Liam R. Howlett [Tue, 21 Jun 2022 20:47:11 +0000 (20:47 +0000)]
mm/mempolicy: use vma iterator & maple state instead of vma linked list
Reworked the way mbind_range() finds the first VMA to reuse the maple
state and limit the number of tree walks needed.
Note, this drops the VM_BUG_ON(!vma) call, which would catch a start
address higher than the last VMA. The code was written in a way that
allowed no VMA updates to occur and still return success. There should be
no functional change to this scenario with the new code.
Matthew Wilcox (Oracle) [Tue, 21 Jun 2022 20:47:08 +0000 (20:47 +0000)]
sched: use maple tree iterator to walk VMAs
The linked list is slower than walking the VMAs using the maple tree. We
can't use the VMA iterator here because it doesn't support moving to an
earlier position.
Liam R. Howlett [Tue, 21 Jun 2022 20:47:07 +0000 (20:47 +0000)]
ipc/shm: use VMA iterator instead of linked list
The VMA iterator is faster than the linked llist, and it can be walked
even when VMAs are being removed from the address space, so there's no
need to keep track of 'next'.
Matthew Wilcox (Oracle) [Tue, 21 Jun 2022 20:47:06 +0000 (20:47 +0000)]
coredump: remove vma linked list walk
Use the Maple Tree iterator instead. This is too complicated for the VMA
iterator to handle, so let's open-code it for now. If this turns out to
be a common pattern, we can migrate it to common code.
Matthew Wilcox (Oracle) [Tue, 21 Jun 2022 20:47:05 +0000 (20:47 +0000)]
cxl: remove vma linked list walk
Use the VMA iterator instead. This requires a little restructuring of the
surrounding code to hoist the mm to the caller. That turns
cxl_prefault_one() into a trivial function, so call cxl_fault_segment()
directly.
Matthew Wilcox (Oracle) [Tue, 21 Jun 2022 20:47:05 +0000 (20:47 +0000)]
xtensa: remove vma linked list walks
Use the VMA iterator instead. Since VMA can no longer be NULL in the
loop, then deal with out-of-memory outside the loop. This means a
slightly longer run time in the failure case (-ENOMEM) - it will run to
the end of the VMAs before erroring instead of in the middle of the loop.
Liam R. Howlett [Tue, 21 Jun 2022 20:47:02 +0000 (20:47 +0000)]
mm/mmap: change do_brk_munmap() to use do_mas_align_munmap()
do_brk_munmap() has already aligned the address and has a maple tree state
to be used. Use the new do_mas_align_munmap() to avoid unnecessary
alignment and error checks.
Liam R. Howlett [Tue, 21 Jun 2022 20:47:01 +0000 (20:47 +0000)]
mm/mmap: reorganize munmap to use maple states
Remove __do_munmap() in favour of do_munmap(), do_mas_munmap(), and
do_mas_align_munmap().
do_munmap() is a wrapper to create a maple state for any callers that have
not been converted to the maple tree.
do_mas_munmap() takes a maple state to mumap a range. This is just a
small function which checks for error conditions and aligns the end of the
range.
do_mas_align_munmap() uses the aligned range to mumap a range.
do_mas_align_munmap() starts with the first VMA in the range, then finds
the last VMA in the range. Both start and end are split if necessary.
Then the VMAs are removed from the linked list and the mm mlock count is
updated at the same time. Followed by a single tree operation of
overwriting the area in with a NULL. Finally, the detached list is
unmapped and freed.
By reorganizing the munmap calls as outlined, it is now possible to avoid
extra work of aligning pre-aligned callers which are known to be safe,
avoid extra VMA lookups or tree walks for modifications.
detach_vmas_to_be_unmapped() is no longer used, so drop this code.
vm_brk_flags() can just call the do_mas_munmap() as it checks for
intersecting VMAs directly.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:59 +0000 (20:46 +0000)]
mm: remove vmacache
By using the maple tree and the maple tree state, the vmacache is no
longer beneficial and is complicating the VMA code. Remove the vmacache
to reduce the work in keeping it up to date and code complexity.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:59 +0000 (20:46 +0000)]
mm/mmap: use advanced maple tree API for mmap_region()
Changing mmap_region() to use the maple tree state and the advanced maple
tree interface allows for a lot less tree walking.
This change removes the last caller of munmap_vma_range(), so drop this
unused function.
Add vma_expand() to expand a VMA if possible by doing the necessary
hugepage check, uprobe_munmap of files, dcache flush, modifications then
undoing the detaches, etc.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:58 +0000 (20:46 +0000)]
mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap()
Avoid allocating a new VMA when it a vma modification can occur. When a
brk() can expand or contract a VMA, then the single store operation will
only modify one index of the maple tree instead of causing a node to split
or coalesce. This avoids unnecessary allocations/frees of maple tree
nodes and VMAs.
Move some limit & flag verifications out of the do_brk_flags() function to
use only relevant checks in the code path of bkr() and vm_brk_flags().
Set the vma to check if it can expand in vm_brk_flags() if extra criteria
are met.
