aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/include/asm-generic (follow)
AgeCommit message (Collapse)AuthorFilesLines
2025-06-03Merge tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linuxLinus Torvalds1-4/+6
Pull hyperv updates from Wei Liu: - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel) - Fixes for Hyper-V UIO driver (Long Li) - Fixes for Hyper-V PCI driver (Michael Kelley) - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley) - Documentation updates for Hyper-V VMBus (Michael Kelley) - Enhance logging for hv_kvp_daemon (Shradha Gupta) * tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits) Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir Documentation: hyperv: Update VMBus doc with new features and info PCI: hv: Remove unnecessary flex array in struct pci_packet Drivers: hv: Remove hv_alloc/free_* helpers Drivers: hv: Use kzalloc for panic page allocation uio_hv_generic: Align ring size to system page uio_hv_generic: Use correct size for interrupt and monitor pages Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary arch/x86: Provide the CPU number in the wakeup AP callback x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap() PCI: hv: Get vPCI MSI IRQ domain from DeviceTree ACPI: irq: Introduce acpi_get_gsi_dispatcher() Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device() Drivers: hv: vmbus: Get the IRQ number from DeviceTree dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties arm64, x86: hyperv: Report the VTL the system boots in arm64: hyperv: Initialize the Virtual Trust Level field Drivers: hv: Provide arch-neutral implementation of get_vtl() Drivers: hv: Enable VTL mode for arm64 ...
2025-06-03Merge tag 'v6.16-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds1-0/+1
Pull crypto fixes from Herbert Xu: "Fix a loongarch header regression and a module name collision on s390" * tag 'v6.16-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: asm-generic: Add sched.h inclusion in simd.h crypto: s390/sha256 - rename module to sha256-s390
2025-06-02Merge tag 'mm-stable-2025-06-01-14-06' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-10/+36
Pull more MM updates from Andrew Morton: - "zram: support algorithm-specific parameters" from Sergey Senozhatsky adds infrastructure for passing algorithm-specific parameters into zram. A single parameter `winbits' is implemented at this time. - "memcg: nmi-safe kmem charging" from Shakeel Butt makes memcg charging nmi-safe, which is required by BFP, which can operate in NMI context. - "Some random fixes and cleanup to shmem" from Kemeng Shi implements small fixes and cleanups in the shmem code. - "Skip mm selftests instead when kernel features are not present" from Zi Yan fixes some issues in the MM selftest code. - "mm/damon: build-enable essential DAMON components by default" from SeongJae Park reworks DAMON Kconfig to make it easier to enable CONFIG_DAMON. - "sched/numa: add statistics of numa balance task migration" from Libo Chen adds more info into sysfs and procfs files to improve visibility into the NUMA balancer's task migration activity. - "selftests/mm: cow and gup_longterm cleanups" from Mark Brown provides various updates to some of the MM selftests to make them play better with the overall containing framework. * tag 'mm-stable-2025-06-01-14-06' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (43 commits) mm/khugepaged: clean up refcount check using folio_expected_ref_count() selftests/mm: fix test result reporting in gup_longterm selftests/mm: report unique test names for each cow test selftests/mm: add helper for logging test start and results selftests/mm: use standard ksft_finished() in cow and gup_longterm selftests/damon/_damon_sysfs: skip testcases if CONFIG_DAMON_SYSFS is disabled sched/numa: add statistics of numa balance task sched/numa: fix task swap by skipping kernel threads tools/testing: check correct variable in open_procmap() tools/testing/vma: add missing function stub mm/gup: update comment explaining why gup_fast() disables IRQs selftests/mm: two fixes for the pfnmap test mm/khugepaged: fix race with folio split/free using temporary reference mm: add CONFIG_PAGE_BLOCK_ORDER to select page block order mmu_notifiers: remove leftover stub macros selftests/mm: deduplicate test names in madv_populate kcov: rust: add flags for KCOV with Rust mm: rust: make CONFIG_MMU ifdefs more narrow mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables() mm/damon/Kconfig: enable CONFIG_DAMON by default ...
2025-05-31mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables()Roman Gushchin1-10/+36
Commit b67fbebd4cf9 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas") added a forced tlbflush to tlb_vma_end(), which is required to avoid a race between munmap() and unmap_mapping_range(). However it added some overhead to other paths where tlb_vma_end() is used, but vmas are not removed, e.g. madvise(MADV_DONTNEED). Fix this by moving the tlb flush out of tlb_end_vma() into new tlb_flush_vmas() called from free_pgtables(), somewhat similar to the stable version of the original commit: commit 895428ee124a ("mm: Force TLB flush for PFNMAP mappings before unlink_file_vma()"). Note, that if tlb->fullmm is set, no flush is required, as the whole mm is about to be destroyed. Link: https://lkml.kernel.org/r/20250522012838.163876-1-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Jann Horn <jannh@google.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Nick Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds4-9/+47
Pull MM updates from Andrew Morton: - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - "Always call constructor for kernel page tables" from Kevin Brodsky ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - "vmscan: enforce mems_effective during demotion" from Gregory Price changes reclaim to respect cpuset.mems_effective during demotion when possible. because presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently. - "Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. * tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits) mm: pcp: increase pcp->free_count threshold to trigger free_high mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range() mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page mm/hugetlb: pass folio instead of page to unmap_ref_private() memcg: objcg stock trylock without irq disabling memcg: no stock lock for cpu hot-unplug memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs memcg: make count_memcg_events re-entrant safe against irqs memcg: make mod_memcg_state re-entrant safe against irqs memcg: move preempt disable to callers of memcg_rstat_updated memcg: memcg_rstat_updated re-entrant safe against irqs mm: khugepaged: decouple SHMEM and file folios' collapse selftests/eventfd: correct test name and improve messages alloc_tag: check mem_profiling_support in alloc_tag_init Docs/damon: update titles and brief introductions to explain DAMOS selftests/damon/_damon_sysfs: read tried regions directories in order mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject() mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat() mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs ...
2025-05-30asm-generic: Add sched.h inclusion in simd.hHuacai Chen1-0/+1
Commit 7ba8df47810f073 ("asm-generic: Make simd.h more resilient") causes a build error for PREEMPT_RT kernels: CC lib/crypto/sha256.o In file included from ./include/asm-generic/simd.h:6, from ./arch/loongarch/include/generated/asm/simd.h:1, from ./include/crypto/internal/simd.h:9, from ./include/crypto/internal/sha2.h:6, from lib/crypto/sha256.c:15: ./include/asm-generic/simd.h: In function 'may_use_simd': ./include/linux/preempt.h:111:34: error: 'current' undeclared (first use in this function) 111 | # define softirq_count() (current->softirq_disable_cnt & SOFTIRQ_MASK) | ^~~~~~~ ./include/linux/preempt.h:112:82: note: in expansion of macro 'softirq_count' 112 | # define irq_count() ((preempt_count() & (NMI_MASK | HARDIRQ_MASK)) | softirq_count()) | ^~~~~~~~~~~~~ ./include/linux/preempt.h:143:34: note: in expansion of macro 'irq_count' 143 | #define in_interrupt() (irq_count()) | ^~~~~~~~~ ./include/asm-generic/simd.h:18:17: note: in expansion of macro 'in_interrupt' 18 | return !in_interrupt(); | ^~~~~~~~~~~~ So add sched.h inclusion in simd.h to fix it. Fixes: 7ba8df47810f073 ("asm-generic: Make simd.h more resilient") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-05-28Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextLinus Torvalds1-1/+2
Pull bpf updates from Alexei Starovoitov: - Fix and improve BTF deduplication of identical BTF types (Alan Maguire and Andrii Nakryiko) - Support up to 12 arguments in BPF trampoline on arm64 (Xu Kuohai and Alexis Lothoré) - Support load-acquire and store-release instructions in BPF JIT on riscv64 (Andrea Parri) - Fix uninitialized values in BPF_{CORE,PROBE}_READ macros (Anton Protopopov) - Streamline allowed helpers across program types (Feng Yang) - Support atomic update for hashtab of BPF maps (Hou Tao) - Implement json output for BPF helpers (Ihor Solodrai) - Several s390 JIT fixes (Ilya Leoshkevich) - Various sockmap fixes (Jiayuan Chen) - Support mmap of vmlinux BTF data (Lorenz Bauer) - Support BPF rbtree traversal and list peeking (Martin KaFai Lau) - Tests for sockmap/sockhash redirection (Michal Luczaj) - Introduce kfuncs for memory reads into dynptrs (Mykyta Yatsenko) - Add support for dma-buf iterators in BPF (T.J. Mercier) - The verifier support for __bpf_trap() (Yonghong Song) * tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (135 commits) bpf, arm64: Remove unused-but-set function and variable. selftests/bpf: Add tests with stack ptr register in conditional jmp bpf: Do not include stack ptr register in precision backtracking bookkeeping selftests/bpf: enable many-args tests for arm64 bpf, arm64: Support up to 12 function arguments bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem() bpf: Avoid __bpf_prog_ret0_warn when jit fails bpftool: Add support for custom BTF path in prog load/loadall selftests/bpf: Add unit tests with __bpf_trap() kfunc bpf: Warn with __bpf_trap() kfunc maybe due to uninitialized variable bpf: Remove special_kfunc_set from verifier selftests/bpf: Add test for open coded dmabuf_iter selftests/bpf: Add test for dmabuf_iter bpf: Add open coded dmabuf iterator bpf: Add dmabuf iterator dma-buf: Rename debugfs symbols bpf: Fix error return value in bpf_copy_from_user_dynptr libbpf: Use mmap to parse vmlinux BTF from sysfs selftests: bpf: Add a test for mmapable vmlinux BTF btf: Allow mmap of vmlinux btf ...
