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22 hoursMerge tag 'bpf-next-7.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 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 ...
25 hoursMerge tag 'modules-7.4-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux Pull module updates from Petr Pavlu: - Ignore local labels and mapping symbols during module load These symbols were already ignored during kallsyms address-to-symbol lookups. Filter them out earlier during module loading to reduce lookup overhead and prevent them from appearing in /proc/kallsyms. - Fix potentially incorrect access of SetOnce<T> when setting Rust module parameters. - Fix a potential read of an uninitialized count when printing taint information for unloaded modules. - Allocate the kmod argument array using kmalloc_array() in preparation for conversion to type-aware allocators. - Clean up includes in linux/kmod.h Add explicit includes of linux/umh.h to files that use usermode helpers. Then clean up the #include list in linux/kmod.h, notably removing the compatibility linux/umh.h include. - Remove the error-injection.h include from linux/module.h Add explicit includes of linux/error-injection.h to files that use the ALLOW_ERROR_INJECTION() macro and currently rely on it being provided indirectly via linux/module.h. Then remove the unnecessary linux/error-injection.h include from linux/module.h. - Replace __MODULE_STRING() with __stringify() in various drivers in preparation for removing the former macro. * tag 'modules-7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: drivers: Replace __MODULE_STRING() with __stringify() module: Fix uninitialized count read of unloaded taint tracking record rust: module_param: Fix potentially incorrect access of `SetOnce<T>` module: Remove the error-injection.h include from linux/module.h drm/xe: Include error-injection.h for ALLOW_ERROR_INJECTION() drm/i915: Include error-injection.h for ALLOW_ERROR_INJECTION() syscalls: Include error-injection.h for ALLOW_ERROR_INJECTION() net: Include error-injection.h for ALLOW_ERROR_INJECTION() block: Include error-injection.h for ALLOW_ERROR_INJECTION() module: Bring includes in linux/kmod.h up to date time/jiffies: Include linux/sysctl.h for proc_int_u2k_conv_uop(), ... umh, treewide: Explicitly include linux/umh.h where needed modules/kmod: Allocate argv with kmalloc_array() module/kallsyms: Ignore local labels and mapping symbols during module load module/kallsyms: Refactor current symbol filtering into is_core_symbol() module/kallsyms: Rename is_mapping_symbol() to is_ignored_kernel_symbol()
27 hoursMerge tag 'mm-stable-2026-10-19-21-33' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 ...
43 hoursMerge tag 'net-next-7.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "This includes a significant number of low-priority fixes - especially in the NIC drivers area - that we deferred from the last few RCs in the previous cycle, which can't be easily outlined in the synopsis below. Core & protocols: - Continue the work on removing rtnl_lock dependencies: - per-netns ARP and ND neighbour tables, with the default settings now configurable per netns (inheritance from init_net is controlled by the new net.core.neigh_inherit_init_net sysctl) - RCU-protected configuration and rtnl_lock-less fill_info() for hsr, netkit, sit, vlan and vxlan devices - per-netns device unregistration for ip tunnel and gre devices - use the netdev instance lock instead of rtnl_lock when reading speed and duplex via sysfs - batch the flushing of uncached routes at device unregistration time, relieving rtnl_lock contention on netns dismantle. - Add hardware pacing offload support, admin-controlled via a new rtnetlink attribute, with sch_fq integration (implemented in idpf). - Re-segment BIG TCP GSO packets into GSO packets fitting the egress device limits instead of plain MSS-sized segments, improving throughput for mixed BIG TCP / non-BIG TCP paths by up to 70%. - Generate RSS keys that spread flows over all the RX queues; the previous random keys could leave some queues unused. - Optimize the bridge VLAN forwarding paths: cache the port-VLAN in fdb entries and consider only VLAN members when flooding, for ~10% more Mpps in the fdb forwarding path. - A few TCP/IP performance improvements aimed at efficient cache usage and reducing contention. - Add the TCP ROCCET congestion control, a CUBIC variant aimed at avoiding bufferbloat in cellular networks. - Continue the conversion of getsockopt callbacks to sockopt_t. - Add an ethtool command to list the front-facing ports of an interface, including SFP cages and modules, using the phy_port representation. - Enable BIG TCP support for bareudp tunnels. - Remove the IPV6_ADDRFORM socket option and disallow buggy TCP state transitions (listen() + shutdown() + connect() and connect() + connect(AF_UNSPEC) + listen()). - Remove most BUG_ON()s from core packet processing, replacing them with error paths. Wireless: - Latency improvements, including lockless station get/dump and beacon updates, plus RTNL reduction and locking cleanups. - Infrastructure for non-station TX/RX with MLO. - NAN (Wi-Fi Aware) Instant Communication support and other NAN improvements. - Control frame Integrity Protocol (CIP) and protected TWT support. - Improvements for AP regulatory checks. Netfilter: - Disable br_netfilter in user namespaces and schedule it for removal in 2027. - Restrict the raw table in nft_compat to the specific family, hook and priority. - Prepare the flowtable for mixed IPv4-over-IPv6 tunneling (and vice versa). - Use GFP_KERNEL_ACCOUNT for most netfilter allocations, for better integration with memcg. - Allow discovering conntrack zone filtering support in ctnetlink dumps, and fix nfnetlink_hook handling of large dumps. Deletions: - Move the LLC type 2 sockets out of tree. There are no known users and the code attracts a never-ending stream of LLM-driven fixes. Device drivers: - New drivers: - Meta Platforms NIC (mpnic), the second-generation NIC from Meta - initial skeleton of the Nebula-matrix NICs driver (nbl) - X-Powers AC200/AC300 Fast Ethernet PHYs - Ethernet high-speed NICs: - Intel: - i40e: XDP metadata support for RX hash and VLAN tag - ice: expose the E825 TSPLL state via the DPLL subsystem - nVidia/Mellanox: - move the data direct infrastructure from IB to core, in preparation for netdev support. - reduce the memory used per offloaded TC rule - Meta (fbnic): - support large io_uring zero-copy RX buffers - Microsoft vNIC (mana): - add BQL support - Ethernet NICs consumer, and embedded: - Airoha: - LRO offload support - Cadence (macb): - context swapping for ringparam and MTU changes, avoiding buffer loss under memory pressure - Mucse (rnpgbe): - TX/RX and link status support - NXP (enetc): - SR-IOV improvements and VF support for ENETC v4 - Qualcomm (ppe): - IPQ5424 support - Realtek PCI (r8169): - phylink support - RSS support for RTL8127 - Renesas (ravb): - gPTP support for R-Car Gen4 - Synopsys (stmmac): - XDP multi-buffer support on the TX side - tc mqprio hw queue priority offload - support for RK3568 SGMII, Allwinner H616 EMAC1, UltraRISC DP1000 and Qualcomm sa8255p - Ethernet switches: - Mediatek (mt7530): - fast age and change conduit support - Microchip (ksz): - support for KSZ8995XA/KS8995XA - Microchip (lan966x): - PCIe FDMA support, ~20x throughput increase in PCIe endpoint - Microchip (sparx5): - Time Aware Shaper (taprio) offload - Motorcomm (yt921x): - LED and SerDes PCS support - Realtek (rtl8365mb): - EEE support - Ethernet PHYs: - Broadcom: - enable jumbo frames on BCM54xx - Realtek: - support for RTL8261CE_CG and RTL8261D_VM - MDIO support for RTL838x and RTL839x - WiFi drivers: - Broadcom (brcmfmac): - FT/OKC roaming offload - Intel (iwlwifi): - UHR sniffer support - support for newer UEFI/BIOS tables - MediaTek (mt76): - mt7925 NAN improvements - offchannel/scan improvements and MLO fixes - Morse Micro (mm81x): - monitor mode support - Qualcomm (ath12k): - IPQ5332 platform infrastructure - Realtek (rtw88): - RTL8723BS support - SDIO TX performance improvements - Realtek (rtw89): - P2P_DEVICE support - BT-coex updates for RTL8922D - Bluetooth: - move H:4 reassembly into the Bluetooth core - add generic support for vendor packets - MGMT: add security level changed event - Bluetooth drivers: - btusb: support Bulk Serialization Mode - Intel: support Draco and Titan Lake, allow unsigned firmware - Mediatek: MT7928 support - Qualcomm: QCC2072 support - Broadcom: Synaptics 4384 support" * tag 'net-next-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2126 commits) Bluetooth: btusb: disable by default Qualcomm multi-subsystem tipc: fix broadcast sender hang on last acker departure tipc: fix use-after-free of broadcast reception link at node release r8169: clear TX LPI on RTL8168h at link up after phylink conversion tun: Require CAP_NET_ADMIN to attach to an ownerless device net/sched/sch_cake: drop dead nla_nest_end() error check net/sched/sch_cake: widen buffer_used to u64 net/sched/sch_cake: reduce parent backlog when clearing a tin net/sched/sch_cake: serialize reconfiguration with the datapath tg3: Add Datto SIRIS 5 1U Server to restart AER quirk table net/mlx5e: Stop asserting for RTNL when closing channels net: shrink the payload-only part of skb dataref to one bit net: wwan: iosm: validate msg_head before indexing msg_ring net: bgmac: rate limit RX error messages selftests: net: veth: test XDP_TX to a peer with GRO enabled veth: schedule the peer's NAPI after XDP_TX when only GRO is enabled pppoe: delete session hash entries by pointer match net: lan969x: don't disable hardirqs in fdma tx clear net: sparx5/lan969x: do not clobber the PSFP cycle timer update period net: lan969x: fix DSM calendar for empty taxis ...
