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392 Commits
| Author | SHA1 | Message | Date | |
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Linus Torvalds
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6cd06ab12d |
gup: make the stack expansion warning a bit more targeted
I added a warning about about GUP no longer expanding the stack in
commit
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Linus Torvalds
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9471f1f2f5 |
Merge branch 'expand-stack'
This modifies our user mode stack expansion code to always take the
mmap_lock for writing before modifying the VM layout.
It's actually something we always technically should have done, but
because we didn't strictly need it, we were being lazy ("opportunistic"
sounds so much better, doesn't it?) about things, and had this hack in
place where we would extend the stack vma in-place without doing the
proper locking.
And it worked fine. We just needed to change vm_start (or, in the case
of grow-up stacks, vm_end) and together with some special ad-hoc locking
using the anon_vma lock and the mm->page_table_lock, it all was fairly
straightforward.
That is, it was all fine until Ruihan Li pointed out that now that the
vma layout uses the maple tree code, we *really* don't just change
vm_start and vm_end any more, and the locking really is broken. Oops.
It's not actually all _that_ horrible to fix this once and for all, and
do proper locking, but it's a bit painful. We have basically three
different cases of stack expansion, and they all work just a bit
differently:
- the common and obvious case is the page fault handling. It's actually
fairly simple and straightforward, except for the fact that we have
something like 24 different versions of it, and you end up in a maze
of twisty little passages, all alike.
- the simplest case is the execve() code that creates a new stack.
There are no real locking concerns because it's all in a private new
VM that hasn't been exposed to anybody, but lockdep still can end up
unhappy if you get it wrong.
- and finally, we have GUP and page pinning, which shouldn't really be
expanding the stack in the first place, but in addition to execve()
we also use it for ptrace(). And debuggers do want to possibly access
memory under the stack pointer and thus need to be able to expand the
stack as a special case.
None of these cases are exactly complicated, but the page fault case in
particular is just repeated slightly differently many many times. And
ia64 in particular has a fairly complicated situation where you can have
both a regular grow-down stack _and_ a special grow-up stack for the
register backing store.
So to make this slightly more manageable, the bulk of this series is to
first create a helper function for the most common page fault case, and
convert all the straightforward architectures to it.
Thus the new 'lock_mm_and_find_vma()' helper function, which ends up
being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa. So we not only convert more
than half the architectures, we now have more shared code and avoid some
of those twisty little passages.
And largely due to this common helper function, the full diffstat of
this series ends up deleting more lines than it adds.
That still leaves eight architectures (ia64, m68k, microblaze, openrisc,
parisc, s390, sparc64 and um) that end up doing 'expand_stack()'
manually because they are doing something slightly different from the
normal pattern. Along with the couple of special cases in execve() and
GUP.
So there's a couple of patches that first create 'locked' helper
versions of the stack expansion functions, so that there's a obvious
path forward in the conversion. The execve() case is then actually
pretty simple, and is a nice cleanup from our old "grow-up stackls are
special, because at execve time even they grow down".
The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because
it's just more straightforward to write out the stack expansion there
manually, instead od having get_user_pages_remote() do it for us in some
situations but not others and have to worry about locking rules for GUP.
And the final step is then to just convert the remaining odd cases to a
new world order where 'expand_stack()' is called with the mmap_lock held
for reading, but where it might drop it and upgrade it to a write, only
to return with it held for reading (in the success case) or with it
completely dropped (in the failure case).
In the process, we remove all the stack expansion from GUP (where
dropping the lock wouldn't be ok without special rules anyway), and add
it in manually to __access_remote_vm() for ptrace().
Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases.
Everything else here felt pretty straightforward, but the ia64 rules for
stack expansion are really quite odd and very different from everything
else. Also thanks to Vegard Nossum who caught me getting one of those
odd conditions entirely the wrong way around.
Anyway, I think I want to actually move all the stack expansion code to
a whole new file of its own, rather than have it split up between
mm/mmap.c and mm/memory.c, but since this will have to be backported to
the initial maple tree vma introduction anyway, I tried to keep the
patches _fairly_ minimal.
Also, while I don't think it's valid to expand the stack from GUP, the
final patch in here is a "warn if some crazy GUP user wants to try to
expand the stack" patch. That one will be reverted before the final
release, but it's left to catch any odd cases during the merge window
and release candidates.
Reported-by: Ruihan Li <lrh2000@pku.edu.cn>
* branch 'expand-stack':
gup: add warning if some caller would seem to want stack expansion
mm: always expand the stack with the mmap write lock held
execve: expand new process stack manually ahead of time
mm: make find_extend_vma() fail if write lock not held
powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
arm/mm: Convert to using lock_mm_and_find_vma()
riscv/mm: Convert to using lock_mm_and_find_vma()
mips/mm: Convert to using lock_mm_and_find_vma()
powerpc/mm: Convert to using lock_mm_and_find_vma()
arm64/mm: Convert to using lock_mm_and_find_vma()
mm: make the page fault mmap locking killable
mm: introduce new 'lock_mm_and_find_vma()' page fault helper
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Linus Torvalds
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6e17c6de3d |
- Yosry Ahmed brought back some cgroup v1 stats in OOM logs.
