Create a helper for duplicating the anon vma when adjusting the vma. This
simplifies the logic of __vma_adjust().
Link: https://lkml.kernel.org/r/20230120162650.984577-47-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce shrink_vma() which uses the vma_prepare() and vma_complete()
functions to reduce the vma coverage.
Convert shift_arg_pages() to use expand_vma() and the new shrink_vma()
function. Remove support from __vma_adjust() to reduce a vma size since
shift_arg_pages() is the only user that shrinks a VMA in this way.
Link: https://lkml.kernel.org/r/20230120162650.984577-46-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stop using vma_adjust() in preparation for removing the function. Export
vma_expand() to use instead.
Link: https://lkml.kernel.org/r/20230120162650.984577-45-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the abstracted locking and maple tree operations. Since __split_vma()
is the only user of the __vma_adjust() function to use the insert
argument, drop that argument. Remove the NULL passed through from
fs/exec's shift_arg_pages() and mremap() at the same time.
Link: https://lkml.kernel.org/r/20230120162650.984577-44-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add init_vma_prep() and init_multi_vma_prep() to set up the struct
vma_prepare. This is to abstract the locking when adjusting the VMAs.
Also change __vma_adjust() variable remove_next int in favour of a pointer
to the VMA to remove. Rename next_next to remove2 since this better
reflects its use.
Link: https://lkml.kernel.org/r/20230120162650.984577-43-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the new locking functions for vma_expand(). This reduces code
duplication.
At the same time change VM_BUG_ON() to VM_WARN_ON()
Link: https://lkml.kernel.org/r/20230120162650.984577-42-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Splitting can be more efficient when the order is not of concern. Change
do_vmi_align_munmap() to reduce walking of the tree during split
operations.
move_vma() must also be altered to remove the dependency of keeping the
original VMA as the active part of the split. Transition to using vma
iterator to look up the prev and/or next vma after munmap.
[Liam.Howlett@oracle.com: fix vma iterator initialization]
Link: https://lkml.kernel.org/r/20230126212011.980350-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20230120162650.984577-39-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move logic of unrolling to the error path as apposed to duplicating it
within the function body. This reduces the potential of missing an update
to one path when making changes.
Link: https://lkml.kernel.org/r/20230120162650.984577-38-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Change the vma_adjust() function definition to accept the vma iterator and
pass it through to __vma_adjust().
Update fs/exec to use the new vma_adjust() function parameters.
Update mm/mremap to use the new vma_adjust() function parameters.
Revert the __split_vma() calls back from __vma_adjust() to vma_adjust()
and pass through the vma iterator.
Link: https://lkml.kernel.org/r/20230120162650.984577-37-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pass the iterator through to be used in __vma_adjust(). The state of the
iterator needs to be correct for the operation that will occur so make the
adjustments.
Link: https://lkml.kernel.org/r/20230120162650.984577-36-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If the vma start address is going to change due to an insert, then it is
safe to not write the vma to the tree. The write of the insert vma will
alter the tree as necessary.
Link: https://lkml.kernel.org/r/20230120162650.984577-35-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator internally for __vma_adjust(). Avoid using the maple
tree interface directly for type safety.
Link: https://lkml.kernel.org/r/20230120162650.984577-32-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Prepare for the removal of the vma_mas_store() function by open coding the
maple tree store in this test code. Set the range of the maple state and
call the store function directly.
Link: https://lkml.kernel.org/r/20230120162650.984577-31-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rename the function to vmi_shrink_vma() indicate it takes the vma
iterator. Use the iterator to preallocate and drop the delete function.
The maple tree is able to do the modification easier than the linked list
and rbtree, so just clear the necessary area in the tree.
add_vma_to_mm() is no longer used, so drop this function.
vmi_add_vma_to_mm() is now only used once, so inline this function into
do_mmap().
Link: https://lkml.kernel.org/r/20230120162650.984577-29-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-27-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-26-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-25-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-24-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-23-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Update the comments to how the vma iterator works. The vma iterator will
keep track of the last vm_end and start the search from vm_end + 1.
Link: https://lkml.kernel.org/r/20230120162650.984577-22-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-21-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-20-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-19-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230120162650.984577-17-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The shm already has the vma iterator in position for a write.
do_vmi_munmap() searches for the correct position and aligns the write, so
it is not the right function to use in this case.
