- 13 May, 2022 40 commits
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Matthew Wilcox (Oracle) authored
Patch series "Folio patches for 5.19", v2. This patch (of 26): For now, return the head page of the folio, but remove use of the old alloc_pages_vma() API. Link: https://lkml.kernel.org/r/20220504182857.4013401-1-willy@infradead.org Link: https://lkml.kernel.org/r/20220504182857.4013401-2-willy@infradead.orgSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
Zi Yan <ziy@nvidia.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Wan Jiabing authored
Fix following checkincludes.pl warning: mm/memory.c: linux/mm_inline.h is included more than once. The include is in line 44. Remove the duplicated here. Link: https://lkml.kernel.org/r/20220427064717.803019-1-wanjiabing@vivo.comSigned-off-by:
Wan Jiabing <wanjiabing@vivo.com> Signed-off-by:
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Wei Yang authored
Now we are sure there is at least one page on page_list, so it is safe to get the nid of it. This means it is not necessary to use NUMA_NO_NODE as an indicator for the beginning of iteration or a page on different node. Link: https://lkml.kernel.org/r/20220429014426.29223-2-richard.weiyang@gmail.comSigned-off-by:
Wei Yang <richard.weiyang@gmail.com> Reviewed-by:
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Wei Yang authored
node_page_list would always be !empty on finishing the loop, except page_list is empty. Let's handle empty page_list before doing any real work including touching PF_MEMALLOC flag. Link: https://lkml.kernel.org/r/20220429014426.29223-1-richard.weiyang@gmail.comSigned-off-by:
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Miaohe Lin authored
Use helper folio_is_file_lru() to check whether folio is file lru. Minor readability improvement. [linmiaohe@huawei.com: use folio_is_file_lru()] Link: https://lkml.kernel.org/r/20220428105802.21389-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220425111232.23182-7-linmiaohe@huawei.comSigned-off-by:
Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by:
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Miaohe Lin authored
Since commit 6b700b5b ("mm/vmscan.c: remove cpu online notification for now"), cpu online notification is removed. So kswapd won't move to proper cpus if cpus are hot-added. Remove this obsolete comment. Link: https://lkml.kernel.org/r/20220425111232.23182-6-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
If the page has buffers, shrink_page_list will try to free the buffer mappings associated with the page and try to free the page as well. In the rare race with speculative reference, the page will be freed shortly by speculative reference. But nr_reclaimed is not incremented correctly when we come across the THP. We need to account all the base pages in this case. Link: https://lkml.kernel.org/r/20220425111232.23182-5-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
Introduce helper function reclaim_page_list() to eliminate the duplicated code of doing shrink_page_list() and putback_lru_page. Also we can separate node reclaim from node page list operation this way. No functional change intended. Link: https://lkml.kernel.org/r/20220425111232.23182-3-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
Patch series "A few cleanup and fixup patches for vmscan This series contains a few patches to remove obsolete comment, introduce helper to remove duplicated code and so no. Also we take all base pages of THP into account in rare race condition. More details can be found in the respective changelogs. This patch (of 6): The MADV_FREE pages check in folio_check_dirty_writeback is a bit hard to follow. Add a comment to make the code clear. Link: https://lkml.kernel.org/r/20220425111232.23182-2-linmiaohe@huawei.comSuggested-by:
Huang, Ying <ying.huang@intel.com> Signed-off-by:
Oscar Salvador <osalvador@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Wei Yang authored
node_page_list is defined with LIST_HEAD and be cleaned until list_empty. So it is not necessary to re-init it again. [akpm@linux-foundation.org: remove unneeded braces] Link: https://lkml.kernel.org/r/20220426021743.21007-1-richard.weiyang@gmail.comSigned-off-by:
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Jagdish Gediya authored