Drop userfaultfd from do_brk_flags() path and only use it in
vm_brk_flags() path since that is the only place a munmap will happen.
Add a wraper for munmap for the brk case called do_brk_munmap().
Liam R. Howlett [Tue, 21 Jun 2022 20:46:58 +0000 (20:46 +0000)]
mm/khugepaged: optimize collapse_pte_mapped_thp() by using vma_lookup()
vma_lookup() will walk the vma tree once and not continue to look for the
next vma. Since the exact vma is checked below, this is a more optimal
way of searching.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:57 +0000 (20:46 +0000)]
mm: optimize find_exact_vma() to use vma_lookup()
Use vma_lookup() to walk the tree to the start value requested. If the
vma at the start does not match, then the answer is NULL and there is no
need to look at the next vma the way that find_vma() would.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:57 +0000 (20:46 +0000)]
xen: use vma_lookup() in privcmd_ioctl_mmap()
vma_lookup() walks the VMA tree for a specific value, find_vma() will
search the tree after walking to a specific value. It is more efficient
to only walk to the requested value since privcmd_ioctl_mmap() will exit
the loop if vm_start != msg->va.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:57 +0000 (20:46 +0000)]
mmap: change zeroing of maple tree in __vma_adjust()
Only write to the maple tree if we are not inserting or the insert isn't
going to overwrite the area to clear. This avoids spanning writes and
node coealescing when unnecessary.
The change requires a custom search for the linked list addition to find
the correct VMA for the prev link.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:56 +0000 (20:46 +0000)]
damon: convert __damon_va_three_regions to use the VMA iterator
This rather specialised walk can use the VMA iterator. If this proves to
be too slow, we can write a custom routine to find the two largest gaps,
but it will be somewhat complicated, so let's see if we need it first.
Update the kunit test case to use the maple tree. This also fixes an
issue with the kunit testcase not adding the last VMA to the list.
Link: https://lkml.kernel.org/r/20220504011215.661968-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20220621204632.3370049-16-Liam.Howlett@oracle.com Fixes: 17ccae8bb5c9 (mm/damon: add kunit tests) Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: SeongJae Park <sj@kernel.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Howells <dhowells@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Liam R. Howlett [Tue, 21 Jun 2022 20:46:55 +0000 (20:46 +0000)]
kernel/fork: use maple tree for dup_mmap() during forking
The maple tree was already tracking VMAs in this function by an earlier
commit, but the rbtree iterator was being used to iterate the list.
Change the iterator to use a maple tree native iterator and switch to the
maple tree advanced API to avoid multiple walks of the tree during insert
operations. Unexport the now-unused vma_store() function.
For performance reasons we bulk allocate the maple tree nodes. The node
calculations are done internally to the tree and use the VMA count and
assume the worst-case node requirements. The VM_DONT_COPY flag does not
allow for the most efficient copy method of the tree and so a bulk loading
algorithm is used.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:55 +0000 (20:46 +0000)]
mm/mmap: use maple tree for unmapped_area{_topdown}
The maple tree code was added to find the unmapped area in a previous
commit and was checked against what the rbtree returned, but the actual
result was never used. Start using the maple tree implementation and
remove the rbtree code.
Add kernel documentation comment for these functions.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:55 +0000 (20:46 +0000)]
mm/mmap: use the maple tree for find_vma_prev() instead of the rbtree
Use the maple tree's advanced API and a maple state to walk the tree for
the entry at the address of the next vma, then use the maple state to walk
back one entry to find the previous entry.
Add kernel documentation comments for this API.
Link: https://lkml.kernel.org/r/20220504010716.661115-14-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20220621204632.3370049-13-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Howells <dhowells@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matthew Wilcox (Oracle) [Tue, 21 Jun 2022 20:46:54 +0000 (20:46 +0000)]
mm: add VMA iterator
This thin layer of abstraction over the maple tree state is for iterating
over VMAs. You can go forwards, go backwards or ask where the iterator
is. Rename the existing vma_next() to __vma_next() -- it will be removed
by the end of this series.
Link: https://lkml.kernel.org/r/20220504010716.661115-11-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20220621204632.3370049-10-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Howells <dhowells@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Liam R. Howlett [Tue, 21 Jun 2022 20:46:53 +0000 (20:46 +0000)]
mm: start tracking VMAs with maple tree
Start tracking the VMAs with the new maple tree structure in parallel with
the rb_tree. Add debug and trace events for maple tree operations and
duplicate the rb_tree that is created on forks into the maple tree.
The maple tree is added to the mm_struct including the mm_init struct,
added support in required mm/mmap functions, added tracking in kernel/fork
for process forking, and used to find the unmapped_area and checked
against what the rbtree finds.
This also moves the mmap_lock() in exit_mmap() since the oom reaper call
does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
When splitting a vma fails due to allocations of the maple tree nodes,
the error path in __split_vma() calls new->vm_ops->close(new). The page
accounting for hugetlb is actually in the close() operation, so it
accounts for the removal of 1/2 of the VMA which was not adjusted. This
results in a negative exit value. To avoid the negative charge, set
vm_start = vm_end and vm_pgoff = 0.
