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1377 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Peter Zijlstra
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5fcc48d521 |
x86/kvm/vmx: Fix VMX vs hrtimer_rearm_deferred()
Vishal reported that KVM unit test 'x2apic' started failing after commit |
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Peter Zijlstra
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0701c9e17b |
x86/kvm/vmx: Move IRQ/NMI dispatch from KVM into x86 core
Move the VMX interrupt dispatch magic into the x86 core code. This isolates KVM from the FRED/IDT decisions and reduces the amount of EXPORT_SYMBOL_FOR_KVM(). Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: "Verma, Vishal L" <vishal.l.verma@intel.com> Tested-by: Zhao Liu <zhao1.liu@intel.com> Tested-by: Zhao Liu <zhao1.liu@intel.com> Tested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Binbin Wu <binbin.wu@linxu.intel.com> Acked-by: Sean Christopherson <seanjc@google.com> Link: https://patch.msgid.link/20260508091829.GO3126523@noisy.programming.kicks-ass.net |
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Guilherme Giacomo Simoes
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b088fe3501 |
x86/vdso: Fix incorrect size in munmap() on map_vdso() failure
In map_vdso(), if a failure occurs during the installation of the VVAR
mappings, the error path attempts to clean up previously allocated mappings
using do_munmap(). However, the cleanup for the VVAR mapping is incorrectly
using image->size (the size of the vDSO text) instead of the actual size
allocated for the VVAR area.
Replace the incorrect do_munmap() image->size parameter with the constant
VDSO_NR_PAGES * PAGE_SIZE. Ensure the unmap size exactly matches the size
used during the vdso_install_vvar_mapping() phase to provide a symmetrical
and complete teardown of the memory region.
Fixes:
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Linus Torvalds
|
334fbe734e |
mm.git review status for linus..mm-stable
Everything: Total patches: 368 Reviews/patch: 1.56 Reviewed rate: 74% Excluding DAMON: Total patches: 316 Reviews/patch: 1.77 Reviewed rate: 81% Excluding DAMON and zram: Total patches: 306 Reviews/patch: 1.81 Reviewed rate: 82% Excluding DAMON, zram and maple_tree: Total patches: 276 Reviews/patch: 2.01 Reviewed rate: 91% Significant patch series in this merge: - The 30 patch series "maple_tree: Replace big node with maple copy" from Liam Howlett is mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - The 12 patch series "mm, swap: swap table phase III: remove swap_map" from Kairui Song offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - The 2 patch series "mm: memfd_luo: preserve file seals" from Pratyush Yadav adds file seal preservation to LUO's memfd code. - The 2 patch series "mm: zswap: add per-memcg stat for incompressible pages" from Jiayuan Chen adds additional userspace stats reportng to zswap. - The 4 patch series "arch, mm: consolidate empty_zero_page" from Mike Rapoport implements some cleanups for our handling of ZERO_PAGE() and zero_pfn. - The 2 patch series "mm/kmemleak: Improve scan_should_stop() implementation" from Zhongqiu Han provides an robustness improvement and some cleanups in the kmemleak code. - The 4 patch series "Improve khugepaged scan logic" from Vernon Yang "improves the khugepaged scan logic and reduces CPU consumption by prioritizing scanning tasks that access memory frequently". - The 2 patch series "Make KHO Stateless" from Jason Miu simplifies Kexec Handover by "transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel" - The 3 patch series "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" from Thomas Ballasi and Steven Rostedt enhances vmscan's tracepointing. - The 5 patch series "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" from Catalin Marinas is a cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation. - The 2 patch series "Fix KASAN support for KHO restored vmalloc regions" from Pasha Tatashin fixes a WARN() which can be emitted the KHO restores a vmalloc area. - The 4 patch series "mm: Remove stray references to pagevec" from Tal Zussman provides several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago. - The 17 patch series "mm: Eliminate fake head pages from vmemmap optimization" from Kiryl Shutsemau simplifies the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page. - The 2 patch series "mm/damon/core: improve DAMOS quota efficiency for core layer filters" from SeongJae Park improves two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used. - The 3 patch series "mm/damon: strictly respect min_nr_regions" from SeongJae Park improves DAMON usability by extending the treatment of the min_nr_regions user-settable parameter. - The 3 patch series "mm/page_alloc: pcp locking cleanup" from Vlastimil Babka is a proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ennsed. - The 16 patch series "mm: cleanups around unmapping / zapping" from David Hildenbrand implements "a bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions". - The 6 patch series "support batched checking of the young flag for MGLRU" from Baolin Wang supports batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64. - The 5 patch series "memcg: obj stock and slab stat caching cleanups" from Johannes Weiner provides memcg cleanup and robustness improvements. - The 5 patch series "Allow order zero pages in page reporting" from Yuvraj Sakshith enhances page_reporting's free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - The 6 patch series "mm: vma flag tweaks" from Lorenzo Stoakes is cleanup work following from the recent conversion of the VMA flags to a bitmap. - The 10 patch series "mm/damon: add optional debugging-purpose sanity checks" from SeongJae Park adds some more developer-facing debug checks into DAMON core. - The 2 patch series "mm/damon: test and document power-of-2 min_region_sz requirement" from SeongJae Park adds an additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling. - The 3 patch series "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" from SeongJae Park fixes a hard-to-hit time overflow issue in DAMON core. - The 7 patch series "mm/damon: improve/fixup/update ratio calculation, test and documentation" from SeongJae Park is a "batch of misc/minor improvements and fixups" for DAMON. - The 4 patch series "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" from David Hildenbrand fixes a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - The 6 patch series "zram: recompression cleanups and tweaks" from Sergey Senozhatsky provides "a somewhat random mix of fixups, recompression cleanups and improvements" in the zram code. - The 11 patch series "mm/damon: support multiple goal-based quota tuning algorithms" from SeongJae Park extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select. - The 4 patch series "mm: thp: reduce unnecessary start_stop_khugepaged()" from Breno Leitao fixes the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged. - The 3 patch series "mm: improve map count checks" from Lorenzo Stoakes provides some cleanups and slight fixes in the mremap, mmap and vma code. - The 5 patch series "mm/damon: support addr_unit on default monitoring targets for modules" from SeongJae Park extends the use of DAMON core's addr_unit tunable. - The 5 patch series "mm: khugepaged cleanups and mTHP prerequisites" from Nico Pache provides cleanups in the khugepaged and is a base for Nico's planned khugepaged mTHP support. - The 15 patch series "mm: memory hot(un)plug and SPARSEMEM cleanups" from David Hildenbrand implements code movement and cleanups in the memhotplug and sparsemem code. - The 2 patch series "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" from David Hildenbrand rationalizes some memhotplug Kconfig support. - The 6 patch series "change young flag check functions to return bool" from Baolin Wang is "a cleanup patchset to change all young flag check functions to return bool". - The 3 patch series "mm/damon/sysfs: fix memory leak and NULL dereference issues" from Josh Law and SeongJae Park fixes a few potential DAMON bugs. - The 25 patch series "mm/vma: convert vm_flags_t to vma_flags_t in vma code" from "converts a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it". Mainly in the vma code. - The 21 patch series "mm: expand mmap_prepare functionality and usage" from Lorenzo Stoakes "expands the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time". Cleanups, documentation, extension of mmap_prepare into filesystem drivers. - The 13 patch series "mm/huge_memory: refactor zap_huge_pmd()" from Lorenzo Stoakes simplifies and cleans up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCad3HDQAKCRDdBJ7gKXxA jrUQAPwNhPk5nPSxnyxjAeQtOBHqgCdnICeEismLajPKd9aYRgEA0s2XAu3tSUYi GrBnWImHG3s4ePQxVcPCegWTsOUrXgQ= =1Q7o -----END PGP SIGNATURE----- Merge tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky) A somewhat random mix of fixups, recompression