Sysfs input conversion to corrosponding bool value e.g. "false" or "0" to false, "true" or "1" to true are currently handled through strncmp at multiple places. Use kstrtobool() to convert sysfs input to bool value. [akpm@linux-foundation.org: propagate kstrtobool() return value, per Andy] Link: https://lkml.kernel.org/r/20220426180203.70782-2-jvgediya@linux.ibm.comSigned-off-by:
Jagdish Gediya <jvgediya@linux.ibm.com> Reviewed-by:
Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by:
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Jagdish Gediya authored
At many places in kernel, It is necessary to convert sysfs input to corresponding bool value e.g. "false" or "0" need to be converted to bool false, "true" or "1" need to be converted to bool true, places where such conversion is needed currently check the input string manually, kstrtobool() can be utilized at such places but currently it doesn't have support to accept "false"/"true". Add support to accept "false"/"true" as valid string in kstrtobool(). [akpm@linux-foundation.org: undo s/iff/if/, per Matthew] Link: https://lkml.kernel.org/r/20220426180203.70782-1-jvgediya@linux.ibm.comSigned-off-by:
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Miaohe Lin authored
Since commit 6b4f7799 ("mm: vmscan: invoke slab shrinkers from shrink_zone()"), slab reclaim and lru page reclaim are done together in the shrink_node. So we should take min_slab_pages into account when try to call shrink_node. Link: https://lkml.kernel.org/r/20220425112118.20924-1-linmiaohe@huawei.comSigned-off-by:
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Zi Yan authored
alloc_contig_range() now only needs to be aligned to pageblock_nr_pages, drop virtio_mem size requirement that it needs to be MAX_ORDER_NR_PAGES. Link: https://lkml.kernel.org/r/20220425143118.2850746-7-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
Now alloc_contig_range() works at pageblock granularity. Change CMA allocation, which uses alloc_contig_range(), to use pageblock_nr_pages alignment. Link: https://lkml.kernel.org/r/20220425143118.2850746-6-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
Now start_isolate_page_range() is ready to handle arbitrary range isolation, so move the alignment check/adjustment into the function body. Do the same for its counterpart undo_isolate_page_range(). alloc_contig_range(), its caller, can pass an arbitrary range instead of a MAX_ORDER_NR_PAGES aligned one. Link: https://lkml.kernel.org/r/20220425143118.2850746-5-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
alloc_contig_range() worked at MAX_ORDER_NR_PAGES granularity to avoid merging pageblocks with different migratetypes. It might unnecessarily convert extra pageblocks at the beginning and at the end of the range. Change alloc_contig_range() to work at pageblock granularity. Special handling is needed for free pages and in-use pages across the boundaries of the range specified by alloc_contig_range(). Because these= Partially isolated pages causes free page accounting issues. The free pages will be split and freed into separate migratetype lists; the in-use= Pages will be migrated then the freed pages will be handled in the aforementioned way. [ziy@nvidia.com: fix deadlock/crash] Link: https://lkml.kernel.org/r/23A7297E-6C84-4138-A9FE-3598234004E6@nvidia.com Link: https://lkml.kernel.org/r/20220425143118.2850746-4-zi.yan@sent.comSigned-off-by:
kernel test robot <lkp@intel.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Zi Yan authored
Enable set_migratetype_isolate() to check specified range for unmovable pages during isolation to prepare arbitrary range page isolation. The functionality will take effect in upcoming commits by adjusting the callers of start_isolate_page_range(), which uses set_migratetype_isolate(). For example, alloc_contig_range(), which calls start_isolate_page_range(), accepts unaligned ranges, but because page isolation is currently done at MAX_ORDER_NR_PAEGS granularity, pages that are out of the specified range but withint MAX_ORDER_NR_PAEGS alignment might be attempted for isolation and the failure of isolating these unrelated pages fails the whole operation undesirably. Link: https://lkml.kernel.org/r/20220425143118.2850746-3-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
