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27 commits
Author | SHA1 | Message | Date | |
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7e2fca52ef |
mm/secretmem: use a folio in secretmem_fault()
Saves four implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230812062612.3184990-1-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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b0cc5e89ca |
mm/mlock: rename mlock_future_check() to mlock_future_ok()
It is felt that the name mlock_future_check() is vague - it doesn't particularly convey the function's operation. mlock_future_ok() is a clearer name for a predicate function. Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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3c54a298db |
mm/mmap: refactor mlock_future_check()
In all but one instance, mlock_future_check() is treated as a boolean function despite returning an error code. In one instance, this error code is ignored and replaced with -ENOMEM. This is confusing, and the inversion of true -> failure, false -> success is not warranted. Convert the function to a bool, lightly refactor and return true if the check passes, false if not. Link: https://lkml.kernel.org/r/20230522082412.56685-1-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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b758fe6df5 |
mm/secretmem: make it on by default
Following the discussion about direct map fragmentaion at LSF/MM [1], it appears that direct map fragmentation has a negligible effect on kernel data accesses. Since the only reason that warranted secretmem to be disabled by default was concern about performance regression caused by the direct map fragmentation, it makes perfect sense to lift this restriction and make secretmem enabled. secretmem obeys RLIMIT_MEMBLOCK and as such it is not expected to cause large fragmentation of the direct map or meaningfull increase in page tables allocated during split of the large mappings in the direct map. The secretmem.enable parameter is retained to allow system administrators to disable secretmem at boot. Switch the default setting of secretmem.enable parameter to 1. Link: https://lwn.net/Articles/931406/ [1] Link: https://lkml.kernel.org/r/20230515083400.3563974-1-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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3822a7c409 |
- Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY/PoPQAKCRDdBJ7gKXxA jlvpAPsFECUBBl20qSue2zCYWnHC7Yk4q9ytTkPB/MMDrFEN9wD/SNKEm2UoK6/K DmxHkn0LAitGgJRS/W9w81yrgig9tAQ= =MlGs -----END PGP SIGNATURE----- Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ... |
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1c71222e5f |
mm: replace vma->vm_flags direct modifications with modifier calls
Replace direct modifications to vma->vm_flags with calls to modifier functions to be able to track flag changes and to keep vma locking correctness. [akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo] Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjun Roy <arjunroy@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Oskolkov <posk@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Punit Agrawal <punit.agrawal@bytedance.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Song Liu <songliubraving@fb.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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98001fd63d |
mm/secretmem: remove redundant initiialization of pointer file
The pointer file is being initialized with a value that is never read, it is being re-assigned later on. Clean up code by removing the redundant initialization. Link: https://lkml.kernel.org/r/20230116164332.79500-1-colin.i.king@gmail.com Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foudation.org> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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c1632a0f11
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fs: port ->setattr() to pass mnt_idmap
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
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f7c5b1aab5 |
mm/secretmem: remove reduntant return value
The return value @ret is always 0, so remove it and return 0 directly. Link: https://lkml.kernel.org/r/20220920012205.246217-1-xiujianfeng@huawei.com Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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1ea41595f6 |
mm/secretmem: add __init annotation to secretmem_init()
It's a fs_initcall entry, add __init annotation to it. Link: https://lkml.kernel.org/r/20220915011602.176967-1-xiujianfeng@huawei.com Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Cc: Mike Rapoport <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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4eb5bbde3c |
mm: fix dereferencing possible ERR_PTR
Smatch checker complains that 'secretmem_mnt' dereferencing possible
ERR_PTR(). Let the function return if 'secretmem_mnt' is ERR_PTR, to
avoid deferencing it.