cleanups and improvements in the zram code - "mm/damon: support multiple goal-based quota tuning algorithms" (SeongJae Park) Extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao) Fix the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged - "mm: improve map count checks" (Lorenzo Stoakes) Provide some cleanups and slight fixes in the mremap, mmap and vma code - "mm/damon: support addr_unit on default monitoring targets for modules" (SeongJae Park) Extend the use of DAMON core's addr_unit tunable - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache) Cleanups to khugepaged and is a base for Nico's planned khugepaged mTHP support - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand) Code movement and cleanups in the memhotplug and sparsemem code - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" (David Hildenbrand) Rationalize some memhotplug Kconfig support - "change young flag check functions to return bool" (Baolin Wang) Cleanups to change all young flag check functions to return bool - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh Law and SeongJae Park) Fix a few potential DAMON bugs - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo Stoakes) Convert a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. Mainly in the vma code. - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes) Expand the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. Cleanups, documentation, extension of mmap_prepare into filesystem drivers - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes) Simplify and clean up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. * tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm: fix deferred split queue races during migration mm/khugepaged: fix issue with tracking lock mm/huge_memory: add and use has_deposited_pgtable() mm/huge_memory: add and use normal_or_softleaf_folio_pmd() mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio() mm/huge_memory: separate out the folio part of zap_huge_pmd() mm/huge_memory: use mm instead of tlb->mm mm/huge_memory: remove unnecessary sanity checks mm/huge_memory: deduplicate zap deposited table call mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE() mm/huge_memory: add a common exit path to zap_huge_pmd() mm/huge_memory: handle buggy PMD entry in zap_huge_pmd() mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc mm/huge: avoid big else branch in zap_huge_pmd() mm/huge_memory: simplify vma_is_specal_huge() mm: on remap assert that input range within the proposed VMA mm: add mmap_action_map_kernel_pages[_full]() uio: replace deprecated mmap hook with mmap_prepare in uio_info drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers ... |
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Linus Torvalds
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9f2bb6c7b3 |
- Complete LASS enabling: deal with vsyscall and EFI
- Clean up CPUID usage in newer Intel audio driver -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmndDsMACgkQaDWVMHDJ krAOhRAAi3BsToTbmKayQJKWwVr5aGbLYXe3FiBv5juPprsJDF4otd0ALkdbf5Ls n7nND4L9RBfcGZBu25vo60Y1I1b2JReu9Y8YXxsrEx+WIxTPYClOJa7AqakyNxc4 zbTCTv6TuEyXqG5VWe3AItWrMToc49TvUVoN2fi+V89fLWA8IOkMoIhbAWwQPBFI ir0N4UwC/RtRBFf9qc9jesirqGSgh6SEAK6oBYM3C2PV/njoKljTconaCnF7uJlq WxxVcb07dIvOdpdE941OZ6jyS6eePr2feXOazNjnPb0py5Ai4WCsEGdK68ltQ5fM EhY24Ex6ltudgphB/cajKIKZ8LUCWgnMwTotY8IQMQiQ47JKmyrucdLUwvhl0qTD IAWiOMvb5d3X+CoKt3lXlzc29WhbogXzvxjZE29ad8Dm7DVBEOV57bXDwhnHb7LS rro7odiohsw7FMhfqxlb6NhYzCbdpBbmY3IFzXVgTZlWIXU1g/yBVz/2O0qsKLaw QQ2NKre6lioP2H3pWc0fi53336svzCSuuExCiu47Hx9WcYBX1Poq/AkpAoxPErq+ DRn8lXVwqMpefevlHK9XlZjSpwwwltULmId3LFxh3Z53b1NABrKpVEEJ/VChpzzA xC8dLdu1pbJa2jdccL6mBDYlMvyWLCmKfAlAHdRh8nLmOZxKRHg= =kPr7 -----END PGP SIGNATURE----- Merge tag 'x86_cpu_for_7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu updates from Dave Hansen: - Complete LASS enabling: deal with vsyscall and EFI The existing Linear Address Space Separation (LASS) support punted on support for common EFI and vsyscall configs. Complete the implementation by supporting EFI and vsyscall=xonly. - Clean up CPUID usage in newer Intel "avs" audio driver and update the x86-cpuid-db file * tag 'x86_cpu_for_7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tools/x86/kcpuid: Update bitfields to x86-cpuid-db v3.0 ASoC: Intel: avs: Include CPUID header at file scope ASoC: Intel: avs: Check maximum valid CPUID leaf x86/cpu: Remove LASS restriction on vsyscall emulation x86/vsyscall: Disable LASS if vsyscall mode is set to EMULATE x86/vsyscall: Restore vsyscall=xonly mode under LASS x86/traps: Consolidate user fixups in the #GP handler x86/vsyscall: Reorganize the page fault emulation code x86/cpu: Remove LASS restriction on EFI x86/efi: Disable LASS while executing runtime services x86/cpu: Defer LASS enabling until userspace comes up |
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Linus Torvalds
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49b30f3e9c |
x86/vdso changes for v7.1, by Thomas Weißschuh:
- Clean up remnants of VDSO32_NOTE_MASK - Drop pointless #ifdeffery in vvar_vclock_fault() Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmncs7MRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1hy/Q//SPYPyHlpuCHCRa8z/7NlVjrU9bEX1EqR NInMe4GERseJePLwBF1KD4MQJy4B6Cnuf9PA4m5bTlWuQRyzLeoKNxP/K6z2JtFO 5kU6tn58p68/hUqCzzSJHtHNC8pSMvG8nXVLrSFwDePwAhjFcE8LvV9nkxni1nd7 rntT/hen0mVmPfYofmKbJhnl73SjdV847mQOzY3V7Yhs8mh2v/wjmUpDMqUjq7hc wEGMoFgooM+gmV+LnGXrd5WbA39Go28YB5FYZcZ8HFHGPwVNzir6l1HmDDoaQTYq baq7vlUgrpU/Lt6VEhMyMfJmz1bN8vo3/1uNwruaA6bz77265wE0Lh+ajNnmSwLF kukxtT/7JU7SQnY/ND318gkqHkjIgjNA2WzZfXjBko8pcaO9nWFCuIkDiE4rKHzi +Wh3pjHvSAHVO4qOgUHlAWKw4f6cmVZ9XdDO4vwyn8zCc7Y0DWfbVSeXEuCMIfZB xoslglYrZ+yVkJt9P+B+xYdsvE7aEFtO6LOfMTcNUevWaKBXwS4Ldp94SAyYR7h7 aXd0Wz96yCIBsE5g2fC7+2jV7zFhHwULmIX+a8tLesYzMmhFabIaMsEWgUbEfQiT 8S/wmWaPCYPSzlwwFvL2o8mbf6JfscuobTAdo5Cn9dKgLI4D+o9X5I9NkCqIgRXL 3XYA/fVaAM4= =C60b -----END PGP SIGNATURE----- Merge tag 'x86-vdso-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso updates from Ingo Molnar: "vdso cleanups by Thomas Weißschuh: - Clean up remnants of VDSO32_NOTE_MASK - Drop pointless #ifdeffery in vvar_vclock_fault()" * tag 'x86-vdso-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Drop pointless #ifdeffery in vvar_vclock_fault() x86/vdso: Clean up remnants of VDSO32_NOTE_MASK |
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Linus Torvalds
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f21f7b5162 |
Update to the VDSO subsystem:
- Make the handling of compat functions consistent and more robust
- Rework the underlying data store so that it is dynamically
allocated, which allows the conversion of the last holdout SPARC64
to the generic VDSO implementation
- Rework the SPARC64 VDSO to utilize the generic implementation
- Mop up the left overs of the non-generic VDSO support in the core
code.
- Expand the VDSO selftest and make them more robust
- Allow time namespaces to be enabled independently of the generic
VDSO support, which was not possible before due to SPARC64 not
using it.
- Various cleanups and improvements in the related code.
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Merge tag 'timers-vdso-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull vdso updates from Thomas Gleixner:
- Make the handling of compat functions consistent and more robust
- Rework the underlying data store so that it is dynamically allocated,
which allows the conversion of the last holdout SPARC64 to the
generic VDSO implementation
- Rework the SPARC64 VDSO to utilize the generic implementation
- Mop up the left overs of the non-generic VDSO support in the core
code
- Expand the VDSO selftest and make them more robust
- Allow time namespaces to be enabled independently of the generic VDSO
support, which was not possible before due to SPARC64 not using it
- Various cleanups and improvements in the related code
* tag 'timers-vdso-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
timens: Use task_lock guard in timens_get*()
timens: Use mutex guard in proc_timens_set_offset()
timens: Simplify some calls to put_time_ns()
timens: Add a __free() wrapper for put_time_ns()
timens: Remove dependency on the vDSO
vdso/timens: Move functions to new file
selftests: vDSO: vdso_test_correctness: Add a test for time()
selftests: vDSO: vdso_test_correctness: Use facilities from parse_vdso.c
selftests: vDSO: vdso_test_correctness: Handle different tv_usec types
selftests: vDSO: vdso_test_correctness: Drop SYS_getcpu fallbacks
selftests: vDSO: vdso_test_gettimeofday: Remove nolibc checks
Revert "selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers"
random: vDSO: Remove ifdeffery
random: vDSO: Trim vDSO includes
vdso/datapage: Trim down unnecessary includes
vdso/datapage: Remove inclusion of gettimeofday.h
vdso/helpers: Explicitly include vdso/processor.h
vdso/gettimeofday: Add explicit includes
random: vDSO: Add explicit includes
MIPS: vdso: Explicitly include asm/vdso/vdso.h
...
