Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Wen Yang 28f04308d7 mm/page-writeback.c: avoid potential division by zero in wb_min_max_ratio() ... commit 6d9e8c651dd979aa666bee15f086745f3ea9c4b3 upstream. Patch series "use div64_ul() instead of div_u64() if the divisor is unsigned long". We were first inspired by commit b0ab99e773 ("sched: Fix possible divide by zero in avg_atom () calculation"), then refer to the recently analyzed mm code, we found this suspicious place. 201 if (min) { 202 min *= this_bw; 203 do_div(min, tot_bw); 204 } And we also disassembled and confirmed it: /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 201 0xffffffff811c37da <__wb_calc_thresh+234>: xor %r10d,%r10d 0xffffffff811c37dd <__wb_calc_thresh+237>: test %rax,%rax 0xffffffff811c37e0 <__wb_calc_thresh+240>: je 0xffffffff811c3800 <__wb_calc_thresh+272> /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 202 0xffffffff811c37e2 <__wb_calc_thresh+242>: imul %r8,%rax /usr/src/debug/kernel-4.9.168-016.ali3000/linux-4.9.168-016.ali3000.alios7.x86_64/mm/page-writeback.c: 203 0xffffffff811c37e6 <__wb_calc_thresh+246>: mov %r9d,%r10d ---> truncates it to 32 bits here 0xffffffff811c37e9 <__wb_calc_thresh+249>: xor %edx,%edx 0xffffffff811c37eb <__wb_calc_thresh+251>: div %r10 0xffffffff811c37ee <__wb_calc_thresh+254>: imul %rbx,%rax 0xffffffff811c37f2 <__wb_calc_thresh+258>: shr $0x2,%rax 0xffffffff811c37f6 <__wb_calc_thresh+262>: mul %rcx 0xffffffff811c37f9 <__wb_calc_thresh+265>: shr $0x2,%rdx 0xffffffff811c37fd <__wb_calc_thresh+269>: mov %rdx,%r10 This series uses div64_ul() instead of div_u64() if the divisor is unsigned long, to avoid truncation to 32-bit on 64-bit platforms. This patch (of 3): The variables 'min' and 'max' are unsigned long and do_div truncates them to 32 bits, which means it can test non-zero and be truncated to zero for division. Fix this issue by using div64_ul() instead. Link: http://lkml.kernel.org/r/20200102081442.8273-2-wenyang@linux.alibaba.com Fixes: 693108a8a6 ("writeback: make bdi->min/max_ratio handling cgroup writeback aware") Signed-off-by: Wen Yang <wenyang@linux.alibaba.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Qian Cai <cai@lca.pw> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-01-23 08:19:40 +01:00
..
kasan	kasan: avoid -Wmaybe-uninitialized warning	2019-05-08 07:19:07 +02:00
backing-dev.c	writeback: synchronize sync(2) against cgroup writeback membership switches	2019-05-21 18:49:01 +02:00
balloon_compaction.c	mm: balloon: use general non-lru movable page feature	2016-07-26 16:19:19 -07:00
bootmem.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
cleancache.c	cleancache: constify cleancache_ops structure	2016-01-27 09:09:57 -05:00
cma.c	mm/cma.c: fail if fixed declaration can't be honored	2019-08-06 18:29:37 +02:00
cma.h
cma_debug.c	mm/cma_debug.c: fix the break condition in cma_maxchunk_get()	2019-06-22 08:17:12 +02:00
compaction.c	mm, compaction: fix NR_ISOLATED_* stats for pfn based migration	2017-01-12 11:39:32 +01:00
debug.c	mm: get rid of vmacache_flush_all() entirely	2018-09-19 22:47:17 +02:00
debug_page_ref.c	mm/page_ref: add tracepoint to track down page reference manipulation	2016-03-17 15:09:34 -07:00
dmapool.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
early_ioremap.c	mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep	2018-02-25 11:05:49 +01:00
fadvise.c	mm/fadvise.c: fix signed overflow UBSAN complaint	2018-09-15 09:42:57 +02:00
failslab.c	mm: fault-inject take over bootstrap kmem_cache check	2016-03-15 16:55:16 -07:00
filemap.c	mm/filemap.c: don't initiate writeback if mapping has no dirty pages	2019-11-12 19:16:10 +01:00
frame_vector.c	mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()'	2018-11-10 07:42:52 -08:00
