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2023-04-18selftests/mm: merge util.h into vm_util.hPeter Xu
There're two util headers under mm/ kselftest. Merge one with another. It turns out util.h is the easy one to move. When merging, drop PAGE_SIZE / PAGE_SHIFT because they're unnecessary wrappers to page_size() / page_shift(), meanwhile rename them to psize() and pshift() so as to not conflict with some existing definitions in some test files that includes vm_util.h. Link: https://lkml.kernel.org/r/20230412164120.327731-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18selftests/mm: dump a summary in run_vmtests.shPeter Xu
Dump a summary after running whatever test specified. Useful for human runners to identify any kind of failures (besides exit code). Link: https://lkml.kernel.org/r/20230412164117.327720-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18selftests/mm: update .gitignore with two missing testsPeter Xu
Patch series "selftests/mm: Split / Refactor userfault test", v2. This patchset splits userfaultfd.c into two tests: - uffd-stress: the "vanilla", old and powerful stress test - uffd-unit-tests: all the unit tests will be moved here This is on my todo list for a long time but I never did it for real. The uffd test is growing into a small and cute monster. I start to notice it's going harder to maintain such a test and make it useful. A few issues I found when looking at userfaultfd test: - We have a bunch of unit tests in userfaultfd.c, but they always need to be run only after a stress type. No way to not do it. - We can only run an unit test for one memory type only, if we want to do a quick smoke test to check regressions, there's no good way. The best to come currently is "bash ./run_vmtests.sh -t userfaultfd" thanks to the most recent changes to run_vmtests.sh on tagging. Still, that needs to run the stress tests always and hard to see what's wrong. - It's hard to add a new unit test to userfaultfd.c, we don't really know what's happening, not until we mostly read the whole file. - We did a bunch of useless tests, e.g. we run twice the whole suite of stress test just to verify both syscall and /dev/userfaultfd. They're all using userfaultfd_new() to create the handle, everything should really be the same underneath. One simple unit test should cover that! - We have tens of global variables in one file but shared with all the tests. Some of them are not suitable to be a global var from maintainance pov. It enforces every unit test to consider how these vars affects the stress test and vice versa, but that's logically not necessary. - Userfaultfd test is not friendly to old kernels. Mostly it only works on the latest kernel tree. It's preferrable to be run on all kernels and properly report what's missing. I'll stop here, I feel like I can still list some.. This patchset should resolve all issues above, and actually we can do even more on top. I stopped doing that until I found I already got 29 patches and 2000+ LOC changes. That's already a patchset terrible enough so we should move in small steps. After the whole set applied, "./run_vmtests.sh -t userfaultfd" looks like this: ===8<=== vm.nr_hugepages = 1024 ------------------------- running ./uffd-unit-tests ------------------------- Testing UFFDIO_API (with syscall)... done Testing UFFDIO_API (with /dev/userfaultfd)... done Testing register-ioctls on anon... done Testing register-ioctls on shmem... done Testing register-ioctls on shmem-private... done Testing register-ioctls on hugetlb... done Testing register-ioctls on hugetlb-private... done Testing zeropage on anon... done Testing zeropage on shmem... done Testing zeropage on shmem-private... done Testing zeropage on hugetlb... done Testing zeropage on hugetlb-private... done Testing pagemap on anon... done Testing wp-unpopulated on anon... done Testing minor on shmem... done Testing minor on hugetlb... done Testing minor-wp on shmem... done Testing minor-wp on hugetlb... done Testing minor-collapse on shmem... done Testing sigbus on anon... done Testing sigbus on shmem... done Testing sigbus on shmem-private... done Testing sigbus on hugetlb... done Testing sigbus on hugetlb-private... done Testing sigbus-wp on anon... done Testing sigbus-wp on shmem... done Testing sigbus-wp on shmem-private... done Testing sigbus-wp on hugetlb... done Testing sigbus-wp on hugetlb-private... done Testing events on anon... done Testing events on shmem... done Testing events on shmem-private... done Testing events on hugetlb... done Testing events on hugetlb-private... done Testing events-wp on anon... done Testing events-wp on shmem... done Testing events-wp on shmem-private... done Testing events-wp on hugetlb... done Testing events-wp on hugetlb-private... done Userfaults unit tests: pass=39, skip=0, fail=0 (total=39) [PASS] -------------------------------- running ./uffd-stress anon 20 16 -------------------------------- nr_pages: 5120, nr_pages_per_cpu: 640 bounces: 15, mode: rnd racing ver poll, userfaults: 345 missing (26+48+61+102+30+12+59+7) 1596 wp (120+139+317+346+215+67+306+86) [...] [PASS] ------------------------------------ running ./uffd-stress hugetlb 128 32 ------------------------------------ nr_pages: 64, nr_pages_per_cpu: 8 bounces: 31, mode: rnd racing ver poll, userfaults: 29 missing (6+6+6+5+4+2+0+0) 104 wp (20+19+22+18+7+12+5+1) [...] [PASS] -------------------------------------------- running ./uffd-stress hugetlb-private 128 32 -------------------------------------------- nr_pages: 64, nr_pages_per_cpu: 8 bounces: 31, mode: rnd racing ver poll, userfaults: 33 missing (12+9+7+0+5+0+0+0) 111 wp (24+25+14+14+11+17+5+1) [...] [PASS] --------------------------------- running ./uffd-stress shmem 20 16 --------------------------------- nr_pages: 5120, nr_pages_per_cpu: 640 bounces: 