2025-05-26Merge tag 'x86-core-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-2/+2
Pull core x86 updates from Ingo Molnar: "Boot code changes: - A large series of changes to reorganize the x86 boot code into a better isolated and easier to maintain base of PIC early startup code in arch/x86/boot/startup/, by Ard Biesheuvel. Motivation & background: | Since commit | | c88d71508e36 ("x86/boot/64: Rewrite startup_64() in C") | | dated Jun 6 2017, we have been using C code on the boot path in a way | that is not supported by the toolchain, i.e., to execute non-PIC C | code from a mapping of memory that is different from the one provided | to the linker. It should have been obvious at the time that this was a | bad idea, given the need to sprinkle fixup_pointer() calls left and | right to manipulate global variables (including non-pointer variables) | without crashing. | | This C startup code has been expanding, and in particular, the SEV-SNP | startup code has been expanding over the past couple of years, and | grown many of these warts, where the C code needs to use special | annotations or helpers to access global objects. This tree includes the first phase of this work-in-progress x86 boot code reorganization. Scalability enhancements and micro-optimizations: - Improve code-patching scalability (Eric Dumazet) - Remove MFENCEs for X86_BUG_CLFLUSH_MONITOR (Andrew Cooper) CPU features enumeration updates: - Thorough reorganization and cleanup of CPUID parsing APIs (Ahmed S. Darwish) - Fix, refactor and clean up the cacheinfo code (Ahmed S. Darwish, Thomas Gleixner) - Update CPUID bitfields to x86-cpuid-db v2.3 (Ahmed S. Darwish) Memory management changes: - Allow temporary MMs when IRQs are on (Andy Lutomirski) - Opt-in to IRQs-off activate_mm() (Andy Lutomirski) - Simplify choose_new_asid() and generate better code (Borislav Petkov) - Simplify 32-bit PAE page table handling (Dave Hansen) - Always use dynamic memory layout (Kirill A. Shutemov) - Make SPARSEMEM_VMEMMAP the only memory model (Kirill A. Shutemov) - Make 5-level paging support unconditional (Kirill A. Shutemov) - Stop prefetching current->mm->mmap_lock on page faults (Mateusz Guzik) - Predict valid_user_address() returning true (Mateusz Guzik) - Consolidate initmem_init() (Mike Rapoport) FPU support and vector computing: - Enable Intel APX support (Chang S. Bae) - Reorgnize and clean up the xstate code (Chang S. Bae) - Make task_struct::thread constant size (Ingo Molnar) - Restore fpu_thread_struct_whitelist() to fix CONFIG_HARDENED_USERCOPY=y (Kees Cook) - Simplify the switch_fpu_prepare() + switch_fpu_finish() logic (Oleg Nesterov) - Always preserve non-user xfeatures/flags in __state_perm (Sean Christopherson) Microcode loader changes: - Help users notice when running old Intel microcode (Dave Hansen) - AMD: Do not return error when microcode update is not necessary (Annie Li) - AMD: Clean the cache if update did not load microcode (Boris Ostrovsky) Code patching (alternatives) changes: - Simplify, reorganize and clean up the x86 text-patching code (Ingo Molnar) - Make smp_text_poke_batch_process() subsume smp_text_poke_batch_finish() (Nikolay Borisov) - Refactor the {,un}use_temporary_mm() code (Peter Zijlstra) Debugging support: - Add early IDT and GDT loading to debug relocate_kernel() bugs (David Woodhouse) - Print the reason for the last reset on modern AMD CPUs (Yazen Ghannam) - Add AMD Zen debugging document (Mario Limonciello) - Fix opcode map (!REX2) superscript tags (Masami Hiramatsu) - Stop decoding i64 instructions in x86-64 mode at opcode (Masami Hiramatsu) CPU bugs and bug mitigations: - Remove X86_BUG_MMIO_UNKNOWN (Borislav Petkov) - Fix SRSO reporting on Zen1/2 with SMT disabled (Borislav Petkov) - Restructure and harmonize the various CPU bug mitigation methods (David Kaplan) - Fix spectre_v2 mitigation default on Intel (Pawan Gupta) MSR API: - Large MSR code and API cleanup (Xin Li) - In-kernel MSR API type cleanups and renames (Ingo Molnar) PKEYS: - Simplify PKRU update in signal frame (Chang S. Bae) NMI handling code: - Clean up, refactor and simplify the NMI handling code (Sohil Mehta) - Improve NMI duration console printouts (Sohil Mehta) Paravirt guests interface: - Restrict PARAVIRT_XXL to 64-bit only (Kirill A. Shutemov) SEV support: - Share the sev_secrets_pa value again (Tom Lendacky) x86 platform changes: - Introduce the <asm/amd/> header namespace (Ingo Molnar) - i2c: piix4, x86/platform: Move the SB800 PIIX4 FCH definitions to <asm/amd/fch.h> (Mario Limonciello) Fixes and cleanups: - x86 assembly code cleanups and fixes (Uros Bizjak) - Misc fixes and cleanups (Andi Kleen, Andy Lutomirski, Andy Shevchenko, Ard Biesheuvel, Bagas Sanjaya, Baoquan He, Borislav Petkov, Chang S. Bae, Chao Gao, Dan Williams, Dave Hansen, David Kaplan, David Woodhouse, Eric Biggers, Ingo Molnar, Josh Poimboeuf, Juergen Gross, Malaya Kumar Rout, Mario Limonciello, Nathan Chancellor, Oleg Nesterov, Pawan Gupta, Peter Zijlstra, Shivank Garg, Sohil Mehta, Thomas Gleixner, Uros Bizjak, Xin Li)" * tag 'x86-core-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (331 commits) x86/bugs: Fix spectre_v2 mitigation default on Intel x86/bugs: Restructure ITS mitigation x86/xen/msr: Fix uninitialized variable 'err' x86/msr: Remove a superfluous inclusion of <asm/asm.h> x86/paravirt: Restrict PARAVIRT_XXL to 64-bit only x86/mm/64: Make 5-level paging support unconditional x86/mm/64: Make SPARSEMEM_VMEMMAP the only memory model x86/mm/64: Always use dynamic memory layout x86/bugs: Fix indentation due to ITS merge x86/cpuid: Rename hypervisor_cpuid_base()/for_each_possible_hypervisor_cpuid_base() to cpuid_base_hypervisor()/for_each_possible_cpuid_base_hypervisor() x86/cpu/intel: Rename CPUID(0x2) descriptors iterator parameter x86/cacheinfo: Rename CPUID(0x2) descriptors iterator parameter x86/cpuid: Rename cpuid_get_leaf_0x2_regs() to cpuid_leaf_0x2() x86/cpuid: Rename have_cpuid_p() to cpuid_feature() x86/cpuid: Set <asm/cpuid/api.h> as the main CPUID header x86/cpuid: Move CPUID(0x2) APIs into <cpuid/api.h> x86/msr: Add rdmsrl_on_cpu() compatibility wrapper x86/mm: Fix kernel-doc descriptions of various pgtable methods x86/asm-offsets: Export certain 'struct cpuinfo_x86' fields for 64-bit asm use too x86/boot: Defer initialization of VM space related global variables ...