There is also a potential accounting issue in special mappings from
insert_vm_struct() failing to allocate, so reverse the charge there in
the failure scenario.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:48 +0000 (20:46 +0000)]
radix tree test suite: add allocation counts and size to kmem_cache
Add functions to get the number of allocations, and total allocations from
a kmem_cache. Also add a function to get the allocated size and a way to
zero the total allocations.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:48 +0000 (20:46 +0000)]
radix tree test suite: add kmem_cache_set_non_kernel()
kmem_cache_set_non_kernel() is a mechanism to allow a certain number of
kmem_cache_alloc requests to succeed even when GFP_KERNEL is not set in
the flags. This functionality allows for testing different paths though
the code.
Liam R. Howlett [Tue, 21 Jun 2022 20:46:47 +0000 (20:46 +0000)]
Maple Tree: add new data structure
Patch series "Introducing the Maple Tree".
The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.
The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.
The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.
The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.
Davidlor said
: Yes I like the maple tree, and at this stage I don't think we can ask for
: more from this series wrt the MM - albeit there seems to still be some
: folks reporting breakage. Fundamentally I see Liam's work to (re)move
: complexity out of the MM (not to say that the actual maple tree is not
: complex) by consolidating the three complimentary data structures very
: much worth it considering performance does not take a hit. This was very
: much a turn off with the range locking approach, which worst case scenario
: incurred in prohibitive overhead. Also as Liam and Matthew have
: mentioned, RCU opens up a lot of nice performance opportunities, and in
: addition academia[1] has shown outstanding scalability of address spaces
: with the foundation of replacing the locked rbtree with RCU aware trees.
A similar work has been discovered in the academic press
Sheer coincidence. We designed our tree with the intention of solving the
hardest problem first. Upon settling on a b-tree variant and a rough
outline, we researched ranged based b-trees and RCU b-trees and did find
that article. So it was nice to find reassurances that we were on the
right path, but our design choice of using ranges made that paper unusable
for us.
This patch (of 69):
The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.
The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.
The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.
The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.
drivers/android/binder_alloc_selftest.c: In function 'binder_selftest_alloc':
drivers/android/binder_alloc_selftest.c:290:43: error: 'struct binder_alloc' has no member named 'vma'
290 | if (!binder_selftest_run || !alloc->vma)
Cc: Christian Brauner (Microsoft) <brauner@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hridya Valsaraju <hridya@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Martijn Coenen <maco@android.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Todd Kjos <tkjos@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Liam R. Howlett [Tue, 21 Jun 2022 01:09:09 +0000 (21:09 -0400)]
android: binder: stop saving a pointer to the VMA
Do not record a pointer to a VMA outside of the mmap_lock for later use.
This is unsafe and there are a number of failure paths *after* the
recorded VMA pointer may be freed during setup. There is no callback to
the driver to clear the saved pointer from generic mm code. Furthermore,
the VMA pointer may become stale if any number of VMA operations end up
freeing the VMA so saving it was fragile to being with.
Instead, change the binder_alloc struct to record the start address of the
VMA and use vma_lookup() to get the vma when needed. Add lockdep
mmap_lock checks on updates to the vma pointer to ensure the lock is held
and depend on that lock for synchronization of readers and writers - which
was already the case anyways, so the smp_wmb()/smp_rmb() was not
necessary.
Link: https://lkml.kernel.org/r/20220621140212.vpkio64idahetbyf@revolver Fixes: da1b9564e85b ("android: binder: fix the race mmap and alloc_new_buf_locked") Reported-by: syzbot+58b51ac2b04e388ab7b0@syzkaller.appspotmail.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Christian Brauner (Microsoft) <brauner@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hridya Valsaraju <hridya@google.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Martijn Coenen <maco@android.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Todd Kjos <tkjos@android.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
NeilBrown [Sun, 26 Jun 2022 22:40:31 +0000 (15:40 -0700)]
mm: discard __GFP_ATOMIC
__GFP_ATOMIC serves little purpose. Its main effect is to set
ALLOC_HARDER which adds a few little boosts to increase the chance of an
allocation succeeding, one of which is to lower the water-mark at which it
will succeed.
It is *always* paired with __GFP_HIGH which sets ALLOC_HIGH which also
adjusts this watermark. It is probable that other users of __GFP_HIGH
should benefit from the other little bonuses that __GFP_ATOMIC gets.
__GFP_ATOMIC also gives a warning if used with __GFP_DIRECT_RECLAIM.
There is little point to this. We already get a might_sleep() warning if
__GFP_DIRECT_RECLAIM is set.
__GFP_ATOMIC allows the "watermark_boost" to be side-stepped. It is
probable that testing ALLOC_HARDER is a better fit here.
__GFP_ATOMIC is used by tegra-smmu.c to check if the allocation might
sleep. This should test __GFP_DIRECT_RECLAIM instead.