15, mode: rnd racing ver poll, userfaults: 247 missing (15+17+34+60+81+37+3+0) 2038 wp (180+114+276+400+381+318+165+204) [...] [PASS] ----------------------------------------- running ./uffd-stress shmem-private 20 16 ----------------------------------------- nr_pages: 5120, nr_pages_per_cpu: 640 bounces: 15, mode: rnd racing ver poll, userfaults: 235 missing (52+29+55+56+13+9+16+5) 2849 wp (218+406+461+531+328+284+430+191) [...] [PASS] SUMMARY: PASS=6 SKIP=0 FAIL=0 ===8<=== The output may be different if we miss some features (e.g., hugetlb not allocated, old kernel, less privilege of uffd handle), but they should show up with good reasons. E.g., I tried to run the unit test on my Fedora kernel and it gives me: ===8<=== UFFDIO_API (with syscall)... failed [reason: UFFDIO_API should fail with wrong api but didn't] UFFDIO_API (with /dev/userfaultfd)... skipped [reason: cannot open userfaultfd handle] zeropage on anon... done zeropage on shmem... done zeropage on shmem-private... done zeropage-hugetlb on hugetlb... done zeropage-hugetlb on hugetlb-private... done pagemap on anon... pagemap on anon... pagemap on anon... done wp-unpopulated on anon... skipped [reason: feature missing] minor on shmem... done minor on hugetlb... done minor-wp on shmem... skipped [reason: feature missing] minor-wp on hugetlb... skipped [reason: feature missing] minor-collapse on shmem... done sigbus on anon... skipped [reason: possible lack of priviledge] sigbus on shmem... skipped [reason: possible lack of priviledge] sigbus on shmem-private... skipped [reason: possible lack of priviledge] sigbus on hugetlb... skipped [reason: possible lack of priviledge] sigbus on hugetlb-private... skipped [reason: possible lack of priviledge] sigbus-wp on anon... skipped [reason: possible lack of priviledge] sigbus-wp on shmem... skipped [reason: possible lack of priviledge] sigbus-wp on shmem-private... skipped [reason: possible lack of priviledge] sigbus-wp on hugetlb... skipped [reason: possible lack of priviledge] sigbus-wp on hugetlb-private... skipped [reason: possible lack of priviledge] events on anon... skipped [reason: possible lack of priviledge] events on shmem... skipped [reason: possible lack of priviledge] events on shmem-private... skipped [reason: possible lack of priviledge] events on hugetlb... skipped [reason: possible lack of priviledge] events on hugetlb-private... skipped [reason: possible lack of priviledge] events-wp on anon... skipped [reason: possible lack of priviledge] events-wp on shmem... skipped [reason: possible lack of priviledge] events-wp on shmem-private... skipped [reason: possible lack of priviledge] events-wp on hugetlb... skipped [reason: possible lack of priviledge] events-wp on hugetlb-private... skipped [reason: possible lack of priviledge] Userfaults unit tests: pass=9, skip=24, fail=1 (total=34) ===8<=== Patch layout: - Revert "userfaultfd: don't fail on unrecognized features" Something I found when I got the UFFDIO_API test below. Axel, I still propose to revert it as a whole, but feel free to continue the discussion from the original patch thread. - selftests/mm: Update .gitignore with two missing tests - selftests/mm: Dump a summary in run_vmtests.sh - selftests/mm: Merge util.h into vm_util.h - selftests/mm: Use TEST_GEN_PROGS where proper - selftests/mm: Link vm_util.c always - selftests/mm: Merge default_huge_page_size() into one - selftests/mm: Use PM_* macros in vm_utils.h - selftests/mm: Reuse pagemap_get_entry() in vm_util.h - selftests/mm: Test UFFDIO_ZEROPAGE only when !hugetlb - selftests/mm: Drop test_uffdio_zeropage_eexist Until here, all cleanups here and there. I wanted to keep going, but I found that maybe it'll take a few more days to split the test. Hence I did a split starting from the next one, so we have a working thing first. - selftests/mm: Create uffd-common.[ch] - selftests/mm: Split uffd tests into uffd-stress and uffd-unit-tests This did the major brute force split of common codes into uffd-common.[ch]. That'll be the so far common base for stress and unit tests. Then a new unit test is created. - selftests/mm: uffd_[un]register() - selftests/mm: uffd_open_{dev|sys}() - selftests/mm: UFFDIO_API test This patch hides here to start writting the 1st unit test with UFFDIO_API, also detection of userfaultfd privileges. - selftests/mm: Drop global mem_fd in uffd tests - selftests/mm: Drop global hpage_size in uffd tests - selftests/mm: Rename uffd_stats to uffd_args - selftests/mm: Let uffd_handle_page_fault() takes wp parameter - selftests/mm: Allow allocate_area() to fail properly Some further cleanup that I noticed otherwise hard to move the tests. - selftests/mm: Add framework for uffd-unit-test The major patch provides the framework for most of the rest unit tests. - selftests/mm: Move uffd pagemap test to unit test - selftests/mm: Move uffd minor test to unit test - selftests/mm: Move uffd sig/events tests into uffd unit tests - selftests/mm: Move zeropage test into uffd unit tests Move unit tests and suite them into the new file. - selftests/mm: Workaround no way to detect uffd-minor + wp - selftests/mm: Allow uffd test to skip properly with no privilege - selftests/mm: Drop sys/dev test in uffd-stress test - selftests/mm: Add shmem-private test to uffd-stress A bunch of changes to do better on error reportings, and add shmem-private to the stress test which was long missing. - selftests/mm: Add uffdio register ioctls test One more patch to test uffdio_register.ioctls. This patch (of 30): Update .gitignore with two missing tests. Link: https://lkml.kernel.org/r/20230412163922.327282-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20230412164114.327709-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/vmscan: simplify shrink_node()Haifeng Xu