44 hoursMerge tag 'hardening-v7.4-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: - Provide kmalloc_obj*-style API for devm_kmalloc() - Improve seq_buf API for saner C String handling with several bug fixes along the way (Kees Cook, Bill Wendling) - Overflow helper readability improvements (Bill Wendling) - Unexport native_write_cr4() (Dennis Chen) - um: fix CONFIG_GCOV for built-in code (Johannes Berg) - Improve stackinit test coverage (Justin Stitt) - KMSAN: fix memset() when using fortify-source, again (Arnd Bergmann) - lkdtm: use kmalloc() instead of __get_free_page (Mahad Ibrahim) - signalfd: don't dequeue the forced fatal signals (Oleg Nesterov) - Fix randstruct to recognize new container_of() behavior - coccinelle: kmalloc_obj: Convert multi-byte integral allocations too - Fix a couple remaining allocation return type mismatches * tag 'hardening-v7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (29 commits) overflow: Match arithmetic in both parts of __builtin_choose_expr lkdtm: Make UNSET_SMEP built-in-only and unexport native_write_cr4() extcon: realtek: Remove const from type_c_cfg allocation type coresight: cti: Add const to con_groups allocation type docs: core-api: Document the seq_buf API nvdimm: ndtest: Return the string length from flags_show() powerpc/papr_scm: Return the string length from the sysfs show functions seq_buf: Add seq_buf_init_append() bpf: Remove dead newline stripping from format_disasm_line() seq_buf: Add seq_buf_terminate() seq_buf: Add seq_buf_strlen() seq_buf: Clear what a writer did not claim when a seq_buf overflows seq_buf: Copy what fits when seq_buf_puts() and seq_buf_putmem() overflow scsi: lpfc: Print rx monitor records straight into the seq_buf seq_buf: Do not pop from an overflowed seq_buf seq_buf: Do not print an empty line from an overflowed seq_buf_do_printk() .get_maintainer.ignore: Add Kees Cook devres: Provide kmalloc_obj*-style API for devm_kmalloc mm: Move default_gfp() into gfp_types.h kunit/stackinit: Clean up XFAIL under instrumentation ...
2 daysMerge tag 'soc-drivers-7.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull SoC driver updates from Arnd Bergmann: "There are lots of minor updates for driver subsystems managed through the soc tree (turris-omnia platform, cache driver, tee drivers, arm-cci, bus, memory) as well as soc vendor specific drivers (starfive, xilinx, microchip, nxp, amlogic, imx, renesas, samsung, ti, nvidia). The more notable changes are: - Larger updates for Qualcomm SoCs including support for SM8950 (Maili) SM8975 (Hawi), Glymur, Shikra, and IPQ5424 - Added SoC support for Exynos5515, Tegra264, Tegra410, R8A774A3, and MT8167 in existing drivers - Arm SCMI firmware driver support for ACPI PCC transport and module autoloading of protocol specific drivers - Apple crash log support for CrgA embedded controller" * tag 'soc-drivers-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (176 commits) platform: cznic: turris-omnia-mcu: stop button emulation producers cache: Make cpu_cache_invalidate_memregion() error out if there are no handlers soc: mpfs: use kref cleanup on probe failure arm64: enable HAVE_SHARED_GPIOS for all ARM64 platforms bus: arm-cci: Drop cci-control-port node reference in __cci_ace_get_port() bus: arm-cci: Drop CPU node reference in cci_ace_init_ports() soc: fsl: dpio: Free the IRQ before releasing the I/O object soc: fsl: dpio: Fix cleanup on IRQ registration failure bus: fsl-mc: Annotate fsl_mc_io.portal_virt_addr with __counted_by_ptr bus: fsl-mc: drop the fwnode links of the dpmacs nodes soc: fsl: cpm1: tsa: Fix clock leak in tsa_of_parse_tdms() soc: qcom: geni-se: Drop unused icc_ddr parameter from geni_icc_get() firmware: qcom: scm: Allow QSEECOM on ThinkPad T14s Gen 7 dt-bindings: mailbox: qcom: Document Maili CPUCP mailbox controller dt-bindings: spmi: glymur-spmi-pmic-arb: Add compatible for Qualcomm Maili SoC soc: qcom: pmic_pdcharger_ulog: prevent work requeue during remove ASoC: dt-bindings: qcom,apr: Add modem_apps GLINK channel for shikra firmware: qcom: tzmem: disable SHM bridge for SM7125 platform soc: qcom: ubwc: Add Kalambo UBWC config firmware: qcom: scm: Allow QSEECOM on Kalambo CRD ...
3 daysMerge tag 'kbuild-7.4-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild / Kconfig updates from Nathan Chancellor: "Kbuild: - Suppress compiler flags in debug info for external module builds - Use '-fmacro-prefix-map' in more places in the build - Merge initial set of changes from Lorenzo's speed up series, along with some fixes found through testing: - Avoid allocating .modinfo in vmlinux - Speed up kallsyms by indexing symbols by token and outputting binary data to disk directly then including in assembly via .incbin - Don't sort $(NM) output when unnecessary - Only emit relocations on the final vmlinx link - Reimplement mksysmap in C - Move many cc-option and ld-option calls into the Kconfig stage to cache their results - Use pigz for gzip compression when available - Move gen_init_cpio and gen_initramfs.sh from usr/ to scripts/ - Add a TOML configuration to scripts/container and update documentation accordingly - Add a generic, opt-in mechanism for checking that headers can compile standalone - Update machine function splitting argument for LLVM 24 rename in AutoFDO build - Miscellaneous minor clean ups, fixes, and hardening, mostly found/fixed via LLMs Kconfig: - Turn recursive ranges into an error - Fix savedefconfig for defaults that were adjusted for being out of range and revert a previously applied workaround - Improvements and hardening around integer and hexadecimal values - Emit a warning when selecting or implying a choice symbol, which has no effect - Emit a warning when KCONFIG_PROBABILITY is malformed - Introduce def_string / def_int / def_hex to mirror the existing def_bool / def_tristate to succinctly set a value and type at the same time. - Add cc-option-str and ld-option-str macros to act like Kbuild's cc-option and ld-option, returning the string when the option is supported, allowing many checks to be moved into Kconfig - Minor usability improvements to Kconfig tests" * tag 'kbuild-7.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (59 commits) kbuild: AutoFDO: Update split machine function argument for upstream rename kbuild: Mark the initcall ordering recipe as recursive kbuild: Mark the gzip recipes as recursive localmodconfig: Explicitly report boolean configs during integrity check scripts/make_fit: Ignore schema checks when decomposing DTBs clang-tools: Import os for broken pipe handling kconfig: use the value argument in sym_get_near_range_bound() kconfig: fix infinite loop in conf_choice() when no choice value is visible kconfig: cleanup stale comment about 'keys' array kconfig: Improve ergonomics around disabling warnings with cc-option scripts/Kconfig.toolchain: Drop compiler symbols from dependencies checkkconfigsymbols.py: Parse Git status output line by line gen_init_cpio: stop parsing on lines with a missing argument list .gitignore: drop Module.markers .gitignore: ignore pacman package signatures kbuild: add header check facility as a manually run static analyzer Documentation: dev-tools: refer to user ID rather than id Documentation: dev-tools: update container.rst with config file scripts: add TOML config to container tool kconfig: tests: {old,save}defconfig: Forward dynamic keyword arguments ...
