arch_bpf_timed_may_goto() gets the offset of count and timestamp in the
stack frame in BPF_REG_AX. Arch code adds the frame pointer to it, and
calls bpf_check_timed_may_goto() with the result. On arm64, riscv,
loongarch, powerpc and s390 the asm function does it. On x86-64 the JIT
does it, because the frame pointer is in another register when the prog has
a private stack.
The next patch moves count and timestamp out of the stack frame. So pass
the pointer in BPF_REG_AX, and let the verifier emit the addition:
before after
r12 = -16 r12 = r10
call arch_bpf_timed_may_goto r12 += -16
call arch_bpf_timed_may_goto
The JITs know which register r10 is. The asm functions have a move in place
of the addition, and the special case in the x86-64 JIT goes away.
These insns run when the count is used up: in each 65535th iteration. The
cost of an iteration does not change.
Three tests have the insns of may_goto in them. Update them.
Tested on x86-64, and on arm64 and s390 in QEMU. riscv, loongarch and
powerpc are compile tested only.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20261031215543.682284-7-alexei.starovoitov@gmail.com
The verifier emits BPF_MOV64_PERCPU_REG to turn the address of a per-cpu variable into the address of the copy of this cpu. s390 keeps the per-cpu offset of the cpu in the lowcore. Add it to the register with one insn, the way the JIT reads cpu_nr and current_task for the helpers that it inlines. With bpf_jit_supports_percpu_insn() the verifier inlines the lookup in per-cpu array and per-cpu hash maps, and resolves the address of a value in a per-cpu array. Patch 7 needs the insn for may_goto. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://patch.msgid.link/20261031215543.682284-6-alexei.starovoitov@gmail.com
With CONFIG_CFI=y, every jited line info entry after a function's
first is cfi_get_offset() bytes too high on x86-64, riscv64 and arm64,
so tools that use it show the wrong source line.
The JITs count the insn_to_jit_off[] offsets from the start of the
image. Since the CFI commits below, prog->bpf_func starts
cfi_get_offset() bytes into the image, and bpf_prog_fill_jited_linfo()
adds the offsets to prog->bpf_func. s390 corrects its offsets before
the call, the other three JITs do not.
Subtract cfi_get_offset() once in bpf_prog_fill_jited_linfo() and drop
the s390 correction. jited_linfo[0] stays prog->bpf_func, the
function's ksym address. Without CONFIG_CFI, cfi_get_offset() is 0 and
nothing changes.
Fixes: 4f9087f16651 ("x86/cfi,bpf: Fix BPF JIT call")
Fixes: e63985ecd226 ("bpf, riscv64/cfi: Support kCFI + BPF on riscv64")
Fixes: 710618c760c0 ("arm64/cfi,bpf: Support kCFI + BPF on arm64")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jose Fernandez (Anthropic) <jose.fernandez@linux.dev>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20261030-b4-arm64-bpf-linfo-cfi-v2-1-4eac83435d4b@linux.dev
Closes: https://lore.kernel.org/all/20260904014748.C04AA1F000E9@smtp.kernel.org/
Closes: https://lore.kernel.org/all/DLNXZ2WK7TPD.2RZBUNRS4FA4L@gmail.com/
Pull more MM updates from Andrew Morton:
- "mm: make VMA flag semantics explicit, eliminate VM_SPECIAL" (Lorenzo
Stoakes):
Replace VM_SPECIAL with helpers describing mapping ownership and
behavior. Enforce the mmap flag rules and convert affected drivers,
removing ambiguous tests shared by driver mappings and ordinary
memory.
- "support kselftest on nommu platform" (Hajime Tazaki):
Add opt-in mmap and mremap tests for NOMMU systems. Teach the runner
to avoid its fork-dependent timeout command and document the build
and runtime requirements.
- "mm/collapse: separate a collapse from its callers" (Kiryl
Shutsemau):
Separate huge-page collapse from caller policy. Replace khugepaged
identity checks with explicit permissions, and separate scanning from
collapse with the mmap_lock drop in one place.
- "mm: implement and use vma_has_anon_rmap(), silence KCSAN" (Lorenzo
Stoakes):
Provide a common helper for testing whether a VMA has anonymous
reverse mappings. Document the locking rules, annotate intentional
concurrent reads for KCSAN, and convert the core MM callers.
- "mm/sparse: remove SECTION_MARKED_PRESENT and further cleanups"
(David Hildenbrand):
Remove SECTION_MARKED_PRESENT in favor of the early-section flag.
Simplify sparse memory initialization, section metadata handling and
related PFN validity checks.
- "sh: remove NUMA and SPARSEMEM support" (Mike Rapoport):
Remove SuperH NUMA and SPARSEMEM support. The extra memory banks have
been unusable since the NO_BOOTMEM conversion, leaving only the code
and data overhead.
- "mm: Unify device DAX and HugeTLB vmemmap population paths" (Muchun
Song):
Unify the generic device DAX and HugeTLB vmemmap population paths and
shared tail-page handling. Remove the duplicate DAX machinery while
retaining the powerpc radix implementation.
- "kselftest: mm: fix some failure of split_huge_page_test" (Yeoreum
Yun):
Fix huge-page split tests racing with khugepaged recollapse. Use
pagemap and page flags instead of VMA-boundary assumptions which fail
when glibc has already enabled THP.
- "memcg: move memcgid refcount to objcg to unpin dying memcgs"
(Bingfang Guo):
Let dying memcgs be freed while swapped-out shmem still holds their
IDs. Move ID references to reparentable objcgs, with the necessary
swap accounting and RCU lifetime changes.
- "mm/truncate: fix data loss when truncating straddling large folios"
(Zhang Yi):
Preserve out-of-range data when truncating straddling large folios.
Fix a lookup race and split-failure handling, and handle minimum
folio orders for the forthcoming ext4 iomap buffered I/O path.
- "mm/damon: introduce damos quota goal target metric complement flag"
(SJ Park):
Let DAMOS quota goals use a metric's complement, so utilization can
also express free-memory goals without adding separate metrics. Add
the sysfs interface, documentation and tests.
- "arm64/mm: Standardize printing for pgtable entries" (Anshuman
Khandual):
Use the generic formatter for arm64 page-table entries, ready for
future wider entries. Move the safe-PTE-update check out of the
header to avoid an include cycle.
- "mm: kmsan: fix iounmap metadata teardown" (Dima Koziuk):
Fix KMSAN metadata leaks on iounmap and failed ioremap allocations.
Free backing pages before removing their mappings, and share the
teardown with partial-allocation cleanup.
- "mm/damon/core: preserve quota state when constructing schemes" (Karl
Mehltretter):
Preserve running DAMOS quota state while validating parameter
updates. Even rejected updates could reset accounting and exceed the
quota window; add tests for both accepted and rejected updates.
- "mm/vmalloc: fix vmalloc_dump_obj VA lookup" (Ye Liu):
Fix vmalloc_dump_obj() lookups for last-page addresses and
allocations spanning vmap zones. These allocations were being missed
in diagnostic output.
- "mm: various (urgent?) fixes" (David Hildenbrand):
Fix mmap charge leaks and hugetlb use-after-free, wrong-address
unmapping, stuck locks and endless faults. Also preserve reservations
on failed mremap and handle stale userfaultfd bits.
- "maple_tree: fix maple_range_64 crashes in RCU mode" (Dimitris
Charisis):
Fix pointer and metadata confusion during RCU destruction of
maple_range_64 nodes, avoiding double frees and invalid accesses. Add
a regression test; no in-tree user currently uses this combination.
- "mm: fix hugetlb NR_HUGETLB accounting on folio migration" (Hongfu
Li):
Fix hugetlb migration and preallocation accounting so /proc/vmstat
retains the correct count and memory.numa_stat follows the folio to
its new node.