The difference between sc->nr_reclaimed and nr_reclaimed is computed three times. Introduce a new variable to record the value, so it only needs to be computed once. Link: https://lkml.kernel.org/r/20230411061757.12041-1-haifeng.xu@shopee.com Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mpage: use folios in bio end_io handlerPankaj Raghav
Use folios in the bio end_io handler. This conversion does the appropriate handling on the folios in the respective end_io callback and removes the call to page_endio(), which is soon to be removed. Link: https://lkml.kernel.org/r/20230411122920.30134-4-p.raghav@samsung.com Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Martin Brandenburg <martin@omnibond.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Marshall <hubcap@omnibond.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mpage: split submit_bio and bio end_io handler for reads and writesPankaj Raghav
Split the submit_bio() and bio end_io handler for reads and writes similar to other aops. This is a prep patch before we convert end_io handlers to use folios. Link: https://lkml.kernel.org/r/20230411122920.30134-3-p.raghav@samsung.com Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Martin Brandenburg <martin@omnibond.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Marshall <hubcap@omnibond.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18orangefs: use folios in orangefs_readaheadPankaj Raghav
Patch series "remove page_endio()", v3. It was decided to remove the page_endio() as per the previous RFC discussion[1] of this series and move that functionality into the caller itself. One of the side benefit of doing that is the callers have been modified to directly work on folios as page_endio() already worked on folios. As Christoph is doing ZRAM cleanups[4] which will get rid of page_endio() function usage, I removed the final patch that removes page_endio()[5]. I will send it separately after rc-1 once the zram cleanups are merged. mpage changes were tested with a simple boot testing and running a fio workload on ext2 filesystem. orangefs was tested by Mike Marshall (No code changes since he tested). This patch (of 3): Convert orangefs_readahead() from using struct page to struct folio. This conversion removes the call to page_endio() which is soon to be removed, and simplifies the final page handling. The page error flags is not required to be set in the error case as orangefs doesn't depend on them. Link: https://lkml.kernel.org/r/20230411122920.30134-1-p.raghav@samsung.com Link: https://lkml.kernel.org/r/20230411122920.30134-2-p.raghav@samsung.com Link: https://lore.kernel.org/linux-mm/ZBHcl8Pz2ULb4RGD@infradead.org/ [1] Link: https://lore.kernel.org/linux-mm/20230322135013.197076-1-p.raghav@samsung.com/ [2] Link: https://lore.kernel.org/linux-mm/8adb0770-6124-e11f-2551-6582db27ed32@samsung.com/ [3] Link: https://lore.kernel.org/linux-block/20230404150536.2142108-1-hch@lst.de/T/#t [4] Link: https://lore.kernel.org/lkml/20230403132221.94921-6-p.raghav@samsung.com/ [5] Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Mike Marshall <hubcap@omnibond.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Martin Brandenburg <martin@omnibond.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/huge_memory: conditionally call maybe_mkwrite() and drop pte_wrprotect() ↵David Hildenbrand
in __split_huge_pmd_locked() No need to call maybe_mkwrite() to then wrprotect if the source PMD was not writable. It's worth nothing that this now allows for PTEs to be writable even if the source PMD was not writable: if vma->vm_page_prot includes write permissions. As documented in commit 931298e103c2 ("mm/userfaultfd: rely on vma->vm_page_prot in uffd_wp_range()"), any mechanism that intends to have pages wrprotected (COW, writenotify, mprotect, uffd-wp, softdirty, ...) has to properly adjust vma->vm_page_prot upfront, to not include write permissions. If vma->vm_page_prot includes write permissions, the PTE/PMD can be writable as default. This now mimics the handling in mm/migrate.c:remove_migration_pte() and in mm/huge_memory.c:remove_migration_pmd(), which has been in place for a long time (except that 96a9c287e25d ("mm/migrate: fix wrongly apply write bit after mkdirty on sparc64") temporarily changed it). Link: https://lkml.kernel.org/r/20230411142512.438404-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/huge_memory: revert "Partly revert "mm/thp: carry over dirty bit when thp ↵David Hildenbrand
splits on pmd"" This reverts commit 624a2c94f5b7 ("Partly revert "mm/thp: carry over dirty bit when thp splits on pmd"") and the fixup in commit e833bc503405 ("mm/thp: re-apply mkdirty for small pages after split"). Now that sparc64 mkdirty handling is fixed and no longer sets a PTE/PMD writable that shouldn't be writable, let's revert the temporary fix and remove the stale comment. The mkdirty mm selftest still passes with this change on sparc64. Note that loongarch handling was fixed in commit bf2f34a506e6 ("LoongArch: Set _PAGE_DIRTY only if _PAGE_WRITE is set in {pmd,pte}_mkdirty()") Link: https://lkml.kernel.org/r/20230411142512.438404-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/migrate: revert "mm/migrate: fix wrongly apply write bit after mkdirty on ↵David Hildenbrand
sparc64" This reverts commit 96a9c287e25d ("mm/migrate: fix wrongly apply write bit after mkdirty on sparc64"). Now that sparc64 mkdirty handling is fixed and no longer sets a PTE/PMD writable that shouldn't be writable, let's revert the temporary fix. The mkdirty mm selftest still passes with this change on sparc64. Note that loongarch handling was fixed in commit bf2f34a506e6 ("LoongArch: Set _PAGE_DIRTY only if _PAGE_WRITE is set in {pmd,pte}_mkdirty()"). Link: https://lkml.kernel.org/r/20230411142512.438404-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18sparc/mm: don't unconditionally set HW writable bit when setting PTE dirty ↵David Hildenbrand