3 daysMerge tag 'rust-7.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Update vendored 'zerocopy' crate to v0.8.62 (released 2026-10-08). This update advances 8 releases, with 3 of them carrying most of the changes. It contains new features as well as fixes. However, almost nothing has changed that requires updates on our side (a move of our non-ASCII change and the addition of an SPDX license identifier). - Generate Rust KUnit test suites for doctests reusing the '#[kunit_tests]' and '#[test]' attributes instead of C FFI functions, which allows to remove the generated C glue file. Relatedly, simplify 'kunit_assert!' by using 'file!()' and 'line!()' inside (which doctests override as needed), which allows to remove the 'file' helper and 'CONFIG_RUSTC_HAS_SPAN_FILE'. - Trim the function names in doctests generated by 'rustdoc' < 1.95.0 when building with 'O=', which were not reproducible. - Fix the 'VM_MAYSHARE' value in the generated bindings and its blocklist entry, due to typos. - Build 'core' with '--cfg no_io_statics' to ensure 'core' does not introduce any use of 'core::sync::atomic' into the kernel image since upstream Rust is moving 'std::io::Error' into 'core', which uses a global atomic pointer. Upstream Rust merged a PR to add a test checking that builds of 'core' are warning-free with that 'cfg' enabled. - Enable the unstable 'proc_macro_span' feature in 'proc-macro2', which provides 'Span::join' and thus improves the quality of the diagnostics of all our procedural macros, notably 'pin-init'. This is only used for producing diagnostics, thus there is no hard reliance on the feature. - Globally allow 'clippy::comparison_chain', since its suggestions are not always ideal and upstream downgraded it to 'pedantic' too. 'kernel' crate: - New 'mem' module: add the 'Align<N>' zero-sized type so that alignment can be specified via const generics ('repr(align(...))' only works with integer literals), e.g.: const N: usize = 128; struct S { _align: Align<N>, } assert_eq!(align_of::<S>(), N); - New 'ratelimit' module: add the 'Ratelimit' abstraction for 'struct ratelimit_state' and, based on it, the 'pr_*_ratelimited!' printing macros, which can be used for printing that may be triggered by userspace. In addition, convert Rust Binder to use them. - 'sync' module: to construct a global 'struct ratelimit_state', add a 'const' constructor for 'raw_spinlock_t'. In addition, move the lockdep types into a new 'sync::lockdep' submodule, since there were starting to be too many of them. - 'num' module: add the 'cv!' macro to create constant values ("cv") from an integer constant expression, with validity checked at compile time, inferring the target type from the context. It works for any type that implements the new 'FromConst' trait, e.g.: let a: Alignment = cv!(4096); let b: Bounded<u32, 4> = cv!(15); // Any integer constant expression works, not only literals. let m: NonZero<usize> = cv!(usize::MAX); // Checked narrowing, including in `const` items. const SMALL: u8 = cv!(200u32); // The target type can be given explicitly. let e = cv!(200u32 => u8); // With an explicit primitive target, the expression can use // generic parameters. const fn as_u64<const KEY: u16>() -> u64 { cv!(KEY => u64) } This avoids the verbose turbofish syntax which disincentivized using these types at interface boundaries (e.g. 'Alignment::new::<8>()'). - 'alloc' module: - Allow different error types in 'KBox::pin_slice()', enabling use of infallible initializers. - Add 'NumaNode::id()' accessor to retrieve the underlying NUMA node identifier. - 'time' module: - Add 'Delta::to_jiffies_timeout()' for use in timeout arguments. - Add 'Delta::as_jiffies_unsigned()'. - Make 'Delta::ZERO' generic over the time unit. - Warn and assert when passing out-of-range inputs to 'fsleep' and 'udelay'. - Rename 'ClockSource' to 'ClockId' to better align with naming conventions in C kernel. - Make 'CONFIG_HZ' value available as 'bindings::HZ'. - Add implementation detail documentation for 'HrTimer'. - 'bitmap' module: - Add contiguous area operations ('next_zero_area{,_off}', 'set' and 'clear'), with extra checks compared to the underlying C code, plus additional ones under 'CONFIG_RUST_BITMAP_HARDENED'. It includes tests demonstrating the edge cases. - Restrict bitmap length to at most 'i32::MAX', matching 'BitmapVec::MAX_LEN' and simplifying a few things. This also fixes 'u32' casts truncating in 'copy_and_extend', which could otherwise lead to OOB writes. - 'bug' module: - Fix 'warn_on!' on UML which called 'warn_slowpath_fmt()' with the wrong arguments; and fix its '// SAFETY:' comment too. - Add a KUnit test for 'warn_on!'. - 'id_pool' module: add contiguous ID reservation via the new 'reserve_ids' and 'release_ids' methods, built on top of the new bitmap area operations. - 'sizes' module: add the sub-1K size constants ('SZ_1' to 'SZ_512') and implement 'SizeConstants' for 'Alignment', so that one can write e.g. 'Alignment::SZ_8'. 'macros' crate: - Add '#[optional]' attribute for optional methods in '#[vtable]' to replace the 'build_error!(VTABLE_DEFAULT_ERROR)' boilerplate, e.g.: #[vtable] pub trait Operations: Sized { #[optional] fn f(&self) -> Result; } In addition, apply it to miscdevice and hide generated 'HAS_' constants for required methods. - Allow non-ASCII characters in the 'authors' field of the 'module!' macro, which was unintentionally restricted when multiple authors support was introduced. 'pin-init' crate: [ Extra context from Gary's pull request: "This is a cycle packed with feature updates. Two of the most anticipated features, tuple struct support and safe self reference creation, has been included in this pull request. Safe self reference is a big one and is pushed a bit late in the cycle. The initial plan was to include a minimum subset for this cycle because I was worried about potential soundness issues; however during Plumbers it was agreed that the features should be upstreamed at once. This is because the initial users (Nova, JobQueue) would all need the advanced features, so it is better to ensure that the feature get put into use for real, and it can iterate with users, rather than being fully designed on paper. The existing safety checks are already very comprehensive, and Benno and I are confident that if new ones are discovered, it wouldn't affect the overall design. That said, the the usage of the advanced features (invariance, existential lifetime) shall be limited to the pre-agreed users only, so even in case where the feature needs to be reworked, the blast radius is limited. Another theme in this cycle is to improve the developer experience when things are used wrongly. A lot of work has been done to use proper spans from user-provided tokens so error message point to things that cause them. Many common misuse scenarios also gain additional custom diagnostics." ] - User visible changes: - Support tuple structs. - Allow safe creation of self references. - Vastly improve diagnostics for common misuse scenarios. - Other changes: - Use 'mixed_site' hygiene consistently. 'MAINTAINERS': - Add 'RUST [BUG]' entry for the Rust 'bug' module (i.e. 'warn_on!'), which will be maintained by FUJITA Tomonori -- thank you! - Add Alice Ryhl as co-maintainer for 'Rust [ALLOC]'. And some other fixes, cleanups and improvements. * tag 'rust-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (91 commits) rust: zerocopy: update to v0.8.62 rust: zerocopy: fix link to upstream `README.md` rust: id_pool: add contiguous ID reservation rust: bitmap: add contiguous area operations rust: sizes: implement SizeConstants for Alignment rust: sizes: add sub-1K size constants rust: bitmap: restrict bitmap length to at most i32::MAX rust: bitmap: use function-level cfg on kunit test rust: num: add cv! macro to create values from constant expressions rust: bug: update the SAFETY comment for warn_slowpath_fmt() on UML rust: time: add Delta::as_jiffies_unsigned() rust: time: make Delta::ZERO generic over the time unit rust_binder: use pr_*_ratelimited! for printing rust: add pr_*_ratelimited! macros for printing rust: sync: add const constructor for raw_spinlock_t rust: sync: move lockdep types to rust/kernel/sync/lockdep.rs rust: pin-init: internal: suppress `explicit_outlives_requirements` MAINTAINERS: add entry for the Rust `bug` module rust: pin-init: internal: pin_data: support existential lifetimes rust: pin-init: internal: pin_data: support shared projection ...
4 daysMerge tag 'docs-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "It was a reasonably busy cycle for docs; changes include: - Add the AGENTS.md symbolic link into the top-level directory in the hopes that LLMs will read it and produce better work - The removal of the Assisted-by requirement, as concluded at the Maintainer Summit - A new "testdocs" make target to run the documentation unit tests - Lots of work on the Portuguese, and Chinese translations; there is now maintenance for the traditional Chinese translations as well ...and the usual pile of minor fixes, documentation updates, etc" * tag 'docs-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux: (125 commits) docs: add AGENTS.md as a symlink to README docs: kernel-parameters: adjust reserve_mem build option docs: kernel-parameters: don't mix cmdline options & build options docs/ja_JP: translate submitting-patches.rst (review and report tags) docs: remove Assisted-by references Revert "docs: landlock: fix ENOMSG condition in create_ruleset kernel-doc" docs: kdoc: parse context_lock_struct() as struct declaration docs: timers: hpet: Document userspace API and ioctl commands docs: timers: hpet: Modernize file references Documentation: sched-preemption: Add a SPDX license identifier docs: ABI: sysfs-driver-xdata: use literal blocks for console commands docs: ABI: sysfs-class-firmware-attributes: use literal blocks for console commands ABI: sysfs-bus-usb: use literal block for console commands docs/ABI: testing: aspeed-uart-routing: use literal block for console commands docs: kernel-parameters: fix a truncated sentence for preempt=lazy sched/doc: add a preemption model overview docs: ABI: TMR manager: use literal blocks for console I/O Documentation/ABI: IFS: use literal blocks for commands ABI: sysfs-bus-pci: use literal blocks for commands docs: translations: pt_BR: add debugging index ...
4 daysMerge tag 'alpha-for-v7.4-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lindholm/alpha Pull alpha updates from Magnus Lindholm: "This completes Alpha's conversion to GENERIC_ENTRY and enables a range of kernel features through Kconfig updates, including UBSAN, gcov, kmemleak, page-table checking, fast GUP and sparse IRQs. It includes TLB and MMU context fixes prompted by glibc test-suite failures, HugeTLB support for 64KB, 512KB and 4MB pages, and fixes for poisoned-page faults and page-table checking. Machine-check handling is improved on Tsunami platforms, with bounded EV6 logout decoding, Clipper environmental event reporting and safer firmware console-log scanning. Other changes add self-extracting compressed kernels with support for all kernel compression formats, Alpha-specific XZ tuning, perf register and user-stack sampling, and Alpha support in the seccomp selftests. The series also fixes user stack-pointer reporting and IRQ entry ordering, adds 128-bit shift helpers, cleans up linker sections, and updates Kconfig help" * tag 'alpha-for-v7.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/lindholm/alpha: (57 commits) alpha: add bounded Clipper console-log scanning alpha: decode Clipper environmental events alpha: decode and acknowledge Tsunami system machine checks alpha: bound EV6 logout decoding by the processor area alpha: describe the Tsunami system machine check frame alpha: move Tsunami machine check handling to err_tsunami.c alpha: fill in pc for software event samples alpha: add HAVE_PERF_REGS and HAVE_PERF_USER_STACK_DUMP support alpha: use user_stack_pointer() in KSTK_ESP() and dump_elf_thread() alpha: stop storing the user stack pointer in pt_regs alpha: fix stale user_stack_pointer() selftests/seccomp: add Alpha support to seccomp_bpf alpha: do not skip TLB shootdown IPIs for kthread-borrowed mms alpha: do not clear remote MMU contexts in migrate_flush_tlb_page() alpha: invalidate the local context in flush_icache_user_page() alpha: invalidate the local context in flush_tlb_mm() alpha: fix the local TLB invalidate in the UP flush_tlb_page() alpha: fix the local TLB invalidate in flush_tlb_page() alpha: invalidate the local context in flush_tlb_page() alpha: only use a targeted tbi() when the target mm is really current ...