2025-05-23btf: Allow mmap of vmlinux btfLorenz Bauer1-1/+2
User space needs access to kernel BTF for many modern features of BPF. Right now each process needs to read the BTF blob either in pieces or as a whole. Allow mmaping the sysfs file so that processes can directly access the memory allocated for it in the kernel. remap_pfn_range is used instead of vm_insert_page due to aarch64 compatibility issues. Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Link: https://lore.kernel.org/bpf/20250520-vmlinux-mmap-v5-1-e8c941acc414@isovalent.com
2025-05-23Drivers: hv: Remove hv_alloc/free_* helpersLong Li1-4/+0
There are no users for those functions, remove them. Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1746492997-4599-6-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1746492997-4599-6-git-send-email-longli@linuxonhyperv.com>
2025-05-23Drivers: hv: Provide arch-neutral implementation of get_vtl()Roman Kisel1-0/+6
To run in the VTL mode, Hyper-V drivers have to know what VTL the system boots in, and the arm64/hyperv code does not have the means to compute that. Refactor the code to hoist the function that detects VTL, make it arch-neutral to be able to employ it to get the VTL on arm64. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/20250428210742.435282-5-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-5-romank@linux.microsoft.com>
2025-05-12mm: implement for_each_valid_pfn() for CONFIG_FLATMEMDavid Woodhouse1-1/+9
In the FLATMEM case, the default pfn_valid() just checks that the PFN is within the range [ ARCH_PFN_OFFSET .. ARCH_PFN_OFFSET + max_mapnr ). The for_each_valid_pfn() function can therefore be a simple for() loop using those as min/max respectively. Link: https://lkml.kernel.org/r/20250423133821.789413-3-dwmw2@infradead.org Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Ruihan Li <lrh2000@pku.edu.cn> Cc: Will Deacon <will@kernel.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11mm: call ctor/dtor for kernel PTEsKevin Brodsky1-1/+6
Since [1], constructors/destructors are expected to be called for all page table pages, at all levels and for both user and kernel pgtables. There is however one glaring exception: kernel PTEs are managed via separate helpers (pte_alloc_kernel/pte_free_kernel), which do not call the [cd]tor, at least not in the generic implementation. The most obvious reason for this anomaly is that init_mm is special-cased not to use split page table locks. As a result calling ptlock_init() for PTEs associated with init_mm would be wasteful, potentially resulting in dynamic memory allocation. However, pgtable [cd]tors perform other actions - currently related to accounting/statistics, and potentially more functionally significant in the future. Now that pagetable_pte_ctor() is passed the associated mm, we can make it skip the call to ptlock_init() for init_mm; this allows us to call the ctor from pte_alloc_one_kernel() too. This is matched by a call to the pgtable destructor in pte_free_kernel(); no special-casing is needed on that path, as ptlock_free() is already called unconditionally. (ptlock_free() is a no-op unless a ptlock was allocated for the given PTP.) This patch ensures that all architectures that rely on <asm-generic/pgalloc.h> call the [cd]tor for kernel PTEs. pte_free_kernel() cannot be overridden so changing the generic implementation is sufficient. pte_alloc_one_kernel() can be overridden using __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL, and a few architectures implement it by calling the page allocator directly. We amend those so that they call the generic __pte_alloc_one_kernel() instead, if possible, ensuring that the ctor is called. A few architectures do not use <asm-generic/pgalloc.h>; those will be taken care of separately. [1] https://lore.kernel.org/linux-mm/20250103184415.2744423-1-kevin.brodsky@arm.com/ Link: https://lkml.kernel.org/r/20250408095222.860601-4-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> # s390 Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Linus Waleij <linus.walleij@linaro.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Will Deacon <will@kernel.org> Cc: <x86@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11mm: pass mm down to pagetable_{pte,pmd}_ctorKevin Brodsky1-2/+2
Patch series "Always call constructor for kernel page tables", v2. There has been much confusion around exactly when page table constructors/destructors (pagetable_*_[cd]tor) are supposed to be called. They were initially introduced for user PTEs only (to support split page table locks), then at the PMD level for the same purpose. Accounting was added later on, starting at the PTE level and then moving to higher levels (PMD, PUD). Finally, with my earlier series "Account page tables at all levels" [1], the ctor/dtor is run for all levels, all the way to PGD. I thought this was the end of the story, and it hopefully is for user pgtables, but I was wrong for what concerns kernel pgtables. The current situation there makes very little sense: * At the PTE level, the ctor/dtor is not called (at least in the generic implementation). Specific helpers are used for kernel pgtables at this level (pte_{alloc,free}_kernel()) and those have never called the ctor/dtor, most likely because they were initially irrelevant in the kernel case. * At all other levels, the ctor/dtor is normally called. This is potentially wasteful at the PMD level (more on that later). This series aims to ensure that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. Besides consistency, the main motivation is to guarantee that ctor/dtor hooks are systematically called; this makes it possible to insert hooks to protect page tables [2], for instance. There is however an extra challenge: split locks are not used for kernel pgtables, and it would therefore be wasteful to initialise them (ptlock_init()). It is worth clarifying exactly when split locks are used. They clearly are for user pgtables, but as illustrated in commit 61444cde9170 ("ARM: 8591/1: mm: use fully constructed struct pages for EFI pgd allocations"), they also are for special page tables like efi_mm. The one case where split locks are definitely unused is pgtables owned by init_mm; this is consistent with the behaviour of apply_to_pte_range(). The approach chosen in this series is therefore to pass the mm associated to the pgtables being constructed to pagetable_{pte,pmd}_ctor() (patch 1), and skip ptlock_init() if mm == &init_mm (patch 3 and 7). This makes it possible to call the PTE ctor/dtor from pte_{alloc,free}_kernel() without unintended consequences (patch 3). As a result the accounting functions are now called at all levels for kernel pgtables, and split locks are never initialised. In configurations where ptlocks are dynamically allocated (32-bit, PREEMPT_RT, etc.) and ARCH_ENABLE_SPLIT_PMD_PTLOCK is selected, this series results in the removal of a kmem_cache allocation for every kernel PMD. Additionally, for certain architectures that do not use <asm-generic/pgalloc.h> such as s390, the same optimisation occurs at the PTE level. === Things get more complicated when it comes to special pgtable allocators (patch 8-12). All architectures need such allocators to create initial kernel pgtables; we are not concerned with those as the ctor cannot be called so early in the boot sequence. However, those allocators may also be used later in the boot sequence or during normal operations. There are two main use-cases: 1. Mapping EFI memory: efi_mm (arm, arm64, riscv) 2. arch_add_memory(): init_mm The ctor is already explicitly run (at the PTE/PMD level) in the first case, as required for pgtables that are not associated with init_mm. However the same allocators may also be used for the second use-case (or others), and this is where it gets messy. Patch 1 calls the ctor with NULL as mm in those situations, as the actual mm isn't available. Practically this means that ptlocks will be unconditionally initialised. This is fine on arm - create_mapping_late() is only used for the EFI mapping. On arm64, __create_pgd_mapping() is also used by arch_add_memory(); patch 8/9/11 ensure that ctors are called at all levels with the appropriate mm. The situation is similar on riscv, but propagating the mm down to the ctor would require significant refactoring. Since they are already called unconditionally, this series leaves riscv no worse off - patch 10 adds comments to clarify the situation. From a cursory look at other architectures implementing