frontswap.c	mm, frontswap: convert frontswap_enabled to static key	2016-07-26 16:19:19 -07:00
gup.c	mm: prevent get_user_pages() from overflowing page refcount	2019-06-11 12:22:45 +02:00
highmem.c	mm/highmem: make nr_free_highpages() handles all highmem zones by itself	2016-05-19 19:12:14 -07:00
huge_memory.c	mm, page_owner: handle THP splits correctly	2019-09-06 10:19:39 +02:00
hugetlb.c	hugetlbfs: on restore reserve error path retain subpool reservation	2019-06-22 08:17:12 +02:00
hugetlb_cgroup.c	mm: hugetlb: switch to css_tryget() in hugetlb_cgroup_charge_cgroup()	2019-11-25 09:51:58 +01:00
hwpoison-inject.c
init-mm.c	mm: Add a user_ns owner to mm_struct and fix ptrace permission checks	2017-01-06 10:40:13 +01:00
internal.h	vmscan: return NODE_RECLAIM_NOSCAN in node_reclaim() when CONFIG_NUMA is n	2019-12-05 15:35:02 +01:00
interval_tree.c
Kconfig	mm: don't allow deferred pages with NEED_PER_CPU_KM	2018-05-22 16:57:57 +02:00
Kconfig.debug	PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO	2016-09-13 02:35:27 +02:00
khugepaged.c	coredump: fix race condition between collapse_huge_page() and core dumping	2019-08-06 18:29:41 +02:00
kmemcheck.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak-test.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak.c	mm/kmemleak.c: fix check for softirq context	2019-08-04 09:33:41 +02:00
ksm.c	mm/ksm.c: don't WARN if page is still mapped in remove_stable_node()	2019-11-28 18:28:09 +01:00
list_lru.c	mm/list_lru.c: fix memory leak in __memcg_init_list_lru_node	2019-06-22 08:17:18 +02:00
maccess.c	x86: remove more uaccess_32.h complexity	2016-05-22 17:21:27 -07:00
madvise.c	mm: madvise(MADV_DODUMP): allow hugetlbfs pages	2018-10-10 08:53:20 +02:00
Makefile	Disable the __builtin_return_address() warning globally after all	2016-10-12 10:23:41 -07:00
memblock.c	mm/memblock.c: reversed logic in memblock_discard()	2017-08-30 10:21:47 +02:00
memcontrol.c	mm: memcg: switch to css_tryget() in get_mem_cgroup_from_mm()	2019-11-25 09:51:58 +01:00
memory-failure.c	mm: hwpoison: fix thp split handing in soft_offline_in_use_page()	2019-03-23 13:19:49 +01:00
memory.c	mm: stop leaking PageTables	2019-02-20 10:18:34 +01:00
memory_hotplug.c	mm/memory_hotplug: make add_memory() take the device_hotplug_lock	2019-11-28 18:28:51 +01:00
mempolicy.c	mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified	2019-04-05 22:29:05 +02:00
mempool.c	Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"	2016-07-28 16:07:41 -07:00
memtest.c
migrate.c	hugetlbfs: fix races and page leaks during migration	2019-03-13 14:04:54 -07:00
mincore.c	mm/mincore.c: make mincore() more conservative	2019-05-21 18:48:58 +02:00
mlock.c	mm/mlock.c: change count_mm_mlocked_page_nr return type	2019-07-10 09:55:43 +02:00
mm_init.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
mmap.c	arm64: Revert support for execute-only user mappings	2020-01-12 11:24:15 +01:00
mmu_context.c	mm/mmu_context, sched/core: Fix mmu_context.h assumption	2016-04-28 11:44:19 +02:00
mmu_notifier.c	mm/mmu_notifier: use hlist_add_head_rcu()	2019-08-04 09:33:42 +02:00
mmzone.c	mm, page_alloc: inline the fast path of the zonelist iterator	2016-05-19 19:12:14 -07:00
mprotect.c	x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings	2018-08-15 18:14:45 +02:00
mremap.c	mremap: properly flush TLB before releasing the page	2018-10-20 09:51:31 +02:00
msync.c
nobootmem.c	mm: discard memblock data later	2017-08-24 17:12:19 -07:00
nommu.c	ptrace: Don't allow accessing an undumpable mm	2017-01-06 10:40:13 +01:00
oom_kill.c	oom, oom_reaper: do not enqueue same task twice	2019-02-12 19:45:02 +01:00
page-writeback.c	mm/page-writeback.c: avoid potential division by zero in wb_min_max_ratio()	2020-01-23 08:19:40 +01:00
