 1 from hardened_usercopy __setup() handler 2022-04-08 14:24:14 +02:00
userfaultfd.c userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb 2024-03-01 13:21:43 +01:00
util.c rcu: dump vmalloc memory info safely 2023-09-19 12:22:50 +02:00
vmacache.c
vmalloc.c mm/vmalloc: add a safer version of find_vm_area() for debug 2023-09-19 12:22:50 +02:00
vmpressure.c net-memcg: Fix scope of sockmem pressure indicators 2023-09-19 12:22:33 +02:00
vmscan.c mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations 2024-04-10 16:19:37 +02:00
vmstat.c mm/vmstat: protect per cpu variables with preempt disable on RT 2021-09-08 15:32:34 -07:00
workingset.c memcg: sync flush only if periodic flush is delayed 2022-04-27 14:38:57 +02:00
z3fold.c
zbud.c
zpool.c
zsmalloc.c zsmalloc: fix races between asynchronous zspage free and page migration 2022-06-06 08:43:39 +02:00
zswap.c