This patch:
- removes __GFP_ATOMIC
- causes __GFP_HIGH to set ALLOC_HARDER unless __GFP_NOMEMALLOC is set
(as well as ALLOC_HIGH).
- makes other adjustments as suggested by the above.
The net result is not change to GFP_ATOMIC allocations. Other
allocations that use __GFP_HIGH will benefit from a few different extra
privileges. This affects:
xen, dm, md, ntfs3
the vermillion frame buffer
hibernation
ksm
swap
all of which likely produce more benefit than cost if these selected
allocation are more likely to succeed quickly.
Link: https://lkml.kernel.org/r/163712397076.13692.4727608274002939094@noble.neil.brown.name Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yang Shi [Fri, 13 May 2022 19:17:05 +0000 (12:17 -0700)]
mm/page_vma_mapped.c: check possible huge PMD map with transhuge_vma_suitable()
IIUC page_vma_mapped_walk() checks if the vma is possibly huge PMD mapped
with transparent_hugepage_active() and "pvmw->nr_pages >= HPAGE_PMD_NR".
Actually pvmw->nr_pages is returned by compound_nr() or folio_nr_pages(),
so the page should be THP as long as "pvmw->nr_pages >= HPAGE_PMD_NR".
And it is guaranteed THP is allocated for valid VMA in the first place.
But it may be not PMD mapped if the VMA is file VMA and it is not properly
aligned. The transhuge_vma_suitable() is used to do such check, so
replace transparent_hugepage_active() to it, which is too heavy and
overkilling.
Link: https://lkml.kernel.org/r/20220513191705.457775-1-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yang Shi [Sun, 26 Jun 2022 22:40:30 +0000 (15:40 -0700)]
mm: rmap: use the correct parameter name for DEFINE_PAGE_VMA_WALK
The parameter used by DEFINE_PAGE_VMA_WALK is _page not page, fix the
parameter name. It didn't cause any build error, it is probably because
the only caller is write_protect_page() from ksm.c, which pass in page.
Link: https://lkml.kernel.org/r/20220512174551.81279-1-shy828301@gmail.com Fixes: 2aff7a4755be ("mm: Convert page_vma_mapped_walk to work on PFNs") Signed-off-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit introduced a regression that can cause mount hung. The
changes in __ocfs2_find_empty_slot causes that any node with none-zero
node number can grab the slot that was already taken by node 0, so node 1
will access the same journal with node 0, when it try to grab journal
cluster lock, it will hung because it was already acquired by node 0.
It's very easy to reproduce this, in one cluster, mount node 0 first, then
node 1, you will see the following call trace from node 1.
To fix it, we can just fix __ocfs2_find_empty_slot. But original commit
introduced the feature to mount ocfs2 locally even it is cluster based,
that is a very dangerous, it can easily cause serious data corruption,
there is no way to stop other nodes mounting the fs and corrupting it.
Setup ha or other cluster-aware stack is just the cost that we have to
take for avoiding corruption, otherwise we have to do it in kernel.
Link: https://lkml.kernel.org/r/20220603222801.42488-1-junxiao.bi@oracle.com Fixes: 912f655d78c5("ocfs2: mount shared volume without ha stack") Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <heming.zhao@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Gautam Menghani [Sun, 26 Jun 2022 17:03:55 +0000 (22:33 +0530)]
mm/kasan: fix null pointer dereference warning in qlink_to_cache()
virt_to_slab() declared in slab.h can return NULL if the address does not
belong to a slab. This case is not handled in qlink_to_cache() in
quarantine.c, which can cause a NULL pointer dereference in
"virt_to_slab(qlink)->slab_cache". This issue was discovered by fanalyzer
(my gcc version: 12.1.1 20220507)
Gowans, James [Thu, 23 Jun 2022 05:24:03 +0000 (05:24 +0000)]
mm: split huge PUD on wp_huge_pud fallback
Currently the implementation will split the PUD when a fallback is taken
inside the create_huge_pud function. This isn't where it should be done:
the splitting should be done in wp_huge_pud, just like it's done for PMDs.
Reason being that if a callback is taken during create, there is no PUD
yet so nothing to split, whereas if a fallback is taken when encountering
a write protection fault there is something to split.
It looks like this was the original intention with the commit where the
splitting was introduced, but somehow it got moved to the wrong place
between v1 and v2 of the patch series. Rebase mistake perhaps.
Link: https://lkml.kernel.org/r/6f48d622eb8bce1ae5dd75327b0b73894a2ec407.camel@amazon.com Fixes: 327e9fd48972 ("mm: Split huge pages on write-notify or COW") Signed-off-by: James Gowans <jgowans@amazon.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Christian König <christian.koenig@amd.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ryusuke Konishi [Thu, 23 Jun 2022 08:54:01 +0000 (17:54 +0900)]
nilfs2: fix incorrect masking of permission flags for symlinks
The permission flags of newly created symlinks are wrongly dropped on
nilfs2 with the current umask value even though symlinks should have 777
(rwxrwxrwx) permissions:
David Hildenbrand [Thu, 23 Jun 2022 20:53:32 +0000 (22:53 +0200)]
mm/rmap: fix dereferencing invalid subpage pointer in try_to_migrate_one()
The subpage we calculate is an invalid pointer for device private pages,
because device private pages are mapped via non-present device private
entries, not ordinary present PTEs.