on 64bit On sparc64, there is no HW modified bit, therefore, SW tracks via a SW bit if the PTE is dirty via pte_mkdirty(). However, pte_mkdirty() currently also unconditionally sets the HW writable bit, which is wrong. pte_mkdirty() is not supposed to make a PTE actually writable, unless the SW writable bit -- pte_write() -- indicates that the PTE is not write-protected. Fortunately, sparc64 also defines a SW writable bit. For example, this already turned into a problem in the context of THP splitting as documented in commit 624a2c94f5b7 ("Partly revert "mm/thp: carry over dirty bit when thp splits on pmd""), and for page migration, as documented in commit 96a9c287e25d ("mm/migrate: fix wrongly apply write bit after mkdirty on sparc64"). Also, we might want to use the dirty PTE bit in the context of KSM with shared zeropage [1], whereby setting the page writable would be problematic. But more general, any code that might end up setting a PTE/PMD dirty inside a VM without write permissions is possibly broken, Before this commit (sun4u in QEMU): root@debian:~/linux/tools/testing/selftests/mm# ./mkdirty # [INFO] detected THP size: 8192 KiB TAP version 13 1..6 # [INFO] PTRACE write access not ok 1 SIGSEGV generated, page not modified # [INFO] PTRACE write access to THP not ok 2 SIGSEGV generated, page not modified # [INFO] Page migration ok 3 SIGSEGV generated, page not modified # [INFO] Page migration of THP ok 4 SIGSEGV generated, page not modified # [INFO] PTE-mapping a THP ok 5 SIGSEGV generated, page not modified # [INFO] UFFDIO_COPY not ok 6 SIGSEGV generated, page not modified Bail out! 3 out of 6 tests failed # Totals: pass:3 fail:3 xfail:0 xpass:0 skip:0 error:0 Test #3,#4,#5 pass ever since we added some MM workarounds, the underlying issue remains. Let's fix the remaining issues and prepare for reverting the workarounds by setting the HW writable bit only if both, the SW dirty bit and the SW writable bit are set. We have to move pte_dirty() and pte_write() up. The code patching mechanism and handling constants > 22bit is a bit special on sparc64. The ASM logic in pte_mkdirty() and pte_mkwrite() match the logic in pte_mkold() to create the mask depending on the machine type. The ASM logic in __pte_mkhwwrite() matches the logic in pte_present(), just using an "or" instead of an "and" instruction. With this commit (sun4u in QEMU): root@debian:~/linux/tools/testing/selftests/mm# ./mkdirty # [INFO] detected THP size: 8192 KiB TAP version 13 1..6 # [INFO] PTRACE write access ok 1 SIGSEGV generated, page not modified # [INFO] PTRACE write access to THP ok 2 SIGSEGV generated, page not modified # [INFO] Page migration ok 3 SIGSEGV generated, page not modified # [INFO] Page migration of THP ok 4 SIGSEGV generated, page not modified # [INFO] PTE-mapping a THP ok 5 SIGSEGV generated, page not modified # [INFO] UFFDIO_COPY ok 6 SIGSEGV generated, page not modified # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0 This handling seems to have been in place forever. [1] https://lkml.kernel.org/r/533a7c3d-3a48-b16b-b421-6e8386e0b142@redhat.com Link: https://lkml.kernel.org/r/20230411142512.438404-4-david@redhat.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18selftests/mm: mkdirty: test behavior of (pte|pmd)_mkdirty on VMAs without ↵David Hildenbrand
write permissions Let's add some tests that trigger (pte|pmd)_mkdirty on VMAs without write permissions. If an architecture implementation is wrong, we might accidentally set the PTE/PMD writable and allow for write access in a VMA without write permissions. The tests include reproducers for the two issues recently discovered and worked-around in core-MM for now: (1) commit 624a2c94f5b7 ("Partly revert "mm/thp: carry over dirty bit when thp splits on pmd"") (2) commit 96a9c287e25d ("mm/migrate: fix wrongly apply write bit after mkdirty on sparc64") In addition, some other tests that reveal further issues. All tests pass under x86_64: ./mkdirty # [INFO] detected THP size: 2048 KiB TAP version 13 1..6 # [INFO] PTRACE write access ok 1 SIGSEGV generated, page not modified # [INFO] PTRACE write access to THP ok 2 SIGSEGV generated, page not modified # [INFO] Page migration ok 3 SIGSEGV generated, page not modified # [INFO] Page migration of THP ok 4 SIGSEGV generated, page not modified # [INFO] PTE-mapping a THP ok 5 SIGSEGV generated, page not modified # [INFO] UFFDIO_COPY ok 6 SIGSEGV generated, page not modified # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0 But some fail on sparc64: ./mkdirty # [INFO] detected THP size: 8192 KiB TAP version 13 1..6 # [INFO] PTRACE write access not ok 1 SIGSEGV generated, page not modified # [INFO] PTRACE write access to THP not ok 2 SIGSEGV generated, page not modified # [INFO] Page migration ok 3 SIGSEGV generated, page not modified # [INFO] Page migration of THP ok 4 SIGSEGV generated, page not modified # [INFO] PTE-mapping a THP ok 5 SIGSEGV generated, page not modified # [INFO] UFFDIO_COPY not ok 6 SIGSEGV generated, page not modified Bail out! 3 out of 6 tests failed # Totals: pass:3 fail:3 xfail:0 xpass:0 skip:0 error:0 Reverting both above commits makes all tests fail on sparc64: ./mkdirty # [INFO] detected THP size: 8192 KiB TAP version 13 1..6 # [INFO] PTRACE write access not ok 1 SIGSEGV generated, page not modified # [INFO] PTRACE write access to THP not ok 2 SIGSEGV generated, page not modified # [INFO] Page migration not ok 3 SIGSEGV generated, page not modified # [INFO] Page migration of THP not ok 4 SIGSEGV generated, page not modified # [INFO] PTE-mapping a THP not ok 5 SIGSEGV generated, page not modified # [INFO] UFFDIO_COPY not ok 6 SIGSEGV generated, page not modified Bail out! 6 out of 6 tests failed # Totals: pass:0 fail:6 xfail:0 xpass:0 skip:0 error:0 The tests are useful to detect other problematic archs, to verify new arch fixes, and to stop such issues from reappearing in the future. For now, we don't add any hugetlb tests. Link: https://lkml.kernel.org/r/20230411142512.438404-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18selftests/mm: reuse read_pmd_pagesize() in COW selftestDavid Hildenbrand