- Yosry has also eliminated cgroup's atomic rstat flushing. - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability. - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning. - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface. - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree. - Johannes Weiner has done some cleanup work on the compaction code. - David Hildenbrand has contributed additional selftests for get_user_pages(). - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code. - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code. - Huang Ying has done some maintenance on the swap code's usage of device refcounting. - Christoph Hellwig has some cleanups for the filemap/directio code. - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses. - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings. - John Hubbard has a series of fixes to the MM selftesting code. - ZhangPeng continues the folio conversion campaign. - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock. - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8. - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management. - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code. - Vishal Moola also has done some folio conversion work. - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch. -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZJejewAKCRDdBJ7gKXxA joggAPwKMfT9lvDBEUnJagY7dbDPky1cSYZdJKxxM2cApGa42gEA6Cl8HRAWqSOh J0qXCzqaaN8+BuEyLGDVPaXur9KirwY= =B7yQ -----END PGP SIGNATURE----- Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: - Yosry Ahmed brought back some cgroup v1 stats in OOM logs - Yosry has also eliminated cgroup's atomic rstat flushing - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree - Johannes Weiner has done some cleanup work on the compaction code - David Hildenbrand has contributed additional selftests for get_user_pages() - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code - Huang Ying has done some maintenance on the swap code's usage of device refcounting - Christoph Hellwig has some cleanups for the filemap/directio code - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings - John Hubbard has a series of fixes to the MM selftesting code - ZhangPeng continues the folio conversion campaign - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8 - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code - Vishal Moola also has done some folio conversion work - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch * tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits) mm/hugetlb: remove hugetlb_set_page_subpool() mm: nommu: correct the range of mmap_sem_read_lock in task_mem() hugetlb: revert use of page_cache_next_miss() Revert "page cache: fix page_cache_next/prev_miss off by one" mm/vmscan: fix root proactive reclaim unthrottling unbalanced node mm: memcg: rename and document global_reclaim() mm: kill [add|del]_page_to_lru_list() mm: compaction: convert to use a folio in isolate_migratepages_block() mm: zswap: fix double invalidate with exclusive loads mm: remove unnecessary pagevec includes mm: remove references to pagevec mm: rename invalidate_mapping_pagevec to mapping_try_invalidate mm: remove struct pagevec net: convert sunrpc from pagevec to folio_batch i915: convert i915_gpu_error to use a folio_batch pagevec: rename fbatch_count() mm: remove check_move_unevictable_pages() drm: convert drm_gem_put_pages() to use a folio_batch i915: convert shmem_sg_free_table() to use a folio_batch scatterlist: add sg_set_folio() ... |
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Linus Torvalds
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a425ac5365 |
gup: add warning if some caller would seem to want stack expansion
It feels very unlikely that anybody would want to do a GUP in an unmapped area under the stack pointer, but real users sometimes do some really strange things. So add a (temporary) warning for the case where a GUP fails and expanding the stack might have made it work. It's trivial to do the expansion in the caller as part of getting the mm lock in the first place - see __access_remote_vm() for ptrace, for example - it's just that it's unnecessarily painful to do it deep in the guts of the GUP lookup when we might have to drop and re-take the lock. I doubt anybody actually does anything quite this strange, but let's be proactive: adding these warnings is simple, and will make debugging it much easier if they trigger. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds
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8d7071af89 |
mm: always expand the stack with the mmap write lock held
This finishes the job of always holding the mmap write lock when extending the user stack vma, and removes the 'write_locked' argument from the vm helper functions again. For some cases, we just avoid expanding the stack at all: drivers and page pinning really shouldn't be extending any stacks. Let's see if any strange users really wanted that. It's worth noting that architectures that weren't converted to the new lock_mm_and_find_vma() helper function are left using the legacy "expand_stack()" function, but it has been changed to drop the mmap_lock and take it for writing while expanding the vma. This makes it fairly straightforward to convert the remaining architectures. As a result of dropping and re-taking the lock, the calling conventions for this function have also changed, since the old vma may no longer be valid. So it will now return the new vma if successful, and NULL - and the lock dropped - if the area could not be extended. Tested-by: Vegard Nossum <vegard.nossum@oracle.com> Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # ia64 Tested-by: Frank Scheiner <frank.scheiner@web.de> # ia64 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jason Gunthorpe
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9883c7f840 |
mm/gup: do not return 0 from pin_user_pages_fast() for bad args
These routines are not intended to return zero, the callers cannot do anything sane with a 0 return. They should return an error which means future calls to GUP will not succeed, or they should return some non-zero number of pinned pages which means GUP should be called again. If start + nr_pages overflows it should return -EOVERFLOW to signal the arguments are invalid. Syzkaller keeps tripping on this when fuzzing GUP arguments. Link: https://lkml.kernel.org/r/0-v1-3d5ed1f20d50+104-gup_overflow_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reported-by: syzbot+353c7be4964c6253f24a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000094fdd05faa4d3a4@google.com Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Vishal Moola (Oracle)
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503670ee6d |
mm/gup.c: reorganize try_get_folio()
try_get_folio() takes in a page, then chooses to do some folio operations based on the flags (either FOLL_GET or FOLL_PIN). We can rewrite this function to be more purpose oriented. After calling try_get_folio(), if neither FOLL_GET nor FOLL_PIN are set, warn and fail. If FOLL_GET is set we can return the result. If FOLL_GET is not set then FOLL_PIN is set, so we pin the folio. This change assists with folio conversions, and makes the function more readable. Link: https://lkml.kernel.org/r/20230614021312.34085-5-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ryan Roberts
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c33c794828 |
mm: ptep_get() conversion
