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* cpu: Re-enable CPU mitigations by default for !X86 architecturesSean Christopherson2024-04-251-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename x86's to CPU_MITIGATIONS, define it in generic code, and force it on for all architectures exception x86. A recent commit to turn mitigations off by default if SPECULATION_MITIGATIONS=n kinda sorta missed that "cpu_mitigations" is completely generic, whereas SPECULATION_MITIGATIONS is x86-specific. Rename x86's SPECULATIVE_MITIGATIONS instead of keeping both and have it select CPU_MITIGATIONS, as having two configs for the same thing is unnecessary and confusing. This will also allow x86 to use the knob to manage mitigations that aren't strictly related to speculative execution. Use another Kconfig to communicate to common code that CPU_MITIGATIONS is already defined instead of having x86's menu depend on the common CPU_MITIGATIONS. This allows keeping a single point of contact for all of x86's mitigations, and it's not clear that other architectures *want* to allow disabling mitigations at compile-time. Fixes: f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n") Closes: https://lkml.kernel.org/r/20240413115324.53303a68%40canb.auug.org.au Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240420000556.2645001-2-seanjc@google.com
* Kconfig: add some hidden tabs on purposeLinus Torvalds2024-04-121-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Commit d96c36004e31 ("tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry") removed a hidden tab because it apparently showed breakage in some third-party kernel config parsing tool. It wasn't clear what tool it was, but let's make sure it gets fixed. Because if you can't parse tabs as whitespace, you should not be parsing the kernel Kconfig files. In fact, let's make such breakage more obvious than some esoteric ftrace record size option. If you can't parse tabs, you can't have page sizes. Yes, tab-vs-space confusion is sadly a traditional Unix thing, and 'make' is famous for being broken in this regard. But no, that does not mean that it's ok. I'd add more random tabs to our Kconfig files, but I don't want to make things uglier than necessary. But it *might* bbe necessary if it turns out we see more of this kind of silly tooling. Fixes: d96c36004e31 ("tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry") Link: https://lore.kernel.org/lkml/CAHk-=wj-hLLN_t_m5OL4dXLaxvXKy_axuoJYXif7iczbfgAevQ@mail.gmail.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'hardening-v6.9-rc1-fixes' of ↵Linus Torvalds2024-03-231-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull more hardening updates from Kees Cook: - CONFIG_MEMCPY_SLOW_KUNIT_TEST is no longer needed (Guenter Roeck) - Fix needless UTF-8 character in arch/Kconfig (Liu Song) - Improve __counted_by warning message in LKDTM (Nathan Chancellor) - Refactor DEFINE_FLEX() for default use of __counted_by - Disable signed integer overflow sanitizer on GCC < 8 * tag 'hardening-v6.9-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lkdtm/bugs: Improve warning message for compilers without counted_by support overflow: Change DEFINE_FLEX to take __counted_by member Revert "kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST" arch/Kconfig: eliminate needless UTF-8 character in Kconfig help ubsan: Disable signed integer overflow sanitizer on GCC < 8
| * arch/Kconfig: eliminate needless UTF-8 character in Kconfig helpLiu Song2024-03-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use "find ./linux/* | grep Kconfig | xargs file | grep UTF", can find files with utf-8 encoded characters, these files will display garbled characters in menuconfig, except for characters with special meanings that cannot be modified, modify the characters with obvious errors to eliminate the wrong display under meunconfig. Signed-off-by: Liu Song <liusong@linux.alibaba.com> Suggested-by: Bjorn Helgaas <helgaas@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/lkml/1659435153-119538-1-git-send-email-liusong@linux.alibaba.com/ Signed-off-by: Kees Cook <keescook@chromium.org>
* | Merge tag 'kbuild-v6.9' of ↵Linus Torvalds2024-03-211-0/+12
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Generate a list of built DTB files (arch/*/boot/dts/dtbs-list) - Use more threads when building Debian packages in parallel - Fix warnings shown during the RPM kernel package uninstallation - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to Makefile - Support GCC's -fmin-function-alignment flag - Fix a null pointer dereference bug in modpost - Add the DTB support to the RPM package - Various fixes and cleanups in Kconfig * tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits) kconfig: tests: test dependency after shuffling choices kconfig: tests: add a test for randconfig with dependent choices kconfig: tests: support KCONFIG_SEED for the randconfig runner kbuild: rpm-pkg: add dtb files in kernel rpm kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig() kconfig: check prompt for choice while parsing kconfig: lxdialog: remove unused dialog colors kconfig: lxdialog: fix button color for blackbg theme modpost: fix null pointer dereference kbuild: remove GCC's default -Wpacked-bitfield-compat flag kbuild: unexport abs_srctree and abs_objtree kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1 kconfig: remove named choice support kconfig: use linked list in get_symbol_str() to iterate over menus kconfig: link menus to a symbol kbuild: fix inconsistent indentation in top Makefile kbuild: Use -fmin-function-alignment when available alpha: merge two entries for CONFIG_ALPHA_GAMMA alpha: merge two entries for CONFIG_ALPHA_EV4 kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj) ...