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Linus Torvalds
|
d568788baa |
hardening updates for v7.1-rc1
- randomize_kstack: Improve implementation across arches (Ryan Roberts) - lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test - refcount: Remove unused __signed_wrap function annotations -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRSPkdeREjth1dHnSE2KwveOeQkuwUCad16PwAKCRA2KwveOeQk u7crAP4qz8gXCjes76KsZm/YQS8PtOG5JroAVu5Oa4ohw0RfaQD+K/XLow1plcNF 4Bi8zSuv2ifcLysh9qEAbx5+wcHijgo= =woB3 -----END PGP SIGNATURE----- Merge tag 'hardening-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: - randomize_kstack: Improve implementation across arches (Ryan Roberts) - lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test - refcount: Remove unused __signed_wrap function annotations * tag 'hardening-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test refcount: Remove unused __signed_wrap function annotations randomize_kstack: Unify random source across arches randomize_kstack: Maintain kstack_offset per task |
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Kiryl Shutsemau (Meta)
|
76351f2f0c |
x86/vdso: undefine CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP for vdso32
The 32-bit VDSO build on x86_64 uses fake_32bit_build.h to undefine various kernel configuration options that are not suitable for the VDSO context or may cause build issues when including kernel headers. Undefine CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP in fake_32bit_build.h to prepare for change in HugeTLB Vmemmap Optimization. Link: https://lkml.kernel.org/r/20260227194302.274384-12-kas@kernel.org Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Lameter <cl@gentwo.org> Cc: David Rientjes <rientjes@google.com> Cc: Frank van der Linden <fvdl@google.com> Cc: Harry Yoo <harry.yoo@oracle.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Thomas Weißschuh
|
6ccd0843b9 |
x86/vdso: Drop pointless #ifdeffery in vvar_vclock_fault()
Sparse complains rightfully when CONFIG_PARAVIRT_CLOCK and CONFIG_HYPERV_TIMER are both not set: arch/x86/entry/vdso/vma.c:94:9: warning: switch with no cases The #ifdeffery is not actually necessary as the compiler can optimize away the branches already if these config options are not set. Remove the #ifdeffery to make the code simpler and Sparse happy. Closes: https://lore.kernel.org/lkml/20260117215542.405790227@kernel.org/ Reported-by: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Link: https://patch.msgid.link/20260331-vdso-x86-ifdef-v1-1-6be9a58b1e7e@linutronix.de |
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Ryan Roberts
|
a96ef5848c |
randomize_kstack: Unify random source across arches
Previously different architectures were using random sources of
differing strength and cost to decide the random kstack offset. A number
of architectures (loongarch, powerpc, s390, x86) were using their
timestamp counter, at whatever the frequency happened to be. Other
arches (arm64, riscv) were using entropy from the crng via
get_random_u16().
There have been concerns that in some cases the timestamp counters may
be too weak, because they can be easily guessed or influenced by user
space. And get_random_u16() has been shown to be too costly for the
level of protection kstack offset randomization provides.
So let's use a common, architecture-agnostic source of entropy; a
per-cpu prng, seeded at boot-time from the crng. This has a few
benefits:
- We can remove choose_random_kstack_offset(); That was only there to
try to make the timestamp counter value a bit harder to influence
from user space [*].
- The architecture code is simplified. All it has to do now is call
add_random_kstack_offset() in the syscall path.
- The strength of the randomness can be reasoned about independently
of the architecture.
- Arches previously using get_random_u16() now have much faster
syscall paths, see below results.
[*] Additionally, this gets rid of some redundant work on s390 and x86.
Before this patch, those architectures called
choose_random_kstack_offset() under arch_exit_to_user_mode_prepare(),
which is also called for exception returns to userspace which were *not*
syscalls (e.g. regular interrupts). Getting rid of
choose_random_kstack_offset() avoids a small amount of redundant work
for the non-syscall cases.
In some configurations, add_random_kstack_offset() will now call
instrumentable code, so for a couple of arches, I have moved the call a
bit later to the first point where instrumentation is allowed. This
doesn't impact the efficacy of the mechanism.
There have been some claims that a prng may be less strong than the
timestamp counter if not regularly reseeded. But the prng has a period
of about 2^113. So as long as the prng state remains secret, it should
not be possible to guess. If the prng state can be accessed, we have
bigger problems.
Additionally, we are only consuming 6 bits to randomize the stack, so
there are only 64 possible random offsets. I assert that it would be
trivial for an attacker to brute force by repeating their attack and
waiting for the random stack offset to be the desired one. The prng
approach seems entirely proportional to this level of protection.
Performance data are provided below. The baseline is v6.18 with rndstack
on for each respective arch. (I)/(R) indicate statistically significant
improvement/regression. arm64 platform is AWS Graviton3 (m7g.metal).
x86_64 platform is AWS Sapphire Rapids (m7i.24xlarge):
+-----------------+--------------+---------------+---------------+
| Benchmark | Result Class | per-cpu-prng | per-cpu-prng |
| | | arm64 (metal) | x86_64 (VM) |
+=================+==============+===============+===============+
| syscall/getpid | mean (ns) | (I) -9.50% | (I) -17.65% |
| | p99 (ns) | (I) -59.24% | (I) -24.41% |
| | p99.9 (ns) | (I) -59.52% | (I) -28.52% |
+-----------------+--------------+---------------+---------------+
| syscall/getppid | mean (ns) | (I) -9.52% | (I) -19.24% |
| | p99 (ns) | (I) -59.25% | (I) -25.03% |
| | p99.9 (ns) | (I) -59.50% | (I) -28.17% |
+-----------------+--------------+---------------+---------------+
| syscall/invalid | mean (ns) | (I) -10.31% | (I) -18.56% |
| | p99 (ns) | (I) -60.79% | (I) -20.06% |
| | p99.9 (ns) | (I) -61.04% | (I) -25.04% |
+-----------------+--------------+---------------+---------------+
I tested an earlier version of this change on x86 bare metal and it
showed a smaller but still significant improvement. The bare metal
system wasn't available this time around so testing was done in a VM
instance. I'm guessing the cost of rdtsc is higher for VMs.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://patch.msgid.link/20260303150840.3789438-3-ryan.roberts@arm.com
Signed-off-by: Kees Cook <kees@kernel.org>
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Nikunj A Dadhania
|
3645eb7e39 |
x86/fred: Fix early boot failures on SEV-ES/SNP guests
FRED-enabled SEV-(ES,SNP) guests fail to boot due to the following issues
in the early boot sequence:
* FRED does not have a #VC exception handler in the dispatch logic
* Early FRED #VC exceptions attempt to use uninitialized per-CPU GHCBs
instead of boot_ghcb
Add X86_TRAP_VC case to fred_hwexc() with a new exc_vmm_communication()
function that provides the unified entry point FRED requires, dispatching
to existing user/kernel handlers based on privilege level. The function is
already declared via DECLARE_IDTENTRY_VC().
Fix early GHCB access by falling back to boot_ghcb in
__sev_{get,put}_ghcb() when per-CPU GHCBs are not yet initialized.
Fixes:
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Vladimir Oltean
|
63f8b60151 |
x86/entry/vdso: Fix path of included gettimeofday.c
Commit in Fixes forgot to convert one include path to be relative to the
kernel source directory after adding latter to flags-y.
Fix it.
[ bp: Rewrite commit message. ]
Fixes:
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Sohil Mehta
|
b36d1f53d9 |
x86/vsyscall: Disable LASS if vsyscall mode is set to EMULATE
The EMULATE mode of vsyscall maps the vsyscall page with a high kernel
address directly into user address space. Reading the vsyscall page in
EMULATE mode would cause LASS to trigger a #GP.
Fixing the LASS violation in EMULATE mode would require complex
instruction decoding because the resulting #GP does include the
necessary error information, and the vsyscall address is not
readily available in the RIP.
The EMULATE mode has been deprecated since 2022 and can only be enabled
using the command line parameter vsyscall=emulate. See commit
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Sohil Mehta
|
8376b503b0 |
x86/vsyscall: Restore vsyscall=xonly mode under LASS
Background
==========
The vsyscall page is located in the high/kernel part of the address
space. Prior to LASS, a vsyscall page access from userspace would always
generate a #PF. The kernel emulates the accesses in the #PF handler and
returns the appropriate values to userspace.
Vsyscall emulation has two modes of operation, specified by the
vsyscall={xonly, emulate} kernel command line option. The vsyscall page
behaves as execute-only in XONLY mode or read-execute in EMULATE mode.
XONLY mode is the default and the only one expected to be commonly used.
The EMULATE mode has been deprecated since 2022 and is considered
insecure.
With LASS, a vsyscall page access triggers a #GP instead of a #PF.
Currently, LASS is only enabled when all vsyscall modes are disabled.
LASS with XONLY mode
====================
Now add support for LASS specifically with XONLY vsyscall emulation. For
XONLY mode, all that is needed is the faulting RIP, which is trivially
available regardless of the type of fault. Reuse the #PF emulation code
during the #GP when the fault address points to the vsyscall page.
As multiple fault handlers will now be using the emulation code, add a
sanity check to ensure that the fault truly happened in 64-bit user
mode.
LASS with EMULATE mode
======================
Supporting vsyscall=emulate with LASS is much harder because the #GP
doesn't provide enough error information (such as PFEC and CR2 as in
case of a #PF). So, complex instruction decoding would be required to
emulate this mode in the #GP handler.
This isn't worth the effort as remaining users of EMULATE mode can be
reasonably assumed to be niche users, who are already trading off
security for compatibility. LASS and vsyscall=emulate will be kept
mutually exclusive for simplicity.