Convert all instances of direct pte_t* dereferencing to instead use ptep_get() helper. This means that by default, the accesses change from a C dereference to a READ_ONCE(). This is technically the correct thing to do since where pgtables are modified by HW (for access/dirty) they are volatile and therefore we should always ensure READ_ONCE() semantics. But more importantly, by always using the helper, it can be overridden by the architecture to fully encapsulate the contents of the pte. Arch code is deliberately not converted, as the arch code knows best. It is intended that arch code (arm64) will override the default with its own implementation that can (e.g.) hide certain bits from the core code, or determine young/dirty status by mixing in state from another source. Conversion was done using Coccinelle: ---- // $ make coccicheck \ // COCCI=ptepget.cocci \ // SPFLAGS="--include-headers" \ // MODE=patch virtual patch @ depends on patch @ pte_t *v; @@ - *v + ptep_get(v) ---- Then reviewed and hand-edited to avoid multiple unnecessary calls to ptep_get(), instead opting to store the result of a single call in a variable, where it is correct to do so. This aims to negate any cost of READ_ONCE() and will benefit arch-overrides that may be more complex. Included is a fix for an issue in an earlier version of this patch that was pointed out by kernel test robot. The issue arose because config MMU=n elides definition of the ptep helper functions, including ptep_get(). HUGETLB_PAGE=n configs still define a simple huge_ptep_clear_flush() for linking purposes, which dereferences the ptep. So when both configs are disabled, this caused a build error because ptep_get() is not defined. Fix by continuing to do a direct dereference when MMU=n. This is safe because for this config the arch code cannot be trying to virtualize the ptes because none of the ptep helpers are defined. Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/ Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Airlie <airlied@gmail.com> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Hugh Dickins
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2378118bd9 |
mm/gup: remove FOLL_SPLIT_PMD use of pmd_trans_unstable()
There is now no reason for follow_pmd_mask()'s FOLL_SPLIT_PMD block to distinguish huge_zero_page from a normal THP: follow_page_pte() handles any instability, and here it's a good idea to replace any pmd_none(*pmd) by a page table a.s.a.p, in the huge_zero_page case as for a normal THP; and this removes an unnecessary possibility of -EBUSY failure. (Hmm, couldn't the normal THP case have hit an unstably refaulted THP before? But there are only two, exceptional, users of FOLL_SPLIT_PMD.) Link: https://lkml.kernel.org/r/59fd15dd-4d39-5ec-2043-1d5117f7f85@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Hugh Dickins
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04dee9e85c |
mm/various: give up if pte_offset_map[_lock]() fails
Following the examples of nearby code, various functions can just give up if pte_offset_map() or pte_offset_map_lock() fails. And there's no need for a preliminary pmd_trans_unstable() or other such check, since such cases are now safely handled inside. Link: https://lkml.kernel.org/r/7b9bd85d-1652-cbf2-159d-f503b45e5b@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Hugh Dickins
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26e1a0c327 |
mm: use pmdp_get_lockless() without surplus barrier()
Patch series "mm: allow pte_offset_map[_lock]() to fail", v2. What is it all about? Some mmap_lock avoidance i.e. latency reduction. Initially just for the case of collapsing shmem or file pages to THPs; but likely to be relied upon later in other contexts e.g. freeing of empty page tables (but that's not work I'm doing). mmap_write_lock avoidance when collapsing to anon THPs? Perhaps, but again that's not work I've done: a quick attempt was not as easy as the shmem/file case. I would much prefer not to have to make these small but wide-ranging changes for such a niche case; but failed to find another way, and have heard that shmem MADV_COLLAPSE's usefulness is being limited by that mmap_write_lock it currently requires. These changes (though of course not these exact patches) have been in Google's data centre kernel for three years now: we do rely upon them. What is this preparatory series about? The current mmap locking will not be enough to guard against that tricky transition between pmd entry pointing to page table, and empty pmd entry, and pmd entry pointing to huge page: pte_offset_map() will have to validate the pmd entry for itself, returning NULL if no page table is there. What to do about that varies: sometimes nearby error handling indicates just to skip it; but in many cases an ACTION_AGAIN or "goto again" is appropriate (and if that risks an infinite loop, then there must have been an oops, or pfn 0 mistaken for page table, before). Given the likely extension to freeing empty page tables, I have not limited this set of changes to a THP config; and it has been easier, and sets a better example, if each site is given appropriate handling: even where deeper study might prove that failure could only happen if the pmd table were corrupted. Several of the patches are, or include, cleanup on the way; and by the end, pmd_trans_unstable() and suchlike are deleted: pte_offset_map() and pte_offset_map_lock() then handle those original races and more. Most uses of pte_lockptr() are deprecated, with pte_offset_map_nolock() taking its place. This patch (of 32): Use pmdp_get_lockless() in preference to READ_ONCE(*pmdp), to get a more reliable result with PAE (or READ_ONCE as before without PAE); and remove the unnecessary extra barrier()s which got left behind in its callers. HOWEVER: Note the small print in linux/pgtable.h, where it was designed specifically for fast GUP, and depends on interrupts being disabled for its full guarantee: most callers which have been added (here and before) do NOT have interrupts disabled, so there is still some need for caution. Link: https://lkml.kernel.org/r/f35279a9-9ac0-de22-d245-591afbfb4dc@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Yu Zhao <yuzhao@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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a6e79df92e |
mm/gup: disallow FOLL_LONGTERM GUP-fast writing to file-backed mappings
Writing to file-backed dirty-tracked mappings via GUP is inherently broken as we cannot rule out folios being cleaned and then a GUP user writing to them again and possibly marking them dirty unexpectedly. This is especially egregious for long-term mappings (as indicated by the use of the FOLL_LONGTERM flag), so we disallow this case in GUP-fast as we have already done in the slow path. We have access to less information in the fast path as we cannot examine the VMA containing the mapping, however we can determine whether the folio is anonymous or belonging to a whitelisted filesystem - specifically hugetlb and shmem mappings. We take special care to ensure that both the folio and mapping are safe to access when performing these checks and document folio_fast_pin_allowed() accordingly. It's important to note that there are no APIs allowing users to specify FOLL_FAST_ONLY for a PUP-fast let alone with FOLL_LONGTERM, so we can always rely on the fact that if we fail to pin on the fast path, the code will fall back to the slow path which can perform the more thorough check. Link: https://lkml.kernel.org/r/a27d39b87ded7f3dad5fd4181edb106393660453.1683235180.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Kirill A . Shutemov <kirill@shutemov.name> Suggested-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
|
8ac268436e |
mm/gup: disallow FOLL_LONGTERM GUP-nonfast writing to file-backed mappings
Writing to file-backed mappings which require folio dirty tracking using GUP is a fundamentally broken operation, as kernel write access to GUP mappings do not adhere to the semantics expected by a file system. A GUP caller uses the direct mapping to access the folio, which does not cause write notify to trigger, nor does it enforce that the caller marks the folio dirty. The problem arises when, after an initial write to the folio, writeback results in the folio being cleaned and then the caller, via the GUP interface, writes to the folio again. As a result of the use of this secondary, direct, mapping to the folio no write notify will occur, and if the caller does mark the folio dirty, this will be done so unexpectedly. For example, consider the following scenario:- 1. A folio is written to via GUP which write-faults the memory, notifying the file system and dirtying the folio. 2. Later, writeback is triggered, resulting in the folio being cleaned and the PTE being marked read-only. 3. The GUP caller writes to the folio, as it is mapped read/write via the direct mapping. 4. The GUP caller, now done with the page, unpins it and sets it dirty (though it does not have to). This results in both data being written to a folio without writenotify, and the folio being dirtied unexpectedly (if the caller decides to do so). This issue was first reported by Jan Kara [1] in 2018, where the problem resulted in file system crashes. This is only relevant when the mappings are file-backed and the underlying file system requires folio dirty tracking. File systems which do not, such as shmem or hugetlb, are not at risk and therefore can be written to without issue. Unfortunately this limitation of GUP has been present for some time and requires future rework of the GUP API in order to provide correct write access to such mappings. However, for the time being we introduce this check to prevent the most egregious case of this occurring, use of the FOLL_LONGTERM pin. These mappings are considerably more likely to be written to after folios are cleaned and thus simply must not be permitted to do so. This patch changes only the slow-path GUP functions, a following patch adapts the GUP-fast path along similar lines. [1] https://lore.kernel.org/linux-mm/20180103100430.GE4911@quack2.suse.cz/ Link: https://lkml.kernel.org/r/7282506742d2390c125949c2f9894722750bb68a.1683235180.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Mika Penttilä <mpenttil@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Kirill A . Shutemov <kirill@shutemov.name> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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b2cac24819 |