| * kbuild: Use -fmin-function-alignment when availablePetr Pavlu2024-02-251-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC recently added option -fmin-function-alignment, which should appear in GCC 14. Unlike -falign-functions, this option causes all functions to be aligned at the specified value, including the cold ones. In particular, when an arm64 kernel is built with DYNAMIC_FTRACE_WITH_CALL_OPS=y, the 8-byte function alignment is required for correct functionality. This was done by -falign-functions=8 and having workarounds in the kernel to force the compiler to follow this alignment. The new -fmin-function-alignment option directly guarantees it. Detect availability of -fmin-function-alignment and use it instead of -falign-functions when present. Introduce CC_HAS_SANE_FUNCTION_ALIGNMENT and enable __cold to work as expected when it is set. Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* | arch: consolidate existing CONFIG_PAGE_SIZE_*KB definitionsArnd Bergmann2024-03-061-2/+92
|/ | | | | | | | | These four architectures define the same Kconfig symbols for configuring the page size. Move the logic into a common place where it can be shared with all other architectures. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* scs: add CONFIG_MMU dependency for vfree_atomic()Samuel Holland2024-01-261-0/+1
| | | | | | | | | | | | | | | | The shadow call stack implementation fails to build without CONFIG_MMU: ld.lld: error: undefined symbol: vfree_atomic >>> referenced by scs.c >>> kernel/scs.o:(scs_free) in archive vmlinux.a Link: https://lkml.kernel.org/r/20240122175204.2371009-1-samuel.holland@sifive.com Fixes: a2abe7cbd8fe ("scs: switch to vmapped shadow stacks") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Cc: Will Deacon <will@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'iommu-updates-v6.8' of ↵Linus Torvalds2024-01-191-0/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu updates from Joerg Roedel: "Core changes: - Fix race conditions in device probe path - Retire IOMMU bus_ops - Support for passing custom allocators to page table drivers - Clean up Kconfig around IOMMU_SVA - Support for sharing SVA domains with all devices bound to a mm - Firmware data parsing cleanup - Tracing improvements for iommu-dma code - Some smaller fixes and cleanups ARM-SMMU drivers: - Device-tree binding updates: - Add additional compatible strings for Qualcomm SoCs - Document Adreno clocks for Qualcomm's SM8350 SoC - SMMUv2: - Implement support for the ->domain_alloc_paging() callback - Ensure Secure context is restored following suspend of Qualcomm SMMU implementation - SMMUv3: - Disable stalling mode for the "quiet" context descriptor - Minor refactoring and driver cleanups Intel VT-d driver: - Cleanup and refactoring AMD IOMMU driver: - Improve IO TLB invalidation logic - Small cleanups and improvements Rockchip IOMMU driver: - DT binding update to add Rockchip RK3588 Apple DART driver: - Apple M1 USB4/Thunderbolt DART support - Cleanups Virtio IOMMU driver: - Add support for iotlb_sync_map - Enable deferred IO TLB flushes" * tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (66 commits) iommu: Don't reserve 0-length IOVA region iommu/vt-d: Move inline helpers to header files iommu/vt-d: Remove unused vcmd interfaces iommu/vt-d: Remove unused parameter of intel_pasid_setup_pass_through() iommu/vt-d: Refactor device_to_iommu() to retrieve iommu directly iommu/sva: Fix memory leak in iommu_sva_bind_device() dt-bindings: iommu: rockchip: Add Rockchip RK3588 iommu/dma: Trace bounce buffer usage when mapping buffers iommu/arm-smmu: Convert to domain_alloc_paging() iommu/arm-smmu: Pass arm_smmu_domain to internal functions iommu/arm-smmu: Implement IOMMU_DOMAIN_BLOCKED iommu/arm-smmu: Convert to a global static identity domain iommu/arm-smmu: Reorganize arm_smmu_domain_add_master() iommu/arm-smmu-v3: Remove ARM_SMMU_DOMAIN_NESTED iommu/arm-smmu-v3: Master cannot be NULL in arm_smmu_write_strtab_ent() iommu/arm-smmu-v3: Add a type for the STE iommu/arm-smmu-v3: disable stall for quiet_cd iommu/qcom: restore IOMMU state if needed iommu/arm-smmu-qcom: Add QCM2290 MDSS compatible iommu/arm-smmu-qcom: Add missing GMU entry to match table ...
