kernel_optimize_test/mm
Linus Torvalds eb66ae0308 mremap: properly flush TLB before releasing the page
Jann Horn points out that our TLB flushing was subtly wrong for the
mremap() case.  What makes mremap() special is that we don't follow the
usual "add page to list of pages to be freed, then flush tlb, and then
free pages".  No, mremap() obviously just _moves_ the page from one page
table location to another.

That matters, because mremap() thus doesn't directly control the
lifetime of the moved page with a freelist: instead, the lifetime of the
page is controlled by the page table locking, that serializes access to
the entry.

As a result, we need to flush the TLB not just before releasing the lock
for the source location (to avoid any concurrent accesses to the entry),
but also before we release the destination page table lock (to avoid the
TLB being flushed after somebody else has already done something to that
page).

This also makes the whole "need_flush" logic unnecessary, since we now
always end up flushing the TLB for every valid entry.

Reported-and-tested-by: Jann Horn <jannh@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18 11:30:52 +02:00
..
kasan kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN 2018-08-17 16:20:30 -07:00
backing-dev.c blkcg: delay blkg destruction until after writeback has finished 2018-08-31 14:48:56 -06:00
balloon_compaction.c
bootmem.c
cleancache.c
cma_debug.c mm/cma: remove unsupported gfp_mask parameter from cma_alloc() 2018-08-17 16:20:32 -07:00
cma.c mm/cma: remove unsupported gfp_mask parameter from cma_alloc() 2018-08-17 16:20:32 -07:00
cma.h
compaction.c
debug_page_ref.c
debug.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
dmapool.c
early_ioremap.c
fadvise.c vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
failslab.c
filemap.c
frame_vector.c
frontswap.c
gup_benchmark.c mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl 2018-10-05 16:32:04 -07:00
gup.c mm: Change return type int to vm_fault_t for fault handlers 2018-08-23 18:48:44 -07:00
highmem.c
hmm.c libnvdimm-for-4.19_dax-memory-failure 2018-08-25 18:43:59 -07:00
huge_memory.c mremap: properly flush TLB before releasing the page 2018-10-18 11:30:52 +02:00
hugetlb_cgroup.c
hugetlb.c hugetlb: take PMD sharing into account when flushing tlb/caches 2018-10-05 16:32:04 -07:00
hwpoison-inject.c
init-mm.c
internal.h mm: Change return type int to vm_fault_t for fault handlers 2018-08-23 18:48:44 -07:00
interval_tree.c
Kconfig mm: disable deferred struct page for 32-bit arches 2018-09-20 22:01:11 +02:00
Kconfig.debug mm: clarify CONFIG_PAGE_POISONING and usage 2018-08-22 10:52:44 -07:00
khugepaged.c mm: Change return type int to vm_fault_t for fault handlers 2018-08-23 18:48:44 -07:00
kmemleak-test.c
kmemleak.c kmemleak: always register debugfs file 2018-09-04 16:45:02 -07:00
ksm.c include/linux/compiler*.h: make compiler-*.h mutually exclusive 2018-08-22 17:31:34 -07:00
list_lru.c mm/list_lru: introduce list_lru_shrink_walk_irq() 2018-08-17 16:20:32 -07:00
maccess.c
madvise.c mm: madvise(MADV_DODUMP): allow hugetlbfs pages 2018-10-05 16:32:05 -07:00
Makefile vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
memblock.c mm/memblock.c: replace u64 with phys_addr_t where appropriate 2018-08-17 16:20:30 -07:00
memcontrol.c mm: memcontrol: print proper OOM header when no eligible victim left 2018-09-04 16:45:02 -07:00
memfd.c