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://patch.msgid.link/20260309181029.398498-4-sohil.mehta@intel.com
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Sohil Mehta
|
3ddd2e12c7 |
x86/vsyscall: Reorganize the page fault emulation code
With LASS, vsyscall page accesses will cause a #GP instead of a #PF. Separate out the core vsyscall emulation code from the #PF specific handling in preparation for the upcoming #GP emulation. No functional change intended. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Link: https://patch.msgid.link/20260309181029.398498-2-sohil.mehta@intel.com |
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Thomas Weißschuh
|
56f85f67b3 |
x86/vdso: Use 32-bit CHECKFLAGS for compat vDSO
When building the compat vDSO the CHECKFLAGS from the 64-bit kernel are used. These are combined with the 32-bit CFLAGS. This confuses sparse, producing false-positive warnings or potentially missing real issues. Manually override the CHECKFLAGS for the compat vDSO with the correct 32-bit configuration. Reported-by: Sun Jian <sun.jian.kdev@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://patch.msgid.link/20260302-vdso-compat-checkflags-v2-1-78e55baa58ba@linutronix.de Closes: https://lore.kernel.org/lkml/20260114084529.1676356-1-sun.jian.kdev@gmail.com/ Closes: https://lore.kernel.org/lkml/20260117215542.342638347@kernel.org/ Closes: https://lore.kernel.org/r/202602111941.PIhubgrb-lkp@intel.com/ |
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|
H. Peter Anvin
|
b5ef09a77d |
x86/entry/vdso32: Work around libgcc unwinder bug
The unwinder code in libgcc has a long standing bug which causes it to
fail to pick up the signal frame CFI flag. This is a generic bug
across all platforms.
It affects the __kernel_sigreturn and __kernel_rt_sigreturn vdso entry
points on i386. The x86-64 kernel doesn't provide a sigreturn stub,
and so there is no kernel-provided code that is affected on x86-64.
libgcc does have a legacy fallback path which happens to work as long
as the bytes immediately before each of the sigreturn functions fall
outside any function. This patch adds a nop before the ALIGN to each
of the sigreturn stubs to ensure that this is, indeed, the case.
The rest of the patch is just a comment which documents the invariants
that need to be maintained for this legacy path to work correctly.
This is a manifest bug: in the current vdso, __kernel_vsyscall is a
multiple of 16 bytes long and thus __kernel_sigreturn does not have
any padding in front of it.
Closes: https://lore.kernel.org/lkml/f3412cc3e8f66d1853cc9d572c0f2fab076872b1.camel@xry111.site
Fixes:
|
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|
Andrew Cooper
|
aa280a08e7 |
x86/fred: Correct speculative safety in fred_extint()
array_index_nospec() is no use if the result gets spilled to the stack, as
it makes the believed safe-under-speculation value subject to memory
predictions.
For all practical purposes, this means array_index_nospec() must be used in
the expression that accesses the array.
As the code currently stands, it's the wrong side of irqentry_enter(), and
'index' is put into %ebp across the function call.
Remove the index variable and reposition array_index_nospec(), so it's
calculated immediately before the array access.
Fixes:
|
||
|
Linus Torvalds
|
1ca28333e4 |
x86: keep legacy generated vdso files around in .gitignore file
Commit |
||
|
Linus Torvalds
|
6f7e6393d1 |
* VDSO rework and cleanups
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||
|
Linus Torvalds
|
57cb845067 |
- A nice cleanup to the paravirt code containing a unification of the paravirt
clock interface, taming the include hell by splitting the pv_ops structure and removing of a bunch of obsolete code. Work by Juergen Gross. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmmLKHAACgkQEsHwGGHe VUrURg//Ucf+3EAIkLCmFkH0WwYmQl2JjRYww8bPAw3iJMIVxy4dMnaBbsUiAtUp kYza+pgEtvyAwwd8RIEs85c9VhZn0DKoaWV8goBH3zFH6YvIRiLwb0w2QvjkF+70 FNU+4zlvt/I3FD+tWNElAgVtkFL3Gmzm44qyLLsPtlYaJ71xFl2XB7V+TlqXMHzE m8BMenP9/CrbTlBBdNJGzAkAbWi1uAP+IydvuFNolH/F2lqVM2z5Ta3gUWWCIk/q jWrPLDZCHr2WlBZNUGamKVVH9NEh+7YNwBAGUrSNYGZFoaFjqeX6lN3djzS+wXIj 0nDoW35jN0QNKz239MdXZDf1mfpb6ZQd/iOhFjo4dAvbm+J8WPAMr98ac8wR3Dyb 2LF/BxkoKWRabxQApXSCrLPXEuqT6Qc1+lDA0bNHg51zBoqP5vRNVZRwArnzGB+O LxDKx+o4VYOf+UCaB6oQHjylbSgFvIedZ9p822hBe3QG9act8indRE8LWip7Utld peoJGgvlQ0xtClh6FjVHpvmVfAvk7Zki5ywj2GwmB/TZ0yywuGStAjE3UqY168/M gb7MSajh+HHZNj1/2+b/se4CUYlAgIPDQ+SwHJPm5TqyopvnOVi/2XWmjbx8I5jT jS0nxaxD+SbESSZ6IMAsppnAAxAYbvRHGIS+6mtNCXVkaV1pMbA= =AeFt -----END PGP SIGNATURE----- Merge tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 paravirt updates from Borislav Petkov: - A nice cleanup to the paravirt code containing a unification of the paravirt clock interface, taming the include hell by splitting the pv_ops structure and removing of a bunch of obsolete code (Juergen Gross) * tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/paravirt: Use XOR r32,r32 to clear register in pv_vcpu_is_preempted() x86/paravirt: Remove trailing semicolons from alternative asm templates x86/pvlocks: Move paravirt spinlock functions into own header x86/paravirt: Specify pv_ops array in paravirt macros x86/paravirt: Allow pv-calls outside paravirt.h objtool: Allow multiple pv_ops arrays x86/xen: Drop xen_mmu_ops x86/xen: Drop xen_cpu_ops x86/xen: Drop xen_irq_ops x86/paravirt: Move pv_native_*() prototypes to paravirt.c x86/paravirt: Introduce new paravirt-base.h header x86/paravirt: Move paravirt_sched_clock() related code into tsc.c x86/paravirt: Use common code for paravirt_steal_clock() riscv/paravirt: Use common code for paravirt_steal_clock() loongarch/paravirt: Use common code for paravirt_steal_clock() arm64/paravirt: Use common code for paravirt_steal_clock() arm/paravirt: Use common code for paravirt_steal_clock() sched: Move clock related paravirt code to kernel/sched paravirt: Remove asm/paravirt_api_clock.h x86/paravirt: Move thunk macros to paravirt_types.h ... |
||
|
Linus Torvalds
|
f1c538ca81 |
Updates for the VDSO subsystem:
- Provide the missing 64-bit variant of clock_getres()
This allows the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and
finally the removal of 32-bit time types from the kernel and UAPI.
- Remove the useless and broken getcpu_cache from the VDSO
The intention was to provide a trivial way to retrieve the CPU number from
the VDSO, but as the VDSO data is per process there is no way to make it
work.
- Switch get/put_unaligned() from packed struct to memcpy()
The packed struct violates strict aliasing rules which requires to pass
-fno-strict-aliasing to the compiler. As this are scalar values
__builtin_memcpy() turns them into simple loads and stores
- Use __typeof_unqual__() for __unqual_scalar_typeof()
The get/put_unaligned() changes triggered a new sparse warning when __beNN
types are used with get/put_unaligned() as sparse builds add a special
'bitwise' attribute to them which prevents sparse to evaluate the Generic
in __unqual_scalar_typeof().
Newer sparse versions support __typeof_unqual__() which avoids the problem,
but requires a recent sparse install. So this adds a sanity check to sparse
builds, which validates that sparse is available and capable of handling it.
- Force inline __cvdso_clock_getres_common()
Compilers sometimes un-inline agressively, which results in function call
overhead and problems with automatic stack variable initialization.
Interestingly enough the force inlining results in smaller code than the
un-inlined variant produced by GCC when optimizing for size.
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Merge tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull VDSO updates from Thomas Gleixner:
- Provide the missing 64-bit variant of clock_getres()
This allows the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and
finally the removal of 32-bit time types from the kernel and UAPI.
- Remove the useless and broken getcpu_cache from the VDSO
The intention was to provide a trivial way to retrieve the CPU number
from the VDSO, but as the VDSO data is per process there is no way to
make it work.
- Switch get/put_unaligned() from packed struct to memcpy()
The packed struct violates strict aliasing rules which requires to
pass -fno-strict-aliasing to the compiler. As this are scalar values
__builtin_memcpy() turns them into simple loads and stores
- Use __typeof_unqual__() for __unqual_scalar_typeof()
The get/put_unaligned() changes triggered a new sparse warning when
__beNN types are used with get/put_unaligned() as sparse builds add a
special 'bitwise' attribute to them which prevents sparse to evaluate
the Generic in __unqual_scalar_typeof().
Newer sparse versions support __typeof_unqual__() which avoids the
problem, but requires a recent sparse install. So this adds a sanity
check to sparse builds, which validates that sparse is available and
capable of handling it.
- Force inline __cvdso_clock_getres_common()
Compilers sometimes un-inline agressively, which results in function
call overhead and problems with automatic stack variable
initialization.
Interestingly enough the force inlining results in smaller code than
the un-inlined variant produced by GCC when optimizing for size.
* tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
vdso/gettimeofday: Force inlining of __cvdso_clock_getres_common()
x86/percpu: Make CONFIG_USE_X86_SEG_SUPPORT work with sparse
compiler: Use __typeof_unqual__() for __unqual_scalar_typeof()
powerpc/vdso: Provide clock_getres_time64()
tools headers: Remove unneeded ignoring of warnings in unaligned.h
tools headers: Update the linux/unaligned.h copy with the kernel sources
vdso: Switch get/put_unaligned() from packed struct to memcpy()
parisc: Inline a type punning version of get_unaligned_le32()
vdso: Remove struct getcpu_cache
MIPS: vdso: Provide getres_time64() for 32-bit ABIs
arm64: vdso32: Provide clock_getres_time64()
ARM: VDSO: Provide clock_getres_time64()
ARM: VDSO: Patch out __vdso_clock_getres() if unavailable
x86/vdso: Provide clock_getres_time64() for x86-32
selftests: vDSO: vdso_test_abi: Add test for clock_getres_time64()
selftests: vDSO: vdso_test_abi: Use UAPI system call numbers
selftests: vDSO: vdso_config: Add configurations for clock_getres_time64()
vdso: Add prototype for __vdso_clock_getres_time64()
|
||
|
Linus Torvalds
|
36ae1c45b2 |
Scheduler changes for v7.0:
Scheduler Kconfig space updates:
- Further consolidate configurable preemption modes: reduce
the number of architectures that are allowed to offer
PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number
of preemption models from four to just two: 'full' and 'lazy'
on up-to-date architectures (arm64, loongarch, powerpc,
riscv, s390, x86).
None and voluntary are only available as legacy features
on platforms that don't implement lazy preemption yet,
or which don't even support preemption.
The goal is to eventually remove cond_resched() and
voluntary preemption altogether.
(Peter Zijlstra)
RSEQ based 'scheduler time slice extension' support:
This allows a thread to request a time slice extension when it
enters a critical section to avoid contention on a resource when
the thread is scheduled out inside of the critical section.
- Add fields and constants for time slice extension
- Provide static branch for time slice extensions
- Add statistics for time slice extensions
- Add prctl() to enable time slice extensions
- Implement sys_rseq_slice_yield()
- Implement syscall entry work for time slice extensions
- Implement time slice extension enforcement timer
- Reset slice extension when scheduled
- Implement rseq_grant_slice_extension()
- entry: Hook up rseq time slice extension
- selftests: Implement time slice extension test
(Thomas Gleixner)
- Allow registering RSEQ with slice extension
- Move slice_ext_nsec to debugfs
- Lower default slice extension
- selftests/rseq: Add rseq slice histogram script
(Peter Zijlstra)
Scheduler performance/scalability improvements:
- Update rq->avg_idle when a task is moved to an idle CPU,
which improves the scalability of various workloads.
(Shubhang Kaushik)
- Reorder fields in 'struct rq' for better caching
(Blake Jones)
- Fair scheduler SMP NOHZ balancing code speedups:
- Move checking for nohz cpus after time check
- Change likelyhood of nohz.nr_cpus
- Remove nohz.nr_cpus and use weight of cpumask instead
(Shrikanth Hegde)
- Avoid false sharing for sched_clock_irqtime (Wangyang Guo)
- Drop useless cpumask_empty() in find_energy_efficient_cpu()
- Simplify task_numa_find_cpu()
- Use cpumask_weight_and() in sched_balance_find_dst_group()
(Yury Norov)
DL scheduler updates:
- Add a deadline server for sched_ext tasks (by Andrea Righi and
Joel Fernandes, with fixes by Peter Zijlstra)
RT scheduler updates:
- Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang)
Entry code updates and performance improvements, which is part of the
scheduler tree in this cycle due to interdependencies with the RSEQ
based time slice extension work:
- Remove unused syscall argument from syscall_trace_enter()
- Rework syscall_exit_to_user_mode_work() for architecture reuse
- Add arch_ptrace_report_syscall_entry/exit()
- Inline syscall_exit_work() and syscall_trace_enter()
(Jinjie Ruan)
Scheduler core updates:
- Rework sched_class::wakeup_preempt() and rq_modified_*()
- Avoid rq->lock bouncing in sched_balance_newidle()
- Rename rcu_dereference_check_sched_domain() =>
rcu_dereference_sched_domain()
- <linux/compiler_types.h>: Add the __signed_scalar_typeof() helper
(Peter Zijlstra)
Fair scheduler updates/refactoring:
- Fold the sched_avg update
- Change rcu_dereference_check_sched_domain() to rcu-sched
- Switch to rcu_dereference_all()
- Remove superfluous rcu_read_lock()
- Limit hrtick work
(Peter Zijlstra)
- Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks
- Clean up comments in 'struct cfs_rq'
- Separate se->vlag from se->vprot
- Rename cfs_rq::avg_load to cfs_rq::sum_weight
- Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions
- Introduce and use the vruntime_cmp() and vruntime_op() wrappers
for wrapped-signed aritmetics
- Sort out 'blocked_load*' namespace noise
(Ingo Molnar)
Scheduler debugging code updates:
- Export hidden tracepoints to modules (Gabriele Monaco)
- Convert copy_from_user() + kstrtouint() to kstrtouint_from_user()
(Fushuai Wang)
- Add assertions to QUEUE_CLASS (Peter Zijlstra)
- hrtimer: Fix tracing oddity (Thomas Gleixner)
Misc fixes and cleanups:
- Re-evaluate scheduling when migrating queued tasks out of
throttled cgroups (Zicheng Qu)
- Remove task_struct->faults_disabled_mapping (Christoph Hellwig)
- Fix math notation errors in avg_vruntime comment (Zhan Xusheng)
- sched/cpufreq: Use %pe format for PTR_ERR() printing (zenghongling)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Scheduler Kconfig space updates:
- Further consolidate configurable preemption modes (Peter Zijlstra)
Reduce the number of architectures that are allowed to offer
PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number of
preemption models from four to just two: 'full' and 'lazy' on
up-to-date architectures (arm64, loongarch, powerpc, riscv, s390,
x86).
None and voluntary are only available as legacy features on
platforms that don't implement lazy preemption yet, or which don't
even support preemption.
The goal is to eventually remove cond_resched() and voluntary
preemption altogether.
RSEQ based 'scheduler time slice extension' support (Thomas Gleixner
and Peter Zijlstra):
This allows a thread to request a time slice extension when it enters
a critical section to avoid contention on a resource when the thread
is scheduled out inside of the critical section.
- Add fields and constants for time slice extension
- Provide static branch for time slice extensions
- Add statistics for time slice extensions
- Add prctl() to enable time slice extensions
- Implement sys_rseq_slice_yield()
- Implement syscall entry work for time slice extensions
- Implement time slice extension enforcement timer
- Reset slice extension when scheduled
- Implement rseq_grant_slice_extension()
- entry: Hook up rseq time slice extension
- selftests: Implement time slice extension test
- Allow registering RSEQ with slice extension
- Move slice_ext_nsec to debugfs
- Lower default slice extension
- selftests/rseq: Add rseq slice histogram script
Scheduler performance/scalability improvements:
- Update rq->avg_idle when a task is moved to an idle CPU, which
improves the scalability of various workloads (Shubhang Kaushik)
- Reorder fields in 'struct rq' for better caching (Blake Jones)
- Fair scheduler SMP NOHZ balancing code speedups (Shrikanth Hegde):
- Move checking for nohz cpus after time check
- Change likelyhood of nohz.nr_cpus
- Remove nohz.nr_cpus and use weight of cpumask instead
- Avoid false sharing for sched_clock_irqtime (Wangyang Guo)
- Cleanups (Yury Norov):
- Drop useless cpumask_empty() in find_energy_efficient_cpu()
- Simplify task_numa_find_cpu()
- Use cpumask_weight_and() in sched_balance_find_dst_group()
DL scheduler updates:
- Add a deadline server for sched_ext tasks (by Andrea Righi and Joel
Fernandes, with fixes by Peter Zijlstra)
RT scheduler updates:
- Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang)
Entry code updates and performance improvements (Jinjie Ruan)
This is part of the scheduler tree in this cycle due to inter-
dependencies with the RSEQ based time slice extension work:
- Remove unused syscall argument from syscall_trace_enter()
- Rework syscall_exit_to_user_mode_work() for architecture reuse
- Add arch_ptrace_report_syscall_entry/exit()
- Inline syscall_exit_work() and syscall_trace_enter()
Scheduler core updates (Peter Zijlstra):
- Rework sched_class::wakeup_preempt() and rq_modified_*()
- Avoid rq->lock bouncing in sched_balance_newidle()
- Rename rcu_dereference_check_sched_domain() =>
rcu_dereference_sched_domain()
- <linux/compiler_types.h>: Add the __signed_scalar_typeof() helper
Fair scheduler updates/refactoring (Peter Zijlstra and Ingo Molnar):
- Fold the sched_avg update
- Change rcu_dereference_check_sched_domain() to rcu-sched
- Switch to rcu_dereference_all()
- Remove superfluous rcu_read_lock()
- Limit hrtick work
- Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks
- Clean up comments in 'struct cfs_rq'
- Separate se->vlag from se->vprot
- Rename cfs_rq::avg_load to cfs_rq::sum_weight
- Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions
- Introduce and use the vruntime_cmp() and vruntime_op() wrappers for
wrapped-signed aritmetics
- Sort out 'blocked_load*' namespace noise
Scheduler debugging code updates:
- Export hidden tracepoints to modules (Gabriele Monaco)
- Convert copy_from_user() + kstrtouint() to kstrtouint_from_user()
(Fushuai Wang)
- Add assertions to QUEUE_CLASS (Peter Zijlstra)
- hrtimer: Fix tracing oddity (Thomas Gleixner)
Misc fixes and cleanups:
- Re-evaluate scheduling when migrating queued tasks out of throttled
cgroups (Zicheng Qu)
- Remove task_struct->faults_disabled_mapping (Christoph Hellwig)
- Fix math notation errors in avg_vruntime comment (Zhan Xusheng)
- sched/cpufreq: Use %pe format for PTR_ERR() printing
(zenghongling)"
* tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
sched: Re-evaluate scheduling when migrating queued tasks out of throttled cgroups
sched/cpufreq: Use %pe format for PTR_ERR() printing
sched/rt: Skip currently executing CPU in rto_next_cpu()
sched/clock: Avoid false sharing for sched_clock_irqtime
selftests/sched_ext: Add test for DL server total_bw consistency
selftests/sched_ext: Add test for sched_ext dl_server
sched/debug: Fix dl_server (re)start conditions
sched/debug: Add support to change sched_ext server params
sched_ext: Add a DL server for sched_ext tasks
sched/debug: Stop and start server based on if it was active
sched/debug: Fix updating of ppos on server write ops
sched/deadline: Clear the defer params
entry: Inline syscall_exit_work() and syscall_trace_enter()
entry: Add arch_ptrace_report_syscall_entry/exit()
entry: Rework syscall_exit_to_user_mode_work() for architecture reuse
entry: Remove unused syscall argument from syscall_trace_enter()
sched: remove task_struct->faults_disabled_mapping
sched: Update rq->avg_idle when a task is moved to an idle CPU
selftests/rseq: Add rseq slice histogram script
hrtimer: Fix trace oddity
...