| * iommu: Change kconfig around IOMMU_SVAJason Gunthorpe2023-12-121-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus suggested that the kconfig here is confusing: https://lore.kernel.org/all/CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com/ Let's break it into three kconfigs controlling distinct things: - CONFIG_IOMMU_MM_DATA controls if the mm_struct has the additional fields for the IOMMU. Currently only PASID, but later patches store a struct iommu_mm_data * - CONFIG_ARCH_HAS_CPU_PASID controls if the arch needs the scheduling bit for keeping track of the ENQCMD instruction. x86 will select this if IOMMU_SVA is enabled - IOMMU_SVA controls if the IOMMU core compiles in the SVA support code for iommu driver use and the IOMMU exported API This way ARM will not enable CONFIG_ARCH_HAS_CPU_PASID Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20231027000525.1278806-2-tina.zhang@intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
* | Merge tag 'mm-nonmm-stable-2024-01-09-10-33' of ↵Linus Torvalds2024-01-091-13/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "Quite a lot of kexec work this time around. Many singleton patches in many places. The notable patch series are: - nilfs2 folio conversion from Matthew Wilcox in 'nilfs2: Folio conversions for file paths'. - Additional nilfs2 folio conversion from Ryusuke Konishi in 'nilfs2: Folio conversions for directory paths'. - IA64 remnant removal in Heiko Carstens's 'Remove unused code after IA-64 removal'. - Arnd Bergmann has enabled the -Wmissing-prototypes warning everywhere in 'Treewide: enable -Wmissing-prototypes'. This had some followup fixes: - Nathan Chancellor has cleaned up the hexagon build in the series 'hexagon: Fix up instances of -Wmissing-prototypes'. - Nathan also addressed some s390 warnings in 's390: A couple of fixes for -Wmissing-prototypes'. - Arnd Bergmann addresses the same warnings for MIPS in his series 'mips: address -Wmissing-prototypes warnings'. - Baoquan He has made kexec_file operate in a top-down-fitting manner similar to kexec_load in the series 'kexec_file: Load kernel at top of system RAM if required' - Baoquan He has also added the self-explanatory 'kexec_file: print out debugging message if required'. - Some checkstack maintenance work from Tiezhu Yang in the series 'Modify some code about checkstack'. - Douglas Anderson has disentangled the watchdog code's logging when multiple reports are occurring simultaneously. The series is 'watchdog: Better handling of concurrent lockups'. - Yuntao Wang has contributed some maintenance work on the crash code in 'crash: Some cleanups and fixes'" * tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (157 commits) crash_core: fix and simplify the logic of crash_exclude_mem_range() x86/crash: use SZ_1M macro instead of hardcoded value x86/crash: remove the unused image parameter from prepare_elf_headers() kdump: remove redundant DEFAULT_CRASH_KERNEL_LOW_SIZE scripts/decode_stacktrace.sh: strip unexpected CR from lines watchdog: if panicking and we dumped everything, don't re-enable dumping watchdog/hardlockup: use printk_cpu_sync_get_irqsave() to serialize reporting watchdog/softlockup: use printk_cpu_sync_get_irqsave() to serialize reporting watchdog/hardlockup: adopt softlockup logic avoiding double-dumps kexec_core: fix the assignment to kimage->control_page x86/kexec: fix incorrect end address passed to kernel_ident_mapping_init() lib/trace_readwrite.c:: replace asm-generic/io with linux/io nilfs2: cpfile: fix some kernel-doc warnings stacktrace: fix kernel-doc typo scripts/checkstack.pl: fix no space expression between sp and offset x86/kexec: fix incorrect argument passed to kexec_dprintk() x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs nilfs2: add missing set_freezable() for freezable kthread kernel: relay: remove relay_file_splice_read dead code, doesn't work docs: submit-checklist: remove all of "make namespacecheck" ...
