- 14 Oct, 2020 40 commits
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Michal Hocko authored
There is a general understanding that GFP_ATOMIC/GFP_NOWAIT are to be used from atomic contexts. E.g. from within a spin lock or from the IRQ context. This is correct but there are some atomic contexts where the above doesn't hold. One of them would be an NMI context. Page allocator has never supported that and the general fear of this context didn't let anybody to actually even try to use the allocator there. Good, but let's be more specific about that. Another such a context, and that is where people seem to be more daring, is raw_spin_lock. Mostly because it simply resembles regular spin lock which is supported by the allocator and there is not any implementation difference with !RT kernels in the first place. Be explicit that such a context is not supported by the allocator. The underlying reason is that zone->lock would have to become raw_spin_lock as well and that has turned out to be a problem for RT (http://lkml.kernel.org/r/87mu305c1w.fsf@nanos.tec.linutronix.de). Signed-off-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Reviewed-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Uladzislau Rezki <urezki@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Link: https://lkml.kernel.org/r/20200929123010.5137-1-mhocko@kernel.orgSigned-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
Here is a very rare race which leaks memory: Page P0 is allocated to the page cache. Page P1 is free. Thread A Thread B Thread C find_get_entry(): xas_load() returns P0 Removes P0 from page cache P0 finds its buddy P1 alloc_pages(GFP_KERNEL, 1) returns P0 P0 has refcount 1 page_cache_get_speculative(P0) P0 has refcount 2 __free_pages(P0) P0 has refcount 1 put_page(P0) P1 is not freed Fix this by freeing all the pages in __free_pages() that won't be freed by the call to put_page(). It's usually not a good idea to split a page, but this is a very unlikely scenario. Fixes: e286781d ("mm: speculative page references") Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:
Mike Rapoport <rppt@linux.ibm.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200926213919.26642-1-willy@infradead.orgSigned-off-by:
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Ralph Campbell authored
The function is_huge_zero_page() doesn't call compound_head() to make sure the page pointer is a head page. The call to is_huge_zero_page() in release_pages() is made before compound_head() is called so the test would fail if release_pages() was called with a tail page of the huge_zero_page and put_page_testzero() would be called releasing the page. This is unlikely to be happening in normal use or we would be seeing all sorts of process data corruption when accessing a THP zero page. Looking at other places where is_huge_zero_page() is called, all seem to only pass a head page so I think the right solution is to move the call to compound_head() in release_pages() to a point before calling is_huge_zero_page(). Signed-off-by:
Ralph Campbell <rcampbell@nvidia.com> Signed-off-by:
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Mateusz Nosek authored
Previously 'for_next_zone_zonelist_nodemask' macro parameter 'zlist' was unused so this patch removes it. Signed-off-by:
Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by:
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Yanfei Xu authored
__perform_reclaim()'s single caller expects it to return 'unsigned long', hence change its return value and a local variable to 'unsigned long'. Suggested-by:
Yanfei Xu <yanfei.xu@windriver.com> Signed-off-by:
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Mateusz Nosek authored
finalise_ac() is just 'epilogue' for 'prepare_alloc_pages'. Therefore there is no need to keep them both so 'finalise_ac' content can be merged into prepare_alloc_pages() code. It would make __alloc_pages_nodemask() cleaner when it comes to readability. Signed-off-by:
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Mateusz Nosek authored
Previously in '__init early_init_on_alloc' and '__init early_init_on_free' the return values from 'kstrtobool' were not handled properly. That caused potential garbage value read from variable 'bool_result'. Introduced patch fixes error handling. Signed-off-by:
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Mateusz Nosek authored
Previously flags check was separated into two separated checks with two separated branches. In case of presence of any of two mentioned flags, the same effect on flow occurs. Therefore checks can be merged and one branch can be avoided. Signed-off-by:
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Mateusz Nosek authored
Previously variable 'tmp' was initialized, but was not read later before reassigning. So the initialization can be removed. [akpm@linux-foundation.org: remove `tmp' altogether] Signed-off-by:
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Li Xinhai authored
In has_unmovable_pages(), the page parameter would not always be the first page within a pageblock (see how the page pointer is passed in from start_isolate_page_range() after call __first_valid_page()), so that would cause checking unmovable pages span two pageblocks. After this patch, the checking is enforced within one pageblock no matter the page is first one or not, and obey the semantics of this function. This issue is found by code inspection. Michal said "this might lead to false negatives when an unrelated block would cause an isolation failure". Signed-off-by:
Li Xinhai <lixinhai.lxh@gmail.com> Signed-off-by:
Oscar Salvador <osalvador@suse.de> Acked-by:
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David Hildenbrand authored
Let's document what ZONE_MOVABLE means, how it's used, and which special cases we have regarding unmovable pages (memory offlining vs. migration / allocations). Signed-off-by:
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David Hildenbrand authored
When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather unclear, which is why we special-cased ZONE_MOVABLE such that partially plugged blocks would never end up in ZONE_MOVABLE. Now that the semantics are much clearer (and will be documented in a follow-up patch including the new virtio-mem behavior), let's allow to online partially plugged memory blocks to ZONE_MOVABLE and also consider memory blocks that were onlined to ZONE_MOVABLE when unplugging memory. While unplugged memory pages are, in general, unmovable, they can be skipped when offlining memory. virtio-mem only unplugs fairly big chunks (in the megabyte range) and rather tries to shrink the memory region than randomly choosing memory. In theory, if all other pages in the movable zone would be movable, virtio-mem would only shrink that zone and not create any kind of fragmentation. In the future, we might want to remember the zone again and use the information when (un)plugging memory. For now, let's keep it simple. Note: Support for defragmentation is planned, to deal with fragmentation after unplug due to memory chunks within memory blocks that could not get unplugged before (e.g., somebody pinning pages within ZONE_MOVABLE for a longer time). Signed-off-by:
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David Hildenbrand authored
Let's clean it up a bit, simplifying the exit paths. Signed-off-by:
Baoquan He <bhe@redhat.com> Reviewed-by:
Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Qian Cai <cai@lca.pw> Link: http://lkml.kernel.org/r/20200816125333.7434-5-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Inside has_unmovable_pages(), we have a comment describing how unmovable data could end up in ZONE_MOVABLE - via "movablecore". Also, besides checking if the first page in the pageblock is reserved, we don't perform any further checks in case of ZONE_MOVABLE. In case of memory offlining, we set REPORT_FAILURE, properly dump_page() the page and handle the error gracefully. alloc_contig_pages() users currently never allocate from ZONE_MOVABLE. E.g., hugetlb uses alloc_contig_pages() for the allocation of gigantic pages only, which will never end up on the MOVABLE zone (see htlb_alloc_mask()). Signed-off-by:
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David Hildenbrand authored
Right now, if we have two isolations racing on a pageblock that's in the MOVABLE zone, we would trigger the WARN_ON_ONCE(). Let's just return directly, simplifying error handling. The change was introduced in commit 3d680bdf ("mm/page_isolation: fix potential warning from user"). As far as I can see, we currently don't have alloc_contig_range() users that use the ZONE_MOVABLE (anymore), so it's currently more a cleanup and a preparation for the future than a fix. Signed-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Qian Cai <cai@lca.pw> Cc: Jason Wang <jasowang@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Link: http://lkml.kernel.org/r/20200816125333.7434-3-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Patch series "mm / virtio-mem: support ZONE_MOVABLE", v5. When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather unclear, which is why we special-cased ZONE_MOVABLE such that partially plugged blocks would never end up in ZONE_MOVABLE. Now that the semantics are much clearer (and are documented in patch #6), let's support partially plugged memory blocks in ZONE_MOVABLE, allowing partially plugged memory blocks to be online to ZONE_MOVABLE and also unplugging from such memory blocks. This avoids surprises when onlining of memory blocks suddenly fails, just because they are not completely populated by virtio-mem (yet). This is especially helpful for testing, but also paves the way for virtio-mem optimizations, allowing more memory to get reliably unplugged. Cleanup has_unmovable_pages() and set_migratetype_isolate(), providing better documentation of how ZONE_MOVABLE interacts with different kind of unmovable pages (memory offlining vs. alloc_contig_range()). This patch (of 6): Let's move the split comment regarding bootmem allocations and memory holes, especially in the context of ZONE_MOVABLE, to the PageReserved() check. Signed-off-by:
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David Gow authored
KASAN errors will currently trigger a panic when panic_on_warn is set. This renders kasan_multishot useless, as further KASAN errors won't be reported if the kernel has already paniced. By making kasan_multishot disable this behaviour for KASAN errors, we can still have the benefits of panic_on_warn for non-KASAN warnings, yet be able to use kasan_multishot. This is particularly important when running KASAN tests, which need to trigger multiple KASAN errors: previously these would panic the system if panic_on_warn was set, now they can run (and will panic the system should non-KASAN warnings show up). Signed-off-by:
David Gow <davidgow@google.com> Signed-off-by:
Andrey Konovalov <andreyknvl@google.com> Reviewed-by:
Brendan Higgins <brendanhiggins@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Patricia Alfonso <trishalfonso@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Shuah Khan <shuah@kernel.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lkml.kernel.org/r/20200915035828.570483-6-davidgow@google.com Link: https://lkml.kernel.org/r/20200910070331.3358048-6-davidgow@google.comSigned-off-by:
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Patricia Alfonso authored
Include documentation on how to test KASAN using CONFIG_TEST_KASAN_KUNIT and CONFIG_TEST_KASAN_MODULE. Signed-off-by:
Patricia Alfonso <trishalfonso@google.com> Signed-off-by:
Dmitry Vyukov <dvyukov@google.com> Acked-by:
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Patricia Alfonso authored
Transfer all previous tests for KASAN to KUnit so they can be run more easily. Using kunit_tool, developers can run these tests with their other KUnit tests and see "pass" or "fail" with the appropriate KASAN report instead of needing to parse each KASAN report to test KASAN functionalities. All KASAN reports are still printed to dmesg. Stack tests do not work properly when KASAN_STACK is enabled so those tests use a check for "if IS_ENABLED(CONFIG_KASAN_STACK)" so they only run if stack instrumentation is enabled. If KASAN_STACK is not enabled, KUnit will print a statement to let the user know this test was not run with KASAN_STACK enabled. copy_user_test and kasan_rcu_uaf cannot be run in KUnit so there is a separate test file for those tests, which can be run as before as a module. [trishalfonso@google.com: v14] Link: https://lkml.kernel.org/r/20200915035828.570483-4-davidgow@google.comSigned-off-by:
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Patricia Alfonso authored
Integrate KASAN into KUnit testing framework. - Fail tests when KASAN reports an error that is not expected - Use KUNIT_EXPECT_KASAN_FAIL to expect a KASAN error in KASAN tests - Expected KASAN reports pass tests and are still printed when run without kunit_tool (kunit_tool still bypasses the report due to the test passing) - KUnit struct in current task used to keep track of the current test from KASAN code Make use of "[PATCH v3 kunit-next 1/2] kunit: generalize kunit_resource API beyond allocated resources" and "[PATCH v3 kunit-next 2/2] kunit: add support for named resources" from Alan Maguire [1] - A named resource is added to a test when a KASAN report is expected - This resource contains a struct for kasan_data containing booleans representing if a KASAN report is expected and if a KASAN report is found [1] (https://lore.kernel.org/linux-kselftest/1583251361-12748-1-git-send-email-alan.maguire@oracle.com/T/#t) Signed-off-by: -
Patricia Alfonso authored
Patch series "KASAN-KUnit Integration", v14. This patchset contains everything needed to integrate KASAN and KUnit. KUnit will be able to: (1) Fail tests when an unexpected KASAN error occurs (2) Pass tests when an expected KASAN error occurs Convert KASAN tests to KUnit with the exception of copy_user_test because KUnit is unable to test those. Add documentation on how to run the KASAN tests with KUnit and what to expect when running these tests. This patch (of 5): In order to integrate debugging tools like KASAN into the KUnit framework, add KUnit struct to the current task to keep track of the current KUnit test. Signed-off-by:
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Alexander Gordeev authored
In the context of the anonymous address space lifespan description the 'mm_users' reference counter is confused with 'mm_count'. I.e a "zombie" mm gets released when "mm_count" becomes zero, not "mm_users". Signed-off-by:
Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by:
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Hui Su authored
Fix the comment of find_vm_area() and get_vm_area() Signed-off-by:
Hui Su <sh_def@163.com> Signed-off-by:
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Hui Su authored
Since c67dc624 ("mm/vmalloc: do not call kmemleak_free() on not yet accounted memory"), the __vunmap() have been changed to __vfree(), so update the confusing comment(). Signed-off-by:
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Alex Shi authored
Unlike others we don't use the marco writeback. so let's remove it to tame gcc warning: mm/memory-failure.c:827: warning: macro "writeback" is not used [-Wunused-macros] Signed-off-by:
Alex Shi <alex.shi@linux.alibaba.com> Signed-off-by:
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Xianting Tian authored
There is no need to calculate pgoff in each loop of for_each_process(), so move it to the place before for_each_process(), which can save some CPU cycles. Signed-off-by:
Xianting Tian <tian.xianting@h3c.com> Signed-off-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Link: http://lkml.kernel.org/r/20200818082647.34322-1-tian.xianting@h3c.comSigned-off-by:
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Andy Shevchenko authored
No need to hard code function name when __func__ can be used. While here, replace specifiers for special types like dma_addr_t. Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
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Andy Shevchenko authored
There is a place in the code where open-coded version of list_for_each_entry_safe() is used. Replace that with the standard macro. Signed-off-by:
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Ralph Campbell authored
The variable dmirror_zero_page is unused in the HMM self test driver which was probably intended to demonstrate how a driver could use migrate_vma_setup() to share a single read-only device private zero page similar to how the CPU does. However, this isn't needed for the self tests so remove it. Signed-off-by:
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Ralph Campbell authored
Some tests might not be able to be run if resources like huge pages are not available. Mark these tests as skipped instead of simply passing. Signed-off-by:
Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200827190400.12608-1-rcampbell@nvidia.comSigned-off-by:
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yuleixzhang authored
As mincore_huge_pmd() was dropped, remove the declaration from the header file. Signed-off-by:
Yulei Zhang <yuleixzhang@tencent.com> Signed-off-by:
Zi Yan <ziy@nvidia.com> Link: https://lkml.kernel.org/r/20200922083423.15074-1-yuleixzhang@tencent.comSigned-off-by:
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Peter Xu authored
Both of the mm pointers are not needed after commit 7a4830c3 ("mm/fork: Pass new vma pointer into copy_page_range()"). Jason Gunthorpe also reported that the ordering of copy_page_range() is odd. Since working at it, reorder the parameters to be logical, by (1) always put the dst_* fields to be before src_* fields, and (2) keep the same type of parameters together. [peterx@redhat.com: further reorder some parameters and line format, per Jason] Link: https://lkml.kernel.org/r/20201002192647.7161-1-peterx@redhat.com [peterx@redhat.com: fix warnings] Link: https://lkml.kernel.org/r/20201006200138.GA6026@xz-x1Reported-by:
Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by:
Peter Xu <peterx@redhat.com> Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lkml.kernel.org/r/20200930204950.6668-1-peterx@redhat.comSigned-off-by:
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Liao Pingfang authored
Replace do_brk with do_brk_flags in comment of insert_vm_struct(), since do_brk was removed in following commit. Fixes: bb177a73 ("mm: do not bug_on on incorrect length in __mm_populate()") Signed-off-by:
Liao Pingfang <liao.pingfang@zte.com.cn> Signed-off-by:
Yi Wang <wang.yi59@zte.com.cn> Signed-off-by:
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Miaohe Lin authored
In commit 1da177e4 ("Linux-2.6.12-rc2"), the helper allow_write_access came with the atomic_inc operation of the i_writecount field in the func __remove_shared_vm_struct(). But it forgot to use this helper function. Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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Miaohe Lin authored
Commit 4bb5f5d9 ("mm: allow drivers to prevent new writable mappings") changed i_mmap_writable from unsigned int to atomic_t and add the helper function mapping_allow_writable() to atomic_inc i_mmap_writable. But it forgot to use this helper function in dup_mmap() and __vma_link_file(). Signed-off-by:
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Wei Yang authored
In __vma_adjust(), we do the check on *root* to decide whether to adjust the address_space. It seems to be more meaningful to do the check on *file* itself. This means we are adjusting some data because it is a file backed vma. Since we seem to assume the address_space is valid if it is a file backed vma, let's just replace *root* with *file* here. Signed-off-by:
Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by:
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Wei Yang authored
*root* with type of struct rb_root_cached is an element of *mapping* with type of struct address_space. This implies when we have a valid *root* it must be a part of valid *mapping*. So we can merge these two checks together to make the code more easy to read and to save some cpu cycles. Signed-off-by:
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Randy Dunlap authored
Fix typo/spello of "function". Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Wei Yang authored
Instead of converting adjust_next between bytes and pages number, let's just store the virtual address into adjust_next. Also, this patch fixes one typo in the comment of vma_adjust_trans_huge(). [vbabka@suse.cz: changelog tweak] Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Mike Kravetz <mike.kravetz@oracle.com> Link: http://lkml.kernel.org/r/20200828081031.11306-1-richard.weiyang@linux.alibaba.comSigned-off-by:
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Matthew Wilcox (Oracle) authored
Introduce the new page policy of PF_SECOND which lets us use the normal pageflags generation machinery to create the various DoubleMap manipulation functions. Signed-off-by:
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