arch_add_memory(), s390 and x86 may also need a similar treatment to add constructor calls. This is to be taken care of in a future version or as a follow-up. === The complications in those special pgtable allocators beg the question: does it really make sense to treat efi_mm and init_mm differently in e.g. apply_to_pte_range()? Maybe what we really need is a way to tell if an mm corresponds to user memory or not, and never use split locks for non-user mm's. Feedback and suggestions welcome! This patch (of 12): In preparation for calling constructors for all kernel page tables while eliding unnecessary ptlock initialisation, let's pass down the associated mm to the PTE/PMD level ctors. (These are the two levels where ptlocks are used.) In most cases the mm is already around at the point of calling the ctor so we simply pass it down. This is however not the case for special page table allocators: * arch/arm/mm/mmu.c * arch/arm64/mm/mmu.c * arch/riscv/mm/init.c In those cases, the page tables being allocated are either for standard kernel memory (init_mm) or special page directories, which may not be associated to any mm. For now let's pass NULL as mm; this will be refined where possible in future patches. No functional change in this patch. Link: https://lore.kernel.org/linux-mm/20250103184415.2744423-1-kevin.brodsky@arm.com/ [1] Link: https://lore.kernel.org/linux-hardening/20250203101839.1223008-1-kevin.brodsky@arm.com/ [2] Link: https://lkml.kernel.org/r/20250408095222.860601-1-kevin.brodsky@arm.com Link: https://lkml.kernel.org/r/20250408095222.860601-2-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Linus Waleij <linus.walleij@linaro.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: <x86@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11syscall.h: introduce syscall_set_nr()Dmitry V. Levin1-0/+14
Similar to syscall_set_arguments() that complements syscall_get_arguments(), introduce syscall_set_nr() that complements syscall_get_nr(). syscall_set_nr() is going to be needed along with syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK architectures to implement PTRACE_SET_SYSCALL_INFO API. Link: https://lkml.kernel.org/r/20250303112020.GD24170@strace.io Signed-off-by: Dmitry V. Levin <ldv@strace.io> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Helge Deller <deller@gmx.de> # parisc Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk> # mips Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexey Gladkov (Intel) <legion@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: anton ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Zankel <chris@zankel.net> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Davide Berardi <berardi.dav@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Eugene Syromiatnikov <esyr@redhat.com> Cc: Eugene Syromyatnikov <evgsyr@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonas Bonn <jonas@southpole.se> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Naveen N Rao <naveen@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Renzo Davoi <renzo@cs.unibo.it> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russel King <linux@armlinux.org.uk> Cc: Shuah Khan <shuah@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11syscall.h: add syscall_set_arguments()Dmitry V. Levin1-0/+16
This function is going to be needed on all HAVE_ARCH_TRACEHOOK architectures to implement PTRACE_SET_SYSCALL_INFO API. This partially reverts commit 7962c2eddbfe ("arch: remove unused function syscall_set_arguments()") by reusing some of old syscall_set_arguments() implementations. [nathan@kernel.org: fix compile time fortify checks] Link: https://lkml.kernel.org/r/20250408213131.GA2872426@ax162 Link: https://lkml.kernel.org/r/20250303112009.GC24170@strace.io Signed-off-by: Dmitry V. Levin <ldv@strace.io> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Helge Deller <deller@gmx.de> # parisc Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk> [mips] Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexey Gladkov (Intel) <legion@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: anton ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Zankel <chris@zankel.net> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Davide Berardi <berardi.dav@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Eugene Syromiatnikov <esyr@redhat.com> Cc: Eugene Syromyatnikov <evgsyr@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonas Bonn <jonas@southpole.se> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Naveen N Rao <naveen@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Renzo Davoi <renzo@cs.unibo.it> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russel King <linux@armlinux.org.uk> Cc: Shuah Khan <shuah@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11mm: remove mk_huge_pte()Matthew Wilcox (Oracle)1-5/+0
The only remaining user of mk_huge_pte() is the debug code, so remove the API and replace its use with pfn_pte() which lets us remove the conversion to a page first. We should always call arch_make_huge_pte() to turn this PTE into a huge PTE before operating on it with huge_pte_mkdirty() etc. Link: https://lkml.kernel.org/r/20250402181709.2386022-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Muchun Song <muchun.song@linux.dev> Cc: Richard Weinberger <richard@nod.at> Cc: <x86@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-22vmlinux.lds: Include .data.rel[.local] into .data sectionArd Biesheuvel1-2/+2
When running in -fPIC mode, the compiler may decide to emit statically initialized data objects into .data.rel or .data.rel.local if they contain absolute references to global or local objects, respectively, which require fixing up at load time. This distinction is irrelevant for the kernel, so fold .data.rel and .data.rel.local into .data. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Dionna Amalie Glaze <dionnaglaze@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Loughlin <kevinloughlin@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20250418141253.2601348-9-ardb+git@google.com
2025-04-16asm-generic: Make simd.h more resilientHerbert Xu1-1/+7
Add missing header inclusions and protect against double inclusion. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-04-04Merge tag 'riscv-for-linus-6.15-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linuxLinus Torvalds1-8/+0
Pull RISC-V updates from Palmer Dabbelt: - The sub-architecture selection Kconfig system has been cleaned up, the documentation has been improved, and various detections have been fixed - The vector-related extensions dependencies are now validated when parsing from device tree and in the DT bindings - Misaligned access probing can be overridden via a kernel command-line parameter, along with various fixes to misalign access handling - Support for relocatable !MMU kernels builds - Support for hpge pfnmaps, which should improve TLB utilization - Support for runtime constants, which improves the d_hash() performance - Support for bfloat16, Zicbom, Zaamo, Zalrsc, Zicntr, Zihpm - Various fixes, including: - We were missing a secondary mmu notifier call when flushing the tlb which is required for IOMMU - Fix ftrace panics by saving the registers as expected by ftrace - Fix a couple of stimecmp usage related to cpu hotplug - purgatory_start is now aligned as per the STVEC requirements - A fix for hugetlb when calculating the size of non-present PTEs * tag 'riscv-for-linus-6.15-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (65 commits) riscv: Add norvc after .option arch in runtime const riscv: Make sure toolchain supports zba before using zba instructions riscv/purgatory: 4B align purgatory_start riscv/kexec_file: Handle R_RISCV_64 in purgatory relocator selftests: riscv: fix v_exec_initval_nolibc.c riscv: Fix hugetlb retrieval of number of ptes in case of !present pte riscv: print hartid on bringup riscv: Add norvc after .option arch in runtime const riscv: Remove CONFIG_PAGE_OFFSET riscv: Support CONFIG_RELOCATABLE on riscv32 asm-generic: Always define Elf_Rel and Elf_Rela riscv: Support CONFIG_RELOCATABLE on NOMMU riscv: Allow NOMMU kernels to access all of RAM riscv: Remove duplicate CONFIG_PAGE_OFFSET definition RISC-V: errata: Use medany for relocatable builds dt-bindings: riscv: document vector crypto requirements dt-bindings: riscv: add vector sub-extension dependencies dt-bindings: riscv: d requires f RISC-V: add f & d extension validation checks RISC-V: add vector crypto extension validation checks ...