Patch series "mm: (pte|pmd)_mkdirty() should not unconditionally allow for write access". This is the follow-up on [1], adding selftests (testing for known issues we added workarounds for and other issues that haven't been fixed yet), fixing sparc64, reverting the workarounds, and perform one cleanup. The patch from [1] was modified slightly (updated/extended patch description, dropped one unnecessary NOP instruction from the ASM in __pte_mkhwwrite()). Retested on x86_64 and sparc64 (sun4u in QEMU). I scanned most architectures to make sure their (pte|pmd)_mkdirty() handling is correct. To be sure, we can run the selftests and find out if other architectures are still affectes (loongarch was fixed recently as well). Based on master for now. I don't expect surprises regarding mm-tress, but I can rebase if there are any problems. This patch (of 6): The COW selftest can deal with THP not being configured. So move error handling of read_pmd_pagesize() into the callers such that we can reuse it in the COW selftest. Link: https://lkml.kernel.org/r/20230411142512.438404-1-david@redhat.com Link: https://lkml.kernel.org/r/20221212130213.136267-1-david@redhat.com [1] Link: https://lkml.kernel.org/r/20230411142512.438404-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: return errors from read_from_bdev_syncChristoph Hellwig
Propagate read errors to the caller instead of dropping them on the floor, and stop returning the somewhat dangerous 1 on success from read_from_bdev*. Link: https://lkml.kernel.org/r/20230411171459.567614-18-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: fix synchronous readsChristoph Hellwig
Currently nothing waits for the synchronous reads before accessing the data. Switch them to an on-stack bio and submit_bio_wait to make sure the I/O has actually completed when the work item has been flushed. This also removes the call to page_endio that would unlock a page that has never been locked. Drop the partial_io/sync flag, as chaining only makes sense for the asynchronous reads of the entire page. Link: https://lkml.kernel.org/r/20230411171459.567614-17-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: don't return errors from read_from_bdev_asyncChristoph Hellwig
bio_alloc will never return a NULL bio when it is allowed to sleep, and adding a single page to bio with a single vector also can't fail, so switch to the asserting __bio_add_page variant and drop the error returns. Link: https://lkml.kernel.org/r/20230411171459.567614-16-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: pass a page to read_from_bdevChristoph Hellwig
read_from_bdev always reads a whole page, so pass a page to it instead of the bvec and remove the now pointless zram_bvec_read_from_bdev wrapper. Link: https://lkml.kernel.org/r/20230411171459.567614-15-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: refactor zram_bdev_writeChristoph Hellwig
Split the read/modify/write case into a separate helper. Link: https://lkml.kernel.org/r/20230411171459.567614-14-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: don't pass a bvec to __zram_bvec_writeChristoph Hellwig
__zram_bvec_write only extracts the page from __zram_bvec_write and always expects a full page of input. Pass the page directly instead of the bvec and rename the function to zram_write_page. Link: https://lkml.kernel.org/r/20230411171459.567614-13-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: refactor zram_bdev_readChristoph Hellwig
Split the partial read into a separate helper. Link: https://lkml.kernel.org/r/20230411171459.567614-12-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: directly call zram_read_page in writeback_storeChristoph Hellwig
writeback_store always reads a full page, so just call zram_read_page directly and bypass the boune buffer handling. Link: https://lkml.kernel.org/r/20230411171459.567614-11-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: rename __zram_bvec_read to zram_read_pageChristoph Hellwig
__zram_bvec_read doesn't get passed a bvec, but always read a whole page. Rename it to make the usage more clear. Link: https://lkml.kernel.org/r/20230411171459.567614-10-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: don't use highmem for the bounce buffer in zram_bvec_{read,write}Christoph Hellwig
There is no point in allocation a highmem page when we instantly need to copy from it. Link: https://lkml.kernel.org/r/20230411171459.567614-9-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: refactor highlevel read and write handlingChristoph Hellwig
Instead of having an outer loop in __zram_make_request and then branch out for reads vs writes for each loop iteration in zram_bvec_rw, split the main handler into separat zram_bio_read and zram_bio_write handlers that also include the functionality formerly in zram_bvec_rw. Link: https://lkml.kernel.org/r/20230411171459.567614-8-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: return early on error in zram_bvec_rwChristoph Hellwig
When the low-level access fails, don't clear the idle flag or clear the caches, and just return. Link: https://lkml.kernel.org/r/20230411171459.567614-7-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: move discard handling to zram_submit_bioChristoph Hellwig
Switch on the bio operation in zram_submit_bio and only call into __zram_make_request for read and write operations. Link: https://lkml.kernel.org/r/20230411171459.567614-6-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: simplify bvec iteration in __zram_make_requestChristoph Hellwig