4 daysMerge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Here are the arm64 updates for 7.4. The more interesting bits are the removal of big-endian kernel support (already marked BROKEN for some time), preemptible this_cpu_*() operations and MPAM support for the firmware-backed (Fb) interface. CCA (Arm's confidential compute) is slowly trickling in with host RMI (Realm Management Interface) support and some refactoring, including a dedicated SMCCC bus to advertise firmware services. There are also the usual PMU updates for new hardware and a few fixes/cleanups. Core features: - Remove big-endian kernel support: CONFIG_CPU_BIG_ENDIAN has depended on BROKEN for a while, so drop the remaining code (BE hypervisor object, BPF JIT, assembly/crypto/library routines, endianness helper macros, selftests) and force a little-endian build - Add preemptible this_cpu_*() operations (read/write, RMW, xchg, cmpxchg and cmpxchg128) that no longer need to disable preemption around the per-CPU address generation and access - Preparation patches for implementing CONFIG_HOTPLUG_PARALLEL on arm64 Memory management: - Treat faults taken by EFI runtime firmware as kernel faults - Clear PTE_WRITE for EFI_MEMORY_RO mappings (with hardware dirty state management enabled, this is not truly read-only) - Raise the default ARCH_MMAP_RND_BITS for 48-bit and 52-bit VA configurations (28/26/24 bits for 4K/16K/64K pages) - Implement clear_page[s]() using memset() - Enable BBML2 no-abort (a.k.a. BBML3) for the NVIDIA Rigel CPU Perf and PMU: - Support for HiSilicon's ITS PMU - Add support for some new events: INST_SIMD_ALU_VEC for Apple PMUs and a cycle counter for the latest version of HiSilicon's MN PMU hardware - A bunch of fixes to the CXL PMU driver to address pre-existing issues from Sashiko - Fix generation of PERF_RECORD_ITRACE_START records for SPE and ETM drivers - Reduce excessive stack consumption in the Marvell DDR PMU driver - Minor driver updates and cleanups all over Arm Confidential Compute Architecture (CCA): - Add an Arm SMCCC bus for firmware services discovered through SMCCC and move the TRNG and CCA guest (TSM provider) drivers onto it, removing the dummy CCA platform device and adding a sysfs ABI for Realm guests - Move the Realm Service Interface (RSI) code out of arch/arm64/ into drivers/firmware/arm_rmm/ - Add the host side of the Realm Management Interface (RMI): detect, configure and activate the RMM, add SRO support and wrappers for the Realm RMI commands - Block hibernation (new arch hook in the PM core) and kexec while the RMM is active. To be revisited in the future with proper support for deactivation - Handle Granule Protection Faults (GPFs) taken by the host, caused by accesses to memory delegated to the RMM. In a future patch, the exception table lookup will be limited to is_kdump_kernel() cases MPAM (Memory Partitioning And Monitoring): - Add support for the MPAM firmware-backed (Fb) interface, allowing MSC accesses to be mediated by firmware - Fix a list of theoretical issues with the driver (MSC access error propagation, MBWU monitor save/restore and locking, resctrl class handling, error interrupt restore, maximum number of PARTIDs) - Add the mailing list and a missing file to the MAINTAINERS entry - Document when to set arm64.nompam Errata and CPU features: - Add the NXP i.MX8QM/8QP workaround for the Cortex-A53 cache coherency issue (ERR050104), using a new ARM64_CPUCAP_SOC_ERRATUM capability type for SoC-level errata Miscellaneous: - Mask debug exceptions (DAIF) around the hardware breakpoint register manipulations when called from generic kernel code - Don't zero the SVE state buffer when the SVE state is live - Return -EPERM instead of -EBUSY from the GCS prctl() locking failures (matching x86), with the selftest updated. Slight ABI change but no software deployment yet - kselftest: fix unsound MTE fault skipping by introducing MTE-safe memory accessors, avoid copying each signal test binary more than once - Update sysreg definitions (fix three enum values and two field names, mark architecturally dropped fields as RES0) and remove the TME transaction state check from the BRBE driver - Fix the description of ARM64_HAS_LPA2 and remove a redundant ID_AA64MMFR0 define" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (144 commits) arm64: cpufeature: Enable BBML2 for NVIDIA Rigel arm64: cputype: Add NVIDIA Rigel definitions arm64: raise default ARCH_MMAP_RND_BITS for 48-bit and 52-bit VA arm64/debug: mask debug exceptions when called from common code kselftest/arm64: signal: copy each test binary only once kselftest/arm64: Check for -EPERM not -EBUSY in the locking test arm64: gcs: Return -EPERM not -EBUSY for prctl() locking failures perf: arm_brbe: Remove the check for TME transaction states arm64: sysreg: Mark fields the architecture dropped as RES0 arm64: sysreg: Fix the names of two misspelt fields arm64: sysreg: Fix three incorrect enum values arm64: smp: Defer RCU registration during secondary CPU bringup arm64: smp: Don't bother printing the I-cache policy for each CPU arm64: smp: Defer update of secondary CPU capabilities arm64: smp: Tidy up cpuinfo init and cpufeature updates arm64: smp: Tidy up smp_prepare_cpus() arm64: cpufeature: Store every ID register with its overrides applied arm64: cpufeature: Read MPAMIDR_EL1 in __cpuinfo_store_cpu() arm64: cpufeature: Add read_cpuid_with_overrides() arm64: cpufeature: Check arm64_ftr_regs[] before the first store ...
7 daysxz: add arch-specific tuning for alphaMatt Turner
Alpha has fixed-length, 4-byte-aligned instructions and no XZ BCJ filter, so it wants the same LZMA2 settings as the other 4-byte-aligned targets. Without an entry it hits the default case, which warns scripts/xz_wrap.sh: Arch-specific tuning is missing for 'alpha' and conservatively assumes 2-byte alignment. Alpha gains HAVE_KERNEL_XZ later in this series; the correct alignment also shrinks a UP1500 kernel's XZ image from 6469320 to 6448840 bytes. Signed-off-by: Matt Turner <mattst88@gmail.com> Reviewed-by: Magnus Lindholm <linmag7@gmail.com> Tested-by: Magnus Lindholm <linmag7@gmail.com> Reviewed-by: Lasse Collin <lasse.collin@tukaani.org> Link: https://lore.kernel.org/r/20261017-alpha-kernel-compression-v2-1-c71e6b08dc63@gmail.com Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
7 daysMerge branch 'kbuild-next-speedups' into kbuild-nextNathan Chancellor
This is the first round of commits and fix-ups from Lorenzo's Kbuild speed up series. Signed-off-by: Nathan Chancellor <nathan@kernel.org>
10 dayskbuild: AutoFDO: Update split machine function argument for upstream renameNathan Chancellor
A recent LLVM commit [1] renamed the internal LLVM plugin option '-split-machine-functions' to '-function-splitting=all', breaking the AutoFDO + ThinLTO build with: ld.lld: error: -plugin-opt=-: ld.lld: Unknown command line argument '-split-machine-functions'. Try: 'ld.lld --help' The plugin option is needed for in-process ThinLTO, so handle the rename accordingly using ld-option. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2186 Fixes: 2fd65f7afd5a ("AutoFDO: Enable machine function split optimization for AutoFDO") Link: https://github.com/llvm/llvm-project/commit/3e6acc87c58843e551d6e8e4bf06c26712b04622 [1] Link: https://patch.msgid.link/20261014-update-autofdo-split-machine-function-option-v1-1-5c71b3005e89@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
10 daysBluetooth: enable context analysis for headersPauli Virtanen
Remove context analysis suppression for include/net/bluetooth/*, now that previous commits have resolved the warnings. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
10 daysdocs: remove Assisted-by referencesSasha Levin
Commit 78d979db6cef ("docs: add AI Coding Assistants documentation") asked contributors to add an Assisted-by tag to patches developed with help from an LLM, and commit 816d9992d9ed ("coding-assistants: simplify attribution") later reduced the tag to "Assisted-by: LLM". A proposal to drop the tag was turned down in July [1]. The main argument for keeping it was that maintainers wanted a signal that a patch was LLM-assisted, so that they could review it accordingly. The tag came up again at the 2026 Maintainers Summit [2]. Roughly 10% of the 18,533 non-merge commits in 7.3 through -rc7 carry an Assisted-by tag, while actual LLM use is far more widespread. Some contributors do not know about the rule, others leave the tag off on purpose, and few maintainers ask about it. As a result, the tag does not provide the signal it was kept for: its absence says nothing about how a patch was made, and for developers who use these tools for almost everything, its presence says little more. The choice was between finding a way to enforce the requirement and dropping it, and there was a strong, though not unanimous, consensus in the room to drop it. Greg Kroah-Hartman, who argued for keeping the tag in July, supports removing it now [3]. Maintainers do still want to know how a patch was created, but the view at the Summit was that this belongs in the cover letter, where it can describe how the tools were used, rather than in the changelog. Documentation/process/generated-content.rst already asks contributors to be transparent about tool use and is not changed here. The rules on the DCO and on the submitter's responsibility for the patch stay as they are. Remove the Assisted-by sections from coding-assistants.rst, submitting-patches.rst, and the Italian, Brazilian Portuguese and Traditional Chinese translations, and drop the handling of the tag from checkpatch. [1] https://lore.kernel.org/workflows/2026070224-unholy-commode-cf45@gregkh/ [2] https://lwn.net/Articles/1099594/ [3] https://lore.kernel.org/all/2026101327-cupid-legal-6cf6@gregkh/ Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Reviewed-by: Kees Cook <kees@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: SJ Park <sj@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Daniel Pereira <danielmaraboo@gmail.com> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Weijie Yuan <wy@wyuan.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20261013121501.3738437-1-sashal@kernel.org>