2025-04-01mm: pgtable: remove tlb_remove_page_ptdesc()Qi Zheng1-6/+0
The tlb_remove_ptdesc()/tlb_remove_table() is specially designed for page table pages, and now all architectures have been converted to use it to remove page table pages. So let's remove tlb_remove_page_ptdesc(), it currently has no users and should not be used for page table pages. Link: https://lkml.kernel.org/r/3df04c8494339073b71be4acb2d92e108ecd1b60.1740454179.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickens <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm: pgtable: change pt parameter of tlb_remove_ptdesc() to struct ptdesc*Qi Zheng1-1/+1
All callers of tlb_remove_ptdesc() pass it a pointer of struct ptdesc, so let's change the pt parameter from void * to struct ptdesc * to perform a type safety check. Link: https://lkml.kernel.org/r/60bb44299cf2d731df6592e446e7f694054d0dbe.1740454179.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickens <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01mm: pgtable: make generic tlb_remove_table() use struct ptdescQi Zheng1-3/+3
Patch series "remove tlb_remove_page_ptdesc()", v2. As suggested by Peter Zijlstra below [1], this series aims to remove tlb_remove_page_ptdesc(). : Fundamentally tlb_remove_page() is about removing *pages* as from a PTE, : there should not be a page-table anywhere near here *ever*. : : Yes, some architectures use tlb_remove_page() for page-tables too, but : that is more or less an implementation detail that can be fixed. After this series, all architectures use tlb_remove_table() or tlb_remove_ptdesc() to remove the page table pages. In the future, once all architectures using tlb_remove_table() have also converted to using struct ptdesc (eg. powerpc), it may be possible to use only tlb_remove_ptdesc(). [1] https://lore.kernel.org/linux-mm/20250103111457.GC22934@noisy.programming.kicks-ass.net/ This patch (of 6): Now only arm will call tlb_remove_ptdesc()/tlb_remove_table() when CONFIG_MMU_GATHER_TABLE_FREE is disabled. In this case, the type of the table parameter is actually struct ptdesc * instead of struct page *. Since struct ptdesc still overlaps with struct page and has not been separated from it, forcing the table parameter to struct page * will not cause any problems at this time. But this is definitely incorrect and needs to be fixed. So just like the generic __tlb_remove_table(), let generic tlb_remove_table() use struct ptdesc by default when CONFIG_MMU_GATHER_TABLE_FREE is disabled. Link: https://lkml.kernel.org/r/cover.1740454179.git.zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/5be8c3ab7bd68510bf0db4cf84010f4dfe372917.1740454179.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickens <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds4-38/+41
Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-30Merge tag 'bpf_res_spin_lock' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextLinus Torvalds3-0/+257
Pull bpf relisient spinlock support from Alexei Starovoitov: "This patch set introduces Resilient Queued Spin Lock (or rqspinlock with res_spin_lock() and res_spin_unlock() APIs). This is a qspinlock variant which recovers the kernel from a stalled state when the lock acquisition path cannot make forward progress. This can occur when a lock acquisition attempt enters a deadlock situation (e.g. AA, or ABBA), or more generally, when the owner of the lock (which we’re trying to acquire) isn’t making forward progress. Deadlock detection is the main mechanism used to provide instant recovery, with the timeout mechanism acting as a final line of defense. Detection is triggered immediately when beginning the waiting loop of a lock slow path. Additionally, BPF programs attached to different parts of the kernel can introduce new control flow into the kernel, which increases the likelihood of deadlocks in code not written to handle reentrancy. There have been multiple syzbot reports surfacing deadlocks in internal kernel code due to the diverse ways in which BPF programs can be attached to different parts of the kernel. By switching the BPF subsystem’s lock usage to rqspinlock, all of these issues are mitigated at runtime. This spin lock implementation allows BPF maps to become safer and remove mechanisms that have fallen short in assuring safety when nesting programs in arbitrary ways in the same context or across different contexts. We run benchmarks that stress locking scalability and perform comparison against the baseline (qspinlock). For the rqspinlock case, we replace the default qspinlock with it in the kernel, such that all spin locks in the kernel use the rqspinlock slow path. As such, benchmarks that stress kernel spin locks end up exercising rqspinlock. More details in the cover letter in commit 6ffb9017e932 ("Merge branch 'resilient-queued-spin-lock'")" * tag 'bpf_res_spin_lock' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (24 commits) selftests/bpf: Add tests for rqspinlock bpf: Maintain FIFO property for rqspinlock unlock bpf: Implement verifier support for rqspinlock bpf: Introduce rqspinlock kfuncs bpf: Convert lpm_trie.c to rqspinlock bpf: Convert percpu_freelist.c to rqspinlock bpf: Convert hashtab.c to rqspinlock rqspinlock: Add locktorture support rqspinlock: Add entry to Makefile, MAINTAINERS rqspinlock: Add macros for rqspinlock usage rqspinlock: Add basic support for CONFIG_PARAVIRT rqspinlock: Add a test-and-set fallback rqspinlock: Add deadlock detection and recovery rqspinlock: Protect waiters in trylock fallback from stalls rqspinlock: Protect waiters in queue from stalls rqspinlock: Protect pending bit owners from stalls rqspinlock: Hardcode cond_acquire loops for arm64 rqspinlock: Add support for timeouts rqspinlock: Drop PV and virtualization support rqspinlock: Add rqspinlock.h header ...
2025-03-27Merge tag 'asm-generic-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-genericLinus Torvalds2-29/+17
Pull asm-generic updates from Arnd Bergmann: "This is mainly set of cleanups of asm-generic/io.h, resolving problems with inconsistent semantics of ioread64/iowrite64 that were causing runtime and build issues. The "GENERIC_IOMAP" version that switches between inb()/outb() and readb()/writeb() style accessors is now only used on architectures that have PC-style ISA devices that are not memory mapped (x86, uml, m68k-q40 and powerpc-powernv), while alpha and parisc use a more complicated variant and everything else just maps the ioread interfaces to plan MMIO (readb/writeb etc). In addition there are two small changes from Raag Jadav to simplify the asm-generic/io.h indirect inclusions and from Jann Horn to fix a corner case with read_word_at_a_time" * tag 'asm-generic-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: rwonce: fix crash by removing READ_ONCE() for unaligned read rwonce: handle KCSAN like KASAN in read_word_at_a_time() m68k: coldfire: select PCI_IOMAP for PCI mips: export pci_iounmap() mips: fix PCI_IOBASE definition m68k/nommu: stop using GENERIC_IOMAP mips: drop GENERIC_IOMAP wrapper powerpc: asm/io.h: remove split ioread64/iowrite64 helpers parisc: stop using asm-generic/iomap.h sh: remove duplicate ioread/iowrite helpers alpha: stop using asm-generic/iomap.h io.h: drop unused headers drm/draw: include missing headers asm-generic/io.h: rework split ioread64/iowrite64 helpers
2025-03-26Merge patch series "riscv: Relocatable NOMMU kernels"Palmer Dabbelt1-8/+0
Samuel Holland <samuel.holland@sifive.com> says: Currently, RISC-V NOMMU kernels are linked at CONFIG_PAGE_OFFSET, and since they are not relocatable, must be loaded at this address as well. CONFIG_PAGE_OFFSET is not a user-visible Kconfig option, so its value is not obvious, and users must patch the kernel source if they want to load it at a different address. Make NOMMU kernels more portable by making them relocatable by default. This allows a single kernel binary to work when loaded at any address. * b4-shazam-merge: riscv: Remove CONFIG_PAGE_OFFSET riscv: Support CONFIG_RELOCATABLE on riscv32 asm-generic: Always define Elf_Rel and Elf_Rela riscv: Support CONFIG_RELOCATABLE on NOMMU riscv: Allow NOMMU kernels to access all of RAM riscv: Remove duplicate CONFIG_PAGE_OFFSET definition Link: https://lore.kernel.org/r/20241026171441.3047904-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-03-26asm-generic: Always define Elf_Rel and Elf_RelaSamuel Holland1-8/+0
These definitions are useful for relocating the kernel image as well, regardless of the type of relocations used for modules. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20241026171441.3047904-5-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-03-26rwonce: fix crash by removing READ_ONCE() for unaligned readJann Horn1-1/+6
When arm64 is built with LTO, it upgrades READ_ONCE() to ldar / ldapr (load-acquire) to avoid issues that can be caused by the compiler optimizing away implicit address dependencies. Unlike plain loads, these load-acquire instructions actually require an aligned address. For now, fix it by removing the READ_ONCE() that the buggy commit introduced. Fixes: ece69af2ede1 ("rwonce: handle KCSAN like KASAN in read_word_at_a_time()") Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/r/20250326203926.GA10484@ax162 Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2025-03-25Merge tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linuxLinus Torvalds1-4/+68
Pull hyperv updates from Wei Liu: - Add support for running as the root partition in Hyper-V (Microsoft Hypervisor) by exposing /dev/mshv (Nuno and various people) - Add support for CPU offlining in Hyper-V (Hamza Mahfooz) - Misc fixes and cleanups (Roman Kisel, Tianyu Lan, Wei Liu, Michael Kelley, Thorsten Blum) * tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits) x86/hyperv: fix an indentation issue in mshyperv.h x86/hyperv: Add comments about hv_vpset and var size hypercall input args Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs hyperv: Add definitions for root partition driver to hv headers x86: hyperv: Add mshv_handler() irq handler and setup function Drivers: hv: Introduce per-cpu event ring tail Drivers: hv: Export some functions for use by root partition module acpi: numa: Export node_to_pxm() hyperv: Introduce hv_recommend_using_aeoi() arm64/hyperv: Add some missing functions to arm64 x86/mshyperv: Add support for extended Hyper-V features hyperv: Log hypercall status codes as strings x86/hyperv: Fix check of return value from snp_set_vmsa() x86/hyperv: Add VTL mode callback for restarting the system x86/hyperv: Add VTL mode emergency restart callback hyperv: Remove unused union and structs hyperv: Add CONFIG_MSHV_ROOT to gate root partition support hyperv: Change hv_root_partition into a function hyperv: Convert hypercall statuses to linux error codes drivers/hv: add CPU offlining support ...