- "mm/damon: fix a minor bug, clean code, and add a test" (SJ Park):
Fix 32-bit DAMON age overflow which made old regions look young.
Share hugetlb folio acquisition code and add a regression test for
the previously fixed last-region skipping bug.
- "mm/damon/core: cleanup code, reduce stack usage, and add kunit" (SJ
Park):
Reduce kdamond stack usage and remove unused enums. Add deterministic
PSI quota-goal tests which do not depend on the machine's current
memory pressure.
- "mm/damon: fix the temporal goal tuner's size quota conversion"
(Donggeun Yoo):
Bound the temporal tuner's quota conversion to prevent overflow and
zero effective quotas, which could stop schemes making progress. Add
boundary tests.
- "Don't use GFP_DMA when calling dma_alloc_coherent" (Baoquan He):
Remove redundant GFP_DMA flags from coherent DMA allocation calls.
The DMA API already selects the zone from device limits and ignores
the caller's flag.
- "kselftest: mm: fix intermittent failure khugepaged test" (Yeoreum
Yun):
Propagate child-process failures in the khugepaged tests and prevent
background collapse from racing their checks. This removes false
passes and intermittent failures.
- "MAINTAINERS: cover all hugetlb headers under HUGETLB SUBSYSTEM"
(Enze Li):
Cover all hugetlb headers in MAINTAINERS so get_maintainer.pl finds
the right maintainers. Also label the closing hugetlb_cgroup.h
include guard.
Summary of the 65 singletons in this merge:
The singletons include a few worthwhile performance fixes. Avoiding
unnecessary reverse-map tree updates gave a reported 15.9% improvement
in UnixBench's execl test on a 192-core x86 system. A reclaim retry
fix stops defrag_mode from spinning under memory.low protection; a
reported file-creation stress test ran 5.7 times faster, with far less
memory pressure. Narrower hugetlb invalidations also spare KVM guests
needless refaults: the reported Redis-in-VM P99 QPS penalty while
punching holes fell from 7.09% to 1.45%.
Several fixes prevent lost data or corrupted memory. Lazyfree
huge-page races with mremap()/munmap() could lose data or access freed
memory, and MADV_COLD could lose a concurrent write's dirty bit.
Another fix prevents stale migration entries from outliving large
folios. On filesystems with blocks smaller than a page, extending a
file by 4 GiB or more could expose bytes written past the old EOF
through mmap instead of zeroes. That is fixed, along with
use-after-free races in PAGEMAP_SCAN during process exit and in
memory-cgroup accounting on PREEMPT_RT kernels.
Other fixes stop UFFDIO_MOVE spinning forever on pinned large folios,
which could wedge other memory operations, and stop mremap() leaking
commit charges until allocations fail under strict overcommit. A
further fix keeps userfaultfd tracking intact on neighboring mappings.
NUMA binding no longer prevents long-term pins when the chosen node
has only movable memory, fixing QEMU/VFIO startup and io_uring buffer
registration failures. MGLRU also gets a fix for early-boot crashes
with memory cgroups disabled at boot, notably in small crash kernels.
* tag 'mm-stable-2026-10-25-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (213 commits)
mm: multi-gen LRU: fix NULL lruvec->pgdat deref with memcg disabled on cmdline
mm/page_counter: use WRITE_ONCE() for emin/elow when parent is the root
mm/memcontrol: publish null pointer before dropping css reference
test_maple_tree: test maple_range_64 node in RCU mode
maple_tree: fix maple_range_64 crashes in RCU mode
mm/vma: avoid broken uffd merge on mremap
tools/testing/shared: catch a failed posix_memalign()
mm/damon/core: remove unreachable damos charge_{target,addr}_from
mm/shrinker: allocate shrinker_info_unit from a dedicated kmem_cache
riscv: mm: exclude invalid THP PMDs from page table check
mm/damon/core: filter out damos address filter-split failed region
fs/proc/task_mmu: pin mm_users in do_pagemap_scan()
mm/mempolicy: apply bind policies against the scoped allocation zone
mm/vmscan: reclaim every zone in per-node proactive reclaim
mm/mremap: correctly uncharge accountable VMAs in error path
mm/mremap: populate calculated fields in vrm state correctly
MAINTAINERS: add an entry for MEMORY MANAGEMENT - MEMORY MAP
mm: bdi: reset min_ratio after the sysfs attributes are gone
mm/page_vma_mapped: continue past nonmatching huge PMDs
selftests/mm: skip hugetlb cgroup v2 tests without the needed controllers
...
Pull non-MM updates from Andrew Morton: - "ocfs2: exit recovery thread on mount error path" (Joseph Qi): Stop OCFS2 recovery before freeing failed-mount state and replay slots, closing use-after-free and double-free races. Defer suballocator reclaim to break a transaction-lock deadlock with dismount. - "ocfs2: validate suballoc slot and bit of metadata blocks" (Joseph Qi): Validate OCFS2 metadata suballocator slots, bits and directory index block locations. Reject corrupt metadata with filesystem errors instead of BUGs or out-of-bounds accesses. - "ocfs2: deal with legacy signed name hash values" (Joseph Qi): Restore OCFS2 lookups for non-ASCII names stored with legacy signed hashes. Use stored xattr hashes during bucket splits to avoid duplicate entries and spurious ENOSPC failures. - "ocfs2: stabilize dentry names in file and setattr traces" (Cen Zhang): Snapshot OCFS2 names during file and setattr tracing to prevent rename races using freed storage or mismatched names and lengths. Preserve trace formats and the locked release open-count sample. - "panic: fix panic_force_cpu= redirect races and NMI bypass" (Bradley Morgan): Fix panic_force_cpu races and NMI redirection so crash-kernel CPU selection is honored. Preserve variable arguments on failed redirects and use a static message buffer. - "fat: allocate multiple clusters in fallocate" (Matheus Alves de Almeida): Allocate FAT clusters in batches for FALLOC_FL_KEEP_SIZE and batch FAT updates. This removes repeated single-cluster allocation overhead, particularly on synchronous mounts. - "scripts/gdb: fix radix tree lookup and stack depot diagnostic" (Ting-Han Hou): Fix GDB radix-tree lookup and its handling of XArray sibling, retry and zero entries. Also repair the stack-depot diagnostic for an out-of-range pool index. - "hung_task: Improve warning budget handling and task reporting" (Aaron Tomlin): Reset the hung-task warning budget after recovery so later hangs remain visible. Keep the configured limit intact and emit one summary per scan when detailed reports exhaust the budget. - "bootconfig: Reject unexpected data after null character and cleanups" (Masami Hiramatsu): Reject bootconfig data after an embedded null while accepting trailing padding. Validate the full input in the userspace tool, and retain internal tree sanity checks there rather than in the kernel. - "kbuild: GCOV cleanups following the prefer-atomic fix" (Konstantin Khorenko): Use the actual GCOV build flags in the prefer-atomic compiler probe. Move flag setup into scripts/Makefile.gcov and skip the probe when GCOV is disabled. - "ocfs2: xattr bucket validation fixes" (Joseph Qi): Accept valid OCFS2 xattr buckets spanning 512-byte blocks, avoiding false read-only remounts. Reject misaligned buckets and return errors instead of panicking on corrupt defrag metadata. - "ocfs2: fix metadata reservation for xattr value trees" (Joseph Qi): Reserve enough OCFS2 metadata for new and relocated xattr value trees. Fix shortfalls which could cause ENOSPC, dropped entries and leaked clusters on