13 daysbtf: Relocate and expose module inline BTFAlan Maguire
Module .BTF.inline is split relative to its module BTF. For external modules, module BTF can instead be split relative to a distilled .BTF.base and is relocated against vmlinux when the module loads. Parse ordinary module inline BTF relative to the pre-relocation module BTF. Retain the module relocation ID and string maps, then rebase inline type IDs and string offsets onto the final vmlinux/module BTF space before exposing the result through sysfs. Malformed or unrelocatable optional inline BTF is warned about and omitted without preventing normal module BTF registration. The btf_vmlinux_inline carrier remains on its existing hash-checked, vmalloc-backed publishing path, preserving mmap support for vmlinux.inline when delivered by a module. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://patch.msgid.link/20261009112324.1442319-6-alan.maguire@oracle.com
13 dayskbuild, btf: Expose vmlinux inline BTF through sysfsAlan Maguire
Expose BTF inline-location information from vmlinux .BTF.inline sections in /sys/kernel/btf as vmlinux.inline. Embedded vmlinux inline BTF supports read-only mmap(). Provide runtime support for a module-delivered vmlinux inline BTF carrier. Its link record binds the carrier module name, BTF size, and SHA-256 digest to the running kernel before its data is made available through a lazy vmlinux.inline sysfs attribute. The carrier is handled before ordinary module BTF registration, so its incidental .BTF data is not exposed. Make CONFIG_DEBUG_INFO_BTF_INLINE tristate. When configured as a module, retain vmlinux final split inline BTF for btf_vmlinux_inline.ko instead of embedding it in vmlinux. Reserve .BTF.inline.link in vmlinux and extend the final resolve_btfids patch pass to bind btf_vmlinux_inline to the raw vmlinux.BTF.inline payload. This preserves the normal built-in configuration while allowing the large inline BTF payload to load on demand. Normal module inline BTF is handled separately, after its references have been relocated against the final module BTF. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://patch.msgid.link/20261009112324.1442319-4-alan.maguire@oracle.com
14 dayskbuild: Mark the initcall ordering recipe as recursiveKees Cook
generate_initcall_order.pl, which orders initcalls for Clang LTO, forks a child per input file, up to the job count scripts/jobserver-exec passes it in PARALLELISM. It used to run from link-vmlinux.sh, which the top-level Makefile invokes as a recursive recipe, but commit 5d45950dfbb15 ("kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o") moved it into a recipe without "+". GNU Make passes the jobserver pipe only to recipes it treats as recursive, and the make 4.3 in CentOS Stream 9 also hides it in sub-makes (a backport of the fix for GNU Make bug 58232), so jobserver-exec cannot open it and prints: WARNING: Unable to reopen jobserver read-side pipe: FileNotFoundError(2, 'No such file or directory') PARALLELISM is then left unset, and the script caps its children at the number of online CPUs instead of the free job slots. Mark the recipe as recursive again (this makes "make -n" runs the script again too, as it did from link-vmlinux.sh). Masahiro posted the same change and withdrew it because the script was given only vmlinux.a, and so never ran more than one child [1]. But on arm64, LoongArch, and RISC-V with CONFIG_EFI_STUB, KBUILD_VMLINUX_LIBS also gives it the EFI stub's lib.a. Either way, the warning is silenced. Tested ARCH=x86_64 defconfig with CONFIG_LTO_CLANG_THIN=y, LLVM=1 (Clang 24.0.0git), and GNU Make 4.3 plus CentOS Stream 9's make-4.3-cloexec.patch. Fixes: 5d45950dfbb15 ("kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o") Link: https://lore.kernel.org/all/CAK7LNARCM=rUm8mA8GRQ7ufeyfneGf4OEvHmESKt=zuxs2KrHw@mail.gmail.com/ [1] Assisted-by: LLM Reviewed-by: Nicolas Schier <n.schier@fritz.com> Signed-off-by: Kees Cook <kees@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://patch.msgid.link/20261010081914.540611-2-kees@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
14 dayslocalmodconfig: Explicitly report boolean configs during integrity checkAaron Tomlin
When running make localmodconfig, streamline_config.pl reads loaded modules and maps each module object to its corresponding Kconfig symbol(s) using repository Makefiles. In several instances, a loaded module corresponds to an object controlled by a boolean symbol (e.g. config FOO declared as bool), or is a composite module that depends on a boolean configuration. Because boolean options only accept "=y" or disabled, they cannot be configured as loadable modules ("=m"). Previously, if such a symbol was not already built-in ("=y") in the baseline configuration, the final integrity check emitted an ambiguous diagnostic. For example foo did not have configs CONFIG_FOO Further investigation is required by developers to determine whether the module was out-of-tree, its dependencies were unmet, or it failed due to a type constraint. Address this by: 1. Tracking symbol types in a %types hash during Kconfig parsing. 2. Enhancing the final integrity check when running localmodconfig (!$localyesconfig) to explicitly annotate boolean symbols. For example: module cec did not have configs CONFIG_CEC_CORE (tristate) CONFIG_RAS_CEC (boolean, not supported with =m) Signed-off-by: Aaron Tomlin <atomlin@atomlin.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Link: https://patch.msgid.link/20260925181230.130525-1-atomlin@atomlin.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-09scripts/make_fit: Ignore schema checks when decomposing DTBsTing-Han Hou
With CHECK_DTBS enabled, Kbuild appends a schema validation command to the fdtoverlay command saved in a composite DTB's .cmd file. When DTB decomposition is requested, process_dtb() treats every word after -i as an input file, including the semicolon and the validator arguments. FIT generation then fails with FileNotFoundError while opening or checking the size of those words as files. Limit the input list to the fdtoverlay command before extracting its arguments. This preserves the base DTB and overlay order and ignores the subsequent schema validation command. Fixes: 17c31aded9a1 ("scripts/make_fit: Support decomposing DTBs") Assisted-by: LLM Signed-off-by: Ting-Han Hou <ue081723@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org> Link: https://patch.msgid.link/CA+NtrhQBK8uW32qO3dXxVxO1GSN-0EJfyJ16tnyx0o52T17WtQ@mail.gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-09clang-tools: Import os for broken pipe handlingTing-Han Hou
The BrokenPipeError handler in run-clang-tools.py calls os.open() and os.dup2() without importing os. If this handler is reached, it raises NameError instead of redirecting stdout and exiting with status 1. Import os so the handler can work as intended. Fixes: 87c7ee67deb7 ("scripts: handle BrokenPipeError for python scripts") Assisted-by: LLM Signed-off-by: Ting-Han Hou <ue081723@gmail.com> Link: https://patch.msgid.link/20261009175836.2277-1-ue081723@gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-09kconfig: use the value argument in sym_get_near_range_bound()Leizhen Zhang
sym_get_near_range_bound() is meant to check whether the given value is outside of the active range of an int/hex symbol, and is called with the symbol's current value from sym_calc_value() and with the default value from sym_get_string_default(). Since commit 9b8719973ee2 ("kconfig: use unsigned integers for hex range checks") it ignores its value argument and uses the current value of the symbol (via sym_get_range_val()) instead. As a result, an out-of-range default is no longer clamped in sym_get_string_default(), and savedefconfig writes out values that are equal to the effective default again, for example CONFIG_A=4 for: config A int "a" range 1 4 default 8 The existing savedefconfig_range test did not catch this because it only covers symbols without a prompt. Parse the value argument again, and add a test case for a symbol with a prompt. Found while fuzzing Kconfig input with ASan/UBSan. Fixes: 9b8719973ee2 ("kconfig: use unsigned integers for hex range checks") Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Leizhen Zhang <lzsx618@gmail.com> Tested-by: Julian Braha <julianbraha@gmail.com> Reviewed-by: Julian Braha <julianbraha@gmail.com> Link: https://patch.msgid.link/20261008164540.3686383-1-lzsx618@gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-09kconfig: fix infinite loop in conf_choice() when no choice value is visibleLeizhen Zhang
If a choice is visible but none of its choice values is, conf_choice() counts cnt == 0 visible values and finds no default. When the choice has to be asked, e.g. because a new symbol was added to the same menu (oldconfig, syncconfig) or because stdin is at EOF (oldaskconfig), the loop that maps the answer to a menu entry never finds one and the while (1) loop repeats forever, printing "choice[1-0?]: 0" each time. This happens in the tree for s390 when the compiler supports none of the -march=z* options (e.g. a non-s390 host compiler), so that all values of the "Processor type" choice are invisible: $ make ARCH=s390 defconfig $ sed -i '/^CONFIG_NR_CPUS=/d' .config $ make ARCH=s390 oldconfig # hangs Before the removal of tristate choice support, conf_choice() returned early in this case. Do the same when there is no visible choice value. Found by fuzzing Kconfig input with ASan/UBSan. Fixes: fde192511bdb ("kconfig: remove tristate choice support") Assisted-by: Claude:claude-opus-5-5 libFuzzer Signed-off-by: Leizhen Zhang <lzsx618@gmail.com> Reviewed-by: Julian Braha <julianbraha@gmail.com> Tested-by: Julian Braha <julianbraha@gmail.com> Link: https://patch.msgid.link/20261008164521.3684735-1-lzsx618@gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-09kconfig: cleanup stale comment about 'keys' arrayJulian Braha