Patch series "Use pageblock_order for cma and alloc_contig_range alignment", v11. This patchset tries to remove the MAX_ORDER-1 alignment requirement for CMA and alloc_contig_range(). It prepares for my upcoming changes to make MAX_ORDER adjustable at boot time[1]. The MAX_ORDER - 1 alignment requirement comes from that alloc_contig_range() isolates pageblocks to remove free memory from buddy allocator but isolating only a subset of pageblocks within a page spanning across multiple pageblocks causes free page accounting issues. Isolated page might not be put into the right free list, since the code assumes the migratetype of the first pageblock as the whole free page migratetype. This is based on the discussion at [2]. To remove the requirement, this patchset: 1. isolates pages at pageblock granularity instead of max(MAX_ORDER_NR_PAEGS, pageblock_nr_pages); 2. splits free pages across the specified range or migrates in-use pages across the specified range then splits the freed page to avoid free page accounting issues (it happens when multiple pageblocks within a single page have different migratetypes); 3. only checks unmovable pages within the range instead of MAX_ORDER - 1 aligned range during isolation to avoid alloc_contig_range() failure when pageblocks within a MAX_ORDER - 1 aligned range are allocated separately. 4. returns pages not in the range as it did before. One optimization might come later: 1. make MIGRATE_ISOLATE a separate bit to be able to restore the original migratetypes when isolation fails in the middle of the range. [1] https://lore.kernel.org/linux-mm/20210805190253.2795604-1-zi.yan@sent.com/ [2] https://lore.kernel.org/linux-mm/d19fb078-cb9b-f60f-e310-fdeea1b947d2@redhat.com/ This patch (of 6): has_unmovable_pages() is only used in mm/page_isolation.c. Move it from mm/page_alloc.c and make it static. Link: https://lkml.kernel.org/r/20220425143118.2850746-2-zi.yan@sent.comSigned-off-by:
Mike Rapoport <rppt@linux.ibm.com> Acked-by:
David Hildenbrand <david@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Minchan Kim <minchan@kernel.org> Cc: kernel test robot <lkp@intel.com> Signed-off-by:
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David Vernet authored
alloc_pagecache_max_30M() in the cgroup memcg tests performs a 50MB pagecache allocation, which it expects to be capped at 30MB due to the calling process having a memory.high setting of 30MB. After the allocation, the function contains a check that verifies that MB(29) < memory.current <= MB(30). This check can actually fail non-deterministically. The testcases that use this function are test_memcg_high() and test_memcg_max(), which set memory.min and memory.max to 30MB respectively for the cgroup under test. The allocation can slightly exceed this number in both cases, and for memory.max, the process performing the allocation will not have the OOM killer invoked as it's performing a pagecache allocation. This patchset therefore updates the above check to instead use the verify_close() helper function. Link: https://lkml.kernel.org/r/20220423155619.3669555-6-void@manifault.comSigned-off-by:
David Vernet <void@manifault.com> Acked-by:
Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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David Vernet authored
test_memcg_sock() in the cgroup memcg tests, verifies expected memory accounting for sockets. The test forks a process which functions as a TCP server, and sends large buffers back and forth between itself (as the TCP client) and the forked TCP server. While doing so, it verifies that memory.current and memory.stat.sock look correct. There is currently a check in tcp_client() which asserts memory.current >= memory.stat.sock. This check is racy, as between memory.current and memory.stat.sock being queried, a packet could come in which causes mem_cgroup_charge_skmem() to be invoked. This could cause memory.stat.sock to exceed memory.current. Reversing the order of querying doesn't address the problem either, as memory may be reclaimed between the two calls. Instead, this patch just removes that assertion altogether, and instead relies on the values_close() check that follows to validate the expected accounting. Link: https://lkml.kernel.org/r/20220423155619.3669555-5-void@manifault.comSigned-off-by:
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David Vernet authored
The test_memcg_oom_group_leaf_events() testcase in the cgroup memcg tests validates that processes in a group that perform allocations exceeding memory.oom.group are killed. It also validates that the memory.events.oom_kill events are properly propagated in this case. Commit 06e11c907ea4 ("kselftests: memcg: update the oom group leaf events test") fixed test_memcg_oom_group_leaf_events() to account for the fact that the memory.events.oom_kill events in a child cgroup is propagated up to its parent. This behavior can actually be configured by the memory_localevents mount option, so this patch updates the testcase to properly account for the possible presence of this mount option. Link: https://lkml.kernel.org/r/20220423155619.3669555-4-void@manifault.comSigned-off-by: -