fragmented filesystems; remove duplicate reservations. - "Introduce arch_do_panic" (Mete Durlu): Add arch_do_panic() and move s390 and sparc handling out of generic panic code. The architecture-specific actions now follow the end-of-panic marker. - "checkpatch: userspace improvements" (Petr Vorel): Improve checkpatch's userspace detection and suppress kernel-only checks. Recognize standard inttypes macros and add explicit --userspace and --no-userspace overrides. - "ocfs2: validate dr_fs_generation of dir index root blocks" (Joseph Qi): Check OCFS2 directory index generations and leaf block numbers. Reject stale or misplaced blocks instead of using metadata left by a previously formatted filesystem. - "selftests/membarrier: Skip an unregistered memory barrier test on Musl" (Chris Gellermann): Skip the unregistered membarrier test when libc has already registered the command. Musl does this during thread creation, causing false failures in the multithreaded test. - "init: fix array boundary bugs in boot parameter parsing" (Wilson Felipe Pereira): Fix boot argument boundary cases which leave stale arguments in init's command line or panic when replacing the final environment variable. Clear the last slot and check duplicates before the limit. Summary of the 87 singletons in this merge: The OCFS2 singletons fix deadlocks between xattr updates and inline truncation, and during inode reclaim. Corrupt quota and extent metadata could also crash the kernel or corrupt memory; these paths now check the layout before using it. Other fixes close use-after-free and publication races around cluster reconfiguration, node failure, quota remount errors and shared refcount trees. New files now retain security labels from all stacked LSMs instead of silently dropping all but one. Valid xattr insertions also stop tripping FORTIFY on builds with counted arrays. Elsewhere, a lost wakeup could leave hardware-monitoring reads stuck in unkillable sleep and block further I2C traffic. That is fixed, as are kernel memory leaks in POSIX message-queue notifications and tmpfs casefold setup which could grow until memory is exhausted. A driver removal race which could crash the kernel is fixed too. The hibernation command through reboot() also stops taking the same mutex twice, avoiding a deadlock before suspension. On the boot side, bzip2 decoding now accepts valid full blocks emitted by lbzip2, fixing failures to boot those compressed kernels. Malformed bzip2 streams can no longer overflow the decode buffer, and LZ4 initrds are checked before the decoder can read past their end. FAT rejects geometry which overflows the data-area calculation on 32-bit systems, and rolls back entries when inode setup fails, preventing failed creations from reappearing after remount. The x86 XOR and RAID6 AVX paths also avoid imposing a slowdown on subsequent SSE code. * tag 'mm-nonmm-stable-2026-10-25-14-57' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (134 commits) scripts/gdb: fix stack depot out-of-bounds diagnostic scripts/gdb: fix radix tree lookup pointer handling ocfs2/cluster: remove zero-address nodes from IP tree on teardown ocfs2: snapshot the dentry name while tracing file release ocfs2: snapshot dentry names in file and setattr traces ocfs2/dlm: drain join handlers before releasing module text MAINTAINERS: update Markus's e-mail address mailmap: add entries for Andrew Jones stackdepot: stop preallocating after the final pool ocfs2: drain quorum work before removing the cluster watchdog: force console verbose when reporting lockups profiling: fix sampling step on 64-bit big-endian systems kernel/reboot: avoid potential deadlocks during suspension compat: avoid double rounding in times() ocfs2: pin owning modules for open debugfs files ocfs2/cluster: initialize heartbeat regions before publishing them selftests/proc: proc-pid-vm: fix unused variable warning on non-x86 ocfs2: pin refcount trees before dropping the lookup lock ocfs2: validate the xattr tree root of an indexed xattr block ocfs2/dlm: hold the lookup reference across convert AST enqueue ...
The is_vm_hugetlb_page() predicate is badly named - the mapping can span more than a page and it is inconsistent with other VMA predicates that typically are prefixed by vma_. Rename to vma_is_hugetlb() for consistency, and while we're here update some VM_BUG_ON_VMA() to VM_WARN_ON_ONCE_VMA() as to avoid unnecessary oopses. No functional change intended. Link: https://lore.kernel.org/20261013-b4-mmap-prepare-vma-flag-sanify-v6-28-1aa3c9b139f9@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Anup Patel <anup@brainfault.org> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Leon Romanovsky <leon@kernel.org> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Nico Pache <nico.pache@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Usama Arif <usama.arif@linux.dev> Cc: Kiryl Shutsemau <kas@kernel.org> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: James Bottomley <james.bottomley@hansenpartnership.com> Cc: Martin K. Petersen <mkp@kernel.org> Cc: Simona Vetter <simona@ffwll.ch> Cc: Helge Deller <deller@gmx.de> Cc: Sebastian Reichel <sre@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Rik van Riel <riel@surriel.com> Cc: Harry Yoo <harry@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Jan Kara <jack@suse.cz> Cc: Oliver Upton <oupton@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Chris Li <chrisl@kernel.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Youngjun Park <youngjun.park@lge.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Qi Zheng <qi.zheng@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Wei Xu <weixugc@google.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Michal Hocko <mhocko@kernel.org> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Xu Xin <xu.xin@linux.dev> Cc: Ihor Solodrai <ihor.solodrai@linux.dev> Cc: Bert Karwatzki <spasswolf@web.de>
Verification that the kernel does not have writable + executable mappings is about detecting security risks rather than a pure debug feature. Major distribution configurations enable it in their kernels as well as defconfigs of most architectures that have ARCH_HAS_DEBUG_WX. Rename relevant generic configuration options to use CHECK_WX and move their definitions from mm/Kconfig.debug to mm/Kconfig. Rename *debug_checkwx() funcitons and macros to *pgtable_checkwx(). For arm that does not widely enable it, only rename its variants of the config options. Enabling CHECK_WX adds a few kilobytes to the kernel binary and while the added size can be slightly reduced with churny updates of architecture implementations of ptdump, the core functionality takes most of the added size. It cannot be moved to .init.text because the verification has to happen after init sections are freed. With this, make generic CHECK_WX default to STRICT_KERNEL_RWX while still leaving users targeting small kernels the possibility to opt-out. Link: https://lore.kernel.org/20260926-direct-map-verify-wx-v2-1-efcd64a6b74a@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Suggested-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <chleroy@kernel.org> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@kernel.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Will Deacon <will@kernel.org>
Pull KVM updates from Paolo Bonzini:
"ARM:
- pKVM state isolation: years after pKVM started being enabled
upstream, we finally get the basics in the form of state isolation.