'keys' was removed from 'dialog_textbox' in: commit e14f1242a8be ("kconfig: menuconfig: simplify global jump key assignment") but the comment referencing it was never removed. Let's cleanup this stale comment. Signed-off-by: Julian Braha <julianbraha@gmail.com> Reviewed-by: Nicolas Schier <n.schier@fritz.com> Link: https://patch.msgid.link/20261009094617.17322-1-julianbraha@gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-09kconfig: Improve ergonomics around disabling warnings with cc-optionNathan Chancellor
This is essentially a port of commit 550ccb178de2 ("Make 'cc-option' work correctly for the -Wno-xyzzy pattern") to scripts/Kconfig.include, which simplifies the definition of many of the newly added CC_OPT_WNO_ symbols in scripts/Kconfig.toolchain and matches cc-option's behavior in Kbuild. Reviewed-by: Nicolas Schier <nsc@kernel.org> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20261007-scripts-kconfig-toolchain-improvements-v1-2-1e524178da11@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-09scripts/Kconfig.toolchain: Drop compiler symbols from dependenciesNathan Chancellor
Commit 454e00cf8ee5 ("kbuild: avoid re-running compiler and linker probes") moved many cc-option calls from the main Makefile into Kconfig. In the process, code such as ifdef CONFIG_CC_IS_GCC KBUILD_CFLAGS += $(call cc-option,-foo) endif was converted into Kconfig as config CC_OPT_FOO def_string "$(cc-option-str,-foo)" if CC_IS_GCC The 'if CC_IS_GCC' is generally unnecessary because it does not prevent the cc-option-str call from running (which is the primary reason the ifdef guards exists in the Makefile), as cc-option-str and the like are run before Kconfig even parses the dependency. It only impacts the symbol's visibility, which does not really matter in the general case, so remove these dependencies. Reviewed-by: Nicolas Schier <nsc@kernel.org> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20261007-scripts-kconfig-toolchain-improvements-v1-1-1e524178da11@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-07checkkconfigsymbols.py: Parse Git status output line by lineTing-Han Hou
tree_is_dirty() iterates over the string returned by execute() one character at a time. Its status check therefore examines filenames as well as the two status columns. An otherwise clean tree containing an untracked README is reported as dirty because its name contains letters matched by [URMADC]. This prevents --commit and --diff from running, whereas an untracked notes.txt does not trigger the check. Split the output into lines before examining the two status columns so that filenames do not affect the dirty-tree check. Fixes: b1a3f243485f ("checkkconfigsymbols.py: make it Git aware") Assisted-by: LLM Signed-off-by: Ting-Han Hou <ue081723@gmail.com> Link: https://patch.msgid.link/CA+NtrhQqXgjT+4eg6W4P94Hc=DqdV3gQXz3EKKCxWvdWzfND6A@mail.gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-07gen_init_cpio: stop parsing on lines with a missing argument listLeizhen Zhang
When a line in the cpio list consists of a file type followed only by whitespace and no newline (e.g. "slink " as the last line of the file), strtok(NULL, "\n") returns NULL. main() prints an error and sets ec, but then carries on and passes the NULL args pointer to the type handler, which hands it to sscanf() and crashes: AddressSanitizer: SEGV on unknown address 0x000000000000 #4 __isoc99_sscanf #5 cpio_mkslink_line usr/gen_init_cpio.c:169 Break out of the loop as is already done for the other format error, so that the error is reported and gen_init_cpio exits with a failure status. Found by fuzzing gen_init_cpio built with ASan/UBSan. Reproducer: printf 'slink ' > list && usr/gen_init_cpio list Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Assisted-by: Claude:claude-opus-5-5 ASan UBSan Signed-off-by: Leizhen Zhang <lzsx618@gmail.com> Link: https://patch.msgid.link/20261005085729.872402-1-lzsx618@gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-06mm/sparse: relax struct mem_section size constraintsMuchun Song
Patch series "mm: Introduce section-based vmemmap optimization for HugeTLB", v6. This series is split out from the earlier, larger series "mm: Generalize HVO for HugeTLB and device DAX" [1]. While the parent series generalizes vmemmap optimization across HugeTLB and device DAX, this subset addresses a single, self-contained step: making the generic sparse-vmemmap code section-based optimization aware and switching HugeTLB bootmem pages to this path. HugeTLB vmemmap optimization currently has its own early boot setup path. It pre-populates optimized vmemmap mappings before the normal sparse-vmemmap population code runs, and sparsemem carries SPARSEMEM_VMEMMAP_PREINIT only to support that special case. That makes the HugeTLB vmemmap optimization path harder to share with other users of sparse-vmemmap optimization and leaves a fair amount of HugeTLB-specific boot-time state in the generic memory initialization flow. This series introduces section-based vmemmap optimization support in the sparse-vmemmap code and switches HugeTLB bootmem pages over to it. Instead of having HugeTLB pre-populate optimized vmemmap mappings itself, HugeTLB now records the compound page order in the corresponding memory sections. The generic sparse-vmemmap population path can then allocate or reuse shared tail vmemmap pages based on section metadata. The patches are organized as follows: - patches 1-2 prepare sparsemem and vmemmap optimization metadata - patches 3-8 teach the common sparse-vmemmap paths to use that state - patches 9-10 switch HugeTLB bootmem optimization to the section-based path - patches 11-17 clean up sparsemem and HugeTLB bootmem code that is no longer needed after the conversion This is intended to be the second smaller step toward the broader HVO generalization. The device DAX conversion and the wider HVO consolidation are left for follow-up series. This patch (of 17): struct mem_section is currently forced to a power-of-2 size so the section-to-root lookup can use a mask instead of a modulo. That requirement makes future extensions harder than necessary: adding a small field can require configuration-dependent padding or layout checks just to preserve the lookup scheme. Keep the lookup correct for any struct mem_section size by using a plain modulo instead. Do not leave the layout entirely unconstrained, though. Keep struct mem_section double-word aligned so modest size changes, such as adding another word-sized field on 64-bit systems, still keep a compact and efficient layout. If future fields grow the structure beyond that sweet spot, the lookup remains correct; only the exact layout efficiency changes. Link: https://lore.kernel.org/20260910063256.64386-2-songmuchun@bytedance.com Link: https://lore.kernel.org/all/20260513130542.35604-1-songmuchun@bytedance.com/ [1] Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: David Laight <david.laight.linux@gmail.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Qi Zheng <qi.zheng@linux.dev>
2026-10-06mm: drop stale MAX_ORDER referencesQi Xi
The treewide rename in commit 5e0a760b4441 ("mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER") left a few spots still using the old name: - two comments in include/net/mana/mana.h and mm/page_alloc.c; - the gdb helper scripts/gdb/linux/mm.py, where self.MAX_ORDER is a local mirror of the kernel's MAX_ORDER define. Rename the leftover instances to MAX_PAGE_ORDER so the tree is consistent. No functional changes. Link: https://lore.kernel.org/20260819082052.3338603-1-xiqi2@huawei.com Signed-off-by: Qi Xi <xiqi2@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Konstantin Taranov <kotaranov@microsoft.com> Cc: Long Li <longli@microsoft.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org>
2026-10-03rust: doctest: generate Rust kunit test suitesGary Guo
For doctest, instead of generating C FFI functions, generate a Rust test suite with `#[kunit_tests]` and `#[test]` attributes. This makes the C glue no longer needed. Reviewed-by: David Gow <david@davidgow.net> Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260902-kunit-v2-3-eda3ed6c00c5@garyguo.net [ Removed generated file from `rust/.gitignore` and added it to `scripts/remove-stale-files`. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-10-03rust: kunit: use `line!()` inside `kunit_assert!`Gary Guo
The `diff` parameter is needed currently because doctests want to override the line number. Simplify it by changing it to use `line!()`. Have doctests override `line!()` macro to achieve the current behavior. An existing doctest requires `line!()` to expand to a literal; so update it to use `::core::line!()` instead. Reviewed-by: David Gow <david@davidgow.net> Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260902-kunit-v2-2-eda3ed6c00c5@garyguo.net [ Removed spurious `///`-to-`//` change and adjusted `line!` to match. Added a comment to match `file!`'s. Made `NOTE:` more precise. Reworded to say it is only one doctest being updated. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-10-03rust: kunit: use `file!()` inside `kunit_assert!`Gary Guo
This parameter is needed currently because doctests want to override the file. Simplify it by changing it to use `file!()`. Have doctests override `file!()` macro to achieve the current behavior. This allows us to remove the `file` helper and associated Kconfig options. Reviewed-by: David Gow <david@davidgow.net> Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260902-kunit-v2-1-eda3ed6c00c5@garyguo.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-10-02kbuild: add header check facility as a manually run static analyzerJani Nikula