bio_for_each_segment synthetize bvecs that never cross page boundaries, so don't duplicate that work in an inner loop. Link: https://lkml.kernel.org/r/20230411171459.567614-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: make zram_bio_discard more self-containedChristoph Hellwig
Derive the index and offset variables inside the function, and complete the bio directly in preparation for cleaning up the I/O path. Link: https://lkml.kernel.org/r/20230411171459.567614-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: remove valid_io_requestChristoph Hellwig
All bios hande to drivers from the block layer are checked against the device size and for logical block alignment already (and have been since long before zram was merged), so don't duplicate those checks. Link: https://lkml.kernel.org/r/20230411171459.567614-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18zram: always compile read_from_bdev_syncChristoph Hellwig
Patch series "zram I/O path cleanups and fixups", v3. This series cleans up the zram I/O path, and fixes the handling of synchronous I/O to the underlying device in the writeback_store function or for > 4K PAGE_SIZE systems. The fixes are at the end, as I could not fully reason about them being safe before untangling the callchain. This patch (of 17): read_from_bdev_sync is currently only compiled for non-4k PAGE_SIZE, which means it won't be built with the most common configurations. Replace the ifdef with a check for the PAGE_SIZE in an if instead. The check uses an extra symbol and IS_ENABLED to allow the compiler to eliminate the dead code, leading to the same generated code size: text data bss dec hex filename 16709 1428 12 18149 46e5 drivers/block/zram/zram_drv.o.old 16709 1428 12 18149 46e5 drivers/block/zram/zram_drv.o.new Link: https://lkml.kernel.org/r/20230411171459.567614-1-hch@lst.de Link: https://lkml.kernel.org/r/20230411171459.567614-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18maple_tree: add a test case to check maple_allocPeng Zhang
Add a test case to check whether the number of maple_alloc structures is actually equal to mas->alloc->total. Link: https://lkml.kernel.org/r/20230411041005.26205-2-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm: backing-dev: set variables dev_attr_min,max_bytes ↵Tom Rix
storage-class-specifier to static smatch reports mm/backing-dev.c:266:1: warning: symbol 'dev_attr_min_bytes' was not declared. Should it be static? mm/backing-dev.c:294:1: warning: symbol 'dev_attr_max_bytes' was not declared. Should it be static? These variables are only used in one file so should be static. Link: https://lkml.kernel.org/r/20230408141609.2703647-1-trix@redhat.com Signed-off-by: Tom Rix <trix@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18maple_tree: use correct variable type in sizeofPeng Zhang
The type of variable pointed to by pivs is unsigned long, but the type used in sizeof is a pointer type. Change it to unsigned long. This change has no runtime effect, as sizeof(ul) == sizeof(ul *). Link: https://lkml.kernel.org/r/20230411023513.15227-1-zhangpeng.00@bytedance.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reported-by: David Binderman <dcb314@hotmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18userfaultfd: convert mfill_atomic() to use a folioZhangPeng
Convert mfill_atomic_pte_copy(), shmem_mfill_atomic_pte() and mfill_atomic_pte() to take in a folio pointer. Convert mfill_atomic() to use a folio. Convert page_kaddr to kaddr in mfill_atomic(). Link: https://lkml.kernel.org/r/20230410133932.32288-7-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm: convert copy_user_huge_page() to copy_user_large_folio()ZhangPeng
Replace copy_user_huge_page() with copy_user_large_folio(). copy_user_large_folio() does the same as copy_user_huge_page(), but takes in folios instead of pages. Remove pages_per_huge_page from copy_user_large_folio(), because we can get that from folio_nr_pages(dst). Convert copy_user_gigantic_page() to take in folios. Link: https://lkml.kernel.org/r/20230410133932.32288-6-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18userfaultfd: convert mfill_atomic_hugetlb() to use a folioZhangPeng
Convert hugetlb_mfill_atomic_pte() to take in a folio pointer instead of a page pointer. Convert mfill_atomic_hugetlb() to use a folio. Link: https://lkml.kernel.org/r/20230410133932.32288-5-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18userfaultfd: convert copy_huge_page_from_user() to copy_folio_from_user()ZhangPeng
Replace copy_huge_page_from_user() with copy_folio_from_user(). copy_folio_from_user() does the same as copy_huge_page_from_user(), but takes in a folio instead of a page. Convert page_kaddr to kaddr in copy_folio_from_user() to do indenting cleanup. Link: https://lkml.kernel.org/r/20230410133932.32288-4-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18userfaultfd: use kmap_local_page() in copy_huge_page_from_user()ZhangPeng
kmap() and kmap_atomic() are being deprecated in favor of kmap_local_page() which is appropriate for any thread local context.[1] Let's replace the kmap() and kmap_atomic() with kmap_local_page() in copy_huge_page_from_user(). When allow_pagefault is false, disable page faults to prevent potential deadlock.[2] [1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/ [2] https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com Link: https://lkml.kernel.org/r/20230410133932.32288-3-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18userfaultfd: convert mfill_atomic_pte_copy() to use a folioZhangPeng