The vcpu state is now off-limit for the host for protected VMs
- pKVM also grows a hypervisor-private memory allocator, allowing it
to deal with sub-page allocation, much like everywhere else
- pKVM also lands a trace_printk() equivalent, which hopefully will
make debugging a bit easier
- First shot at annotating portions of the KVM/arm64 code to be
extracted and built on s390. The real fun is yet to come
- Allow pre-faulting of stage-2 canonical mappings from userspace,
joining x86 and s390 in implementing this feature
- Add a reverse mapping infrastructure for shadow stage-2,
significantly improving performance when MMU notifiers kick in, and
avoiding full unmap of all shadow tables for this VM
- Next step of GICv5 enablement, adding support for the IRS block,
and providing both SPI and LPI support. This is the first point
where KVM/arm64 can support an SMP GICv5 guest
- As a preliminary to eventually enabling CCA, add a bunch of
infrastructure to KVM/arm64, splitting some of the basic operations
into individual backends (normal VM, normal pKVM VM, protected pKVM
VM). This allows CCA to later slot in without polluting the rest of
KVM with its firmware-driven nonsense
- Make ID registers immutable from the point where a vcpu is able to
run, even if it fails to run. This prevents KVM from sampling
untrusted values
- Restore some type checking to the EL2 object. KVM/arm64 originally
had some strong type checking between the kernel and the EL2
object, but lost it along the way when the private hypercall
interface was (somewhat pointlessly) converted to SMCCC. Type
checking is back, syscall style, and with added sparse goodies
- Expand the FFA support to FFA_NOTIFICATION_*, and add some
sanitisation of the protocol that pKVM relays to the "trusted"
runtime
- Make GICv3 RD assignment more robust to userspace nonsense
- Convert the remaining MMU fault handler backends to
kvm_s2_fault_vma_info and co., fixing a number of bugs in the
process
- Fix the SError/SEA selftests to be both more robust and less
braindead
- Fix a smattering of documentation bugs, some of them as a result of
our AI friends spitting out credible assertions based on
non-existing symbols
- The usual collection of low impact bug fixes (SMCCC, timers, PMU)
Loongarch:
- Add separate vmid support
- Simplify MSI interrupt injection
- Add crash hypercall support
- Allow to set pv_feature until vCPU run
- Enable HW page table walk automatically in selftests
s390:
- rework page allocation for secure guest variable storage
- Selftests and documentation improvements
- Replace get_zeroed_page with kzalloc
- Fix corner cases of floating interrupt injection
- Initial arm64 on s390 support
x86:
- Clean up the handling of vcpu->arch.xen.long_mode to be consistent
and correctly handle 32-bit/64-bit alignment, and various other bug
fixes have accumulated over the months since v1
- Grab KVM's SRCU "lock" in kvm_zap_gfn_range() to fix a recurring
bug where callers fail to do so
- Fix a variety of issues in the pre-fault code that are mostly
benign in the current code base, but will show up in big ways
if/when the pre-faulting logic is used to implementing
prefetch-on-fault for the TDP MMU
- For PREEMPT_RT=y kernels, drop the rmaps' individual bit-spinlock
and just walk the rmaps' with mmu_lock taken. On the write side
(which always uses mmu_lock), the bit-spinlock was assuming that
preemption was disabled, but that is *not* true when rwlocks become
sleepable
- Prepare a memory_fault exit (paired with -EFAULT) when KVM hits an
error PFN, e.g. so that userspace can resolve transient issues
instead of killing the guest. Convert a variety of WARN()+EFAULT
paths into KVM_BUG_ON()+EIO so that KVM can hard commit to filling
memory_fault on -EFAULTs that occur in the page fault path
- Fix a NX hugepage un-accounting bug where KVM would always uncharge
the shadow MMU, even when handling TDP MMU pages
- Mask off the address space ID when checking for illegal usage of
kvm_set_internal_memslot() to prevent false negatives on the sanity
check
- Explicitly zero reserved flags when delivering a SynIC message to
avoid leaking a byte of stack information to the guest
- Rework TDX's handling of the canonical MMU root level to not rely
on userspace to fill CPUID correctly, as doing so lets userspace
trivially trigger a KVM_BUG_ON()
- Reject KVM_SET_NESTED_STATE if userspace "restores" L1 with
EFER.LMA=1 && EFER.LME=0, which confuses KVM into trying to
configure an 64-bit MMU without PAE
- Ignore EFER.LMA (clear it from KVM's cached save state) if
EFER.LME=0 when preparing L2 state, to fix another way to confuse
KVM's MMU (and because real hardware also ignores EFER.LMA)
- Improve KVM's sanity checks for a misconfigured MMU to (hopefully)
detect all of the ways KVM can botch EFER.LMA vs. CR4.PAE
- Remove the "full" out-param from kvm_x86_ops.flush_tlb_gva() as the
param is only used to avoid what effectively amounts to a single
memory write
- Fix a mostly-benign bug where KVM can write through a guest's
read-only mapping due to not checking the error code when
expediting emulated MMIO page faults
- Honor the guest's view of the "EFER.LMSLE must be zero" defeature
so that userspace can provide migration compatibility between Rome
and Milan+
- Pend a KVM_REQ_EVENT request when an exception is morphed into a
nested VM-Exit, otherwise KVM can fail to actually deliver the
nested VM-Exit, e.g. when injecting a page fault
- Add support for PML on SVM
- Add support for virtualizing Bus Lock Detect on SVM, and fix a
number of DR6 bugs and warts along the way
- Fix a variety of warts in KVM's handling of guest TSC, kvmclock,
and timekeeping in general, as a (big) first step towards
addressing several longstanding problems with the kvmclock
implementation. Most notably, fix a precision issue where
get_kvmclock_ns() computed the clock from the *host* TSC without
applying guest TSC scaling, causing systemic drift from the values
the guest computes from its own TSC
- Rip out KVM's shadow timekeeping structures, now that ktime
snapshots are powerful enough to replace it
- Misc fixes and cleanups
x86 (AMD):
- Fix a benign-in-practice bug where KVM unintentionally sets a
non-zero error code when delivering exceptions to SEV-ES+ guests
- Force a new ASID in both VMCBs on pCPU migration to fix a bug where
KVM can run a VMCB with a stale ASID due to the tracking being
per-CPU, not per-VMCB
- Return INVALID_INPUT to the guest instead of exiting to userspace
with -EIO if KVM can't access "guest request" buffer, i.e. try to
keep the guest alive if the guest or userspace goofs
x86 (Intel):
- Enable Notify VM-Exits (now called Instruction Timeout in the SDM)
and Bus Lock VM-Exits for TDX guests when they're enabled by
userspace (KVM forgot to wire up the TDX Module knobs)
- Move all common (between VMX and TDX) APIs/helpers to
common.h/main.c, and change all namespace prefixes from "vmx" to
"vt"
- Fix a thankfully benign bug (due to other areas of KVM being
hardened) where userspace can bypass INIT_MEM_REGION's address wrap
check by providing a nr_pages that will overflow a u64 when
converted to bytes, and fix an also- benign off-by-one bug in the
check (inclusive vs. exclusive)
- Set the vmcs.GUEST_ACTIVITY_STATE back to ACTIVE when userspace
sets KVM's mp_state to anything other than HALTED, e.g. so that a
vCPU doesn't get stuck in HLT if userspace emulates RESET
guest_memfd:
- Take the invalidate lock when unbinding a dying file to fix a race
with kvm_gmem_invalidate_end() that results in KVM leaving the MMU
invalidation count elevated. Not taking the lock in the first place
was pure misguided paranoid
- When binding a memslot, purge the bindings if storing the new
memslot fails, as Xarray's "store range" API can subtly fail
partway through
- Establish memslot<=>guest_memfd bindings *after* the memslot is
ready, as the memslot becomes reachable the instant the binding is
installed
- Don't grab a page refcount when reloading an SNP VMSA and stop
returning a "struct page" from guest_memfd's PFN lookup altogether,
to ensure that KVM doesn't hold any unnecessary refcounts (the
lifetime of the page is ensured by MMU notifiers and similar
hooks). Preventing unnecessary refcounts greatly simplifies
supporting in-place SHARED=>PRIVATE conversions
- Add support for in-place PRIVATE<=>SHARED conversion, i.e. allow a
single guest_memfd instance to be used for both PRIVATE and SHARED
variations of CoCo guests' memory (though not at the same time).