There have been various attempts at adding a header test or check mechanism in the kernel build system. The header check primarily consists of ensuring headers are self-contained, have include guards, and, in some cases, pass kernel-doc. The main problems have been: - The dependency tracking creates undesirable artefacts (infamously also known as disgusting turds) in the build directory. - Gating the feature behind a kconfig option is complicated due to allyesconfig builds. It's possible, but requires a verbose and confusing negative proxy config option. - Naming the dependency tracking files with a dot prefix or placing them in a dot prefixed subdirectory in the build directory to hide them has been exceedingly difficult to achieve. (In part due to some Makefiles building files in subdirectory hierarchies.) - The debate which headers, if any, should really be self-contained is virtually open-ended. Approach the problem from a slightly different angle. Add a top level "headercheck" static analysis target which you have to explicitly run, and where you have to explicitly state which headers to check: $ make HEADER_CHECK="(headers|dirs)" headercheck For example: $ make HEADER_CHECK="include/drm drivers/gpu/drm/drm_draw_internal.h" headercheck You can specify multiple path/to/header.h or path/to/dir, relative to $(srctree), where path/to/dir is recursively scanned for any .h files. Add a generic %.header-check rule in scripts/Makefile.build to support this. Note that this rule should *not* be used in, say, driver or subsystem makefile targets, precisely because of the problems listed above. While this still generates the .header-check dependency tracking artefacts in the build directory, you will only get them as a result of manually running 'make headercheck', not as part of the regular build. This approach also allows anyone to check any headers in the tree, with no makefile modification or kconfig changes required. What you do with the results is up to you, and the header check facility does not enforce anything like it would as part of the regular build. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicolas Schier <nsc@kernel.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: linux-kbuild@vger.kernel.org Signed-off-by: Jani Nikula <jani.nikula@intel.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://patch.msgid.link/20260915104331.255636-1-jani.nikula@intel.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-10-02scripts: add TOML config to container toolGuillaume Tucker
Add support for a TOML configuration file to the scripts/container tool. This improves user experience by not having to keep passing the same command line options all the time or overly relying on built-in default values. Include the concept of 'profiles' with different named sections in the file to cover various use cases. Command line options take precedence over the config file, and values defined in profile sections take precedence over the default one. Add a -c option to override the location of the .container.toml config file which should otherwise be located in the current working directory. If not found, the file is silently ignored as it is not strictly required unless the -c option is used. Add a -p option to choose a particular profile section in the config file rather than the default. Signed-off-by: Guillaume Tucker <gtucker@gtucker.io> Acked-by: Nicolas Schier <n.schier@fritz.com> Link: https://patch.msgid.link/68b14a76a4cb2e6437c869bab948983a98acffbd.1788779245.git.gtucker@gtucker.io Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-30rust: doctest: trim function name for reproducibilityGary Guo
Currently rustdoc will generate function names like "_doctest_main__home_gary_Projects_linux_rust_kernel_io_rs_824_0" for a doctest located at rust/kernel/io.rs:824, when building with separate outdir using `O=`. This creates overlong symbol names and is also not reproducible. [ `rustdoc` already remaps these paths when we use Rust >= 1.95, thus this fix is needed for older toolchains. - Miguel ] Fix it by doing a custom remapping to trim it to something like `_doctest_main_rust_kernel_io_rs_824_0`. Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260924005052.2805129-1-gary@kernel.org [ Added `TODO` comment about the minimum version bump. Reworded title and comment for typos. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-09-30kconfig: tests: {old,save}defconfig: Forward dynamic keyword argumentsNicolas Schier
Let kconfig test framework forward dynamic keyword arguments for 'olddefconfig' and 'savedefconfig' and update the _run_conf() calls in warn_changed_input to use the corrsponding wrappers instead. The warn_changed_input test needed to use _run_conf() as the {old,save}defconfig wrapper did not provide the necessary flexibility for common calls. With dynamic keyword arguments, there is no need to use the framework-internal _run_conf() any more. Reviewed-by: Julian Braha <julianbraha@gmail.com> Signed-off-by: Nicolas Schier <n.schier@fritz.com> Link: https://patch.msgid.link/20260929-kconfig-tests-minor-updates-v2-4-c5902bee1d0c@fritz.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-30kconfig: tests: warn_changed_input: Simplify by reusing the extra envNicolas Schier
Define the extra environment once and re-use it for the respective _run_conf() calls to increase readability. Reviewed-by: Julian Braha <julianbraha@gmail.com> Signed-off-by: Nicolas Schier <n.schier@fritz.com> Link: https://patch.msgid.link/20260929-kconfig-tests-minor-updates-v2-3-c5902bee1d0c@fritz.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-30kconfig: tests: Provide defconfig outfile for savedefconfigNicolas Schier
Let kconfig test framework's 'savedefconfig' forward the requested output 'defconfig' filename to 'conf'. The original implementation was calling 'conf' with '--savedefconfig' but missed the mandatory filename for the defconfig output file. While at it, honour the 'dot_config' argument which points to the input config file. Fixes: 022a4bf6b59d ("kconfig: tests: add framework for Kconfig unit testing") Reviewed-by: Julian Braha <julianbraha@gmail.com> Signed-off-by: Nicolas Schier <n.schier@fritz.com> Link: https://patch.msgid.link/20260929-kconfig-tests-minor-updates-v2-2-c5902bee1d0c@fritz.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-30kconfig: tests: Reset all KCONFIG_* env variables by defaultNicolas Schier
Reset all environment variables with names starting with 'KCONFIG_' from the user-provided environment. This fixes the 'warn_changed_input' test on systems with KCONFIG_WARN_CHANGED_INPUT=1 and ensures a cleaner test environment. Fixes: 645323a7f4e5 ("kconfig: add optional warnings for changed input values") Signed-off-by: Nicolas Schier <n.schier@fritz.com> Reviewed-by: Julian Braha <julianbraha@gmail.com> Link: https://patch.msgid.link/20260929-kconfig-tests-minor-updates-v2-1-c5902bee1d0c@fritz.com Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-29kbuild: Move gen_init_cpio and gen_initramfs.sh to scripts/Nicolas Schier
gen_init_cpio and gen_initramfs.sh are part of kbuild and required for all kernel builds w/ CONFIG_BLK_DEV_INITRD. Move both to scripts/ to be more clear about their importance. Link: https://lore.kernel.org/all/aSdrCFkUQup3qb-q@derry.ads.avm.de/ Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Nicolas Schier <nsc@kernel.org> Link: https://patch.msgid.link/20260928-move-gen_init_cpio-to-scripts-v4-2-f437a33c40ac@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26kbuild: compress the kernel with pigz if availableLorenzo Stoakes (ARM)
The gzip step of a kernel build is very lengthy, especially for larger builds such as allmodconfig. gzip itself cannot be run in parallel, however an alternative tool exists that can, providing the same feature set as gzip itself - pigz - which works as a drop-in replacement. On a 128-core Threadripper, gzip -9 of a 36 MiB x86-64 vmlinux.bin takes 1.6s, and with pigz it takes 0.09s, so the performance increase is significant. Therefore introduce the KPGZIP build variable which specifies the compressor to use for the kernel image and default it to pigz if available, or KGZIP otherwise (which itself defaults to gzip). Modules, packaging and the embedded kernel configuration (CONFIG_IKCONFIG) continue to use KGZIP which defaults to a single-threaded gzip instance. Module compression is run in parallel by make, so pigz offers no benefit there, packaging sits outside the build and the embedded configuration is too small to matter. pigz is executed using scripts/jobserver-exec, which reserves the job slots make has free - necessary, as otherwise pigz would just grab unbounded CPUs. The kernel image compression step is always performed at the end of the build so should typically have all job slots available. pigz always provides byte-for-byte identical output across runs regardless of thread count, but pigz and gzip are not guaranteed to generate the same binary output, so reproducible builds must use the same tools consistently. Also update Documentation/kbuild/kbuild.rst to describe KPGZIP and Documentation/process/changes.rst to list the optional pigz dependency. While there, add entries for the other compressor programs. Finally, update scripts/ver_linux to include the pigz version there. Every x86 build ends with the compression of vmlinux.bin, 36MB for defconfig and over 200MB for allmodconfig, no-op builds are unchanged. Whole build, 128-thread Threadripper 9980X, best of N runs: before after delta ------------------------------- x86 defconfig, touch mm/vma.c, gcc 7.7s 6.0s -1.7s (-22%) x86 defconfig, touch mm/vma.c, clang 6.9s 5.4s -1.5s (-21%) x86 defconfig, clean, gcc 28.2s 26.3s -1.8s (-6%) x86 defconfig, clean, clang 28.7s 27.2s -1.5s (-5%) x86 allmodconfig, touch mm/vma.c, gcc 23.7s 15.4s -8.3s (-35%) x86 allmodconfig, touch mm/vma.c, clang 22.5s 15.6s -7.0s (-31%) x86 allmodconfig, clean, gcc 294.1s 278.6s -15.5s (-5%) x86 allmodconfig, clean, clang 283.9s 266.8s -17.1s (-6%) Suggested-by: Kees Cook <kees@kernel.org> Link: https://zlib.net/pigz/ Assisted-by: LLM Reviewed-by: Manuel Ebner <manuelebnerli@mailbox.org> Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-22-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26kbuild: avoid re-running compiler and linker probesLorenzo Stoakes (ARM)