|
||
|
Nathan Chancellor
|
3e30278e0c |
x86/entry/vdso32: Omit '.cfi_offset eflags' for LLVM < 16
After commit: |
||
|
Thomas Gleixner
|
99d2592023 |
rseq: Implement sys_rseq_slice_yield()
Provide a new syscall which has the only purpose to yield the CPU after the kernel granted a time slice extension. sched_yield() is not suitable for that because it unconditionally schedules, but the end of the time slice extension is not required to schedule when the task was already preempted. This also allows to have a strict check for termination to catch user space invoking random syscalls including sched_yield() from a time slice extension region. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://patch.msgid.link/20251215155708.929634896@linutronix.de |
||
|
H. Peter Anvin
|
a48acbaf99 |
x86/entry/vdso: Fix filtering of vdso compiler flags
This fixes several typos in the filtering of compiler flags for vdso,
discovered by Chris Mason using an AI script:
1. "-fno-PIE" was written as "fno-PIE".
2. "CC_PLUGINS_FLAGS" was written as "CC_PLUGIN_FLAGS"
To the best of my knowledge, none of these actually had any real
impact on the build at this time but they are genuine bugs which could
break things at any point in the future.
Chris's script also found that "CONFIG_X86_USER_SHADOW_STACK" was
missing "CONFIG_", but it needs a different fix.
[ dhansen: remove CONFIG_X86_USER_SHADOW_STACK munging,
add mention in changelog. ]
Closes: https://lore.kernel.org/20260116035807.2307742-1-clm@meta.com
Fixes:
|
||
|
Thomas Weißschuh
|
7158fc54b2 |
vdso: Remove struct getcpu_cache
The cache parameter of getcpu() is useless nowadays for various reasons. * It is never passed by userspace for either the vDSO or syscalls. * It is never used by the kernel. * It could not be made to work on the current vDSO architecture. * The structure definition is not part of the UAPI headers. * vdso_getcpu() is superseded by restartable sequences in any case. Remove the struct and its header. As a side-effect this gets rid of an unwanted inclusion of the linux/ header namespace from vDSO code. [ tglx: Adapt to s390 upstream changes */ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Link: https://patch.msgid.link/20251230-getcpu_cache-v3-1-fb9c5f880ebe@linutronix.de |
||
|
H. Peter Anvin
|
36d83c249e |
x86/entry/vdso32: When using int $0x80, use it directly
When neither sysenter32 nor syscall32 is available (on either FRED-capable 64-bit hardware or old 32-bit hardware), there is no reason to do a bunch of stack shuffling in __kernel_vsyscall. Unfortunately, just overwriting the initial "push" instructions will mess up the CFI annotations, so suffer the 3-byte NOP if not applicable. Similarly, inline the int $0x80 when doing inline system calls in the vdso instead of calling __kernel_vsyscall. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-11-hpa@zytor.com |
||
|
H. Peter Anvin
|
f49ecf5e11 |
x86/cpufeature: Replace X86_FEATURE_SYSENTER32 with X86_FEATURE_SYSFAST32
In most cases, the use of "fast 32-bit system call" depends either on X86_FEATURE_SEP or X86_FEATURE_SYSENTER32 || X86_FEATURE_SYSCALL32. However, nearly all the logic for both is identical. Define X86_FEATURE_SYSFAST32 which indicates that *either* SYSENTER32 or SYSCALL32 should be used, for either 32- or 64-bit kernels. This defaults to SYSENTER; use SYSCALL if the SYSCALL32 bit is also set. As this removes ALL existing uses of X86_FEATURE_SYSENTER32, which is a kernel-only synthetic feature bit, simply remove it and replace it with X86_FEATURE_SYSFAST32. This leaves an unused alternative for a true 32-bit kernel, but that should really not matter in any way. The clearing of X86_FEATURE_SYSCALL32 can be removed once the patches for automatically clearing disabled features has been merged. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-10-hpa@zytor.com |
||
|
H. Peter Anvin
|
8717b02b8c |
x86/entry/vdso: Include GNU_PROPERTY and GNU_STACK PHDRs
Currently the vdso doesn't include .note.gnu.property or a GNU noexec stack annotation (the -z noexecstack in the linker script is ineffective because we specify PHDRs explicitly.) The motivation is that the dynamic linker currently do not check these. However, this is a weak excuse: the vdso*.so are also supposed to be usable at link libraries, and there is no reason why the dynamic linker might not want or need to check these in the future, so add them back in -- it is trivial enough. Use symbolic constants for the PHDR permission flags. [ v4: drop unrelated formatting changes ] Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-8-hpa@zytor.com |
||
|
H. Peter Anvin
|
884961618e |
x86/entry/vdso32: Remove open-coded DWARF in sigreturn.S
The vdso32 sigreturn.S contains open-coded DWARF bytecode, which includes a hack for gdb to not try to step back to a previous call instruction when backtracing from a signal handler. Neither of those are necessary anymore: the backtracing issue is handled by ".cfi_entry simple" and ".cfi_signal_frame", both of which have been supported for a very long time now, which allows the remaining frame to be built using regular .cfi annotations. Add a few more register offsets to the signal frame just for good measure. Replace the nop on fallthrough of the system call (which should never, ever happen) with a ud2a trap. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-7-hpa@zytor.com |
||
|
H. Peter Anvin
|
98d3e99651 |
x86/entry/vdso32: Remove SYSCALL_ENTER_KERNEL macro in sigreturn.S
A macro SYSCALL_ENTER_KERNEL was defined in sigreturn.S, with the ability of overriding it. The override capability, however, is not used anywhere, and the macro name is potentially confusing because it seems to imply that sysenter/syscall could be used here, which is NOT true: the sigreturn system calls MUST use int $0x80. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-6-hpa@zytor.com |
||
|
H. Peter Anvin
|
6e150b7101 |
x86/entry/vdso32: Don't rely on int80_landing_pad for adjusting ip
There is no fundamental reason to use the int80_landing_pad symbol to adjust ip when moving the vdso. If ip falls within the vdso, and the vdso is moved, we should change the ip accordingly, regardless of mode or location within the vdso. This *currently* can only happen on 32 bits, but there isn't any reason not to do so generically. Note that if this is ever possible from a vdso-internal call, then the user space stack will also needed to be adjusted (as well as the shadow stack, if enabled.) Fortunately this is not currently the case. At the moment, we don't even consider other threads when moving the vdso. The assumption is that it is only used by process freeze/thaw for migration, where this is not an issue. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-5-hpa@zytor.com |
||
|
H. Peter Anvin
|
693c819fed |
x86/entry/vdso: Refactor the vdso build
- Separate out the vdso sources into common, vdso32, and vdso64 directories. - Build the 32- and 64-bit vdsos in their respective subdirectories; this greatly simplifies the build flags handling. - Unify the mangling of Makefile flags between the 32- and 64-bit vdso code as much as possible; all common rules are put in arch/x86/entry/vdso/common/Makefile.include. The remaining is very simple for 32 bits; the 64-bit one is only slightly more complicated because it contains the x32 generation rule. - Define __DISABLE_EXPORTS when building the vdso. This need seems to have been masked by different ordering compile flags before. - Change CONFIG_X86_64 to BUILD_VDSO32_64 in vdso32/system_call.S, to make it compatible with including fake_32bit_build.h. - The -fcf-protection= option was "leaking" from the kernel build, for reasons that was not clear to me. Furthermore, several distributions ship with it set to a default value other than "-fcf-protection=none". Make it match the configuration options for *user space*. Note that this patch may seem large, but the vast majority of it is simply code movement. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-4-hpa@zytor.com |
||
|
H. Peter Anvin
|
a76108d05e |
x86/entry/vdso: Move vdso2c to arch/x86/tools
It is generally better to build tools in arch/x86/tools to keep host cflags proliferation down, and to reduce makefile sequencing issues. Move the vdso build tool vdso2c into arch/x86/tools in preparation for refactoring the vdso makefiles. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-3-hpa@zytor.com |
||
|
H. Peter Anvin
|
93d73005bf |
x86/entry/vdso: Rename vdso_image_* to vdso*_image
The vdso .so files are named vdso*.so. These structures are binary images and descriptions of these files, so it is more consistent for them to have a naming that more directly mirrors the filenames. It is also very slightly more compact (by one character...) and simplifies the Makefile just a little bit. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://patch.msgid.link/20251216212606.1325678-2-hpa@zytor.com |
||
|
Thomas Weißschuh
|
21bbfd7404 |
x86/vdso: Provide clock_getres_time64() for x86-32
For consistency with __vdso_clock_gettime64() there should also be a 64-bit variant of clock_getres(). This will allow the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit time types from the kernel and UAPI. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/20251223-vdso-compat-time32-v1-5-97ea7a06a543@linutronix.de |
||
|
Juergen Gross
|
07f2961235 |
x86/paravirt: Remove not needed includes of paravirt.h
In some places asm/paravirt.h is included without really being needed. Remove the related #include statements. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260105110520.21356-2-jgross@suse.com |
||
|
Sean Christopherson