Let's just not compute broken pointers and fixup later. Move the proper
assignment of the correct subpage to the beginning of the function and
assert that we really only have a single page in our folio.
This currently results in a BUG when tying to compute anon_exclusive,
because:
YueHaibing [Fri, 24 Jun 2022 08:52:36 +0000 (16:52 +0800)]
riscv/mm: fix build error while PAGE_TABLE_CHECK enabled without MMU
mm/page_table_check.c: In function `__page_table_check_pte_clear':
mm/page_table_check.c:148:6: error: implicit declaration of function `pte_user_accessible_page'; did you mean `user_access_save'? [-Werror=implicit-function-declaration]
if (pte_user_accessible_page(pte)) {
^~~~~~~~~~~~~~~~~~~~~~~~
user_access_save
ARCH_SUPPORTS_PAGE_TABLE_CHECK should only enabled with MMU.
Link: https://lkml.kernel.org/r/20220624085236.18544-1-yuehaibing@huawei.com Fixes: 3fee229a8eb9 ("riscv/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Tong Tiangen <tongtiangen@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bagas Sanjaya [Wed, 22 Jun 2022 08:45:46 +0000 (15:45 +0700)]
Documentation: highmem: use literal block for code example in highmem.h comment
When building htmldocs on Linus's tree, there are inline emphasis warnings
on include/linux/highmem.h:
Documentation/vm/highmem:166: ./include/linux/highmem.h:154: WARNING: Inline emphasis start-string without end-string.
Documentation/vm/highmem:166: ./include/linux/highmem.h:157: WARNING: Inline emphasis start-string without end-string.
These warnings above are due to comments in code example at the mentioned
lines above are enclosed by double dash (--), which confuses Sphinx as
inline markup delimiters instead.
Fix these warnings by indenting the code example with literal block
indentation and making the comments C comments.
Link: https://lkml.kernel.org/r/20220622084546.17745-1-bagasdotme@gmail.com Fixes: 85a85e7601263f ("Documentation/vm: move "Using kmap-atomic" to highmem.h") Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Ira Weiny <ira.weiny@intel.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Muchun Song [Mon, 20 Jun 2022 02:30:19 +0000 (10:30 +0800)]
mm: sparsemem: fix missing higher order allocation splitting
Higher order allocations for vmemmap pages from buddy allocator must be
able to be treated as indepdenent small pages as they can be freed
individually by the caller. There is no problem for higher order vmemmap
pages allocated at boot time since each individual small page will be
initialized at boot time. However, it will be an issue for memory hotplug
case since those higher order vmemmap pages are allocated from buddy
allocator without initializing each individual small page's refcount. The
system will panic in put_page_testzero() when CONFIG_DEBUG_VM is enabled
if the vmemmap page is freed.
Link: https://lkml.kernel.org/r/20220620023019.94257-1-songmuchun@bytedance.com Fixes: d8d55f5616cf ("mm: sparsemem: use page table lock to protect kernel pmd operations") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Mon, 20 Jun 2022 02:34:42 +0000 (10:34 +0800)]
mm/damon: use set_huge_pte_at() to make huge pte old
The huge_ptep_set_access_flags() can not make the huge pte old according
to the discussion [1], that means we will always mornitor the young state
of the hugetlb though we stopped accessing the hugetlb, as a result DAMON
will get inaccurate accessing statistics.
So changing to use set_huge_pte_at() to make the huge pte old to fix this
issue.
Geert Uytterhoeven [Mon, 20 Jun 2022 07:01:43 +0000 (09:01 +0200)]
sh: convert nommu io{re,un}map() to static inline functions
Recently, nommu iounmap() was converted from a static inline function to a
macro again, basically reverting commit 4580ba4ad2e6b8dd ("sh: Convert
iounmap() macros to inline functions"). With -Werror, this leads to build
failures like:
drivers/iio/adc/xilinx-ams.c: In function `ams_iounmap_ps':
drivers/iio/adc/xilinx-ams.c:1195:14: error: unused variable `ams' [-Werror=unused-variable]
1195 | struct ams *ams = data;
| ^~~
Fix this by replacing the macros for ioremap() and iounmap() by static
inline functions, based on <asm-generic/io.h>.
Link: https://lkml.kernel.org/r/8d1b1766260961799b04035e7bc39a7f59729f72.1655708312.git.geert+renesas@glider.be Fixes: 13f1fc870dd74713 ("sh: move the ioremap implementation out of line") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Axel Rasmussen [Fri, 10 Jun 2022 17:38:12 +0000 (10:38 -0700)]
mm: userfaultfd: fix UFFDIO_CONTINUE on fallocated shmem pages
When fallocate() is used on a shmem file, the pages we allocate can end up
with !PageUptodate.