memory_hotplug.c mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported. 2018-09-04 16:45:02 -07:00
memory-failure.c libnvdimm-for-4.19_dax-memory-failure 2018-08-25 18:43:59 -07:00
memory.c mm/cow: don't bother write protecting already write-protected pages 2018-08-25 13:15:03 -07:00
mempolicy.c mm: access zone->node via zone_to_nid() and zone_set_nid() 2018-08-22 10:52:45 -07:00
mempool.c mm/mempool.c: add missing parameter description 2018-08-22 10:52:44 -07:00
memtest.c
migrate.c Merge branch 'akpm' 2018-10-05 16:33:03 -07:00
mincore.c
mlock.c dax: remove VM_MIXEDMAP for fsdax and device dax 2018-08-17 16:20:27 -07:00
mm_init.c mm: access zone->node via zone_to_nid() and zone_set_nid() 2018-08-22 10:52:45 -07:00
mmap.c mm/mmap.c: don't clobber partially overlapping VMA with MAP_FIXED_NOREPLACE 2018-10-13 09:31:02 +02:00
mmu_context.c
mmu_notifier.c mm, oom: distinguish blockable mode for mmu notifiers 2018-08-22 10:52:44 -07:00
mmzone.c
mprotect.c
mremap.c mremap: properly flush TLB before releasing the page 2018-10-18 11:30:52 +02:00
msync.c
nobootmem.c
nommu.c mm: provide a fallback for PAGE_KERNEL_EXEC for architectures 2018-08-17 16:20:29 -07:00
oom_kill.c mm, oom: fix missing tlb_finish_mmu() in __oom_reap_task_mm(). 2018-09-04 16:45:02 -07:00
page_alloc.c mm, sched/numa: Remove remaining traces of NUMA rate-limiting 2018-10-09 08:30:51 +02:00
page_counter.c
page_ext.c mm/page_ext.c: constify lookup_page_ext() argument 2018-08-17 16:20:28 -07:00
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page_vma_mapped.c
page-writeback.c notifier: Remove notifier header file wherever not used 2018-08-30 12:56:40 +02:00
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c percpu: stop leaking bitmap metadata blocks 2018-10-07 14:50:12 -07:00
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
rmap.c mm: migration: fix migration of huge PMD shared pages 2018-10-05 16:32:04 -07:00
rodata_test.c
shmem.c mm: shmem.c: Correctly annotate new inodes for lockdep 2018-09-20 22:01:11 +02:00
slab_common.c mm: introduce CONFIG_MEMCG_KMEM as combination of CONFIG_MEMCG && !CONFIG_SLOB 2018-08-17 16:20:30 -07:00
slab.c
slab.h mm: introduce CONFIG_MEMCG_KMEM as combination of CONFIG_MEMCG && !CONFIG_SLOB 2018-08-17 16:20:30 -07:00
slob.c
slub.c notifier: Remove notifier header file wherever not used 2018-08-30 12:56:40 +02:00
sparse-vmemmap.c mm/sparse: delete old sparse_init and enable new one 2018-08-17 16:20:32 -07:00
sparse.c mm/sparse: delete old sparse_init and enable new one 2018-08-17 16:20:32 -07:00
swap_cgroup.c
swap_slots.c mm, swap, get_swap_pages: use entry_size instead of cluster in parameter 2018-08-22 10:52:44 -07:00
swap_state.c
swap.c
swapfile.c mm/swapfile.c: put_swap_page: share more between huge/normal code path 2018-08-22 10:52:44 -07:00
truncate.c
usercopy.c
userfaultfd.c
util.c mm/util.c: improve kvfree() kerneldoc 2018-09-04 16:45:02 -07:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
vmalloc.c mm: provide a fallback for PAGE_KERNEL_EXEC for architectures 2018-08-17 16:20:29 -07:00
vmpressure.c
vmscan.c mm/vmscan.c: fix int overflow in callers of do_shrink_slab() 2018-10-05 16:32:05 -07:00
vmstat.c mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly 2018-10-05 16:32:05 -07:00
workingset.c mm/list_lru: introduce list_lru_shrink_walk_irq() 2018-08-17 16:20:32 -07:00
z3fold.c
zbud.c
zpool.c
zsmalloc.c mm/zsmalloc.c: make several functions and a struct static 2018-08-17 16:20:30 -07:00
zswap.c