Link: https://lkml.kernel.org/r/20220904074647.GA64291@cloud-MacBookPro
Fixes:
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f00654007f |
Folio changes for 6.0
- Fix an accounting bug that made NR_FILE_DIRTY grow without limit when running xfstests - Convert more of mpage to use folios - Remove add_to_page_cache() and add_to_page_cache_locked() - Convert find_get_pages_range() to filemap_get_folios() - Improvements to the read_cache_page() family of functions - Remove a few unnecessary checks of PageError - Some straightforward filesystem conversions to use folios - Split PageMovable users out from address_space_operations into their own movable_operations - Convert aops->migratepage to aops->migrate_folio - Remove nobh support (Christoph Hellwig) -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEejHryeLBw/spnjHrDpNsjXcpgj4FAmLpViQACgkQDpNsjXcp gj5pBgf/f3+K7Hi3qw7aYQCYJQ7IA/bLyE/DLWI59kuiao6wDSve40B9YH9X++Ha mRLp55bkQS+bwS2xa4jlqrIDJzAfNoWlXaXZHUXGL1C/52ChTF6jaH2cvO9PVlDS 7fLv1hy2LwiIdzpKJkUW7T+kcQGj3QLKqtQ4x8zD0LGMg055yvt/qndHSUi41nWT /58+6W8Sk4vvRgkpeChFzF1lGLy00+FGT8y5V2kM9uRliFQ7XPCwqB2a3e5jbW6z C1NXQmRnopCrnOT1TFIhK3DyX6MDIWV5qcikNAmCKFb9fQFPmjDLPt9iSoMGjw2M Z+UVhJCaU3ISccd0DG5Ra/vzs9/O9Q== =DgUi -----END PGP SIGNATURE----- Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache Pull folio updates from Matthew Wilcox: - Fix an accounting bug that made NR_FILE_DIRTY grow without limit when running xfstests - Convert more of mpage to use folios - Remove add_to_page_cache() and add_to_page_cache_locked() - Convert find_get_pages_range() to filemap_get_folios() - Improvements to the read_cache_page() family of functions - Remove a few unnecessary checks of PageError - Some straightforward filesystem conversions to use folios - Split PageMovable users out from address_space_operations into their own movable_operations - Convert aops->migratepage to aops->migrate_folio - Remove nobh support (Christoph Hellwig) * tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits) fs: remove the NULL get_block case in mpage_writepages fs: don't call ->writepage from __mpage_writepage fs: remove the nobh helpers jfs: stop using the nobh helper ext2: remove nobh support ntfs3: refactor ntfs_writepages mm/folio-compat: Remove migration compatibility functions fs: Remove aops->migratepage() secretmem: Convert to migrate_folio hugetlb: Convert to migrate_folio aio: Convert to migrate_folio f2fs: Convert to filemap_migrate_folio() ubifs: Convert to filemap_migrate_folio() btrfs: Convert btrfs_migratepage to migrate_folio mm/migrate: Add filemap_migrate_folio() mm/migrate: Convert migrate_page() to migrate_folio() nfs: Convert to migrate_folio btrfs: Convert btree_migratepage to migrate_folio mm/migrate: Convert expected_page_refs() to folio_expected_refs() mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio() ... |
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79802ada87 |
selinux/stable-6.0 PR 20220801
-----BEGIN PGP SIGNATURE----- iQJIBAABCAAyFiEES0KozwfymdVUl37v6iDy2pc3iXMFAmLoEeIUHHBhdWxAcGF1 bC1tb29yZS5jb20ACgkQ6iDy2pc3iXNSOhAAwWwRcmcHnk+k2agT9QjKrLo26NCO MQLE89o4y2ChEFHxC7F7SKoQRxtfYa323p1vmlGzKrlB+IZ6oqERVp4QNQQbXsfn n9VvVpxjRNHAetcRhCM9ZOchWjUdw6AMaJ8e3fdRNRESadAUUFDxifw1wpjgG9+i LmtDbfZ7vLs2grTf9OZy3JIl1VF3lVRUTI7ZBQggfJncMa+LXNWdVNmEe3yfyboA 1MwpSao7K2si0hBGAQo/UGQz4b19Tm4xMg8bSy7oTsP5Lae5ciPkeI3qazvs9usp WScZYhQ8NugqLbDbjs7dm6QCpj4x3dUs6ei48LKe3GF2mcGesFfOPo9sNHao4kKv C9t0f9qw+EhGvnNL7uQIDDf8OuTjuLWDvZSrMLID/IJKFF5NJ3y+XzaS9aPM3VEY qyOsX+cEzheXGhD6xE1sCo+AyPUDYqNDMIKBj2wlIGCKlzDGa8RT6VsQuvgf3c3K 43CnRCQeWDWOHCq3MnRe/fmYtW+JB7tsXiKAq4OJADacwPP36bsP3bqU8AlWYwDt tnuMa+LKusHnMEQpMPI8FW8qGdxwGSen+mymfLFIMgtwNGkV7WGRJ6Lbyn0SaR6v HyXgZASIOQRnamK3yZCDpxo0K81IVxPWJIjHyg53znqT5TCpXccPyV4HwbJKI/KG 8PtHrXOdPOGCZ2g= =WWq1 -----END PGP SIGNATURE----- Merge tag 'selinux-pr-20220801' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "A relatively small set of patches for SELinux this time, eight patches in total with really only one significant change. The highlights are: - Add support for proper labeling of memfd_secret anonymous inodes. This will allow LSMs that implement the anonymous inode hooks to apply security policy to memfd_secret() fds. - Various small improvements to memory management: fixed leaks, freed memory when needed, boundary checks. - Hardened the selinux_audit_data struct with __randomize_layout. - A minor documentation tweak to fix a formatting/style issue" * tag 'selinux-pr-20220801' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: selinux_add_opt() callers free memory selinux: Add boundary check in put_entry() selinux: fix memleak in security_read_state_kernel() docs: selinux: add '=' signs to kernel boot options mm: create security context for memfd_secret inodes selinux: fix typos in comments selinux: drop unnecessary NULL check selinux: add __randomize_layout to selinux_audit_data |