Since UFFDIO_CONTINUE tries to find the existing page the user wants to
map with SGP_READ, we would fail to find such a page, since
shmem_getpage_gfp returns with a "NULL" pagep for SGP_READ if it discovers
!PageUptodate. As a result, UFFDIO_CONTINUE returns -EFAULT, as it would
do if the page wasn't found in the page cache at all.
This isn't the intended behavior. UFFDIO_CONTINUE is just trying to find
if a page exists, and doesn't care whether it still needs to be cleared or
not. So, instead of SGP_READ, pass in SGP_NOALLOC. This is the same,
except for one critical difference: in the !PageUptodate case, SGP_NOALLOC
will clear the page and then return it. With this change, UFFDIO_CONTINUE
works properly (succeeds) on a shmem file which has been fallocated, but
otherwise not modified.
Link: https://lkml.kernel.org/r/20220610173812.1768919-1-axelrasmussen@google.com Fixes: 153132571f02 ("userfaultfd/shmem: support UFFDIO_CONTINUE for shmem") Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Waiman Long [Tue, 14 Jun 2022 22:03:59 +0000 (18:03 -0400)]
mm/kmemleak: prevent soft lockup in first object iteration loop of kmemleak_scan()
The first RCU-based object iteration loop has to modify the object count.
So we cannot skip taking the object lock.
One way to avoid soft lockup is to insert occasional cond_resched() call
into the loop. This cannot be done while holding the RCU read lock which
is to protect objects from being freed. However, taking a reference to
the object will prevent it from being freed. We can then do a
cond_resched() call after every 64k objects safely.
Link: https://lkml.kernel.org/r/20220614220359.59282-4-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Waiman Long [Tue, 14 Jun 2022 22:03:58 +0000 (18:03 -0400)]
mm/kmemleak: skip unlikely objects in kmemleak_scan() without taking lock
There are 3 RCU-based object iteration loops in kmemleak_scan(). Because
of the need to take RCU read lock, we can't insert cond_resched() into the
loop like other parts of the function. As there can be millions of
objects to be scanned, it takes a while to iterate all of them. The
kmemleak functionality is usually enabled in a debug kernel which is much
slower than a non-debug kernel. With sufficient number of kmemleak
objects, the time to iterate them all may exceed 22s causing soft lockup.
watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [kmemleak:625]
In this particular bug report, the soft lockup happen in the 2nd iteration
loop.
In the 2nd and 3rd loops, most of the objects are checked and then skipped
under the object lock. Only a selected fews are modified. Those objects
certainly need lock protection. However, the lock/unlock operation is
slow especially with interrupt disabling and enabling included.
We can actually do some basic check like color_white() without taking the
lock and skip the object accordingly. Of course, this kind of check is
racy and may miss objects that are being modified concurrently. The cost
of missed objects, however, is just that they will be discovered in the
next scan instead. The advantage of doing so is that iteration can be
done much faster especially with LOCKDEP enabled in a debug kernel.
With a debug kernel running on a 2-socket 96-thread x86-64 system
(HZ=1000), the 2nd and 3rd iteration loops speedup with this patch on the
first kmemleak_scan() call after bootup is shown in the table below.
Before patch After patch
Loop # # of objects Elapsed time # of objects Elapsed time
------ ------------ ------------ ------------ ------------
2 2,599,850 2.392s 2,596,364 0.266s
3 2,600,176 2.171s 2,597,061 0.260s
This patch reduces loop iteration times by about 88%. This will greatly
reduce the chance of a soft lockup happening in the 2nd or 3rd iteration
loops.
Even though the first loop runs a little bit faster, it can still be
problematic if many kmemleak objects are there. As the object count has
to be modified in every object, we cannot avoid taking the object lock.
So other way to prevent soft lockup will be needed.
Link: https://lkml.kernel.org/r/20220614220359.59282-3-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Waiman Long [Tue, 14 Jun 2022 22:03:57 +0000 (18:03 -0400)]
mm/kmemleak: use _irq lock/unlock variants in kmemleak_scan/_clear()
Patch series "mm/kmemleak: Avoid soft lockup in kmemleak_scan()", v2.
There are 3 RCU-based object iteration loops in kmemleak_scan(). Because
of the need to take RCU read lock, we can't insert cond_resched() into the
loop like other parts of the function. As there can be millions of
objects to be scanned, it takes a while to iterate all of them. The
kmemleak functionality is usually enabled in a debug kernel which is much
slower than a non-debug kernel. With sufficient number of kmemleak
objects, the time to iterate them all may exceed 22s causing soft lockup.
watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [kmemleak:625]
This patch series make changes to the 3 object iteration loops in
kmemleak_scan() to prevent them from causing soft lockup.
This patch (of 3):
kmemleak_scan() is called only from the kmemleak scan thread or from write
to the kmemleak debugfs file. Both are in task context and so we can
directly use the simpler _irq() lock/unlock calls instead of the more
complex _irqsave/_irqrestore variants.
Similarly, kmemleak_clear() is called only from write to the kmemleak
debugfs file. The same change can be applied.