mm/gup: remove vmas array from internal GUP functions
Now we have eliminated all callers to GUP APIs which use the vmas parameter, eliminate it altogether. This eliminates a class of bugs where vmas might have been kept around longer than the mmap_lock and thus we need not be concerned about locks being dropped during this operation leaving behind dangling pointers. This simplifies the GUP API and makes it considerably clearer as to its purpose - follow flags are applied and if pinning, an array of pages is returned. Link: https://lkml.kernel.org/r/6811b4b2b4b3baf3dd07f422bb18853bb2cd09fb.1684350871.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian König <christian.koenig@amd.com> Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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4c630f3074 |
mm/gup: remove vmas parameter from pin_user_pages()
We are now in a position where no caller of pin_user_pages() requires the vmas parameter at all, so eliminate this parameter from the function and all callers. This clears the way to removing the vmas parameter from GUP altogether. Link: https://lkml.kernel.org/r/195a99ae949c9f5cb589d2222b736ced96ec199a.1684350871.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> [qib] Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> [drivers/media] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian König <christian.koenig@amd.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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ca5e863233 |
mm/gup: remove vmas parameter from get_user_pages_remote()
The only instances of get_user_pages_remote() invocations which used the vmas parameter were for a single page which can instead simply look up the VMA directly. In particular:- - __update_ref_ctr() looked up the VMA but did nothing with it so we simply remove it. - __access_remote_vm() was already using vma_lookup() when the original lookup failed so by doing the lookup directly this also de-duplicates the code. We are able to perform these VMA operations as we already hold the mmap_lock in order to be able to call get_user_pages_remote(). As part of this work we add get_user_page_vma_remote() which abstracts the VMA lookup, error handling and decrementing the page reference count should the VMA lookup fail. This forms part of a broader set of patches intended to eliminate the vmas parameter altogether. [akpm@linux-foundation.org: avoid passing NULL to PTR_ERR] Link: https://lkml.kernel.org/r/d20128c849ecdbf4dd01cc828fcec32127ed939a.1684350871.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> (for arm64) Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> (for s390) Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Christian König <christian.koenig@amd.com> Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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0b295316b3 |
mm/gup: remove unused vmas parameter from pin_user_pages_remote()
No invocation of pin_user_pages_remote() uses the vmas parameter, so remove it. This forms part of a larger patch set eliminating the use of the vmas parameters altogether. Link: https://lkml.kernel.org/r/28f000beb81e45bf538a2aaa77c90f5482b67a32.1684350871.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian König <christian.koenig@amd.com> Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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54d020692b |
mm/gup: remove unused vmas parameter from get_user_pages()
Patch series "remove the vmas parameter from GUP APIs", v6. (pin_/get)_user_pages[_remote]() each provide an optional output parameter for an array of VMA objects associated with each page in the input range. These provide the means for VMAs to be returned, as long as mm->mmap_lock is never released during the GUP operation (i.e. the internal flag FOLL_UNLOCKABLE is not specified). In addition, these VMAs can only be accessed with the mmap_lock held and become invalidated the moment it is released. The vast majority of invocations do not use this functionality and of those that do, all but one case retrieve a single VMA to perform checks upon. It is not egregious in the single VMA cases to simply replace the operation with a vma_lookup(). In these cases we duplicate the (fast) lookup on a slow path already under the mmap_lock, abstracted to a new get_user_page_vma_remote() inline helper function which also performs error checking and reference count maintenance. The special case is io_uring, where io_pin_pages() specifically needs to assert that the VMAs underlying the range do not result in broken long-term GUP file-backed mappings. As GUP now internally asserts that FOLL_LONGTERM mappings are not file-backed in a broken fashion (i.e. requiring dirty tracking) - as implemented in "mm/gup: disallow FOLL_LONGTERM GUP-nonfast writing to file-backed mappings" - this logic is no longer required and so we can simply remove it altogether from io_uring. Eliminating the vmas parameter eliminates an entire class of danging pointer errors that might have occured should the lock have been incorrectly released. In addition, the API is simplified and now clearly expresses what it is intended for - applying the specified GUP flags and (if pinning) returning pinned pages. This change additionally opens the door to further potential improvements in GUP and the possible marrying of disparate code paths. I have run this series against gup_test with no issues. Thanks to Matthew Wilcox for suggesting this refactoring! This patch (of 6): No invocation of get_user_pages() use the vmas parameter, so remove it. The GUP API is confusing and caveated. Recent changes have done much to improve that, however there is more we can do. Exporting vmas is a prime target as the caller has to be extremely careful to preclude their use after the mmap_lock has expired or otherwise be left with dangling pointers. Removing the vmas parameter focuses the GUP functions upon their primary purpose - pinning (and outputting) pages as well as performing the actions implied by the input flags. This is part of a patch series aiming to remove the vmas parameter altogether. Link: https://lkml.kernel.org/r/cover.1684350871.git.lstoakes@gmail.com Link: https://lkml.kernel.org/r/589e0c64794668ffc799651e8d85e703262b1e9d.1684350871.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Christian König <christian.koenig@amd.com> (for radeon parts) Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Sean Christopherson <seanjc@google.com> (KVM) Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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311150343e |
mm/gup: add missing gup_must_unshare() check to gup_huge_pgd()
All other instances of gup_huge_pXd() perform the unshare check, so update the PGD-specific function to do so as well. While checking pgd_write() might seem unusual, this function already performs such a check via pgd_access_permitted() so this is in line with the existing implementation. David said: : This change makes unshare handling across all GUP-fast variants : consistent, which is desirable as GUP-fast is complicated enough : already even when consistent. : : This function was the only one I seemed to have missed (or left out and : forgot why -- maybe because it's really dead code for now). The COW : selftest would identify the problem, so far there was no report. : Either the selftest wasn't run on corresponding architectures with that : hugetlb size, or that code is still dead code and unused by : architectures. : : the original commit(s) that added unsharing explain why we care about : these checks: : : |