|
a05385d84b |
perf/x86/core: Register a new vector for handling mediated guest PMIs
Wire up system vector 0xf5 for handling PMIs (i.e. interrupts delivered through the LVTPC) while running KVM guests with a mediated PMU. Perf currently delivers all PMIs as NMIs, e.g. so that events that trigger while IRQs are disabled aren't delayed and generate useless records, but due to the multiplexing of NMIs throughout the system, correctly identifying NMIs for a mediated PMU is practically infeasible. To (greatly) simplify identifying guest mediated PMU PMIs, perf will switch the CPU's LVTPC between PERF_GUEST_MEDIATED_PMI_VECTOR and NMI when guest PMU context is loaded/put. I.e. PMIs that are generated by the CPU while the guest is active will be identified purely based on the IRQ vector. Route the vector through perf, e.g. as opposed to letting KVM attach a handler directly a la posted interrupt notification vectors, as perf owns the LVTPC and thus is the rightful owner of PERF_GUEST_MEDIATED_PMI_VECTOR. Functionally, having KVM directly own the vector would be fine (both KVM and perf will be completely aware of when a mediated PMU is active), but would lead to an undesirable split in ownership: perf would be responsible for installing the vector, but not handling the resulting IRQs. Add a new perf_guest_info_callbacks hook (and static call) to allow KVM to register its handler with perf when running guests with mediated PMUs. Note, because KVM always runs guests with host IRQs enabled, there is no danger of a PMI being delayed from the guest's perspective due to using a regular IRQ instead of an NMI. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Xudong Hao <xudong.hao@intel.com> Link: https://patch.msgid.link/20251206001720.468579-9-seanjc@google.com |
||
|
Linus Torvalds
|
a7610b8465 |
* Fix 64-bit identifier structure member name in fred_ss
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||
|
Linus Torvalds
|
e2aa39b368 |
* Make MSR-induced taint easier for users to track down
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||
|
Linus Torvalds
|
2b09f480f0 |
A large overhaul of the restartable sequences and CID management:
The recent enablement of RSEQ in glibc resulted in regressions which are
caused by the related overhead. It turned out that the decision to invoke
the exit to user work was not really a decision. More or less each
context switch caused that. There is a long list of small issues which
sums up nicely and results in a 3-4% regression in I/O benchmarks.
The other detail which caused issues due to extra work in context switch
and task migration is the CID (memory context ID) management. It also
requires to use a task work to consolidate the CID space, which is
executed in the context of an arbitrary task and results in sporadic
uncontrolled exit latencies.
The rewrite addresses this by:
- Removing deprecated and long unsupported functionality
- Moving the related data into dedicated data structures which are
optimized for fast path processing.
- Caching values so actual decisions can be made
- Replacing the current implementation with a optimized inlined variant.
- Separating fast and slow path for architectures which use the generic
entry code, so that only fault and error handling goes into the
TIF_NOTIFY_RESUME handler.
- Rewriting the CID management so that it becomes mostly invisible in the
context switch path. That moves the work of switching modes into the
fork/exit path, which is a reasonable tradeoff. That work is only
required when a process creates more threads than the cpuset it is
allowed to run on or when enough threads exit after that. An artificial
thread pool benchmarks which triggers this did not degrade, it actually
improved significantly.
The main effect in migration heavy scenarios is that runqueue lock held
time and therefore contention goes down significantly.
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Merge tag 'core-rseq-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull rseq updates from Thomas Gleixner:
"A large overhaul of the restartable sequences and CID management:
The recent enablement of RSEQ in glibc resulted in regressions which
are caused by the related overhead. It turned out that the decision to
invoke the exit to user work was not really a decision. More or less
each context switch caused that. There is a long list of small issues
which sums up nicely and results in a 3-4% regression in I/O
benchmarks.
The other detail which caused issues due to extra work in context
switch and task migration is the CID (memory context ID) management.
It also requires to use a task work to consolidate the CID space,
which is executed in the context of an arbitrary task and results in
sporadic uncontrolled exit latencies.
The rewrite addresses this by:
- Removing deprecated and long unsupported functionality
- Moving the related data into dedicated data structures which are
optimized for fast path processing.
- Caching values so actual decisions can be made
- Replacing the current implementation with a optimized inlined
variant.
- Separating fast and slow path for architectures which use the
generic entry code, so that only fault and error handling goes into
the TIF_NOTIFY_RESUME handler.
- Rewriting the CID management so that it becomes mostly invisible in
the context switch path. That moves the work of switching modes
into the fork/exit path, which is a reasonable tradeoff. That work
is only required when a process creates more threads than the
cpuset it is allowed to run on or when enough threads exit after
that. An artificial thread pool benchmarks which triggers this did
not degrade, it actually improved significantly.
The main effect in migration heavy scenarios is that runqueue lock
held time and therefore contention goes down significantly"
* tag 'core-rseq-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
sched/mmcid: Switch over to the new mechanism
sched/mmcid: Implement deferred mode change
irqwork: Move data struct to a types header
sched/mmcid: Provide CID ownership mode fixup functions
sched/mmcid: Provide new scheduler CID mechanism
sched/mmcid: Introduce per task/CPU ownership infrastructure
sched/mmcid: Serialize sched_mm_cid_fork()/exit() with a mutex
sched/mmcid: Provide precomputed maximal value
sched/mmcid: Move initialization out of line
signal: Move MMCID exit out of sighand lock
sched/mmcid: Convert mm CID mask to a bitmap
cpumask: Cache num_possible_cpus()
sched/mmcid: Use cpumask_weighted_or()
cpumask: Introduce cpumask_weighted_or()
sched/mmcid: Prevent pointless work in mm_update_cpus_allowed()
sched/mmcid: Move scheduler code out of global header
sched: Fixup whitespace damage
sched/mmcid: Cacheline align MM CID storage
sched/mmcid: Use proper data structures
sched/mmcid: Revert the complex CID management
...
|
||
|
Linus Torvalds
|
4a26e7032d |
Core kernel bug handling infrastructure changes for v6.19:
- Improve WARN(), which has vararg printf like arguments,
to work with the x86 #UD based WARN-optimizing infrastructure
by hiding the format in the bug_table and replacing this
first argument with the address of the bug-table entry,
while making the actual function that's called a UD1 instruction.
(Peter Zijlstra)
- Introduce the CONFIG_DEBUG_BUGVERBOSE_DETAILED Kconfig switch
(Ingo Molnar, s390 support by Heiko Carstens)
Fixes and cleanups:
- bugs/s390: Remove private WARN_ON() implementation (Heiko Carstens)
- <asm/bugs.h>: Make i386 use GENERIC_BUG_RELATIVE_POINTERS
(Peter Zijlstra)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-bugs-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull bug handling infrastructure updates from Ingo Molnar:
"Core updates:
- Improve WARN(), which has vararg printf like arguments, to work
with the x86 #UD based WARN-optimizing infrastructure by hiding the
format in the bug_table and replacing this first argument with the
address of the bug-table entry, while making the actual function
that's called a UD1 instruction (Peter Zijlstra)
- Introduce the CONFIG_DEBUG_BUGVERBOSE_DETAILED Kconfig switch (Ingo
Molnar, s390 support by Heiko Carstens)
Fixes and cleanups:
- bugs/s390: Remove private WARN_ON() implementation (Heiko Carstens)
- <asm/bugs.h>: Make i386 use GENERIC_BUG_RELATIVE_POINTERS (Peter
Zijlstra)"
* tag 'core-bugs-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
x86/bugs: Make i386 use GENERIC_BUG_RELATIVE_POINTERS
x86/bug: Fix BUG_FORMAT vs KASLR
x86_64/bug: Inline the UD1
x86/bug: Implement WARN_ONCE()
x86_64/bug: Implement __WARN_printf()
x86/bug: Use BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILED
x86/bug: Add BUG_FORMAT basics
bug: Allow architectures to provide __WARN_printf()
bug: Implement WARN_ON() using __WARN_FLAGS()
bug: Add report_bug_entry()
bug: Add BUG_FORMAT_ARGS infrastructure
bug: Clean up CONFIG_GENERIC_BUG_RELATIVE_POINTERS
bug: Add BUG_FORMAT infrastructure
x86: Rework __bug_table helpers
bugs/s390: Remove private WARN_ON() implementation
bugs/core: Reorganize fields in the first line of WARNING output, add ->comm[] output
bugs/sh: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output
bugs/parisc: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output
bugs/riscv: Concatenate 'cond_str' with '__FILE__' in __BUG_FLAGS(), to extend WARN_ON/BUG_ON output
bugs/riscv: Pass in 'cond_str' to __BUG_FLAGS()
...
|
||
|
Peter Zijlstra
|
5b472b6e5b |
x86_64/bug: Implement __WARN_printf()
The basic idea is to have __WARN_printf() be a vararg function such
that the compiler can do the optimal calling convention for us. This
function body will be a #UD and then set up a va_list in the exception
from pt_regs.