Gautam Menghani [Sun, 12 Jun 2022 18:23:20 +0000 (11:23 -0700)]
mm/sparse-vmemmap.c: remove unwanted initialization in vmemmap_populate_compound_pages()
Remove unnecessary initialization for the variable 'next'. This fixes
the clang scan warning: Value stored to 'next' during its
initialization is never read [deadcode.DeadStores]
Link: https://lkml.kernel.org/r/20220612182320.160651-1-gautammenghani201@gmail.com Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joel Savitz [Thu, 9 Jun 2022 20:32:17 +0000 (16:32 -0400)]
selftests: make use of GUP_TEST_FILE macro
Commit 17de1e559cf1 ("selftests: clarify common error when running
gup_test") had most of its hunks dropped due to a conflict with another
patch accepted into Linux around the same time that implemented the same
behavior as a subset of other changes.
However, the remaining hunk defines the GUP_TEST_FILE macro without making
use of it. This patch makes use of the macro in the two relevant places.
Furthermore, the above mentioned commit's log message erroneously
describes the changes that were dropped from the patch.
This patch corrects the record.
Link: https://lkml.kernel.org/r/20220609203217.3206247-1-jsavitz@redhat.com Fixes: 17de1e559cf1 ("selftests: clarify common error when running gup_test") Signed-off-by: Joel Savitz <jsavitz@redhat.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Nico Pache <npache@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vasily Averin [Fri, 3 Jun 2022 04:19:43 +0000 (07:19 +0300)]
net: set proper memcg for net_init hooks allocations
__register_pernet_operations() executes init hook of registered
pernet_operation structure in all existing net namespaces.
Typically, these hooks are called by a process associated with the
specified net namespace, and all __GFP_ACCOUNT marked allocation are
accounted for corresponding container/memcg.
However __register_pernet_operations() calls the hooks in the same
context, and as a result all marked allocations are accounted to one memcg
for all processed net namespaces.
This patch adjusts active memcg for each net namespace and helps to
account memory allocated inside ops_init() into the proper memcg.
Link: https://lkml.kernel.org/r/f9394752-e272-9bf9-645f-a18c56d1c4ec@openvz.org Signed-off-by: Vasily Averin <vvs@openvz.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Michal Koutný <mkoutny@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Florian Westphal <fw@strlen.de> Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Linux Kernel Functional Testing <lkft@linaro.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Roman Gushchin [Fri, 10 Jun 2022 18:03:10 +0000 (11:03 -0700)]
mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe
Currently mem_cgroup_from_obj() is not working properly with objects
allocated using vmalloc(). It creates problems in some cases, when it's
called for static objects belonging to modules or generally allocated
using vmalloc().
This patch makes mem_cgroup_from_obj() safe to be called on objects
allocated using vmalloc().
It also introduces mem_cgroup_from_slab_obj(), which is a faster version
to use in places when we know the object is either a slab object or a
generic slab page (e.g. when adding an object to a lru list).
Link: https://lkml.kernel.org/r/20220610180310.1725111-1-roman.gushchin@linux.dev Suggested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Acked-by: Shakeel Butt <shakeelb@google.com> Tested-by: Vasily Averin <vvs@openvz.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Qian Cai <quic_qiancai@quicinc.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Thu, 9 Jun 2022 12:13:05 +0000 (20:13 +0800)]
mm/memremap: fix memunmap_pages() race with get_dev_pagemap()
Think about the below scene:
CPU1 CPU2
memunmap_pages
percpu_ref_exit
__percpu_ref_exit
free_percpu(percpu_count);
/* percpu_count is freed here! */
get_dev_pagemap
xa_load(&pgmap_array, PHYS_PFN(phys))
/* pgmap still in the pgmap_array */
percpu_ref_tryget_live(&pgmap->ref)
if __ref_is_percpu
/* __PERCPU_REF_ATOMIC_DEAD not set yet */
this_cpu_inc(*percpu_count)
/* access freed percpu_count here! */
ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD;
/* too late... */
pageunmap_range
To fix the issue, do percpu_ref_exit() after pgmap_array is emptied. So
we won't do percpu_ref_tryget_live() against a being freed percpu_ref.
Link: https://lkml.kernel.org/r/20220609121305.2508-1-linmiaohe@huawei.com Fixes: b7b3c01b1915 ("mm/memremap_pages: support multiple ranges per invocation") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patrick Wang [Sat, 11 Jun 2022 03:55:51 +0000 (11:55 +0800)]
mm: kmemleak: check physical address when scan
Check the physical address of objects for its boundary when scan instead
of in kmemleak_*_phys().
Link: https://lkml.kernel.org/r/20220611035551.1823303-5-patrick.wang.shcn@gmail.com Fixes: 23c2d497de21 ("mm: kmemleak: take a full lowmem check in kmemleak_*_phys()") Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Yee Lee <yee.lee@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patrick Wang [Sat, 11 Jun 2022 03:55:50 +0000 (11:55 +0800)]
mm: kmemleak: add rbtree and store physical address for objects allocated with PA
Add object_phys_tree_root to store the objects allocated with physical
address. Distinguish it from object_tree_root by OBJECT_PHYS flag or
function argument. The physical address is stored directly in those
objects.