2025-03-25Merge tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-8/+19
Pull VDSO infrastructure updates from Thomas Gleixner: - Consolidate the VDSO storage The VDSO data storage and data layout has been largely architecture specific for historical reasons. That increases the maintenance effort and causes inconsistencies over and over. There is no real technical reason for architecture specific layouts and implementations. The architecture specific details can easily be integrated into a generic layout, which also reduces the amount of duplicated code for managing the mappings. Convert all architectures over to a unified layout and common mapping infrastructure. This splits the VDSO data layout into subsystem specific blocks, timekeeping, random and architecture parts, which provides a better structure and allows to improve and update the functionalities without conflict and interaction. - Rework the timekeeping data storage The current implementation is designed for exposing system timekeeping accessors, which was good enough at the time when it was designed. PTP and Time Sensitive Networking (TSN) change that as there are requirements to expose independent PTP clocks, which are not related to system timekeeping. Replace the monolithic data storage by a structured layout, which allows to add support for independent PTP clocks on top while reusing both the data structures and the time accessor implementations. * tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) sparc/vdso: Always reject undefined references during linking x86/vdso: Always reject undefined references during linking vdso: Rework struct vdso_time_data and introduce struct vdso_clock vdso: Move architecture related data before basetime data powerpc/vdso: Prepare introduction of struct vdso_clock arm64/vdso: Prepare introduction of struct vdso_clock x86/vdso: Prepare introduction of struct vdso_clock time/namespace: Prepare introduction of struct vdso_clock vdso/namespace: Rename timens_setup_vdso_data() to reflect new vdso_clock struct vdso/vsyscall: Prepare introduction of struct vdso_clock vdso/gettimeofday: Prepare helper functions for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_coarse_timens() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_coarse() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_hres_timens() for introduction of struct vdso_clock vdso/gettimeofday: Prepare do_hres() for introduction of struct vdso_clock vdso/gettimeofday: Prepare introduction of struct vdso_clock vdso/helpers: Prepare introduction of struct vdso_clock vdso/datapage: Define vdso_clock to prepare for multiple PTP clocks vdso: Make vdso_time_data cacheline aligned arm64: Make asm/cache.h compatible with vDSO ...
2025-03-25rwonce: handle KCSAN like KASAN in read_word_at_a_time()Jann Horn1-2/+5
read_word_at_a_time() is allowed to read out of bounds by straddling the end of an allocation (and the caller is expected to then mask off out-of-bounds data). This works as long as the caller guarantees that the access won't hit a pagefault (either by ensuring that addr is aligned or by explicitly checking where the next page boundary is). Such out-of-bounds data could include things like KASAN redzones, adjacent allocations that are concurrently written to, or simply an adjacent struct field that is concurrently updated. KCSAN should ignore racy reads of OOB data that is not actually used, just like KASAN, so (similar to the code above) change read_word_at_a_time() to use __no_sanitize_or_inline instead of __no_kasan_or_inline, and explicitly inform KCSAN that we're reading the first byte. We do have an instrument_read() helper that calls into both KASAN and KCSAN, but I'm instead open-coding that here to avoid having to pull the entire instrumented.h header into rwonce.h. Also, since this read can be racy by design, we should technically do READ_ONCE(), so add that. Fixes: dfd402a4c4ba ("kcsan: Add Kernel Concurrency Sanitizer infrastructure") Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Marco Elver <elver@google.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2025-03-24Merge tag 'x86-fpu-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+0
Pull x86/fpu updates from Ingo Molnar: - Improve crypto performance by making kernel-mode FPU reliably usable in softirqs ((Eric Biggers) - Fully optimize out WARN_ON_FPU() (Eric Biggers) - Initial steps to support Support Intel APX (Advanced Performance Extensions) (Chang S. Bae) - Fix KASAN for arch_dup_task_struct() (Benjamin Berg) - Refine and simplify the FPU magic number check during signal return (Chang S. Bae) - Fix inconsistencies in guest FPU xfeatures (Chao Gao, Stanislav Spassov) - selftests/x86/xstate: Introduce common code for testing extended states (Chang S. Bae) - Misc fixes and cleanups (Borislav Petkov, Colin Ian King, Uros Bizjak) * tag 'x86-fpu-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu/xstate: Fix inconsistencies in guest FPU xfeatures x86/fpu: Clarify the "xa" symbolic name used in the XSTATE* macros x86/fpu: Use XSAVE{,OPT,C,S} and XRSTOR{,S} mnemonics in xstate.h x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs x86/fpu/xstate: Simplify print_xstate_features() x86/fpu: Refine and simplify the magic number check during signal return selftests/x86/xstate: Fix spelling mistake "hader" -> "header" x86/fpu: Avoid copying dynamic FP state from init_task in arch_dup_task_struct() vmlinux.lds.h: Remove entry to place init_task onto init_stack selftests/x86/avx: Add AVX tests selftests/x86/xstate: Clarify supported xstates selftests/x86/xstate: Consolidate test invocations into a single entry selftests/x86/xstate: Introduce signal ABI test selftests/x86/xstate: Refactor ptrace ABI test selftests/x86/xstate: Refactor context switching test selftests/x86/xstate: Enumerate and name xstate components selftests/x86/xstate: Refactor XSAVE helpers for general use selftests/x86: Consolidate redundant signal helper functions x86/fpu: Fix guest FPU state buffer allocation size x86/fpu: Fully optimize out WARN_ON_FPU()
2025-03-24Merge tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-38/+12