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David Howells
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1101fb8f89 |
mm: Provide a function to get an additional pin on a page
Provide a function to get an additional pin on a page that we already have a pin on. This will be used in fs/direct-io.c when dispatching multiple bios to a page we've extracted from a user-backed iter rather than redoing the extraction. Signed-off-by: David Howells <dhowells@redhat.com> cc: Christoph Hellwig <hch@infradead.org> cc: David Hildenbrand <david@redhat.com> cc: Lorenzo Stoakes <lstoakes@gmail.com> cc: Andrew Morton <akpm@linux-foundation.org> cc: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: Matthew Wilcox <willy@infradead.org> cc: Jan Kara <jack@suse.cz> cc: Jeff Layton <jlayton@kernel.org> cc: Jason Gunthorpe <jgg@nvidia.com> cc: Logan Gunthorpe <logang@deltatee.com> cc: Hillf Danton <hdanton@sina.com> cc: Christian Brauner <brauner@kernel.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-kernel@vger.kernel.org cc: linux-mm@kvack.org Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20230526214142.958751-3-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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David Howells
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c8070b7875 |
mm: Don't pin ZERO_PAGE in pin_user_pages()
Make pin_user_pages*() leave a ZERO_PAGE unpinned if it extracts a pointer to it from the page tables and make unpin_user_page*() correspondingly ignore a ZERO_PAGE when unpinning. We don't want to risk overrunning a zero page's refcount as we're only allowed ~2 million pins on it - something that userspace can conceivably trigger. Add a pair of functions to test whether a page or a folio is a ZERO_PAGE. Signed-off-by: David Howells <dhowells@redhat.com> cc: Christoph Hellwig <hch@infradead.org> cc: David Hildenbrand <david@redhat.com> cc: Lorenzo Stoakes <lstoakes@gmail.com> cc: Andrew Morton <akpm@linux-foundation.org> cc: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: Matthew Wilcox <willy@infradead.org> cc: Jan Kara <jack@suse.cz> cc: Jeff Layton <jlayton@kernel.org> cc: Jason Gunthorpe <jgg@nvidia.com> cc: Logan Gunthorpe <logang@deltatee.com> cc: Hillf Danton <hdanton@sina.com> cc: Christian Brauner <brauner@kernel.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-kernel@vger.kernel.org cc: linux-mm@kvack.org Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20230526214142.958751-2-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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Linus Torvalds
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6014bc2756 |
x86-64: make access_ok() independent of LAM
The linear address masking (LAM) code made access_ok() more complicated,
in that it now needs to untag the address in order to verify the access
range. See commit
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Linus Torvalds
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22b8cc3e78 |
Add support for new Linear Address Masking CPU feature. This is similar
to ARM's Top Byte Ignore and allows userspace to store metadata in some bits of pointers without masking it out before use. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmRK/WIACgkQaDWVMHDJ krAL+RAAw33EhsWyYVkeAtYmYBKkGvlgeSDULtfJKe5bynJBTHkGKfM6RE9MSJIt 5fHWaConGh8HNpy0Us1sDvd/aWcWRm5h7ZcCVD+R4qrgh/vc7ULzM+elXe5jzr4W cyuTckF2eW6SVrYg6fH5q+6Uy/moDtrdkLRvwRBf+AYeepB8gvSSH5XixKDNiVBE pjNy1xXVZQokqD4tjsFelmLttyacR5OabiE/aeVNoFYf9yTwfnN8N3T6kwuOoS4l Lp6NA+/0ux+oBlR+Is+JJG8Mxrjvz96yJGZYdR2YP5k3bMQtHAAjuq2w+GgqZm5i j3/E6KQepEGaCfC+bHl68xy/kKx8ik+jMCEcBalCC25J3uxbLz41g6K3aI890wJn +5ZtfcmoDUk9pnUyLxR8t+UjOSBFAcRSUE+FTjUH1qEGsMPK++9a4iLXz5vYVK1+ +YCt1u5LNJbkDxE8xVX3F5jkXh0G01SJsuUVAOqHSNfqSNmohFK8/omqhVRrRqoK A7cYLtnOGiUXLnvjrwSxPNOzRrG+GAwqaw8gwOTaYogETWbTY8qsSCEVl204uYwd m8io9rk2ZXUdDuha56xpBbPE0JHL9hJ2eKCuPkfvRgJT9YFyTh+e0UdX20k+nDjc ang1S350o/Y0sus6rij1qS8AuxJIjHucG0GdgpZk3KUbcxoRLhI= =qitk -----END PGP SIGNATURE----- Merge tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 LAM (Linear Address Masking) support from Dave Hansen: "Add support for the new Linear Address Masking CPU feature. This is similar to ARM's Top Byte Ignore and allows userspace to store metadata in some bits of pointers without masking it out before use" * tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/iommu/sva: Do not allow to set FORCE_TAGGED_SVA bit from outside x86/mm/iommu/sva: Fix error code for LAM enabling failure due to SVA selftests/x86/lam: Add test cases for LAM vs thread creation selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA test cases for linear-address masking selftests/x86/lam: Add inherit test cases for linear-address masking selftests/x86/lam: Add io_uring test cases for linear-address masking selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address masking selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking x86/mm/iommu/sva: Make LAM and SVA mutually exclusive iommu/sva: Replace pasid_valid() helper with mm_valid_pasid() mm: Expose untagging mask in /proc/$PID/status x86/mm: Provide arch_prctl() interface for LAM x86/mm: Reduce untagged_addr() overhead for systems without LAM x86/uaccess: Provide untagged_addr() and remove tags before address check mm: Introduce untagged_addr_remote() x86/mm: Handle LAM on context switch x86: CPUID and CR3/CR4 flags for Linear Address Masking x86: Allow atomic MM_CONTEXT flags setting x86/mm: Rework address range check in get_user() and put_user() |
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Jingyu Wang
|
5da1a8687a |
mm/gup.c: fix typo in comments
Link: https://lkml.kernel.org/r/20230309104813.170309-1-jingyuwang_vip@163.com Signed-off-by: Jingyu Wang <jingyuwang_vip@163.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kirill A. Shutemov
|
428e106ae1 |
mm: Introduce untagged_addr_remote()
untagged_addr() removes tags/metadata from the address and brings it to the canonical form. The helper is implemented on arm64 and sparc. Both of them do untagging based on global rules. However, Linear Address Masking (LAM) on x86 introduces per-process settings for untagging. As a result, untagged_addr() is now only suitable for untagging addresses for the current proccess. The new helper untagged_addr_remote() has to be used when the address targets remote process. It requires the mmap lock for target mm to be taken. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Alexander Potapenko <glider@google.com> Link: https://lore.kernel.org/all/20230312112612.31869-6-kirill.shutemov%40linux.intel.com |
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Baolin Wang
|
be2d575638 |
mm: change to return bool for folio_isolate_lru()
Patch series "Change the return value for page isolation functions", v3.
Now the page isolation functions did not return a boolean to indicate
success or not, instead it will return a negative error when failed
to isolate a page. So below code used in most places seem a boolean
success/failure thing, which can confuse people whether the isolation
is successful.
if (folio_isolate_lru(folio))
continue;
Moreover the page isolation functions only return 0 or -EBUSY, and
most users did not care about the negative error except for few users,
thus we can convert all page isolation functions to return a boolean
value, which can remove the confusion to make code more clear.
No functional changes intended in this patch series.
This patch (of 4):
Now the folio_isolate_lru() did not return a boolean value to indicate
isolation success or not, however below code checking the return value can
make people think that it was a boolean success/failure thing, which makes
people easy to make mistakes (see the fix patch[1]).
if (folio_isolate_lru(folio))
continue;
Thus it's better to check the negative error value expilictly returned by
folio_isolate_lru(), which makes code more clear per Linus's
suggestion[2]. Moreover Matthew suggested we can convert the isolation
functions to return a boolean[3], since most users did not care about the
negative error value, and can also remove the confusing of checking return
value.
So this patch converts the folio_isolate_lru() to return a boolean value,
which means return 'true' to indicate the folio isolation is successful,
and 'false' means a failure to isolation. Meanwhile changing all users'
logic of checking the isolation state.
No functional changes intended.