Link: https://lkml.kernel.org/r/20220611035551.1823303-4-patrick.wang.shcn@gmail.com Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Yee Lee <yee.lee@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patrick Wang [Sat, 11 Jun 2022 03:55:49 +0000 (11:55 +0800)]
mm: kmemleak: add OBJECT_PHYS flag for objects allocated with physical address
Add OBJECT_PHYS flag for object. This flag is used to identify the
objects allocated with physical address. The create_object_phys()
function is added as well to set that flag and is used by
kmemleak_alloc_phys().
Link: https://lkml.kernel.org/r/20220611035551.1823303-3-patrick.wang.shcn@gmail.com Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Yee Lee <yee.lee@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patrick Wang [Sat, 11 Jun 2022 03:55:48 +0000 (11:55 +0800)]
mm: kmemleak: remove kmemleak_not_leak_phys() and the min_count argument to kmemleak_alloc_phys()
Patch series "mm: kmemleak: store objects allocated with physical address
separately and check when scan", v4.
The kmemleak_*_phys() interface uses "min_low_pfn" and "max_low_pfn" to
check address. But on some architectures, kmemleak_*_phys() is called
before those two variables initialized. The following steps will be
taken:
1) Add OBJECT_PHYS flag and rbtree for the objects allocated
with physical address
2) Store physical address in objects if allocated with OBJECT_PHYS
3) Check the boundary when scan instead of in kmemleak_*_phys()
This patch set will solve:
https://lore.kernel.org/r/20220527032504.30341-1-yee.lee@mediatek.com
https://lore.kernel.org/r/9dd08bb5-f39e-53d8-f88d-bec598a08c93@gmail.com
Miaohe Lin [Thu, 9 Jun 2022 13:08:35 +0000 (21:08 +0800)]
lib/test_hmm: avoid accessing uninitialized pages
If make_device_exclusive_range() fails or returns pages marked for
exclusive access less than required, remaining fields of pages will left
uninitialized. So dmirror_atomic_map() will access those yet
uninitialized fields of pages. To fix it, do dmirror_atomic_map() iff all
pages are marked for exclusive access (we will break if mapped is less
than required anyway) so we won't access those uninitialized fields of
pages.
Link: https://lkml.kernel.org/r/20220609130835.35110-1-linmiaohe@huawei.com Fixes: b659baea7546 ("mm: selftests for exclusive device memory") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Daniel Vetter [Sun, 5 Jun 2022 15:25:39 +0000 (17:25 +0200)]
mm/mempool: use might_alloc()
mempool are generally used for GFP_NOIO, so this wont benefit all that
much because might_alloc currently only checks GFP_NOFS. But it does
validate against mmu notifier pte zapping, some might catch some drivers
doing really silly things, plus it's a bit more meaningful in what we're
checking for here.
Link: https://lkml.kernel.org/r/20220605152539.3196045-3-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Daniel Vetter [Sun, 5 Jun 2022 15:25:38 +0000 (17:25 +0200)]
mm/slab: delete cache_alloc_debugcheck_before()
It only does a might_sleep_if(GFP_RECLAIM) check, which is already covered
by the might_alloc() in slab_pre_alloc_hook(). And all callers of
cache_alloc_debugcheck_before() call that beforehand already.
Link: https://lkml.kernel.org/r/20220605152539.3196045-2-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Daniel Vetter [Sun, 5 Jun 2022 15:25:37 +0000 (17:25 +0200)]
mm/page_alloc: use might_alloc()
... instead of open coding it. Completely equivalent code, just a notch
more meaningful when reading.
Link: https://lkml.kernel.org/r/20220605152539.3196045-1-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fabio M. De Francesco [Mon, 6 Jun 2022 14:15:33 +0000 (16:15 +0200)]
mm/highmem: delete memmove_page()
Matthew Wilcox reported that, while he was looking at memmove_page(), he
realized that it can't actually work.
The reasons are hidden in its implementation, which makes use of memmove()
on logical addresses provided by kmap_local_page(). memmove() does the
wrong thing when it tests "if (dest <= src)".
Therefore, delete memmove_page().
No need to change any other code because we have no call sites of
memmove_page() across the whole kernel.
Link: https://lkml.kernel.org/r/20220606141533.555-1-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reported-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Qi Zheng [Sat, 4 Jun 2022 08:22:09 +0000 (16:22 +0800)]
mm: memcontrol: add {pgscan,pgsteal}_{kswapd,direct} items in memory.stat of cgroup v2
There are already statistics of {pgscan,pgsteal}_kswapd and
{pgscan,pgsteal}_direct of memcg event here, but now only the sum of the
two is displayed in memory.stat of cgroup v2.
In order to obtain more accurate information during monitoring and
debugging, and to align with the display in /proc/vmstat, it better to
display {pgscan,pgsteal}_kswapd and {pgscan,pgsteal}_direct separately.
Also, for forward compatibility, we still display pgscan and pgsteal items
so that it won't break existing applications.
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