Patch series "userfaultfd: convert userfaultfd functions to use folios", v6. This patch series converts several userfaultfd functions to use folios. This patch (of 6): Call vma_alloc_folio() directly instead of alloc_page_vma() and convert page_kaddr to kaddr in mfill_atomic_pte_copy(). Removes several calls to compound_head(). Link: https://lkml.kernel.org/r/20230410133932.32288-1-zhangpeng362@huawei.com Link: https://lkml.kernel.org/r/20230410133932.32288-2-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18smaps: fix defined but not used smaps_shmem_walk_opsSteven Price
When !CONFIG_SHMEM smaps_shmem_walk_ops is defined but not used, triggering a compiler warning. To avoid the warning remove the #ifdef around the usage. This has no effect because shmem_mapping() is a stub returning false when !CONFIG_SHMEM so the code will be compiled out, however we now need to also provide a stub for shmem_swap_usage(). Link: https://lkml.kernel.org/r/20230405103819.151246-1-steven.price@arm.com Fixes: 7b86ac3371b7 ("pagewalk: separate function pointers from iterator data") Signed-off-by: Steven Price <steven.price@arm.com> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202304031749.UiyJpxzF-lkp@intel.com/ Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm, page_alloc: use check_pages_enabled static key to check tail pagesVlastimil Babka
Commit 700d2e9a36b9 ("mm, page_alloc: reduce page alloc/free sanity checks") has introduced a new static key check_pages_enabled to control when struct pages are sanity checked during allocation and freeing. Mel Gorman suggested that free_tail_pages_check() could use this static key as well, instead of relying on CONFIG_DEBUG_VM. That makes sense, so do that. Also rename the function to free_tail_page_prepare() because it works on a single tail page and has a struct page preparation component as well as the optional checking component. Also remove some unnecessary unlikely() within static_branch_unlikely() statements that Mel pointed out for commit 700d2e9a36b9. Link: https://lkml.kernel.org/r/20230405142840.11068-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Suggested-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Alexander Halbuer <halbuer@sra.uni-hannover.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/userfaultfd: don't consider uffd-wp bit of writable migration entriesDavid Hildenbrand
If we end up with a writable migration entry that has the uffd-wp bit set, we already messed up: the source PTE/PMD was writable, which means we could have modified the page without notifying uffd first. Setting the uffd-wp bit always implies converting migration entries to !writable migration entries. Commit 8f34f1eac382 ("mm/userfaultfd: fix uffd-wp special cases for fork()") documents that "3. Forget to carry over uffd-wp bit for a write migration huge pmd entry", but it doesn't really say why that should be relevant. So let's remove that code to avoid hiding an eventual underlying issue (in the future, we might want to warn when creating writable migration entries that have the uffd-wp bit set -- or even better when turning a PTE writable that still has the uffd-wp bit set). This now matches the handling for hugetlb migration entries in hugetlb_change_protection(). In copy_huge_pmd()/copy_nonpresent_pte()/copy_hugetlb_page_range(), we still transfer the uffd-bit also for writable migration entries, but simply because we have unified handling for "writable" and "readable-exclusive" migration entries, and we care about transferring the uffd-wp bit for the latter. Link: https://lkml.kernel.org/r/20230405160236.587705-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm: mlock: use folios_put() in mlock_folio_batch()Qi Zheng
Since we have updated mlock to use folios, it's better to call folios_put() instead of calling release_pages() directly. Link: https://lkml.kernel.org/r/20230405161854.6931-2-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18prctl: add PR_GET_AUXV to copy auxv to userspaceJosh Triplett
If a library wants to get information from auxv (for instance, AT_HWCAP/AT_HWCAP2), it has a few options, none of them perfectly reliable or ideal: - Be main or the pre-main startup code, and grub through the stack above main. Doesn't work for a library. - Call libc getauxval. Not ideal for libraries that are trying to be libc-independent and/or don't otherwise require anything from other libraries. - Open and read /proc/self/auxv. Doesn't work for libraries that may run in arbitrarily constrained environments that may not have /proc mounted (e.g. libraries that might be used by an init program or a container setup tool). - Assume you're on the main thread and still on the original stack, and try to walk the stack upwards, hoping to find auxv. Extremely bad idea. - Ask the caller to pass auxv in for you. Not ideal for a user-friendly library, and then your caller may have the same problem. Add a prctl that copies current->mm->saved_auxv to a userspace buffer. Link: https://lkml.kernel.org/r/d81864a7f7f43bca6afa2a09fc2e850e4050ab42.1680611394.git.josh@joshtriplett.org Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18maple_tree: simplify mas_wr_node_walk()Peng Zhang
Simplify code of mas_wr_node_walk() without changing functionality, and improve readability. Remove some special judgments. Instead of dynamically recording the min and max in the loop, get the final min and max directly at the end. Link: https://lkml.kernel.org/r/20230314124203.91572-3-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18m68k/mm: use correct bit number in _PAGE_SWP_EXCLUSIVE commentDavid Hildenbrand
As noticed by Geert, commit b5c88f21531c ("microblaze/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE") modified m68k code by accident. While replacing 0x080 by CF_PAGE_NOCACHE is correct, although it should have been part of commit ed4154067a08 ("m68k/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE"), replacing "bit 7" by "bit 24" in the comment was wrong. Let's revert to the previous, correct, comment. Link: https://lkml.kernel.org/r/20230404085636.121409-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/madvise: use vma_lookup() instead of find_vma()ZhangPeng