The shm VMA tree modification is similar to the brk munmap situation, the
vma iterator is in position and the VMA is already known. This patch
generalizes the brk munmap function do_brk_munmap() to be used for any
other callers with the vma iterator already in position to munmap a VMA.
Link: https://lkml.kernel.org/r/20230126212049.980501-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Link: https://lore.kernel.org/linux-mm/yt9dh6wec21a.fsf@linux.ibm.com/
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
These wrappers are short-lived in this patch set so that each user can be
converted on its own. In the end, these functions are renamed in one
commit.
Link: https://lkml.kernel.org/r/20230120162650.984577-15-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator instead of the maple state for type safety and for
consistency through the mm code.
Link: https://lkml.kernel.org/r/20230120162650.984577-14-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Start passing the vma iterator through the mm code. This will allow for
reuse of the state and cleaner invalidation if necessary.
Link: https://lkml.kernel.org/r/20230120162650.984577-13-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation of passing the vma state through split, the pre-allocation
that occurs before the split has to be moved to after. Since the
preallocation would then live right next to the store, just call store
instead of preallocating. This effectively restores the potential error
path of splitting and not munmap'ing which pre-dates the maple tree.
Link: https://lkml.kernel.org/r/20230120162650.984577-12-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the vma iterator API for the brk() system call. This will provide
type safety at compile time.
Link: https://lkml.kernel.org/r/20230120162650.984577-9-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add wrappers for the maple tree to the vma iterator. This will provide
type safety at compile time.
Link: https://lkml.kernel.org/r/20230120162650.984577-8-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When mas_prev() does not find anything, set the state to MAS_NONE.
Handle the MAS_NONE in mas_find() like a MAS_START.
Link: https://lkml.kernel.org/r/20230120162650.984577-7-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: <syzbot+502859d610c661e56545@syzkaller.appspotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a testcase to ensure the iterator detects bad states on modifications
and does what the user expects
Link: https://lkml.kernel.org/r/20230120162650.984577-5-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When iterating, a user may operate on the tree and cause the maple state
to be altered and left in an unintuitive state. Detect this scenario and
correct it by setting to the limit and invalidating the state.
Link: https://lkml.kernel.org/r/20230120162650.984577-4-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "VMA tree type safety and remove __vma_adjust()", v4.
This patchset does two things: 1. Clean up, including removal of
__vma_adjust() and 2. Extends the VMA iterator API to provide type safety
to the VMA operations using the maple tree, as requested by Linus [1].
It also addresses another issue of usability brought up by Linus about
needing to modify the maple state within the loops. The maple state has
been replaced by the VMA iterator and the iterator is now modified within
the MM code so the caller should not need to worry about doing the work
themselves when tree modifications occur.
This brought up a potential inconsistency of the iterator state and what
the user expects, so the inconsistency is addressed to keep the VMA
iterator safe for use after the looping over a VMA range. This is
addressed in patch 3 ("maple_tree: Reduce user error potential") and 4
("test_maple_tree: Test modifications while iterating").
While cleaning up the state, the duplicate locking code in mm/mmap.c
introduced by the maple tree has been address by abstracting it to two
functions: vma_prepare() and vma_complete(). These abstractions allowed
for a much simpler __vma_adjust(), which eventually leads to the removal
of the __vma_adjust() function by placing the logic into the vma_merge()
function itself.
1. https://lore.kernel.org/linux-mm/CAHk-=wg9WQXBGkNdKD2bqocnN73rDswuWsavBB7T-tekykEn_A@mail.gmail.com/
This patch (of 49):
Add a function that will zero out the maple state struct and set some
basic defaults.
Link: https://lkml.kernel.org/r/20230120162650.984577-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20230120162650.984577-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If we have a HIGHMEM system with a large folio, 'offset' may be larger
than PAGE_SIZE, and so min_t will cap at 'len' instead of the intended
end-of-page. That can overflow into the next page which is likely to be
unmapped and fault, but could theoretically copy the wrong data.
Link: https://lkml.kernel.org/r/Y919vmSrtAgsf6K3@casper.infradead.org
Fixes: 00cdf76012 ("mm: add memcpy_from_file_folio()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We're masking with the number of type bits instead of the type mask, which
is obviously wrong.
Link: https://lkml.kernel.org/r/39fd91e3-c93b-23c6-afc6-cbe473bb0ca9@redhat.com
Fixes: 20aae9eff5 ("arm/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Liam R. Howlett