This eliminates the need to double allocate guest memory for TDX
and SNP, and is basically a hard requirement for pKVM, which relies
on being able to preserve memory contents on conversions
- Hack-a-fix a deadlock bug in ->error_remove_folio() by returning
-EBUSY if the filemap invalidate lock is contended. Punt on a
proper fix for the moment, as a proper fix likely involves
reworking truncate_error_folio()
- Add a pile of selftests for in-place conversions
- Misc guest_memfd cleanups
Generic:
- Move some configuration items to preprocessor symbols, to help with
arm-on-s390's need to compile the same code twice with different
values
- Allow KVM implementations to choose alternative device names, also
for s390's support of ARM virtualmachines
- Switch the KVM-VFIO interface and external consumers over to
standard file-based reference counting, eliminating all external
KVM symbol exports
Selftests:
- Rework KVM selftest's handling of memory regions all so that PPC
can force its page table allocations to be naturally aligned
- PPC support
- Fix emulation of VMPTRST and VMPTRLD when eVMCS is in-use to match
real Hyper-V's behavior
- Saturate L2's TSC frequency if stacking L1 and L2 scaling
multipliers exceeds what hardware supports, as attempting to run L2
with an illegal multiplier will either cause VM-Entry to fail (VMX)
or trigger a #GP when writing MSR_AMD64_TSC_RATIO (SVM). The #GP is
thankfully benign in the grand scheme as even "unsafe" WRMSRs have
exception fixup
- Rework KVM selftest's handling of memory regions so that PPC can
force its page table allocations to be naturally aligned
- Clean up selftest's VMX instruction helpers, and drop an absurd
number of completely useless return values, e.g. functions that
unconditionally return %true and then have every caller assert
success
- Add selftests support for Zhaoxin CPUs
- Overhaul the TSC scaling test to add a regression test for the
saturation behavior, and to increase its coverage in general
- Fix selftests usage various NUMA syscalls to account for an
undocumented, but known since 2007, off-by-one kernel bug. Add
helpers to try and avoid re-introducing the same flaws in the
future
- Automatically run xAPIC IPI migration test (between NUMA nodes)
when possible, as the entire point of the test is verify KVM's
handling of page migration of the APIC backing page
- Misc cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (506 commits)
KVM: always make in-place conversion a compile-time constant when possible
KVM: x86: leave the legacy private attribute in for TDX and SEV
KVM: split CONFIG_KVM_PRIVATE_MEMATTR_VM out of KVM_VM_MEMORY_ATTRIBUTES
selftests: kvm: remove useless comma operator
arm64: Use proper include variant
MAINTAINERS: Add entry for ARM on s390 KVM
KVM: s390: arm64: Integrate arm on s390
KVM: s390: arm64: Implement basic page fault handler
KVM: s390: arm64: Implement vCPU IOCTLs
KVM: s390: arm64: Implement vm/vcpu create destroy
KVM: s390: arm64: Implement required functions
KVM: s390: Add basic arm64 kvm module
s390/hwcaps: Report SAE support as hwcap
KVM: s390: arm64: Introduce host definitions
s390: Introduce Start Arm Execution instruction
KVM: s390: Use arm64 code
s390/tools: Use arm64 headers
KVM: s390: Use dedicated function for migration mode
s390/Kconfig: remove PCI dependency from HAS_IOMEM
KVM: s390: Kick PV cpus at the right time for service irqs
...
Pull bpf updates from Alexei Starovoitov:
"Major changes:
- Introduce scalar evolution (SCEV) analysis in the verifier.
It infers how registers and stack slots change in a loop and lets
the verifier check bounded loops with induction variables as ranges
instead of walking every iteration. The number of processed insns
drops ten fold in programs with loops (Eduard Zingerman)
- Add 'callx' instruction: indirect call of a static BPF subprogram.
The address is taken with ld_imm64 or loaded from read-only data.
Supported by x86-64, arm64 and riscv64 JITs (Alexei Starovoitov, Pu
Lehui)
- Add unwind_goto and unwind_exit instructions, so that Rust panic or
C++ exception can run destructors of every frame it passes through.
The normal path is free of unwind code. Supported by x86-64 and
arm64 JITs (Alexei Starovoitov)
- Support programs compiled by rust-bpf: treat load and store through
a number as arena access with BPF_F_ARENA_SCALAR, accept rust names
in BTF (Alexei Starovoitov)
- Raise BPF program stack size from 512 bytes to 2 KiB on x86-64 and
arm64 (Kumar Kartikeya Dwivedi)
- Support struct, union and __int128 up to 16 bytes passed and
returned by value in BPF subprograms and kfuncs, and fix x86-64 and
arm64 trampolines for such arguments (Yonghong Song)
- Introduce a common way to attach struct_ops to a cgroup via
bpf_link. bpf_tcp_ops is the first user and mirrors TCP sock_ops
callbacks (Martin KaFai Lau, Amery Hung)
- Describe inlined functions in BTF. New kinds tell where the inline
sites are and how to fetch the arguments there.
CONFIG_DEBUG_INFO_BTF_INLINE keeps it apart from the main BTF in
.BTF.inline section or in btf_vmlinux_inline.ko (Alan Maguire)
- Fix many memory safety, lifetime and locking bugs in BPF core,
verifier, iterators, local storage, dynptr, devmap, cpumap and
seg6local (Josef Bacik, Alexei Starovoitov)
- Diff stat is dominated by selftests and by removal of
lib/test_bpf.c. Its 16k lines of instruction tests were converted
to BPF selftests that BPF CI runs on every architecture it covers
(Daniel Borkmann)
Other features and fixes:
- Add KASAN checks to memory accesses of JITed programs on x86-64
(Alexis Lothoré)
- Complete unification of helper, kfunc and subprog argument checks
in the verifier (Amery Hung)
- Add bpf_copy_from_user_mm[_str]() kfuncs (Anastasios Papagiannis)
- Various features and fixes (Daniel Borkmann):
- Add .bpf keyring for program signature verification, modelled
after dm-verity keyring, and support ML-DSA in signing tools
- Emit shorter and faster code in x86-64 JIT for patterns that
LLVM generates
- Fix various issues in gotox handling
- Let BPF LSM set xattrs at inode creation with bpf_inode_init_xattr()
(David Windsor, Daniel Borkmann)
- Use sleepable page allocation in sleepable arena paths. Fix races
between arena free, allocation and user page fault (Emil Tsalapatis)
- Switch BPF crypto from lskcipher to AES-CBC and AES-ECB libraries
(Eric Biggers)
- Add bpf_proactive_reclaim() kfunc (Hui Zhu)
- Render decl_tags in libbpf btf_dump and add tests for bpftool C
dump (Ihor Solodrai)
- Speed up tracing_multi attach on x86 (Jiri Olsa)
- Various features and fixes (Kumar Kartikeya Dwivedi):
- Add BPF_PROG_STREAM_OPEN command to read BPF streams through a
file descriptor with poll support
- Let kernel structs publish arena pointers with __arena type tag
- Fix __uninit kfunc output buffers and fastcall rewrite with
indirect stack accesses
- Refuse CO-RE relocations for signed programs
- Add enqueue_rcvq and dequeue_rcvq hooks to bpf_tcp_ops to adjust
sk_rcvlowat and avoid unnecessary wakeups (Kuniyuki Iwashima)
- Add bpf_ksock_sendto() kfunc and allow ksock connect and send from
bpf_wq (Mahe Tardy)
- Fix racy plt target update in arm64 bpf_arch_text_poke()
(Matthew Wood)
- Restructure BPF selftests Makefile as a layered build
(Mykola Lysenko)
- Speed up hash map lookups for u32 and u64 keys (Mykyta Yatsenko)
- Add signed div/mod, movsx, bswap and gotol to MIPS JITs, signed
div/mod to parisc JITs (Nicholas Dudar, Johan Almbladh)
- Fix stack overflow in build ID parser on 32-bit (Nickolai
Zeldovich)
- Add stack arguments, signed arena loads and gotox to riscv64 JIT.