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5409548df3 |
secretmem: Convert to migrate_folio
This is little more than changing the types over; there's no real work being done in this function. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> |
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81218f80a7 |
secretmem: Remove isolate_page
The isolate_page operation is never called for filesystems, only for device drivers which call SetPageMovable. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> |
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84ac013046 |
secretmem: fix unhandled fault in truncate
syzkaller reports the following issue: BUG: unable to handle page fault for address: ffff888021f7e005 PGD |
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2bfe15c526 |
mm: create security context for memfd_secret inodes
Create a security context for the inodes created by memfd_secret(2) via the LSM hook inode_init_security_anon to allow a fine grained control. As secret memory areas can affect hibernation and have a global shared limit access control might be desirable. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> |
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6612ed24a2 |
secretmem: Convert to free_folio
Prepare for any size of folio, even though secretmem only uses order-0 folios for now. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> |
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f9b141f936 |
mm/secretmem: fix panic when growing a memfd_secret
When one tries to grow an existing memfd_secret with ftruncate, one gets a panic [1]. For example, doing the following reliably induces the panic: fd = memfd_secret(); ftruncate(fd, 10); ptr = mmap(NULL, 10, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); strcpy(ptr, "123456789"); munmap(ptr, 10); ftruncate(fd, 20); The basic reason for this is, when we grow with ftruncate, we call down into simple_setattr, and then truncate_inode_pages_range, and eventually we try to zero part of the memory. The normal truncation code does this via the direct map (i.e., it calls page_address() and hands that to memset()). For memfd_secret though, we specifically don't map our pages via the direct map (i.e. we call set_direct_map_invalid_noflush() on every fault). So the address returned by page_address() isn't useful, and when we try to memset() with it we panic. This patch avoids the panic by implementing a custom setattr for memfd_secret, which detects resizes specifically (setting the size for the first time works just fine, since there are no existing pages to try to zero), and rejects them with EINVAL. One could argue growing should be supported, but I think that will require a significantly more lengthy change. So, I propose a minimal fix for the benefit of stable kernels, and then perhaps to extend memfd_secret to support growing in a separate patch. [1]: BUG: unable to handle page fault for address: ffffa0a889277028 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD afa01067 P4D afa01067 PUD 83f909067 PMD 83f8bf067 PTE 800ffffef6d88060 Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI CPU: 0 PID: 281 Comm: repro Not tainted 5.17.0-dbg-DEV #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:memset_erms+0x9/0x10 Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 RSP: 0018:ffffb932c09afbf0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffda63c4249dc0 RCX: 0000000000000fd8 RDX: 0000000000000fd8 RSI: 0000000000000000 RDI: ffffa0a889277028 RBP: ffffb932c09afc00 R08: 0000000000001000 R09: ffffa0a889277028 R10: 0000000000020023 R11: 0000000000000000 R12: ffffda63c4249dc0 R13: ffffa0a890d70d98 R14: 0000000000000028 R15: 0000000000000fd8 FS: 00007f7294899580(0000) GS:ffffa0af9bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffa0a889277028 CR3: 0000000107ef6006 CR4: 0000000000370ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? zero_user_segments+0x82/0x190 truncate_inode_partial_folio+0xd4/0x2a0 truncate_inode_pages_range+0x380/0x830 truncate_setsize+0x63/0x80 simple_setattr+0x37/0x60 notify_change+0x3d8/0x4d0 do_sys_ftruncate+0x162/0x1d0 __x64_sys_ftruncate+0x1c/0x20 do_syscall_64+0x44/0xa0 entry_SYSCALL_64_after_hwframe+0x44/0xae Modules linked in: xhci_pci xhci_hcd virtio_net net_failover failover virtio_blk virtio_balloon uhci_hcd ohci_pci ohci_hcd evdev ehci_pci ehci_hcd 9pnet_virtio 9p netfs 9pnet CR2: ffffa0a889277028 [lkp@intel.com: secretmem_iops can be static] Signed-off-by: kernel test robot <lkp@intel.com> [axelrasmussen@google.com: return EINVAL] Link: https://lkml.kernel.org/r/20220324210909.1843814-1-axelrasmussen@google.com Link: https://lkml.kernel.org/r/20220412193023.279320-1-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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46de8b9794 |
fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
This is a mechanical change. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs |
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855d44434f |
mm/secretmem: avoid letting secretmem_users drop to zero
Quoting Dmitry:
"refcount_inc() needs to be done before fd_install(). After
fd_install() finishes, the fd can be used by userspace and
we can have secret data in memory before the refcount_inc().
A straightforward misuse where a user will predict the returned
fd in another thread before the syscall returns and will use it
to store secret data is somewhat dubious because such a user just
shoots themself in the foot.
But a more interesting misuse would be to close the predicted fd
and decrement the refcount before the corresponding refcount_inc,
this way one can briefly drop the refcount to zero while there are
other users of secretmem."
Move fd_install() after refcount_inc().
Link: https://lkml.kernel.org/r/20211021154046.880251-1-keescook@chromium.org
Link: https://lore.kernel.org/lkml/CACT4Y+b1sW6-Hkn8HQYw_SsT7X3tp-CJNh2ci0wG3ZnQz9jjig@mail.gmail.com
Fixes:
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cb68543239 |
secretmem: Prevent secretmem_users from wrapping to zero
Commit |
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87066fdd2e |
Revert "mm/secretmem: use refcount_t instead of atomic_t"
This reverts commit
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110860541f |
mm/secretmem: use refcount_t instead of atomic_t
When a secret memory region is active, memfd_secret disables hibernation. One of the goals is to keep the secret data from being written to persistent-storage. It accomplishes this by maintaining a reference count to `secretmem_users`. Once this reference is held your system can not be hibernated due to the check in `hibernation_available()`. However, because `secretmem_users` is of type `atomic_t`, reference counter overflows are possible. As you can see there's an `atomic_inc` for each `memfd` that is opened in the `memfd_secret` syscall. If a local attacker succeeds to open 2^32 memfd's, the counter will wrap around to 0. This implies that you may hibernate again, even though there are still regions of this secret memory, thereby bypassing the security check. In an attempt to fix this I have used `refcount_t` instead of `atomic_t` which prevents reference counter overflows. Link: https://lkml.kernel.org/r/20210820043339.2151352-1-jordy@pwning.systems Signed-off-by: Jordy Zomer <jordy@pwning.systems> Cc: Kees Cook <keescook@chromium.org>, Cc: Jordy Zomer <jordy@jordyzomer.github.io> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Mike Rapoport <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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af64237461 |
mm/secretmem: wire up ->set_page_dirty
Make secretmem up to date with the changes done in commit |
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9a436f8ff6 |
PM: hibernate: disable when there are active secretmem users
It is unsafe to allow saving of secretmem areas to the hibernation snapshot as they would be visible after the resume and this essentially will defeat the purpose of secret memory mappings. Prevent hibernation whenever there are active secret memory users. Link: https://lkml.kernel.org/r/20210518072034.31572-6-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Bottomley <jejb@linux.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tycho Andersen <tycho@tycho.ws> Cc: Will Deacon <will@kernel.org> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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1507f51255 |
mm: introduce memfd_secret system call to create "secret" memory areas
Introduce "memfd_secret" system call with the ability to create memory
areas visible only in the context of the owning process and not mapped not
only to other processes but in the kernel page tables as well.