page_alloc.c	mem-hotplug: fix node spanned pages when we have a node with only ZONE_MOVABLE	2019-06-22 08:17:12 +02:00
page_counter.c
page_ext.c	mm/page_ext.c: fix an imbalance with kmemleak	2019-04-05 22:29:06 +02:00
page_idle.c	mm/page_idle.c: fix oops because end_pfn is larger than max_pfn	2019-07-10 09:55:38 +02:00
page_io.c	mm/page_io.c: replace some BUG_ON()s with VM_BUG_ON_PAGE()	2016-10-07 18:46:29 -07:00
page_isolation.c	mm/page_isolation: fix typo: "paes" -> "pages"	2016-10-07 18:46:29 -07:00
page_owner.c	mm/page_owner: don't define fields on struct page_ext by hard-coding	2016-10-07 18:46:27 -07:00
page_poison.c	mm: check the return value of lookup_page_ext for all call sites	2016-06-03 15:06:22 -07:00
pagewalk.c	mm/pagewalk.c: report holes in hugetlb ranges	2017-11-24 08:33:42 +01:00
percpu-km.c	mm: percpu: use pr_fmt to prefix output	2016-03-17 15:09:34 -07:00
percpu-vm.c
percpu.c	percpu: stop printing kernel addresses	2019-04-27 09:34:47 +02:00
pgtable-generic.c	mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range	2016-03-17 15:09:34 -07:00
process_vm_access.c	mm: remove write/force parameters from __get_user_pages_unlocked()	2016-10-18 14:13:37 -07:00
quicklist.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
readahead.c	mm: silently skip readahead for DAX inodes	2016-08-26 17:39:35 -07:00
rmap.c	mm: migration: fix migration of huge PMD shared pages	2018-11-21 09:26:03 +01:00
shmem.c	mm/shmem.c: cast the type of unmap_start to u64	2019-12-21 10:42:18 +01:00
slab.c	mm/slab.c: fix an infinite loop in leaks_show()	2019-06-22 08:17:13 +02:00
slab.h	slub: move synchronize_sched out of slab_mutex on shrink	2017-03-22 12:43:38 +01:00
slab_common.c	mm: don't warn about large allocations for slab	2018-12-01 09:44:19 +01:00
slob.c	slub: move synchronize_sched out of slab_mutex on shrink	2017-03-22 12:43:38 +01:00
slub.c	mm/slub: fix a deadlock in show_slab_objects()	2019-10-29 09:15:23 +01:00
sparse-vmemmap.c	treewide: replace obsolete _refok by __ref	2016-08-02 17:31:41 -04:00
sparse.c	mm/memory_hotplug: set magic number to page->freelist instead of page->lru.next	2017-10-21 17:21:36 +02:00
swap.c	thp: reduce usage of huge zero page's atomic counter	2016-10-07 18:46:28 -07:00
swap_cgroup.c	mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff()	2017-07-05 14:40:17 +02:00
swap_state.c	mm, swap: use offset of swap entry as key of swap cache	2016-10-07 18:46:28 -07:00
swapfile.c	x86/speculation/l1tf: Limit swap file size to MAX_PA/2	2018-08-15 18:14:45 +02:00
truncate.c	mm: cleancache: fix corruption on missed inode invalidation	2018-12-08 13:05:09 +01:00
usercopy.c	usercopy: Avoid HIGHMEM pfn warning	2019-10-17 13:42:06 -07:00
userfaultfd.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
util.c	mm: page_mapped: don't assume compound page is huge or THP	2019-01-16 22:12:32 +01:00
vmacache.c	mm: get rid of vmacache_flush_all() entirely	2018-09-19 22:47:17 +02:00
vmalloc.c	mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()	2019-08-25 10:51:20 +02:00
vmpressure.c	mm: vmpressure: fix sending wrong events on underflow	2017-03-12 06:41:43 +01:00
vmscan.c	mm: remove seemingly spurious reclaimability check from laptop_mode gating	2018-09-19 22:47:12 +02:00
vmstat.c	mm, vmstat: hide /proc/pagetypeinfo from normal users	2019-11-12 19:15:43 +01:00
workingset.c	mm: workingset: fix premature shadow node shrinking with cgroups	2017-04-08 09:30:36 +02:00
z3fold.c	mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup	2016-06-03 16:02:55 -07:00
zbud.c	mm/zbud.c: use list_last_entry() instead of list_tail_entry()	2016-01-15 11:40:52 -08:00
zpool.c
zsmalloc.c	mm/zsmalloc.c: fix the migrated zspage statistics.	2020-01-12 11:24:13 +01:00
zswap.c	zswap: re-check zswap_is_full() after do zswap_shrink()	2018-09-05 09:20:02 +02:00