Pu Lehui is now co-maintainer of riscv BPF JITs (Pu Lehui, Chen
Pei, Feng Jiang)
- Add bpf_call_rcu() and bpf_call_rcu_tasks_trace() kfuncs. Support
fetching and/or/xor atomics in arena on x86-64 (Puranjay Mohan)
- Fix flaky selftests, selftests with clang 23 and bpf-gcc
(Qiliang Yuan, KaFai Wan, Vineet Gupta)
- Fix builds broken by fatal resolve_btfids warnings, BTF generation
on ARC, and define arch_cmpxchg_local() on arc, hexagon and
openrisc (Sasha Levin)
- Reduce memory use of hash maps by up to 50% per element
(T.J. Mercier)
- Mark pointer fields of sched_ext ops arguments as trusted (Tejun
Heo)
- Remove legacy bpf_asm, bpf_dbg and bpf_jit_disasm tools (Xia Yan)
- Fix index overflow in queue and stack maps, arena range tree after
allocation failure, tail call loop after freplace detach, lost
signal in bpf_send_signal() (Yuan Chen)
- Many more fixes and cleanups"
* tag 'bpf-next-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (660 commits)
selftests/bpf: Time tc_edt from its first packet with data
selftests/bpf: Test unwind_exit of an exception callback
selftests/bpf: Tests for 32-bit scalar evolution bounds computation
bpf: Reject unwind_goto and unwind_exit in offloaded progs
bpf: Support 32-bit linear scalar evolution
bpf: Make unwind_exit of an exception callback exit in JITs
selftests/bpf: Test forbidden bpf_ksock_sendto() LSM attach
selftests/bpf: Test ksock sendto()
bpf: Add bpf_ksock_sendto() kfunc
selftests/bpf: Test unwinding from R0: R2 subprog
selftests/bpf: Add a C++ prog with exceptions
selftests/bpf: Add tests for unwind_goto and unwind_exit
bpf, arm64: Support unwind_goto and unwind_exit
bpf, x86: Support unwind_goto and unwind_exit
bpf: Add unwind_goto and unwind_exit insns
tools/bpf: Remove legacy BPF tools
bpf: Annotate data races on bpf_lru_node type
selftests/bpf: Add arena allocation race tests
bpf: Fix arena race between page free and alloc leading to incoherency
bpf: Revalidate faulted arena pages before installing user mappings
...
Pull MM updates from Andrew Morton:
- "selftests/mm: improve khugepaged coverage" (Kiryl Shutsemau):
Give khugepaged a proper workout. Extend the tests to all supported
mTHP orders, check exactly which windows collapsed, and make scan
completion deterministic. Race collapse against faults, pinning, fork
and remap; verify that the contents survive.
Add coverage for whole-page-table zaps and memory pressure too.
- "selftests/mm: separate GUP microbenchmarking from functional testing"
(Sarthak Sharma):
Untangle GUP benchmarking from correctness testing. Move the
benchmark into tools/mm, add a standalone harness-based GUP selftest,
and move shared helpers into tools/lib/mm. Give each tool one job
instead of mixing timing measurements with correctness checks.
Cover the mapping, pinning and batch-size combinations explicitly.
- "mm: Switch device DAX to section-based vmemmap optimization" (Muchun
Song):
Apply section-based vmemmap optimization to device DAX. Rework the
backing metadata layout to save memory while preserving the handling
of device memory hotplug and its different alignment and lifetime
requirements.
- "mm: Introduce section-based vmemmap optimization for HugeTLB"
(Muchun Song):
Cut the memory consumed by HugeTLB's struct page array with
section-based vmemmap optimization. Arrange the metadata so large
huge pages need fewer backing pages, while keeping initialization,
teardown and the various hugepage configurations straight.
- "mm/huge_memory: clean up and decouple the anon and file split
helpers" (Kairui Song):
Separate anonymous and file-backed folio splitting, which have rather
different locking and bookkeeping requirements. Move the work into
separate helpers, drop dead checks and tidy swap-cache handling. Fix
error paths, including one that could leave a folio frozen.
Keep the swap cache cases separate from file-cache splitting.
- "mm: Unconditional per-VMA locks and cleanups" (Dave Hansen):
Make per-VMA locking unconditional and clean up the old conditional
code around it. This removes configuration-dependent plumbing and
lets callers depend on one locking model rather than carrying both
cases along.
- "memcg: remove the v1 soft limit" (Shakeel Butt):
Remove the old cgroup v1 memory soft-limit machinery. This has long
since been superseded by the newer memory-control interfaces; hauling
around a separate reclaim scheme for it no longer buys us much.
- "read proc/pid/smaps_rollup under per-vma lock" (Suren Baghdasaryan):
Read /proc/PID/smaps_rollup using per-VMA locks where possible,
rather than holding mmap_lock across the entire walk. Retain the
contention fallback and add tearing tests. This considerably reduces
latency when another thread is busy changing its mappings.
- "mm/damon: introduce data access-as-a-data attribute" (SJ Park):
Teach DAMON to expose memory access observations as data attributes,
making them available to the probe and filtering machinery. Extend
the interfaces, documentation and tests so the new information can be
used rather than merely collected.
- "Remove PG_private by using page/folio->private checks instead" (Zi
Yan):
Get rid of PG_private and use the folio's private pointer to say
whether private data is attached. Convert the filesystem users,
including erofs, f2fs and md, and clean up the old accessors and
flags. There are a few special cases, notably swapcache and hugetlb,
which need explicit care.
- "mm: make userland page table freeing RCU-safe" (Lorenzo Stoakes):
Make freeing userspace page tables safe against RCU readers. Sort out
the page-table lifetime and locking rules so walkers cannot stumble
over freed tables while mappings are being torn down.
- "make unused huge shrinker memcg aware" (Qi Zheng):
Make shmem's unused-huge-folio shrinker aware of memory cgroups, so
reclaim can find those folios under the right memcg. Wire up the
per-memcg tracking and its lifetime rules, and give the shrinklist
its own lockdep class to avoid spurious dependency reports.
- "mm: Drop pxd_ERROR()" (Anshuman Khandual):
Remove the old pxd_ERROR() page-table checks and their
architecture-specific baggage. Simplify the common page-table
interfaces and callers now that these checks no longer serve a
useful purpose.
- "memcg: group struct fields by access pattern" (Shakeel Butt):
Rearrange memcg's hot and cold fields according to how they're
actually accessed. Keep frequently updated counters and their
neighboring state from fighting over cachelines and reduce needless
cacheline traffic.
- "mm/damon/core: fix the size charged for a filter-trimmed region"
(Donggeun Yoo):
Fix DAMOS quota accounting when a filter trims a monitoring region.
Charge only the part left after filtering, not the original region,
and add KUnit coverage. Previously the excluded memory could eat into
the quota and make schemes run more slowly than requested.
- "mm/damon: add kunit and selftests for probes and probe weights" (SJ
Park):
Add more tests for DAMON probes and their weights, including
validation and the results reported to userspace. This is mostly
about catching regressions in the newer probe infrastructure before
they become harder to diagnose.
- "mm: memcontrol: constify the read side of the read side of the memcg
API" (Tal Zussman):
Mark the read-only parts of the memcg interface const, from folio and
lruvec accessors to counters and swap helpers. Most of this is
mechanical, but it makes the contracts clearer and lets the compiler
catch accidental writes.
- "mm/damon/vaddr: support {prep,apply}_probes" (SJ Park):
Support the new prepare/apply probe operations in DAMON's
virtual-address backend. This brings vaddr monitoring into line with
the probe infrastructure and makes the added probe types useful there
too.
- "mm/mglru: clean up folio counters and flag usage" (Kairui Song):
Simplify MGLRU's folio counters and flag handling. Remove redundant
accounting paths and make the state transitions easier to follow
without changing the intended reclaim policy.
- "arch, mm/execmem: resolve confusion about set_direct_map_valid_noflush()"
(Mike Rapoport (Microsoft)):
Clarify and straighten out the set_direct_map_valid_noflush()
interface across architectures and execmem. Make the requested
mapping changes and the callers' expectations agree, rather than
relying on subtly different architecture behavior.
- "mm: zswap: free cold writeback folios promptly" (Alexandre Ghiti):
Free zswap writeback folios as soon as their disk write completes.
They are cold temporary buffers, so putting them on the LRU only
makes reclaim rediscover them later. Extend swap-cache dropbehind and
let zswap keep these folios off the LRU altogether.
- "mm: gup: cleanup gup_fast call chain" (Aristeu Rozanski):
Clean up the GUP-fast call chain and simplify how the fast-path
helpers pass their arguments and results around. Keep the page-pin
behavior the same while making the call sequence easier to maintain.