Using vma_lookup() verifies the address is contained in the found vma. This results in easier to read the code. Link: https://lkml.kernel.org/r/20230404094515.1883552-1-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18memcg v1: provide read access to memory.pressure_levelFlorian Schmidt
cgroups v1 has a unique way of setting up memory pressure notifications: the user opens "memory.pressure_level" of the cgroup they want to monitor for pressure, then open "cgroup.event_control" and write the fd (among other things) to that file. memory.pressure_level has no other use, specifically it does not support any read or write operations. Consequently, no handlers are provided, and cgroup_file_mode() sets the permissions to 000. However, to actually use the mechanism, the subscribing user must have read access to the file and open the fd for reading, see memcg_write_event_control(). This is all fine as long as the subscribing process runs as root and is otherwise unconfined by further restrictions. However, if you add strict access controls such as selinux, the permission bits will be enforced, and opening memory.pressure_level for reading will fail, preventing the process from subscribing, even as root. To work around this issue, introduce a dummy read handler. When memory.pressure_level is created, cgroup_file_mode() will notice the existence of a handler, and therefore add read permissions to the file. Link: https://lkml.kernel.org/r/20230404105900.2005-1-flosch@nutanix.com Signed-off-by: Florian Schmidt <flosch@nutanix.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/khugepaged: maintain page cache uptodate flagDavid Stevens
Make sure that collapse_file doesn't interfere with checking the uptodate flag in the page cache by only inserting hpage into the page cache after it has been updated and marked uptodate. This is achieved by simply not replacing present pages with hpage when iterating over the target range. The present pages are already locked, so replacing them with the locked hpage before the collapse is finalized is unnecessary. However, it is necessary to stop freezing the present pages after validating them, since leaving long-term frozen pages in the page cache can lead to deadlocks. Simply checking the reference count is sufficient to ensure that there are no long-term references hanging around that would the collapse would break. Similar to hpage, there is no reason that the present pages actually need to be frozen in addition to being locked. This fixes a race where folio_seek_hole_data would mistake hpage for an fallocated but unwritten page. This race is visible to userspace via data temporarily disappearing from SEEK_DATA/SEEK_HOLE. This also fixes a similar race where pages could temporarily disappear from mincore. Link: https://lkml.kernel.org/r/20230404120117.2562166-5-stevensd@google.com Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by: David Stevens <stevensd@chromium.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18mm/khugepaged: skip shmem with userfaultfdDavid Stevens
Make sure that collapse_file respects any userfaultfds registered with MODE_MISSING. If userspace has any such userfaultfds registered, then for any page which it knows to be missing, it may expect a UFFD_EVENT_PAGEFAULT. This means collapse_file needs to be careful when collapsing a shmem range would result in replacing an empty page with a THP, to avoid breaking userfaultfd. Synchronization when checking for userfaultfds in collapse_file is tricky because the mmap locks can't be used to prevent races with the registration of new userfaultfds. Instead, we provide synchronization by ensuring that userspace cannot observe the fact that pages are missing before we check for userfaultfds. Although this allows registration of a userfaultfd to race with collapse_file, it ensures that userspace cannot observe any pages transition from missing to present after such a race occurs. This makes such a race indistinguishable to the collapse occurring immediately before the userfaultfd registration. The first step to provide this synchronization is to stop filling gaps during the loop iterating over the target range, since the page cache lock can be dropped during that loop. The second step is to fill the gaps with XA_RETRY_ENTRY after the page cache lock is acquired the final time, to avoid races with accesses to the page cache that only take the RCU read lock. The fact that we don't fill holes during the initial iteration means that collapse_file now has to handle faults occurring during the collapse. This is done by re-validating the number of missing pages after acquiring the page cache lock for the final time. This fix is targeted at khugepaged, but the change also applies to MADV_COLLAPSE. MADV_COLLAPSE on a range with a userfaultfd will now return EBUSY if there are any missing pages (instead of succeeding on shmem and returning EINVAL on anonymous memory). There is also now a window during MADV_COLLAPSE where a fault on a missing page will cause the syscall to fail with EAGAIN. The fact that intermediate page cache state can no longer be observed before the rollback of a failed collapse is also technically a userspace-visible change (via at least SEEK_DATA and SEEK_END), but it is exceedingly unlikely that anything relies on being able to observe that transient state. Link: https://lkml.kernel.org/r/20230404120117.2562166-4-stevensd@google.com Signed-off-by: David Stevens <stevensd@chromium.org> Acked-by: Peter Xu <peterx@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
generated by cgit (git 2.34.1) at 2025-03-23 21:46:32 +0000