But because the trap will be in a called function, the bug_entry must
be passed in. Have that be the first argument, with the format tucked
away inside the bug_entry.
The comments should clarify the real fun details.
The big downside is that all WARNs will now show:
RIP: 0010:__WARN_trap:+0
One possible solution is to simply discard the top frame when
unwinding. A follow up patch takes care of this slightly differently
by abusing the x86 static_call implementation.
This changes (with the next patches):
WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET,
"corrupted preempt_count: %s/%d/0x%x\n",
from:
cmpl $2, %ecx #, _7
jne .L1472
...
.L1472:
cmpb $0, __already_done.11(%rip)
je .L1513
...
.L1513
movb $1, __already_done.11(%rip)
movl 1424(%r14), %edx # _15->pid, _15->pid
leaq 1912(%r14), %rsi #, _17
movq $.LC43, %rdi #,
call __warn_printk #
ud2
.pushsection __bug_table,"aw"
2:
.long 1b - . # bug_entry::bug_addr
.long .LC1 - . # bug_entry::file
.word 5093 # bug_entry::line
.word 2313 # bug_entry::flags
.org 2b + 12
.popsection
.pushsection .discard.annotate_insn,"M", @progbits, 8
.long 1b - .
.long 8 # ANNOTYPE_REACHABLE
.popsection
into:
cmpl $2, %ecx #, _7
jne .L1442 #,
...
.L1442:
lea (2f)(%rip), %rdi
1:
.pushsection __bug_table,"aw"
2:
.long 1b - . # bug_entry::bug_addr
.long .LC43 - . # bug_entry::format
.long .LC1 - . # bug_entry::file
.word 5093 # bug_entry::line
.word 2323 # bug_entry::flags
.org 2b + 16
.popsection
movl 1424(%r14), %edx # _19->pid, _19->pid
leaq 1912(%r14), %rsi #, _13
ud1 (%edx), %rdi
Notably, by pushing everything into the exception handler it can take
care of the ONCE thing.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251110115758.213813530@infradead.org
|
||
|
Sean Christopherson
|
6276c67f2b |
x86: Restrict KVM-induced symbol exports to KVM modules where obvious/possible
Extend KVM's export macro framework to provide EXPORT_SYMBOL_FOR_KVM(), and use the helper macro to export symbols for KVM throughout x86 if and only if KVM will build one or more modules, and only for those modules. To avoid unnecessary exports when CONFIG_KVM=m but kvm.ko will not be built (because no vendor modules are selected), let arch code #define EXPORT_SYMBOL_FOR_KVM to suppress/override the exports. Note, the set of symbols to restrict to KVM was generated by manual search and audit; any "misses" are due to human error, not some grand plan. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Kai Huang <kai.huang@intel.com> Link: https://patch.msgid.link/20251112173944.1380633-5-seanjc%40google.com |
||
|
Thomas Gleixner
|
54a5ab5624 |
entry: Remove syscall_enter_from_user_mode_prepare()
Open code the only user in the x86 syscall code and reduce the zoo of functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://patch.msgid.link/20251027084306.652839989@linutronix.de |
||
|
Christian Brauner
|
b36d4b6aa8
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arch: hookup listns() system call
Add the listns() system call to all architectures. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-20-2e6f823ebdc0@kernel.org Tested-by: syzbot@syzkaller.appspotmail.com Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
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Andrew Cooper
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4ab13be5ed |
x86/fred: Fix 64bit identifier in fred_ss
FRED can only be enabled in Long Mode. This is the 64bit mode (as opposed to compatibility mode) identifier, rather than being something hard-wired at 1. No functional change. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Xin Li (Intel) <xin@zytor.com> Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com> Acked-by: H. Peter Anvin (Intel) <hpa@zytor.com> |
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Linus Torvalds
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9591fdb061 |
- Remove a bunch of asm implementing condition flags testing in KVM's
emulator in favor of int3_emulate_jcc() which is written in C - Replace KVM fastops with C-based stubs which avoids problems with the fastop infra related to latter not adhering to the C ABI due to their special calling convention and, more importantly, bypassing compiler control-flow integrity checking because they're written in asm - Remove wrongly used static branches and other ugliness accumulated over time in hyperv's hypercall implementation with a proper static function call to the correct hypervisor call variant - Add some fixes and modifications to allow running FRED-enabled kernels in KVM even on non-FRED hardware - Add kCFI improvements like validating indirect calls and prepare for enabling kCFI with GCC. Add cmdline params documentation and other code cleanups - Use the single-byte 0xd6 insn as the official #UD single-byte undefined opcode instruction as agreed upon by both x86 vendors - Other smaller cleanups and touchups all over the place -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmjqXxkACgkQEsHwGGHe VUq9QBAAsjaay99a1+Dc53xyP1/HzCUFZDOzEYhj9zF85I8/xA9vTXZr7Qg2m6os +4EEmnlwU43AR5KgwGJcuszLF9qSqTMz5qkAdFpvnoQ1Hbc8b49A+3yo9/hM7NA2 gPGH0gVZVBcffoETiQ8tJN6C9H6Ec0nTZwKTbasWwxz5oUAw+ppjP+aF4rFQ2/5w b1ofrcga5yucjvSlXjBOEwHvd21l7O9iMre1oGEn6b0E2LU8ldToRkJkVZIhkWeL 2Iq3gYtVNN4Ao06WbV/EfXAqg5HWXjcm5bLcUXDtSF+Blae+gWoCjrT7XQdQGyEq J12l4FbIZk5Ha8eWAC425ye9i3Wwo+oie3Cc4SVCMdv5A+AmOF0ijAlo1hcxq0rX eGNWm8BKJOJ9zz1kxLISO7CfjULKgpsXLabF5a19uwoCsQgj5YrhlJezaIKHXbnK OWwHWg9IuRkN2KLmJa7pXtHkuAHp4MtEV9TP9kU2WCvCInrNrzp3gYtds3pri82c 8ove+WA3yb/AQ6RCq5vAMLYXBxMRbN7FrmY5ZuwgWJTMi6cp1Sp02mhobwJOgNhO H7nKWCZnQMyCLPzVeg97HTSgqSXw13dSrujWX9gWYVWBMfZO1B9HcUrhtiOhH7Q9 cvELkcqaxKrCKdRHLLYgHeMIQU2tdpsQ5TXHm7C7liEcZPZpk+g= =3Otb -----END PGP SIGNATURE----- Merge tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x86 updates from Borislav Petkov: - Remove a bunch of asm implementing condition flags testing in KVM's emulator in favor of int3_emulate_jcc() which is written in C - Replace KVM fastops with C-based stubs which avoids problems with the fastop infra related to latter not adhering to the C ABI due to their special calling convention and, more importantly, bypassing compiler control-flow integrity checking because they're written in asm - Remove wrongly used static branches and other ugliness accumulated over time in hyperv's hypercall implementation with a proper static function call to the correct hypervisor call variant - Add some fixes and modifications to allow running FRED-enabled kernels in KVM even on non-FRED hardware - Add kCFI improvements like validating indirect calls and prepare for enabling kCFI with GCC. Add cmdline params documentation and other code cleanups - Use the single-byte 0xd6 insn as the official #UD single-byte undefined opcode instruction as agreed upon by both x86 vendors - Other smaller cleanups and touchups all over the place * tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86,retpoline: Optimize patch_retpoline() x86,ibt: Use UDB instead of 0xEA x86/cfi: Remove __noinitretpoline and __noretpoline x86/cfi: Add "debug" option to "cfi=" bootparam x86/cfi: Standardize on common "CFI:" prefix for CFI reports x86/cfi: Document the "cfi=" bootparam options x86/traps: Clarify KCFI instruction layout compiler_types.h: Move __nocfi out of compiler-specific header objtool: Validate kCFI calls x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware x86/fred: Install system vector handlers even if FRED isn't fully enabled x86/hyperv: Use direct call to hypercall-page x86/hyperv: Clean up hv_do_hypercall() KVM: x86: Remove fastops KVM: x86: Convert em_salc() to C KVM: x86: Introduce EM_ASM_3WCL KVM: x86: Introduce EM_ASM_1SRC2 KVM: x86: Introduce EM_ASM_2CL KVM: x86: Introduce EM_ASM_2W ... |