- "mm: optimize zone-device memmap initialization" (Li Zhe):
Speed up initialization of zone-device struct pages. Avoid redundant
work when setting up large device-memory ranges, where touching every
descriptor can get expensive.
- "mm/zswap: shrink zswap_entry via a pool id" (Jianyue Wu):
Reduce the size of zswap_entry by storing a compact pool identifier
instead of a full pointer. Keep the pool lookup and lifetime handling
correct while saving per-entry metadata.
- "mm/damon: support access monitoring of hugetlb-backed memory"
(Krishna Iyer):
Let DAMON monitor hugetlb-backed memory too. Extend the relevant
access checks and add coverage so those mappings no longer fall
through a hole in the monitoring machinery.
- "mm/execmem: fixes and cleanups for the ROX cache" (Mike Rapoport):
Tidy execmem's read-only-executable cache and fix its handling of the
awkward allocation and release cases. The aim is to make the cache's
ownership and permission transitions more predictable.
- "zsmallc: remove old object read API" (Sergey Senozhatsky):
Drop zsmalloc's old object-read API and move its remaining users to
the supported access mechanism. This removes a duplicate interface
which we no longer need.
- "mm/mempolicy: stop copying state in the interleave paths" (Gregory
Price):
Stop copying mempolicy state in the interleave paths when a reference
to the existing policy will do. This avoids extra work and makes the
ownership rules less obscure.
- "mm/mglru: speed up inc_min_seq() and fix cold/hot inversions" (Barry
Song):
Make MGLRU's generation advancement cheaper and fix cases where cold
and hot folios end up in the wrong order. Adjust the counter and list
handling so reclaim doesn't keep passing over the better eviction
candidates.
- "mm: Fix MF_DELAYED handling on memory failure" (Lisa Wang):
Treat MF_DELAYED as a partially completed memory-failure operation,
not an outright failure. Propagate that result correctly through
shmem and the generic handler, fix the extra-reference accounting,
and add tests for the resulting SIGBUS behavior.
- "tools/mm/page_owner_sort: fix --sort, add module filter, improve
usage" (Ye Liu):
Fix page_owner_sort's --sort handling, add module-based filtering and
make the usage output more helpful. This makes the tool less
frustrating when tracking down who is holding on to pages.
- "mm/damon: move damos filter range arguments validation to core" (SJ
Park):
Move DAMOS filter range validation into the core, where all callers
can share it. Also close the sysfs read-twice races which could pass
inconsistent ranges, and add tests for invalid input.
- "mm/damon: misc cleanups" (Zenghui Yu):
Clean up a collection of small DAMON rough edges in the core,
interfaces and tests. No large behavior change here, just simpler
code and fewer opportunities for confusion.
- "mm/damon: cleanup code, add test cases, and update guidances in
docs" (SJ Park):
Clean up DAMON's core and interfaces, add missing test cases and
bring the documentation into line with the code. These changes should
make the newer facilities easier to understand and maintain.
- "mm/damon: introduce hugepage_size probe filter" (SJ Park):
Add a DAMON probe filter for hugepage size. Let users select a range
of folio sizes through sysfs, validate the range and document the new
interface, so monitoring can concentrate on memory backed by the
desired hugepage sizes.
- "selftests/mm: pagemap_ioctl test fixes and cleanups" (Zenghui Yu):
Fix some pagemap ioctl test assumptions and clean up their setup and
reporting. Make failures point to the operation that went wrong
rather than to test harness bookkeeping.
- "mm: avoid large folio splits when swap is unavailable" (Johannes
Weiner):
Avoid splitting large folios merely to attempt swap when no swap
space is available. There is little point paying for an expensive
split when reclaim cannot actually swap the resulting pages out.
- "mm: workingset: fix the shadow node budget under MGLRU" (Hui Zhu):
Fix the workingset shadow-node budget with MGLRU enabled. Keep the
shadow entries within the intended limits so refault tracking does
not quietly consume more metadata than it should.
- "selftests/mm: TAP output and global-state fixes" (Song Hu):
Fix selftests which produce misleading TAP output or fail to restore
global settings after a run. A test ought to leave the system as it
found it, particularly when a whole suite follows behind.
- "mm: remove page_swap_entry()" (Tal Zussman):
Remove page_swap_entry() and convert its remaining users to the folio
and swap-entry helpers. Lose an old page-level interface and make the
swap paths a little more consistent.
- "mm: refactor zonelist constructors and iterators" (Gregory Price):
Refactor the zonelist construction and walk helpers to reduce
duplicated logic. Keep the allocation ordering rules intact while
making it clearer how zones are selected.
- "mm: kmemleak: batch the struct page scan" (Breno Leitao):
Scan adjacent struct pages in batches instead of taking kmemleak_lock
once for every single page. This preserves scan coverage and the
lock-hold bound, while cutting overhead substantially on debug
kernels.
- "mm/damon: misc improvements in tests and documents" (Zenghui Yu):
Fix some DAMON selftests which leave kdamond running or fail under
Python safe-path mode, and improve the KUnit coverage and
documentation. Nothing especially glamorous, but these are worth
doing.
- "mm/damon: introduce probe_hits_wsum DAMOS core filter" (SJ Park):
Add a DAMOS core filter using weighted probe-hit counts. This gives
schemes another way to select regions based on what the monitoring
probes observed.
- "mm/mglru: fix ineffective memory protection for non-kswapd reclaim"
(Ridong Chen):
Fix MGLRU's memory protection handling for reclaim outside kswapd.
The protection settings weren't having the intended effect in these
paths, leaving protected memory more exposed than requested.
- "mm/damon: improve readability, clarity and test coverage" (SJ Park):
Simplify a handful of DAMON core helpers, clarify their behavior and
expand test coverage. There are no intended userspace-visible changes
in this batch.
- "mm: replace PF_KCOMPACTD/PF_KSWAPD with kthread_func()" (Kefeng
Wang):
Stop identifying reclaim and compaction workers through the PF_KSWAPD
and PF_KCOMPACTD task flags. Use their kthread functions instead and
remove the redundant flag plumbing.
- "mm/hugetlb: fix surplus accounting and availability checks during
demotion" (Longlong Xia):
Fix HugeTLB surplus accounting and availability checks when demoting
huge pages. Keep the counters and reservation decisions consistent as
one huge page turns into several smaller ones.
- "mm/damon: add kunit tests for probe_hits handling and probe params
validation" (Jason Angelov):
Add KUnit tests for DAMON probe-hit handling and invalid probe
parameters. These cover edge cases that were too easy to miss in
ordinary monitoring tests.
- "mm/damon: fix misc bugs in kunit, quota goals and sysfs refresh_ms"
(SJ Park):
Fix a few DAMON bugs in KUnit tests, quota-goal handling and the
sysfs refresh interval. Small fixes, but the incorrect results and
control behavior were real.
- "mm: zswap: optimize zswap invalidate and store" (Kefeng Wang):
Simplify zswap's invalidate and store paths to avoid avoidable
lookups and work. Keep the entry lifetime rules intact while making
those frequent operations cheaper.
- "mm: replace custom ratelimiting logic" (Pedro Falcato):
Replace hand-rolled MM rate limiting with the common kernel helpers.
There is no need to maintain another local version of the same
mechanism.
- "mm/vmalloc: minor cleanups" (Ye Liu):
Tidy some vmalloc initialization and reporting code, and pull
duplicated vmap-area insertion work into a helper. No functional
changes are intended.
- "mm/mglru: clean up isolate_folios for readability and clarity"
(Ridong Chen):
Clean up MGLRU's isolate_folios() so the decisions are easier to read
and verify. Keep reclaim behavior unchanged while removing
unnecessary twists in the control flow.
- "Catch automatic storage in IDA and Maple Tree definitions" (Yury
Norov):
Catch IDA and maple-tree definitions placed in automatic storage
where the lifetime rules are wrong or easy to get wrong. Add checks
so such mistakes are harder to slip through unnoticed.