| * | arch: remove ARCH_TASK_STRUCT_ON_STACKHeiko Carstens2023-12-111-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | IA-64 was the only architecture which selected ARCH_TASK_STRUCT_ON_STACK. IA-64 was removed with commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"). Therefore remove support for ARCH_TASK_STRUCT_ON_STACK as well. Note: this also reveals a potential bug in powerpc code, which makes use of __init_task_data without selecting ARCH_TASK_STRUCT_ON_STACK which makes __init_task_data a no-op. This is broken since commit d11ed3ab3166 ("Expand INIT_TASK() in init/init_task.c and remove") from 2018 and needs to be addressed separately. Link: https://lkml.kernel.org/r/20231116133638.1636277-4-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * | arch: remove ARCH_TASK_STRUCT_ALLOCATORHeiko Carstens2023-12-111-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | IA-64 was the only architecture which selected ARCH_TASK_STRUCT_ALLOCATOR. IA-64 was removed with commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"). Therefore remove support for ARCH_THREAD_STACK_ALLOCATOR as well. Link: https://lkml.kernel.org/r/20231116133638.1636277-3-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * | arch: remove ARCH_THREAD_STACK_ALLOCATORHeiko Carstens2023-12-111-4/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Remove unused code after IA-64 removal". While looking into something different I noticed that there are a couple of Kconfig options which were only selected by IA-64 and which are now unused. So remove them and simplify the code a bit. This patch (of 3): IA-64 was the only architecture which selected ARCH_THREAD_STACK_ALLOCATOR. IA-64 was removed with commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"). Therefore remove support for ARCH_THREAD_STACK_ALLOCATOR as well. Link: https://lkml.kernel.org/r/20231116133638.1636277-1-hca@linux.ibm.com Link: https://lkml.kernel.org/r/20231116133638.1636277-2-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* / mm/mglru: add CONFIG_ARCH_HAS_HW_PTE_YOUNGKinsey Ho2024-01-051-0/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm/mglru: Kconfig cleanup", v4. This series is the result of the following discussion: https://lore.kernel.org/47066176-bd93-55dd-c2fa-002299d9e034@linux.ibm.com/ It mainly avoids building the code that walks page tables on CPUs that use it, i.e., those don't support hardware accessed bit. Specifically, it introduces a new Kconfig to guard some of functions added by commit bd74fdaea146 ("mm: multi-gen LRU: support page table walks") on CPUs like POWER9, on which the series was tested. This patch (of 5): Some architectures are able to set the accessed bit in PTEs when PTEs are used as part of linear address translations. Add CONFIG_ARCH_HAS_HW_PTE_YOUNG for such architectures to be able to override arch_has_hw_pte_young(). Link: https://lkml.kernel.org/r/20231227141205.2200125-1-kinseyho@google.com Link: https://lkml.kernel.org/r/20231227141205.2200125-2-kinseyho@google.com Signed-off-by: Kinsey Ho <kinseyho@google.com> Co-developed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Tested-by: Donet Tom <donettom@linux.vnet.ibm.com> Acked-by: Yu Zhao <yuzhao@google.com> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* arch: Remove Itanium (IA-64) architectureArd Biesheuvel2023-09-111-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Itanium architecture is obsolete, and an informal survey [0] reveals that any residual use of Itanium hardware in production is mostly HP-UX or OpenVMS based. The use of Linux on Itanium appears to be limited to enthusiasts that occasionally boot a fresh Linux kernel to see whether things are still working as intended, and perhaps to churn out some distro packages that are rarely used in practice. None of the original companies behind Itanium still produce or support any hardware or software for the architecture, and it is listed as 'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers that contributed on behalf of those companies (nor anyone else, for that matter) have been willing to support or maintain the architecture upstream or even be responsible for applying the odd fix. The Intel firmware team removed all IA-64 support from the Tianocore/EDK2 reference implementation of EFI in 2018. (Itanium is the original architecture for which EFI was developed, and the way Linux supports it deviates significantly from other architectures.) Some distros, such as Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have dropped support years ago. While the argument is being made [1] that there is a 'for the common good' angle to being able to build and run existing projects such as the Grid Community Toolkit [2] on Itanium for interoperability testing, the fact remains that none of those projects are known to be deployed on Linux/ia64, and very few people actually have access to such