Pull core x86 updates from Ingo Molnar: "x86 CPU features support: - Generate the <asm/cpufeaturemasks.h> header based on build config (H. Peter Anvin, Xin Li) - x86 CPUID parsing updates and fixes (Ahmed S. Darwish) - Introduce the 'setcpuid=' boot parameter (Brendan Jackman) - Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan Jackman) - Utilize CPU-type for CPU matching (Pawan Gupta) - Warn about unmet CPU feature dependencies (Sohil Mehta) - Prepare for new Intel Family numbers (Sohil Mehta) Percpu code: - Standardize & reorganize the x86 percpu layout and related cleanups (Brian Gerst) - Convert the stackprotector canary to a regular percpu variable (Brian Gerst) - Add a percpu subsection for cache hot data (Brian Gerst) - Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak) - Construct __percpu_seg_override from __percpu_seg (Uros Bizjak) MM: - Add support for broadcast TLB invalidation using AMD's INVLPGB instruction (Rik van Riel) - Rework ROX cache to avoid writable copy (Mike Rapoport) - PAT: restore large ROX pages after fragmentation (Kirill A. Shutemov, Mike Rapoport) - Make memremap(MEMREMAP_WB) map memory as encrypted by default (Kirill A. Shutemov) - Robustify page table initialization (Kirill A. Shutemov) - Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn) - Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW (Matthew Wilcox) KASLR: - x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir Singh) CPU bugs: - Implement FineIBT-BHI mitigation (Peter Zijlstra) - speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta) - speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan Gupta) - RFDS: Exclude P-only parts from the RFDS affected list (Pawan Gupta) System calls: - Break up entry/common.c (Brian Gerst) - Move sysctls into arch/x86 (Joel Granados) Intel LAM support updates: (Maciej Wieczor-Retman) - selftests/lam: Move cpu_has_la57() to use cpuinfo flag - selftests/lam: Skip test if LAM is disabled - selftests/lam: Test get_user() LAM pointer handling AMD SMN access updates: - Add SMN offsets to exclusive region access (Mario Limonciello) - Add support for debugfs access to SMN registers (Mario Limonciello) - Have HSMP use SMN through AMD_NODE (Yazen Ghannam) Power management updates: (Patryk Wlazlyn) - Allow calling mwait_play_dead with an arbitrary hint - ACPI/processor_idle: Add FFH state handling - intel_idle: Provide the default enter_dead() handler - Eliminate mwait_play_dead_cpuid_hint() Build system: - Raise the minimum GCC version to 8.1 (Brian Gerst) - Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor) Kconfig: (Arnd Bergmann) - Add cmpxchg8b support back to Geode CPUs - Drop 32-bit "bigsmp" machine support - Rework CONFIG_GENERIC_CPU compiler flags - Drop configuration options for early 64-bit CPUs - Remove CONFIG_HIGHMEM64G support - Drop CONFIG_SWIOTLB for PAE - Drop support for CONFIG_HIGHPTE - Document CONFIG_X86_INTEL_MID as 64-bit-only - Remove old STA2x11 support - Only allow CONFIG_EISA for 32-bit Headers: - Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI headers (Thomas Huth) Assembly code & machine code patching: - x86/alternatives: Simplify alternative_call() interface (Josh Poimboeuf) - x86/alternatives: Simplify callthunk patching (Peter Zijlstra) - KVM: VMX: Use named operands in inline asm (Josh Poimboeuf) - x86/hyperv: Use named operands in inline asm (Josh Poimboeuf) - x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra) - x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h> (Uros Bizjak) - Use named operands in inline asm (Uros Bizjak) - Improve performance by using asm_inline() for atomic locking instructions (Uros Bizjak) Earlyprintk: - Harden early_serial (Peter Zijlstra) NMI handler: - Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus() (Waiman Long) Miscellaneous fixes and cleanups: - by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar, Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner, Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly Kuznetsov, Xin Li, liuye" * tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits) zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault x86/asm: Make asm export of __ref_stack_chk_guard unconditional x86/mm: Only do broadcast flush from reclaim if pages were unmapped perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones perf/x86/intel, x86/cpu: Simplify Intel PMU initialization x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions x86/asm: Use asm_inline() instead of asm() in clwb() x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h> x86/hweight: Use asm_inline() instead of asm() x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm() x86/hweight: Use named operands in inline asm() x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP x86/head/64: Avoid Clang < 17 stack protector in startup code x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h> x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro x86/cpu/intel: Limit the non-architectural constant_tsc model checks x86/mm/pat: Replace Intel x86_model checks with VFM ones x86/cpu/intel: Fix fast string initialization for extended Families ...
2025-03-24Merge tag 'docs-6.15' of git://git.lwn.net/linuxLinus Torvalds1-3/+3
Pull documentation updates from Jonathan Corbet: "It has been a reasonably busy cycle for docs... - Significant changes throughout the tree to bring Python code up to current standards and raise the minimum Python required to 3.9 Much of this is preparatory to replacing the ancient Perl scripts/kernel-doc horror with a slightly less horrifying Python implementation, expected for 6.16 - Update the minimum Sphinx required to 3.4.3, allowing us to remove a bunch of older compatibility code - Rework and improve the generation of the ABI documentation (All of the above done by Mauro) - Lots of translation updates. Alex Shi and Yanteng Si are taking on responsibility for the Chinese translations going forward; that work will still get to you via docs-next - Try to standardize the format for indicating a developer's affiliation in commit tags - Clarify the TAB's role in CoC enforcement actions - Try to spell out the rules for when a commit tag can name another developer without their explicit permission Plus lots of other typo fixes and updates" * tag 'docs-6.15' of git://git.lwn.net/linux: (98 commits) docs/zh_CN: fix spelling mistake docs/Chinese: change the disclaimer words docs/zh_CN: Add snp-tdx-threat-model index Chinese translation docs: driver-api: firmware: clarify userspace requirements docs: clarify rules wrt tagging other people docs: Remove outdated highuid.rst documentation Documentation: dma-buf: heaps: Add heap name definitions docs/.../submit-checklist: Use Documentation/admin-guide/abi.rst for cross-ref of README docs: Correct installation instruction Documentation: kcsan: fix "Plain Accesses and Data Races" URL in kcsan.rst Documentation/CoC: Spell out the TAB role in enforcement decisions Documentation: ocxl.rst: Update consortium site scripts: get_feat.pl: substitute s390x with s390 scripts/kernel-doc: drop dead code for Wcontents_before_sections scripts/kernel-doc: don't add not needed new lines docs: driver-api/infiniband.rst: fix Kerneldoc markup drivers: firewire: firewire-cdev.h: fix identation on a kernel-doc markup drivers: media: intel-ipu3.h: fix identation on a kernel-doc markup include/asm-generic/io.h: fix kerneldoc markup Docs/arch/arm64: Fix spelling in amu.rst ...