- "mm, swap: some random fixes and cleanups" (Kemeng Shi):
Fix and simplify a few unrelated swap paths, removing redundant work
and tidying up error handling. A small collection of things which
were better fixed than left lying around.
- "mm/page_io: folio conversion cleanups" (Tal Zussman):
Finish some page-to-folio conversions in swap I/O, removing obsolete
wrappers and using folio operations consistently. The I/O behavior is
intended to remain the same.
- "mm/swap: skip empty clusters in the swapoff scan" (Youngjun Park):
Skip empty swap clusters during swapoff instead of walking slots
which have nothing to release. This avoids pointless work on sparsely
used swap devices.
- "mm: trace: decode architecture-specific VMA flags" (Meijing Zhao):
Teach the VMA trace output to decode architecture-specific flags,
rather than leaving them as unexplained bits. That should make
tracing a good deal more useful when debugging unusual mappings.
- "mm, swap: don't spin on a bad swap entry" (Breno Leitao):
Stop repeatedly retrying a swap entry which is already known to be
bad. Make the error path terminate cleanly instead of wasting CPU
chasing an entry that cannot be used.
- "mm/page_isolation: fix UBSAN shift-out-of-bounds in
isolate_single_pageblock" (Qi Xi):
Fix an out-of-range shift in isolate_single_pageblock() and tighten
its associated boundary handling. UBSAN found the issue; the result
should be more robust pageblock isolation.
- "mm: khugepaged: fix tracepoint UAF" (Vernon Yang):
Fix a use-after-free in khugepaged tracepoint handling. Make sure the
information recorded by tracing stays valid for as long as the trace
event needs it.
- "mm/damon: fix DAMOS bugs in core, paddr and vaddr" (SJ Park):
Fix several DAMOS problems across the core and physical- and
virtual-address backends. The changes close error cases and bring the
implementations back into agreement.
- "mm/hugetlb_cgroup: move the per-node usage along with the folio"
(Hongfu Li):
Move HugeTLB per-node usage accounting when folios migrate between
nodes or are reparented to another cgroup. Otherwise numa_stat can
retain stale charges and even underflow when the folio is freed.
- "docs/core-api: memory-allocation: add k[mz]alloc_obj() and clarify
kmalloc" (Mike Rapoport):
Document the typed k[mz]alloc_obj() allocation helpers and clear up
some kmalloc guidance. Make it easier for callers to choose the right
interface.
- "selftests/mm: Validate selections and scope memfd_secret setup"
(Tianyi Chen):
Check selftest selections before running and confine memfd_secret
setup to the cases that actually need it. Avoid confusing failures
caused by the test harness itself.
- "mm/damon: move zero damos quota target_value handling to the core
layer" (SJ Park):
Handle a zero DAMOS quota goal target in the core rather than making
each user of the interface invent its own rule. Keep quota decisions
consistent across callers.
- "mm/damon: Introduce a huge page collapsing mechanism using auto
tuning" (Asier Gutierrez):
Add an auto-tuned DAMON mechanism for collapsing huge pages. Use
monitoring feedback to decide when collapse is worthwhile rather than
forcing one fixed policy onto every workload.
- "kmemleak: fix stale documentation and raise the verbose default"
(Breno Leitao):
Bring the kmemleak documentation up to date and require a third
confirming scan before verbose kernels print a suspected leak. The
extra scan helps suppress transient false positives in noisy debug
builds.
- "mm/memory: improve insert_pages() error handling" (Avi Weiss):
Tighten insert_pages() error handling so partial failures are
reported and cleaned up consistently. The caller should not have to
guess how far the operation got.
- "mm/damon: allow NULL or unstarted damon_ctx parameter for
damon_call()" (SJ Park):
Make damon_call() handle NULL and not-yet-started contexts safely.
Simplify the rules for callers and avoid an indefinite wait on an
invalid state.
- "mm/damon: introduce pgidle_set probe filter type" (SJ Park):
Add a pgidle_set DAMON probe filter, giving monitoring users another
way to select pages by their idle-tracking state. Wire it through the
filter interfaces and tests.
- "mm/damon/core: remove unused helper functions" (Cheng-Han Wu):
Remove DAMON core helpers which no longer have callers. Keep the API
surface smaller rather than retaining dead code just in case.
- "mm: stop calling pmd_folio() on special PMDs" (Gregory Price):
Avoid calling pmd_folio() on special PMD mappings that have no struct
page. The old assumption could fault in procfs walkers; use the
normal-folio checks and handle those mappings properly.
- "mm: remove three unused helpers from mm.h" (Tal Zussman):
Remove three unused helpers from mm.h. Fewer obsolete interfaces for
the next person to stumble over.
- "mm/damon: improvements in efficiency, error handling, documents"
(Liew Rui Yan):
Skip needless DAMOS quota work once the quota is full, propagate a
missing sysfs error and tidy a couple of comments. The ignored error
could make a monitoring-start request appear successful when it
wasn't.
- "docs/mm/damon/design: add explanation of nr_snapshots" (Liew Rui
Yan):
Explain DAMON's nr_snapshots accounting in the design documentation
and straighten out the associated terminology. Make it clearer what
users should expect from that counter.
- "selftests/cgroup: fixes for test_zswap on single core VM" (Wilson
Felipe Pereira):
Fix two test_zswap failures on single-CPU VMs. Wait for the exiting
child's cgroup to become unpopulated before reconfiguring it, and
avoid another test assumption which breaks under constrained
scheduling.
- "docs/ksm: fix advisor documentation and comment" (Jinjiang Tu):
Correct the KSM advisor documentation and a misleading code comment.
Keep the description aligned with how the advisor actually works.
- "Fix bugs in HugeTLB allocation when mem_cgroup_charge_hugetlb()
fails" (Ackerley Tng):
Fix HugeTLB allocation cleanup when the memcg charge fails. Make sure
failure exits undo what was allocated rather than leaving stale
accounting or resources behind.
- "mm, memcg: fix memory.peak reset clobbering other fds' watermark"
(Ridong Chen):
Fix memory.peak reset handling so resetting one file descriptor
doesn't overwrite the watermark kept for another. Keep those per-open
measurements independent as intended.
- "mm: reject zone device folios in more folio walkers" (Gregory
Price):
Reject zone-device folios in page walkers that cannot safely handle
them. Extend the existing checks rather than assuming every folio has
ordinary system-memory backing.
- "percpu: remove code with no effect" (Sang-Heon Jeon):
Remove a few pieces of percpu code which no longer do anything. There
is no reason to keep maintaining dead paths.
* tag 'mm-stable-2026-10-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (539 commits)
mm: shmem: assign a lock class to the unused huge shrinklist
mm: vmscan: put rotation-missed folios at the LRU tail
mm: kmemleak: scan the struct page array in MAX_SCAN_SIZE batches
mm: kmemleak: move the struct page scan into a helper
mm/damon: document that a zero sample_interval is accepted
mm/damon: fix typos in comments
mm/damon/sysfs: propagate damon_call() error in turn_damon_on
mm/damon/core: skip quota score setup when the quota is full
mm/damon/tests/core-kunit: test the size charged for a filter-trimmed region
mm/damon/core: charge only the part of a region the filter left
mm: disallow raw PFN mappings of huge/shared zeropage
selftests/mm: zap whole PTE tables in the khugepaged race harness
selftests/mm: add memory-pressure threads to the khugepaged race harness
selftests/mm: race the collapse of windows with holes
selftests/mm: add khugepaged race harness
selftests/mm: check that one khugepaged pass collapses one window
selftests/mm: run every supported collapse order by default
selftests/mm: cover a shared-source collapse write race
selftests/mm: parameterize the mixed-source collapse case by source order
selftests/mm: add order-parameterized khugepaged collapse cases
...