David Vernet authored
The test_memcg_low() testcase in test_memcontrol.c verifies the expected behavior of groups using the memory.low knob. Part of the testcase verifies that a group with memory.low that experiences reclaim due to memory pressure elsewhere in the system, observes memory.events.low events as a result of that reclaim. In commit 8a931f80 ("mm: memcontrol: recursive memory.low protection"), the memory controller was updated to propagate memory.low and memory.min protection from a parent group to its children via a configurable memory_recursiveprot mount option. This unfortunately broke the memcg tests, which asserts that a sibling that experienced reclaim but had a memory.low value of 0, would not observe any memory.low events. This patch updates test_memcg_low() to account for the new behavior introduced by memory_recursiveprot. So as to make the test resilient to multiple configurations, the patch also adds a new proc_mount_contains() helper that checks for a string in /proc/mounts, and is used to toggle behavior based on whether the default memory_recursiveprot was present. Link: https://lkml.kernel.org/r/20220423155619.3669555-3-void@manifault.comSigned-off-by:
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David Vernet authored
Patch series "Fix bugs in memcontroller cgroup tests", v2. tools/testing/selftests/cgroup/test_memcontrol.c contains a set of testcases which validate expected behavior of the cgroup memory controller. Roman Gushchin recently sent out a patchset that fixed a few issues in the test. This patchset continues that effort by fixing a few more issues that were causing non-deterministic failures in the suite. With this patchset, I'm unable to reproduce any more errors after running the tests in a continuous loop for many iterations. Before, I was able to reproduce at least one of the errors fixed in this patchset with just one or two runs. This patch (of 5): In test_memcg_min() and test_memcg_low(), there is an array of four sibling cgroups. All but one of these sibling groups does a 50MB allocation, and the group that does no allocation is the third of four in the array. This is not a problem per se, but makes it a bit tricky to do some assertions in test_memcg_low(), as we want to make assertions on the siblings based on whether or not they performed allocations. Having a static index before which all groups have performed an allocation makes this cleaner. This patch therefore reorders the sibling groups so that the group that performs no allocations is the last in the array. A follow-on patch will leverage this to fix a bug in the test that incorrectly asserts that a sibling group that had performed an allocation, but only had protection from its parent, will not observe any memory.events.low events during reclaim. Link: https://lkml.kernel.org/r/20220423155619.3669555-1-void@manifault.com Link: https://lkml.kernel.org/r/20220423155619.3669555-2-void@manifault.comSigned-off-by:
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Peter Xu authored
We used to have USERFAULTFD configs stored in init/. It makes sense as a start because that's the default place for storing syscall related configs. However userfaultfd evolved a bit in the past few years and some more config options were added. They're no longer related to syscalls and start to be not suitable to be kept in the init/ directory anymore, because they're pure mm concepts. But it's not ideal either to keep the userfaultfd configs separate from each other. Hence this patch moves the userfaultfd configs under init/ to be under mm/ so that we'll start to group all userfaultfd configs together. We do have quite a few examples of syscall related configs that are not put under init/Kconfig: FTRACE_SYSCALLS, SWAP, FILE_LOCKING, MEMFD_CREATE.. They all reside in the dir where they're more suitable for the concept. So it seems there's no restriction to keep the role of having syscall related CONFIG_* under init/ only. Link: https://lkml.kernel.org/r/20220420144823.35277-1-peterx@redhat.comSigned-off-by:
Peter Xu <peterx@redhat.com> Suggested-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Axel Rasmussen <axelrasmussen@google.com> Signed-off-by:
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Guo Zhengkui authored
Address the following coccicheck warning: tools/testing/selftests/vm/userfaultfd.c:1536:21-22: WARNING opportunity for swap(). tools/testing/selftests/vm/userfaultfd.c:1540:33-34: WARNING opportunity for swap(). by using swap() for the swapping of variable values and drop `tmp_area` that is not needed any more. `swap()` macro in userfaultfd.c is introduced in commit 68169686 ("selftests: vm: remove dependecy from internal kernel macros") It has been tested with gcc (Debian 8.3.0-6) 8.3.0. Link: https://lkml.kernel.org/r/20220407123141.4998-1-guozhengkui@vivo.comSigned-off-by:
Guo Zhengkui <guozhengkui@vivo.com> Reviewed-by:
Muchun Song <songmuchun@bytedance.com> Reviewed-by:
Shuah Khan <skhan@linuxfoundation.org> Signed-off-by:
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Peter Xu authored
After we added support for shmem and hugetlbfs, we can turn uffd-wp test on always now. Link: https://lkml.kernel.org/r/20220405014932.15212-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
Enable PTE markers by default. On x86_64 it means it'll auto-enable PTE_MARKER_UFFD_WP as well. [peterx@redhat.com: hide PTE_MARKER option] Link: https://lkml.kernel.org/r/20220419202531.27415-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20220405014929.15158-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
We've had all the necessary changes ready for both shmem and hugetlbfs. Turn on all the shmem/hugetlbfs switches for userfaultfd-wp. We can expand UFFD_API_RANGE_IOCTLS_BASIC with _UFFDIO_WRITEPROTECT too because all existing types now support write protection mode. Since vma_can_userfault() will be used elsewhere, move into userfaultfd_k.h. Link: https://lkml.kernel.org/r/20220405014926.15101-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
This requires the pagemap code to be able to recognize the newly introduced swap special pte for uffd-wp, meanwhile the general case for hugetlb that we recently start to support. It should make pagemap uffd-wp support complete. Link: https://lkml.kernel.org/r/20220405014923.15047-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
When we're trying to collapse a 2M huge shmem page, don't retract pgtable pmd page if it's registered with uffd-wp, because that pgtable could have pte markers installed. Recycling of that pgtable means we'll lose the pte markers. That could cause data loss for an uffd-wp enabled application on shmem. Instead of disabling khugepaged on these files, simply skip retracting these special VMAs, then the page cache can still be merged into a huge thp, and other mm/vma can still map the range of file with a huge thp when proper. Note that checking VM_UFFD_WP needs to be done with mmap_sem held for write, that avoids race like: khugepaged user thread ========== =========== check VM_UFFD_WP, not set UFFDIO_REGISTER with uffd-wp on shmem wr-protect some pages (install markers) take mmap_sem write lock erase pmd and free pmd page --> pte markers are dropped unnoticed! Link: https://lkml.kernel.org/r/20220405014921.14994-1-peterx@redhat.comSigned-off-by: -
Peter Xu authored
Firstly, we'll need to pass in dst_vma into copy_hugetlb_page_range() because for uffd-wp it's the dst vma that matters on deciding how we should treat uffd-wp protected ptes. We should recognize pte markers during fork and do the pte copy if needed. [lkp@intel.com: vma_needs_copy can be static] Link: https://lkml.kernel.org/r/Ylb0CGeFJlc4EzLk@7ec4ff11d4ae Link: https://lkml.kernel.org/r/20220405014918.14932-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
As with shmem uffd-wp special ptes, only drop the uffd-wp special swap pte if unmapping an entire vma or synchronized such that faults can not race with the unmap operation. This requires passing zap_flags all the way to the lowest level hugetlb unmap routine: __unmap_hugepage_range. In general, unmap calls originated in hugetlbfs code will pass the ZAP_FLAG_DROP_MARKER flag as synchronization is in place to prevent faults. The exception is hole punch which will first unmap without any synchronization. Later when hole punch actually removes the page from the file, it will check to see if there was a subsequent fault and if so take the hugetlb fault mutex while unmapping again. This second unmap will pass in