2025-03-20x86: hyperv: Add mshv_handler() irq handler and setup functionNuno Das Neves1-0/+1
Add mshv_handler() to process messages related to managing guest partitions such as intercepts, doorbells, and scheduling messages. In a (non-nested) root partition, the same interrupt vector is shared between the vmbus and mshv_root drivers. Introduce a stub for mshv_handler() and call it in sysvec_hyperv_callback alongside vmbus_handler(). Even though both handlers will be called for every Hyper-V interrupt, the messages for each driver are delivered to different offsets within the SYNIC message page, so they won't step on each other. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Introduce hv_recommend_using_aeoi()Nuno Das Neves1-0/+13
Factor out the check for enabling auto eoi, to be reused in root partition code. No functional changes. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20arm64/hyperv: Add some missing functions to arm64Nuno Das Neves1-2/+4
These non-nested msr and fast hypercall functions are present in x86, but they must be available in both architectures for the root partition driver code. While at it, remove the redundant 'extern' keywords from the hv_do_hypercall() variants in asm-generic/mshyperv.h. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-4-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-4-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20x86/mshyperv: Add support for extended Hyper-V featuresStanislav Kinsburskii1-0/+1
Extend the "ms_hyperv_info" structure to include a new field, "ext_features", for capturing extended Hyper-V features. Update the "ms_hyperv_init_platform" function to retrieve these features using the cpuid instruction and include them in the informational output. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1741980536-3865-3-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-3-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Log hypercall status codes as stringsNuno Das Neves1-0/+13
Introduce hv_status_printk() macros as a convenience to log hypercall errors, formatting them with the status code (HV_STATUS_*) as a raw hex value and also as a string, which saves some time while debugging. Create a table of HV_STATUS_ codes with strings and mapped errnos, and use it for hv_result_to_string() and hv_result_to_errno(). Use the new hv_status_printk()s in hv_proc.c, hyperv-iommu.c, and irqdomain.c hypercalls to aid debugging in the root partition. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Add CONFIG_MSHV_ROOT to gate root partition supportNuno Das Neves1-4/+20
CONFIG_MSHV_ROOT allows kernels built to run as a normal Hyper-V guest to exclude the root partition code, which is expected to grow significantly over time. This option is a tristate so future driver code can be built as a (m)odule, allowing faster development iteration cycles. If CONFIG_MSHV_ROOT is disabled, don't compile hv_proc.c, and stub hv_root_partition() to return false unconditionally. This allows the compiler to optimize away root partition code blocks since they will be disabled at compile time. In the case of booting as root partition *without* CONFIG_MSHV_ROOT enabled, print a critical error (the kernel will likely crash). Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-19bpf: Introduce rqspinlock kfuncsKumar Kartikeya Dwivedi1-0/+7
Introduce four new kfuncs, bpf_res_spin_lock, and bpf_res_spin_unlock, and their irqsave/irqrestore variants, which wrap the rqspinlock APIs. bpf_res_spin_lock returns a conditional result, depending on whether the lock was acquired (NULL is returned when lock acquisition succeeds, non-NULL upon failure). The memory pointed to by the returned pointer upon failure can be dereferenced after the NULL check to obtain the error code. Instead of using the old bpf_spin_lock type, introduce a new type with the same layout, and the same alignment, but a different name to avoid type confusion. Preemption is disabled upon successful lock acquisition, however IRQs are not. Special kfuncs can be introduced later to allow disabling IRQs when taking a spin lock. Resilient locks are safe against AA deadlocks, hence not disabling IRQs currently does not allow violation of kernel safety. __irq_flag annotation is used to accept IRQ flags for the IRQ-variants, with the same semantics as existing bpf_local_irq_{save, restore}. These kfuncs will require additional verifier-side support in subsequent commits, to allow programs to hold multiple locks at the same time. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-23-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Add entry to Makefile, MAINTAINERSKumar Kartikeya Dwivedi1-0/+1
Ensure that the rqspinlock code is only built when the BPF subsystem is compiled in. Depending on queued spinlock support, we may or may not end up building the queued spinlock slowpath, and instead fallback to the test-and-set implementation. Also add entries to MAINTAINERS file. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-18-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Add macros for rqspinlock usageKumar Kartikeya Dwivedi1-0/+87
Introduce helper macros that wrap around the rqspinlock slow path and provide an interface analogous to the raw_spin_lock API. Note that in case of error conditions, preemption and IRQ disabling is automatically unrolled before returning the error back to the caller. Ensure that in absence of CONFIG_QUEUED_SPINLOCKS support, we fallback to the test-and-set implementation. Add some comments describing the subtle memory ordering logic during unlock, and why it's safe. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-17-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Add basic support for CONFIG_PARAVIRTKumar Kartikeya Dwivedi1-0/+14
We ripped out PV and virtualization related bits from rqspinlock in an earlier commit, however, a fair lock performs poorly within a virtual machine when the lock holder is preempted. As such, retain the virt_spin_lock fallback to test and set lock, but with timeout and deadlock detection. We can do this by simply depending on the resilient_tas_spin_lock implementation from the previous patch. We don't integrate support for CONFIG_PARAVIRT_SPINLOCKS yet, as that requires more involved algorithmic changes and introduces more complexity. It can be done when the need arises in the future. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-15-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Add a test-and-set fallbackKumar Kartikeya Dwivedi1-0/+17
Include a test-and-set fallback when queued spinlock support is not available. Introduce a rqspinlock type to act as a fallback when qspinlock support is absent. Include ifdef guards to ensure the slow path in this file is only compiled when CONFIG_QUEUED_SPINLOCKS=y. Subsequent patches will add further logic to ensure fallback to the test-and-set implementation when queued spinlock support is unavailable on an architecture. Unlike other waiting loops in rqspinlock code, the one for test-and-set has no theoretical upper bound under contention, therefore we need a longer timeout than usual. Bump it up to a second in this case. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-14-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Add deadlock detection and recoveryKumar Kartikeya Dwivedi1-0/+100
While the timeout logic provides guarantees for the waiter's forward progress, the time until a stalling waiter unblocks can still be long. The default timeout of 1/4 sec can be excessively long for some use cases. Additionally, custom timeouts may exacerbate recovery time. Introduce logic to detect common cases of deadlocks and perform quicker recovery. This is done by dividing the time from entry into the locking slow path until the timeout into intervals of 1 ms. Then, after each interval elapses, deadlock detection is performed, while also polling the lock word to ensure we can quickly break out of the detection logic and proceed with lock acquisition. A 'held_locks' table is maintained per-CPU where the entry at the bottom denotes a lock being waited for or already taken. Entries coming before it denote locks that are already held. The current CPU's table can thus be looked at to detect AA deadlocks. The tables from other CPUs can be looked at to discover ABBA situations. Finally, when a matching entry for the lock being taken on the current CPU is found on some other CPU, a deadlock situation is detected. This function can take a long time, therefore the lock word is constantly polled in each loop iteration to ensure we can preempt detection and proceed with lock acquisition, using the is_lock_released check. We set 'spin' member of rqspinlock_timeout struct to 0 to trigger deadlock checks immediately to perform faster recovery. Note: Extending lock word size by 4 bytes to record owner CPU can allow faster detection for ABBA. It is typically the owner which participates in a ABBA situation. However, to keep compatibility with existing lock words in the kernel (struct qspinlock), and given deadlocks are a rare event triggered by bugs, we choose to favor compatibility over faster detection. The release_held_lock_entry function requires an smp_wmb, while the release store on unlock will provide the necessary ordering for us. Add comments to document the subtleties of why this is correct. It is possible for stores to be reordered still, but in the context of the deadlock detection algorithm, a release barrier is sufficient and needn't be stronger for unlock's case. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-13-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Protect pending bit owners from stallsKumar Kartikeya Dwivedi1-1/+1
The pending bit is used to avoid queueing in case the lock is uncontended, and has demonstrated benefits for the 2 contender scenario, esp. on x86. In case the pending bit is acquired and we wait for the locked bit to disappear, we may get stuck due to the lock owner not making progress. Hence, this waiting loop must be protected with a timeout check. To perform a graceful recovery once we decide to abort our lock acquisition attempt in this case, we must unset the pending bit since we own it. All waiters undoing their changes and exiting gracefully allows the lock word to be restored to the unlocked state once all participants (owner, waiters) have been recovered, and the lock remains usable. Hence, set the pending bit back to zero before returning to the caller. Introduce a lockevent (rqspinlock_lock_timeout) to capture timeout event statistics. Reviewed-by: Barret Rhoden <brho@google.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-10-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Add support for timeoutsKumar Kartikeya Dwivedi1-0/+6
Introduce policy macro RES_CHECK_TIMEOUT which can be used to detect when the timeout has expired for the slow path to return an error. It depends on being passed two variables initialized to 0: ts, ret. The 'ts' parameter is of type rqspinlock_timeout. This macro resolves to the (ret) expression so that it can be used in statements like smp_cond_load_acquire to break the waiting loop condition. The 'spin' member is used to amortize the cost of checking time by dispatching to the implementation every 64k iterations. The 'timeout_end' member is used to keep track of the timestamp that denotes the end of the waiting period. The 'ret' parameter denotes the status of the timeout, and can be checked in the slow path to detect timeouts after waiting loops. The 'duration' member is used to store the timeout duration for each waiting loop. The default timeout value defined in the header (RES_DEF_TIMEOUT) is 0.25 seconds. This macro will be used as a condition for waiting loops in the slow path. Since each waiting loop applies a fresh timeout using the same rqspinlock_timeout, we add a new RES_RESET_TIMEOUT as well to ensure the values can be easily reinitialized to the default state. Reviewed-by: Barret Rhoden <brho@google.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-8-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-19rqspinlock: Add rqspinlock.h headerKumar Kartikeya Dwivedi1-0/+19
This header contains the public declarations usable in the rest of the kernel for rqspinlock. Let's also type alias qspinlock to rqspinlock_t to ensure consistent use of the new lock type. We want to remove dependence on the qspinlock type in later patches as we need to provide a test-and-set fallback, hence begin abstracting away from now onwards. Reviewed-by: Barret Rhoden <brho@google.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20250316040541.108729-6-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>