Each kernel make invocation begins with ~30 compiler and linker runs each of which performs duplicate probe for a number of compiler and linker options. This is useless work - the compiler and its version is known, so use these to determine which options are available, once. Using the newly introduced cc-option-str, track the result of each probe in CC_OPT_*, LD_OPT_* variables and have Makefile's simply append the symbol. Some care has to be taken around negative options, i.e. -Wno-xxx, as gcc accepts an unknown -Wno- without complaint and only complains later, so instead probe the positive form for these cases. Use CC_HAS_* For those probes that gate a Makefile conditional rather than a simple option, as per the established pattern for this. This change avoids a subtle issue with ppc32 (big endian) - clang doesn't accept -fno-stack-clash-protection on this sub-target, so keep this option in the Makefile. With gcc and clang, defconfig and allmodconfig, the recorded command lines are unchanged, a build with nothing to do rebuilds nothing and W=1 continues to function correctly. Doing this improves all builds, but has a particularly positive impact on no-op builds (builds where nothing has changed). Whole build, 128-thread Threadripper 9980X, best of N runs: before after delta ------------------------------- x86 defconfig, no-op make, gcc 0.78s 0.60s -0.18s (-23%) x86 defconfig, no-op make, clang 0.94s 0.66s -0.28s (-30%) x86 defconfig, touch mm/vma.c, gcc 8.6s 8.5s -0.16s (-2%) x86 defconfig, touch mm/vma.c, clang 8.0s 7.7s -0.24s (-3%) x86 defconfig, clean, clang 29.8s 29.4s -0.37s (-1%) x86 allmodconfig, no-op make, gcc 12.9s 12.7s -0.23s (-2%) x86 allmodconfig, no-op make, clang 14.2s 13.9s -0.29s (-2%) x86 allmodconfig, touch mm/vma.c, clang 32.2s 31.9s -0.30s (-1%) Assisted-by: LLM Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-12-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26kbuild: move the toolchain checks into scripts/Kconfig.toolchainLorenzo Stoakes (ARM)
init/Kconfig opens with two hundred lines identifying the compiler, assembler, linker and rustc and probing which options they support, none of it to do with init. Move them into their own file, sourced from the top of init/Kconfig, so that the next commit can add to them without growing init/Kconfig further. Also update MAINTAINERS to put the new file in the KCONFIG entry. No functional change intended. Assisted-by: LLM Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-11-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26kallsyms: reimplement mksysmap in CLorenzo Stoakes (ARM)
mksysmap is a sed script consisting of 30 patterns which link-vmlinux.sh uses to generate *.syms files, and which kallsyms is then called against to generate *.kallsyms files, with the final vmlinux build ultimately generating System.map. For an x86-64 allmodconfig build, this involves three nm runs over a 250 MiB file and half a million lines written and read each time - 0.5s per pass for llvm-nm, and 0.2s for GNU nm, with parsing on top of that. This is unnecessary, instead have kallsyms simply read the ELF file directly making use of the existing elf-parse library in scripts/. This changes kallsyms such that its input is no longer the output from nm, but rather an ELF file. However, if the input file is empty, it outputs an empty table, which retains the same behaviour on first pass that the build system expects. System.map is byte-identical to nm | mksysmap for GNU nm and llvm-nm on two x86 configurations each, and for llvm-nm on arm64, arm, s390 and loongarch defconfigs, so are the kallsyms tables of every pass. Relinking vmlinux, link steps included: before after allmodconfig clang 9.1s 7.9s allmodconfig gcc 7.8s 7.6s defconfig clang 3.7s 3.0s defconfig gcc 3.5s 3.4s Whole build, 128-thread Threadripper 9980X, best of N runs: before after delta ------------------------------- x86 defconfig, touch mm/vma.c, gcc 9.1s 8.6s -0.43s (-5%) x86 defconfig, touch mm/vma.c, clang 9.0s 8.0s -1.1s (-12%) x86 defconfig, clean, gcc 29.5s 28.9s -0.64s (-2%) x86 defconfig, clean, clang 31.2s 29.8s -1.4s (-5%) x86 allmodconfig, touch mm/vma.c, gcc 35.8s 35.0s -0.77s (-2%) x86 allmodconfig, touch mm/vma.c, clang 35.8s 33.7s -2.0s (-6%) Assisted-by: LLM Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-8-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26elf-parse: add section flags, symbol binding and mapping helpersLorenzo Stoakes (ARM)
Extend elf-parse to be able to read the symbol table of vmlinux in kallsyms. This requires the ability to open ELF files in read-only mode, so provide elf_map_ro() to do so. It also requires accessors for section flags and symbol bindings, so provide these via shdr_flags() and sym_bind(). It's useful to be able to open an ELF file, map it, and then have easy access to its section headers, names and symbol table, so introduce struct elf_file to store this. In order to obtain this data also provide elf_open_ro() and elf_close(). Also, check for the file being an ELF file first in elf_parse(). This is the logical thing to check for first, but additionally prevents kallsyms from having to check this it self. Assisted-by: LLM Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-7-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26kbuild: only emit vmlinux relocations when requiredLorenzo Stoakes (ARM)
A kernel build consists of more than one linking pass on vmlinux.o and vmlinux, at minimum two, and with CONFIG_KALLSYMS and BTF enabled on x86-64 for example there are 5 such stages. For architectures that build their own relocation tables (x86, riscv, mips, s390), vmlinux is linked with the --emit-relocs parameter specified. However, this is only required on the final vmlinux link. Symbol tables of trial links preceding it don't need it because they already check that System.map matches kallsyms symbols on each build. GNU ld is slow at emitting relocation tables, so this results in a reduction in build time. Whole build, 128-thread Threadripper 9980X, best of N runs: before after delta ------------------------------- x86 defconfig, touch mm/vma.c, gcc 9.5s 9.1s -0.42s (-4%) x86 defconfig, clean, gcc 30.1s 29.5s -0.59s (-2%) x86 allmodconfig, touch mm/vma.c, gcc 37.2s 35.8s -1.4s (-4%) Note that this has little impact on LLVM ld which performs this operation more efficiently. Assisted-by: LLM Reviewed-by: Nicolas Schier <n.schier@fritz.com> Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-6-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26kbuild: do not sort nm output where the order is irrelevantLorenzo Stoakes (ARM)
Unless instructed otherwise, nm sorts by name. There are places where this is unnecessary - an invocation from scripts/sorttable every vmlinux link, scripts/check-function-names.sh run after every vmlinux.o link, and the x86 VOFFSET and ZOFFSET listings between vmlinux and bzImage. Both GNU nm and llvm-nm accept the same '-p' parameter to disable sorting in these instances, so use that to prevent this unnecessary work. Each nm run on its own, x86-64, median of 5: GNU nm 2.47 llvm-nm 22 before after delta before after delta defconfig sorttable, nm -S vmlinux 0.080s 0.039s -0.041s 0.265s 0.113s -0.152s check-function-names.sh 0.072s 0.033s -0.039s 0.244s 0.102s -0.142s VOFFSET 0.077s 0.034s -0.043s 0.261s 0.113s -0.148s ZOFFSET 0.007s 0.005s -0.002s 0.005s 0.005s 0.000s TOTAL -0.125s -0.442s allmodconfig sorttable, nm -S vmlinux 0.156s 0.063s -0.093s 0.539s 0.223s -0.316s check-function-names.sh 0.149s 0.054s -0.095s 0.537s 0.217s -0.320s VOFFSET 0.146s 0.052s -0.094s 0.524s 0.221s -0.303s ZOFFSET 0.007s 0.005s -0.002s 0.006s 0.004s -0.002s TOTAL -0.284s -0.941s llvm-nm appears to be a lot slower than GNU nm, so these builds naturally improve the most. The four run one after another in the serial tail of every build that links vmlinux so impact kernel builds directly. In an allmodconfig the decompressor is built in parallel while the modules, so only the two before the vmlinux link contribute to build time. The build outputs remain unchanged. Whole build, 128-thread Threadripper 9980X, best of N runs: before after delta --------------------------------- x86 defconfig, touch mm/vma.c, gcc 9.7s 9.5s -0.18s (-2%) x86 defconfig, touch mm/vma.c, clang 9.3s 9.0s -0.27s (-3%) x86 defconfig, clean, gcc 30.3s 30.1s -0.16s (-1%) x86 defconfig, clean, clang 31.7s 31.2s -0.55s (-2%) x86 allmodconfig, touch mm/vma.c, clang 36.4s 35.8s -0.67s (-2%) Assisted-by: LLM Reviewed-by: Nicolas Schier <n.schier@fritz.com> Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-5-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-09-26sorttable: parse nm output correctlyLorenzo Stoakes (ARM)
sorttable reads a list of functions from vmlinux, provided by the output of nm, with the -S flag specified providing function sizes. It does so using fscanf(fp, "%16s %16s %c %*s\n", ...) reading address, size, type (a single character) and name. However, nm outputs no size for a symbol which has none, meaning that it misinterprets these entries - interpreting the type character as the size, and, if the name is a single character, ignores the newline and swallows the address of the next entry. Size-less single character names exist (e.g. the assemblers' loop counters left over as local absolute symbols): 0000000000000001 a i 000000000000000f a i 0000000000000050 a j 0000000000000052 a t 000000000000009f a i 0000000000000200 a i sorttable is looking for functions and these are not that, and with nm's output sorted, it just so happens to be that what's swallowed is never a function. However the next commit in this series stops sorting nm's output, so this bug can results in function names being lost. Fix the issue by using '%*[^\n]' in fscanf() rather than '%*s' such that the scan cannot move past the newline. Then, compare the address and size fields (which are always padded to the same width if output by nm) - if they differ, then this is a misread, so simply discard the entry. It's fine to discard these, as sorttable's raison d'être is to discover whether a call site is contained within a function and an empty function can't contain anything. Assisted-by: LLM Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Link: https://patch.msgid.link/20260923-build-speedup-v4-4-73128809a4a4@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>