[1] https://lore.kernel.org/all/20230131063206.28820-1-Kuan-Ying.Lee@mediatek.com/T/#u
[2] https://lore.kernel.org/all/CAHk-=wiBrY+O-4=2mrbVyxR+hOqfdJ=Do6xoucfJ9_5az01L4Q@mail.gmail.com/
[3] https://lore.kernel.org/all/Y+sTFqwMNAjDvxw3@casper.infradead.org/
Link: https://lkml.kernel.org/r/cover.1676424378.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/8a4e3679ed4196168efadf7ea36c038f2f7d5aa9.1676424378.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
Sidhartha Kumar
|
6aa3a92012 |
mm/hugetlb: convert isolate_hugetlb to folios
Patch series "continue hugetlb folio conversion", v3. This series continues the conversion of core hugetlb functions to use folios. This series converts many helper funtions in the hugetlb fault path. This is in preparation for another series to convert the hugetlb fault code paths to operate on folios. This patch (of 8): Convert isolate_hugetlb() to take in a folio and convert its callers to pass a folio. Use page_folio() to convert the callers to use a folio is safe as isolate_hugetlb() operates on a head page. Link: https://lkml.kernel.org/r/20230113223057.173292-1-sidhartha.kumar@oracle.com Link: https://lkml.kernel.org/r/20230113223057.173292-2-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Andrew Morton
|
f67d6b2664 |
Merge branch 'mm-hotfixes-stable' into mm-stable
To pick up depended-upon changes |
||
|
Jason Gunthorpe
|
9198a9196e |
mm/gup: make get_user_pages_fast_only() return the common return value
There are only two callers, both can handle the common return code: - get_user_page_fast_only() checks == 1 - gfn_to_page_many_atomic() already returns -1, and the only caller checks for negative return values Remove the restriction against returning negative values. Link: https://lkml.kernel.org/r/11-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jason Gunthorpe
|
edad1bb1fb |
mm/gup: remove pin_user_pages_fast_only()
Commit
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Jason Gunthorpe
|
9a863a6a51 |
mm/gup: make locked never NULL in the internal GUP functions
Now that NULL locked doesn't have a special meaning we can just make it non-NULL in all cases and remove the special tests. get_user_pages() and pin_user_pages() can safely pass in a locked = 1 get_user_pages_remote) and pin_user_pages_remote() can swap in a local variable for locked if NULL is passed. Remove all the NULL checks. Link: https://lkml.kernel.org/r/9-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jason Gunthorpe
|
f04740f545 |
mm/gup: add FOLL_UNLOCKABLE
Setting FOLL_UNLOCKABLE allows GUP to lock/unlock the mmap lock on its own. It is a more explicit replacement for locked != NULL. This clears the way for passing in locked = 1, without intending that the lock can be unlocked. Set the flag in all cases where it is used, eg locked is present in the external interface or locked is used internally with locked = 0. Link: https://lkml.kernel.org/r/8-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jason Gunthorpe
|
6e4382c706 |
mm/gup: remove locked being NULL from faultin_vma_page_range()
The only caller of this function always passes in a non-NULL locked, so just remove this obsolete comment. Link: https://lkml.kernel.org/r/7-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jason Gunthorpe
|
961ba47242 |
mm/gup: add an assertion that the mmap lock is locked
Since commit
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Jason Gunthorpe
|
d64e2dbc33 |
mm/gup: simplify the external interface functions and consolidate invariants
The GUP family of functions have a complex, but fairly well defined, set of invariants for their arguments. Currently these are sprinkled about, sometimes in duplicate through many functions. Internally we don't follow all the invariants that the external interface has to follow, so place these checks directly at the exported interface. This ensures the internal functions never reach a violated invariant. Remove the duplicated invariant checks. The end result is to make these functions fully internal: __get_user_pages_locked() internal_get_user_pages_fast() __gup_longterm_locked() And all the other functions call directly into one of these. Link: https://lkml.kernel.org/r/5-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Suggested-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jason Gunthorpe
|
afa3c33e26 |
mm/gup: don't call __gup_longterm_locked() if FOLL_LONGTERM cannot be set
get_user_pages_remote(), get_user_pages_unlocked() and get_user_pages() are never called with FOLL_LONGTERM, so directly call __get_user_pages_locked() The next patch will add an assertion for this. Link: https://lkml.kernel.org/r/3-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Suggested-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jason Gunthorpe
|
b2a72dff85 |
mm/gup: have internal functions get the mmap_read_lock()
Patch series "Simplify the external interface for GUP", v2. It is quite a maze of EXPORTED symbols leading up to the three actual worker functions of GUP. Simplify this by reorganizing some of the code so the EXPORTED symbols directly call the correct internal function with validated and consistent arguments. Consolidate all the assertions into one place at the top of the call chains. Remove some dead code. Move more things into the mm/internal.h header This patch (of 13): __get_user_pages_locked() and __gup_longterm_locked() both require the mmap lock to be held. They have a slightly unusual locked parameter that is used to allow these functions to unlock and relock the mmap lock and convey that fact to the caller. Several places wrap these functions with a simple mmap_read_lock() just so they can follow the optimized locked protocol. Consolidate this internally to the functions. Allow internal callers to set locked = 0 to cause the functions to acquire and release the lock on their own. Reorganize __gup_longterm_locked() to use the autolocking in __get_user_pages_locked(). Replace all the places obtaining the mmap_read_lock() just to call __get_user_pages_locked() with the new mechanism. Replace all the internal callers of get_user_pages_unlocked() with direct calls to __gup_longterm_locked() using the new mechanism. A following patch will add assertions ensuring the external interface continues to always pass in locked = 1. Link: https://lkml.kernel.org/r/0-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Link: https://lkml.kernel.org/r/1-v2-987e91b59705+36b-gup_tidy_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kuan-Ying Lee
|
aa1e6a932c |
mm/gup: add folio to list when folio_isolate_lru() succeed
If we call folio_isolate_lru() successfully, we will get return value 0.
We need to add this folio to the movable_pages_list.