The secretmem feature is off by default and the user must explicitly
enable it at the boot time.
Once secretmem is enabled, the user will be able to create a file
descriptor using the memfd_secret() system call. The memory areas created
by mmap() calls from this file descriptor will be unmapped from the kernel
direct map and they will be only mapped in the page table of the processes
that have access to the file descriptor.
Secretmem is designed to provide the following protections:
* Enhanced protection (in conjunction with all the other in-kernel
attack prevention systems) against ROP attacks. Seceretmem makes
"simple" ROP insufficient to perform exfiltration, which increases the
required complexity of the attack. Along with other protections like
the kernel stack size limit and address space layout randomization which
make finding gadgets is really hard, absence of any in-kernel primitive
for accessing secret memory means the one gadget ROP attack can't work.
Since the only way to access secret memory is to reconstruct the missing
mapping entry, the attacker has to recover the physical page and insert
a PTE pointing to it in the kernel and then retrieve the contents. That
takes at least three gadgets which is a level of difficulty beyond most
standard attacks.
* Prevent cross-process secret userspace memory exposures. Once the
secret memory is allocated, the user can't accidentally pass it into the
kernel to be transmitted somewhere. The secreremem pages cannot be
accessed via the direct map and they are disallowed in GUP.
* Harden against exploited kernel flaws. In order to access secretmem,
a kernel-side attack would need to either walk the page tables and
create new ones, or spawn a new privileged uiserspace process to perform
secrets exfiltration using ptrace.
The file descriptor based memory has several advantages over the
"traditional" mm interfaces, such as mlock(), mprotect(), madvise(). File
descriptor approach allows explicit and controlled sharing of the memory
areas, it allows to seal the operations. Besides, file descriptor based
memory paves the way for VMMs to remove the secret memory range from the
userspace hipervisor process, for instance QEMU. Andy Lutomirski says:
"Getting fd-backed memory into a guest will take some possibly major
work in the kernel, but getting vma-backed memory into a guest without
mapping it in the host user address space seems much, much worse."
memfd_secret() is made a dedicated system call rather than an extension to
memfd_create() because it's purpose is to allow the user to create more
secure memory mappings rather than to simply allow file based access to
the memory. Nowadays a new system call cost is negligible while it is way
simpler for userspace to deal with a clear-cut system calls than with a
multiplexer or an overloaded syscall. Moreover, the initial
implementation of memfd_secret() is completely distinct from
memfd_create() so there is no much sense in overloading memfd_create() to
begin with. If there will be a need for code sharing between these
implementation it can be easily achieved without a need to adjust user
visible APIs.
The secret memory remains accessible in the process context using uaccess
primitives, but it is not exposed to the kernel otherwise; secret memory
areas are removed from the direct map and functions in the
follow_page()/get_user_page() family will refuse to return a page that
belongs to the secret memory area.
Once there will be a use case that will require exposing secretmem to the
kernel it will be an opt-in request in the system call flags so that user
would have to decide what data can be exposed to the kernel.
Removing of the pages from the direct map may cause its fragmentation on
architectures that use large pages to map the physical memory which
affects the system performance. However, the original Kconfig text for
CONFIG_DIRECT_GBPAGES said that gigabyte pages in the direct map "... can
improve the kernel's performance a tiny bit ..." (commit
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