ZAP_FLAG_DROP_MARKER. The justification of "whether to apply ZAP_FLAG_DROP_MARKER flag when unmap a hugetlb range" is (IMHO): we should never reach a state when a page fault could errornously fault in a page-cache page that was wr-protected to be writable, even in an extremely short period. That could happen if e.g. we pass ZAP_FLAG_DROP_MARKER when hugetlbfs_punch_hole() calls hugetlb_vmdelete_list(), because if a page faults after that call and before remove_inode_hugepages() is executed, the page cache can be mapped writable again in the small racy window, that can cause unexpected data overwritten. [peterx@redhat.com: fix sparse warning] Link: https://lkml.kernel.org/r/Ylcdw8I1L5iAoWhb@xz-m1.local [akpm@linux-foundation.org: move zap_flags_t from mm.h to mm_types.h to fix build issues] Link: https://lkml.kernel.org/r/20220405014915.14873-1-peterx@redhat.comSigned-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by:
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Peter Xu authored
Teach hugetlbfs code to wr-protect none ptes just in case the page cache existed for that pte. Meanwhile we also need to be able to recognize a uffd-wp marker pte and remove it for uffd_wp_resolve. Since at it, introduce a variable "psize" to replace all references to the huge page size fetcher. Link: https://lkml.kernel.org/r/20220405014912.14815-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
Allow hugetlb code to handle pte markers just like none ptes. It's mostly there, we just need to make sure we don't assume hugetlb_no_page() only handles none pte, so when detecting pte change we should use pte_same() rather than pte_none(). We need to pass in the old_pte to do the comparison. Check the original pte to see whether it's a pte marker, if it is, we should recover uffd-wp bit on the new pte to be installed, so that the next write will be trapped by uffd. Link: https://lkml.kernel.org/r/20220405014909.14761-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
This starts from passing cp_flags into hugetlb_change_protection() so hugetlb will be able to handle MM_CP_UFFD_WP[_RESOLVE] requests. huge_pte_clear_uffd_wp() is introduced to handle the case where the UFFDIO_WRITEPROTECT is requested upon migrating huge page entries. Link: https://lkml.kernel.org/r/20220405014906.14708-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
Pass the wp_copy variable into hugetlb_mcopy_atomic_pte() thoughout the stack. Apply the UFFD_WP bit if UFFDIO_COPY_MODE_WP is with UFFDIO_COPY. Hugetlb pages are only managed by hugetlbfs, so we're safe even without setting dirty bit in the huge pte if the page is installed as read-only. However we'd better still keep the dirty bit set for a read-only UFFDIO_COPY pte (when UFFDIO_COPY_MODE_WP bit is set), not only to match what we do with shmem, but also because the page does contain dirty data that the kernel just copied from the userspace. Link: https://lkml.kernel.org/r/20220405014904.14643-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
Hook up hugetlbfs_fault() with the capability to handle userfaultfd-wp faults. We do this slightly earlier than hugetlb_cow() so that we can avoid taking some extra locks that we definitely don't need. Link: https://lkml.kernel.org/r/20220405014901.14590-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
They will be used in the follow up patches to either check/set/clear uffd-wp bit of a huge pte. So far it reuses all the small pte helpers. Archs can overwrite these versions when necessary (with __HAVE_ARCH_HUGE_PTE_UFFD_WP* macros) in the future. Link: https://lkml.kernel.org/r/20220405014858.14531-1-peterx@redhat.comSigned-off-by:
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Peter Xu authored
Normally we skip copy page when fork() for VM_SHARED shmem, but we can't skip it anymore if uffd-wp is enabled on dst vma. This should only happen when the src uffd has UFFD_FEATURE_EVENT_FORK enabled on uffd-wp shmem vma, so that VM_UFFD_WP will be propagated onto dst vma too, then we should copy the pgtables with uffd-wp bit and pte markers, because these information will be lost otherwise. Since the condition checks will become even more complicated for deciding "whether a vma needs to copy the pgtable during fork()", introduce a helper vma_needs_copy() for it, so everything will be clearer. Link: https://lkml.kernel.org/r/20220405014855.14468-1-peterx@redhat.comSigned-off-by:
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