Link: https://lkml.kernel.org/r/20230131063206.28820-1-Kuan-Ying.Lee@mediatek.com
Fixes:
|
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Jongwoo Han
|
c5acf1f6f0 |
mm/gup.c: fix typo in comments
Link: https://lkml.kernel.org/r/20230125180847.4542-1-jongwooo.han@gmail.com Signed-off-by: Jongwoo Han <jongwooo.han@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
|
94688e8eb4 |
mm: remove folio_pincount_ptr() and head_compound_pincount()
We can use folio->_pincount directly, since all users are guarded by tests of compound/large. Link: https://lkml.kernel.org/r/20230111142915.1001531-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Linus Torvalds
|
4f292c4de4 |
New Feature:
* Randomize the per-cpu entry areas Cleanups: * Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open coding it * Move to "native" set_memory_rox() helper * Clean up pmd_get_atomic() and i386-PAE * Remove some unused page table size macros -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmOc53UACgkQaDWVMHDJ krCUHw//SGZ+La0hLZLAiAiZTXLZZHpYkOmg1Oj1+11qSU11uZzTFqDpauhaKpRS cJCSh+D+RXe5e2ipgt0+Zl0hESLt7pJf8258OE4ra0DL/IlyO9uqruAs9Kn3eRS/ Fk76nG8gdEU+JKJqpG02GqOLslYQuIy96n9hpuj1x25b614+uezPfC7S4XEat0NT MbJQ+jnVDf16aJIJkzT+iSwhubDVeh+bSHeO0SSCzX23WLUqDeg5NvlyxoCHGbBh UpUTWggV/0pYAkBKRHToeJs8qTWREwuuH/8JGewpe9A0tjdB5wyZfNL2PuracweN 9MauXC3T5f0+Ca4yIIaPq1fF7Ny/PR2dBFihk27rOD0N7tjaZxNwal2pB1sZcmvZ +PAokjyTPVH5ZXjkMYGGAUe1jyjwr2+TgFSZxhTnDuGtyVQiY4pihGKOifLCX6tv x6khvYeTBw7wfaDRtKEAf+2kLHYn+71HszHP/8bNKX9T03h+Zf0i1wdZu5xbM5Gc VK2wR7bCC+UftJJYG0pldcHg2qaF19RBHK2tLwp7zngUv7lTbkKfkgKjre73KV2a D4b76lrqdUMo6UYwYdw7WtDyarZS4OVLq2DcNhwwMddBCaX8kyN5a4AqwQlZYJ0u dM+kuMofE8U3yMxmMhJimkZUsj09yLHIqfynY0jbAcU3nhKZZNY= =wwVF -----END PGP SIGNATURE----- Merge tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Dave Hansen: "New Feature: - Randomize the per-cpu entry areas Cleanups: - Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open coding it - Move to "native" set_memory_rox() helper - Clean up pmd_get_atomic() and i386-PAE - Remove some unused page table size macros" * tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) x86/mm: Ensure forced page table splitting x86/kasan: Populate shadow for shared chunk of the CPU entry area x86/kasan: Add helpers to align shadow addresses up and down x86/kasan: Rename local CPU_ENTRY_AREA variables to shorten names x86/mm: Populate KASAN shadow for entire per-CPU range of CPU entry area x86/mm: Recompute physical address for every page of per-CPU CEA mapping x86/mm: Rename __change_page_attr_set_clr(.checkalias) x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias() x86/mm: Untangle __change_page_attr_set_clr(.checkalias) x86/mm: Add a few comments x86/mm: Fix CR3_ADDR_MASK x86/mm: Remove P*D_PAGE_MASK and P*D_PAGE_SIZE macros mm: Convert __HAVE_ARCH_P..P_GET to the new style mm: Remove pointless barrier() after pmdp_get_lockless() x86/mm/pae: Get rid of set_64bit() x86_64: Remove pointless set_64bit() usage x86/mm/pae: Be consistent with pXXp_get_and_clear() x86/mm/pae: Use WRITE_ONCE() x86/mm/pae: Don't (ab)use atomic64 mm/gup: Fix the lockless PMD access ... |
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|
Linus Torvalds
|
8fa590bf34 |
ARM64:
* Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. * Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. * Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on (see merge commit |
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Peter Zijlstra
|
1180e732c9 |
mm/gup: Fix the lockless PMD access
On architectures where the PTE/PMD is larger than the native word size (i386-PAE for example), READ_ONCE() can do the wrong thing. Use pmdp_get_lockless() just like we use ptep_get_lockless(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221022114424.906110403%40infradead.org |
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Linus Torvalds
|
e2ca6ba6ba |
MM patches for 6.2-rc1.
- More userfaultfs work from Peter Xu. - Several convert-to-folios series from Sidhartha Kumar and Huang Ying. - Some filemap cleanups from Vishal Moola. - David Hildenbrand added the ability to selftest anon memory COW handling. - Some cpuset simplifications from Liu Shixin. - Addition of vmalloc tracing support by Uladzislau Rezki. - Some pagecache folioifications and simplifications from Matthew Wilcox. - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it. - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series shold have been in the non-MM tree, my bad. - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages. - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages. - Peter Xu utilized the PTE marker code for handling swapin errors. - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient. - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand. - zram support for multiple compression streams from Sergey Senozhatsky. - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway. - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations. - Vishal Moola removed the try_to_release_page() wrapper. - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache. - David Hildenbrand did some cleanup and repair work on KSM COW breaking. - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend. - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range(). - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen. - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect. - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages(). - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting. - David Hildenbrand has fixed some of our MM selftests for 32-bit machines. - Many singleton patches, as usual. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY5j6ZwAKCRDdBJ7gKXxA jkDYAP9qNeVqp9iuHjZNTqzMXkfmJPsw2kmy2P+VdzYVuQRcJgEAgoV9d7oMq4ml CodAgiA51qwzId3GRytIo/tfWZSezgA= =d19R -----END PGP SIGNATURE----- Merge tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ... |
||
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Linus Torvalds
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ce8a79d560 |
for-6.2/block-2022-12-08
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Merge tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe pull requests via Christoph:
- Support some passthrough commands without CAP_SYS_ADMIN (Kanchan
Joshi)
- Refactor PCIe probing and reset (Christoph Hellwig)
- Various fabrics authentication fixes and improvements (Sagi
Grimberg)
- Avoid fallback to sequential scan due to transient issues (Uday
Shankar)
- Implement support for the DEAC bit in Write Zeroes (Christoph
Hellwig)
- Allow overriding the IEEE OUI and firmware revision in configfs
for nvmet (Aleksandr Miloserdov)
- Force reconnect when number of queue changes in nvmet (Daniel
Wagner)
- Minor fixes and improvements (Uros Bizjak, Joel Granados, Sagi
Grimberg, Christoph Hellwig, Christophe JAILLET)
- Fix and cleanup nvme-fc req allocation (Chaitanya Kulkarni)
- Use the common tagset helpers in nvme-pci driver (Christoph
Hellwig)
- Cleanup the nvme-pci removal path (Christoph Hellwig)
- Use kstrtobool() instead of strtobool (Christophe JAILLET)
- Allow unprivileged passthrough of Identify Controller (Joel
Granados)
- Support io stats on the mpath device (Sagi Grimberg)
- Minor nvmet cleanup (Sagi Grimberg)
- MD pull requests via Song:
- Code cleanups (Christoph)
- Various fixes
- Floppy pull request from Denis:
- Fix a memory leak in the init error path (Yuan)
- Series fixing some batch wakeup issues with sbitmap (Gabriel)
- Removal of the pktcdvd driver that was deprecated more than 5 years
ago, and subsequent removal of the devnode callback in struct
block_device_operations as no users are now left (Greg)
- Fix for partition read on an exclusively opened bdev (Jan)
- Series of elevator API cleanups (Jinlong, Christoph)
- Series of fixes and cleanups for blk-iocost (Kemeng)
- Series of fixes and cleanups for blk-throttle (Kemeng)
- Series adding concurrent support for sync queues in BFQ (Yu)
- Series bringing drbd a bit closer to the out-of-tree maintained
version (Christian, Joel, Lars, Philipp)
- Misc drbd fixes (Wang)
- blk-wbt fixes and tweaks for enable/disable (Yu)
- Fixes for mq-deadline for zoned devices (Damien)
- Add support for read-only and offline zones for null_blk
(Shin'ichiro)
- Series fixing the delayed holder tracking, as used by DM (Yu,
Christoph)
- Series enabling bio alloc caching for IRQ based IO (Pavel)
- Series enabling userspace peer-to-peer DMA (Logan)
- BFQ waker fixes (Khazhismel)
- Series fixing elevator refcount issues (Christoph, Jinlong)
- Series cleaning up references around queue destruction (Christoph)
- Series doing quiesce by tagset, enabling cleanups in drivers
(Christoph, Chao)
- Series untangling the queue kobject and queue references (Christoph)
- Misc fixes and cleanups (Bart, David, Dawei, Jinlong, Kemeng, Ye,
Yang, Waiman, Shin'ichiro, Randy, Pankaj, Christoph)
* tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux: (247 commits)
blktrace: Fix output non-blktrace event when blk_classic option enabled
block: sed-opal: Don't include <linux/kernel.h>
sed-opal: allow using IOC_OPAL_SAVE for locking too
blk-cgroup: Fix typo in comment
block: remove bio_set_op_attrs
nvmet: don't open-code NVME_NS_ATTR_RO enumeration
nvme-pci: use the tagset alloc/free helpers
nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set
nvme: only set reserved_tags in nvme_alloc_io_tag_set for fabrics controllers
nvme: consolidate setting the tagset flags
nvme: pass nr_maps explicitly to nvme_alloc_io_tag_set
block: bio_copy_data_iter
nvme-pci: split out a nvme_pci_ctrl_is_dead helper
nvme-pci: return early on ctrl state mismatch in nvme_reset_work
nvme-pci: rename nvme_disable_io_queues
nvme-pci: cleanup nvme_suspend_queue
nvme-pci: remove nvme_pci_disable
nvme-pci: remove nvme_disable_admin_queue
nvme: merge nvme_shutdown_ctrl into nvme_disable_ctrl
nvme: use nvme_wait_ready in nvme_shutdown_ctrl
...
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||
David Hildenbrand
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f7355e99d9 |
mm/gup: remove FOLL_MIGRATION
Fortunately, the last user (KSM) is gone, so let's just remove this rather special code from generic GUP handling -- especially because KSM never required the PMD handling as KSM only deals with individual base pages. [akpm@linux-foundation.org: fix merge snafu]Link: https://lkml.kernel.org/r/20221021101141.84170-10-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
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Andrew Morton
|
3b91010500 | Merge branch 'mm-hotfixes-stable' into mm-stable | ||
John Starks
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fcd0ccd836 |
mm/gup: fix gup_pud_range() for dax
For dax pud, pud_huge() returns true on x86. So the function works as long as hugetlb is configured. However, dax doesn't depend on hugetlb. Commit |
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David Hildenbrand
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f347454d03 |
mm/gup: disallow FOLL_FORCE|FOLL_WRITE on hugetlb mappings
hugetlb does not support fake write-faults (write faults without write
permissions). However, we are currently able to trigger a
FAULT_FLAG_WRITE fault on a VMA without VM_WRITE.
If we'd ever want to support FOLL_FORCE|FOLL_WRITE, we'd have to teach
hugetlb to:
(1) Leave the page mapped R/O after the fake write-fault, like
maybe_mkwrite() does.
(2) Allow writing to an exclusive anon page that's mapped R/O when
FOLL_FORCE is set, like can_follow_write_pte(). E.g.,
__follow_hugetlb_must_fault() needs adjustment.
For now, it's not clear if that added complexity is really required.
History tolds us that FOLL_FORCE is dangerous and that we better limit its
use to a bare minimum.
--------------------------------------------------------------------------
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdint.h>
#include <sys/mman.h>
#include <linux/mman.h>
int main(int argc, char **argv)
{
char *map;
int mem_fd;
map = mmap(NULL, 2 * 1024 * 1024u, PROT_READ,
MAP_PRIVATE|MAP_ANON|MAP_HUGETLB|MAP_HUGE_2MB, -1, 0);
if (map == MAP_FAILED) {
fprintf(stderr, "mmap() failed: %d\n", errno);
return 1;
}
mem_fd = open("/proc/self/mem", O_RDWR);
if (mem_fd < 0) {
fprintf(stderr, "open(/proc/self/mem) failed: %d\n", errno);
return 1;
}
if (pwrite(mem_fd, "0", 1, (uintptr_t) map) == 1) {
fprintf(stderr, "write() succeeded, which is unexpected\n");
return 1;
}
printf("write() failed as expected: %d\n", errno);
return 0;
}
--------------------------------------------------------------------------
Fortunately, we have a sanity check in hugetlb_wp() in place ever since
commit
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||
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David Hildenbrand
|
84209e87c6 |
mm/gup: reliable R/O long-term pinning in COW mappings
We already support reliable R/O pinning of anonymous memory. However,
assume we end up pinning (R/O long-term) a pagecache page or the shared
zeropage inside a writable private ("COW") mapping. The next write access
will trigger a write-fault and replace the pinned page by an exclusive
anonymous page in the process page tables to break COW: the pinned page no
longer corresponds to the page mapped into the process' page table.
Now that FAULT_FLAG_UNSHARE can break COW on anything mapped into a
COW mapping, let's properly break COW first before R/O long-term
pinning something that's not an exclusive anon page inside a COW
mapping. FAULT_FLAG_UNSHARE will break COW and map an exclusive anon page
instead that can get pinned safely.
With this change, we can stop using FOLL_FORCE|FOLL_WRITE for reliable
R/O long-term pinning in COW mappings.
With this change, the new R/O long-term pinning tests for non-anonymous
memory succeed:
# [RUN] R/O longterm GUP pin ... with shared zeropage
ok 151 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with memfd
ok 152 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with tmpfile
ok 153 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with huge zeropage
ok 154 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with memfd hugetlb (2048 kB)
ok 155 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with memfd hugetlb (1048576 kB)
ok 156 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with shared zeropage
ok 157 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with memfd
ok 158 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with tmpfile
ok 159 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with huge zeropage
ok 160 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (2048 kB)
ok 161 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (1048576 kB)
ok 162 Longterm R/O pin is reliable
Note 1: We don't care about short-term R/O-pinning, because they have
snapshot semantics: they are not supposed to observe modifications that
happen after pinning.
As one example, assume we start direct I/O to read from a page and store
page content into a file: modifications to page content after starting
direct I/O are not guaranteed to end up in the file. So even if we'd pin
the shared zeropage, the end result would be as expected -- getting zeroes
stored to the file.
Note 2: For shared mappings we'll now always fallback to the slow path to
lookup the VMA when R/O long-term pining. While that's the necessary price
we have to pay right now, it's actually not that bad in practice: most
FOLL_LONGTERM users already specify FOLL_WRITE, for example, along with
FOLL_FORCE because they tried dealing with COW mappings correctly ...
Note 3: For users that use FOLL_LONGTERM right now without FOLL_WRITE,
such as VFIO, we'd now no longer pin the shared zeropage. Instead, we'd
populate exclusive anon pages that we can pin. There was a concern that
this could affect the memlock limit of existing setups.
For example, a VM running with VFIO could run into the memlock limit and
fail to run. However, we essentially had the same behavior already in
commit
|