a system in the first place. Even if there were ways imaginable in which Linux/ia64 could be put to good use today, what matters is whether anyone is actually doing that, and this does not appear to be the case. There are no emulators widely available, and so boot testing Itanium is generally infeasible for ordinary contributors. GCC still supports IA-64 but its compile farm [3] no longer has any IA-64 machines. GLIBC would like to get rid of IA-64 [4] too because it would permit some overdue code cleanups. In summary, the benefits to the ecosystem of having IA-64 be part of it are mostly theoretical, whereas the maintenance overhead of keeping it supported is real. So let's rip off the band aid, and remove the IA-64 arch code entirely. This follows the timeline proposed by the Debian/ia64 maintainer [5], which removes support in a controlled manner, leaving IA-64 in a known good state in the most recent LTS release. Other projects will follow once the kernel support is removed. [0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/ [1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/ [2] https://gridcf.org/gct-docs/latest/index.html [3] https://cfarm.tetaneutral.net/machines/list/ [4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/ [5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/ Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
* Merge tag 'x86_shstk_for_6.6-rc1' of ↵Linus Torvalds2023-08-311-0/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 shadow stack support from Dave Hansen: "This is the long awaited x86 shadow stack support, part of Intel's Control-flow Enforcement Technology (CET). CET consists of two related security features: shadow stacks and indirect branch tracking. This series implements just the shadow stack part of this feature, and just for userspace. The main use case for shadow stack is providing protection against return oriented programming attacks. It works by maintaining a secondary (shadow) stack using a special memory type that has protections against modification. When executing a CALL instruction, the processor pushes the return address to both the normal stack and to the special permission shadow stack. Upon RET, the processor pops the shadow stack copy and compares it to the normal stack copy. For more information, refer to the links below for the earlier versions of this patch set" Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/ Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/ * tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) x86/shstk: Change order of __user in type x86/ibt: Convert IBT selftest to asm x86/shstk: Don't retry vm_munmap() on -EINTR x86/kbuild: Fix Documentation/ reference x86/shstk: Move arch detail comment out of core mm x86/shstk: Add ARCH_SHSTK_STATUS x86/shstk: Add ARCH_SHSTK_UNLOCK x86: Add PTRACE interface for shadow stack selftests/x86: Add shadow stack test x86/cpufeatures: Enable CET CR4 bit for shadow stack x86/shstk: Wire in shadow stack interface x86: Expose thread features in /proc/$PID/status x86/shstk: Support WRSS for userspace x86/shstk: Introduce map_shadow_stack syscall x86/shstk: Check that signal frame is shadow stack mem x86/shstk: Check that SSP is aligned on sigreturn x86/shstk: Handle signals for shadow stack x86/shstk: Introduce routines modifying shstk x86/shstk: Handle thread shadow stack x86/shstk: Add user-mode shadow stack support ...
| * mm: Rename arch pte_mkwrite()'s to pte_mkwrite_novma()Rick Edgecombe2023-07-111-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 Shadow stack feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. One of these unusual properties is that shadow stack memory is writable, but only in limited ways. These limits are applied via a specific PTE bit combination. Nevertheless, the memory is writable, and core mm code will need to apply the writable permissions in the typical paths that call pte_mkwrite(). The goal is to make pte_mkwrite() take a VMA, so that the x86 implementation of it can know whether to create regular writable or shadow stack mappings. But there are a couple of challenges to this. Modifying the signatures of each arch pte_mkwrite() implementation would be error prone because some are generated with macros and would need to be re-implemented. Also, some pte_mkwrite() callers operate on kernel memory without a VMA. So this can be done in a three step process. First pte_mkwrite() can be renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite() added that just calls pte_mkwrite_novma(). Next callers without a VMA can be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers can be changed to take/pass a VMA. Start the process by renaming pte_mkwrite() to pte_mkwrite_novma() and adding the pte_mkwrite() wrapper in linux/pgtable.h. Apply the same pattern for pmd_mkwrite(). Since not all archs have a pmd_mkwrite_novma(), create a new arch config HAS_HUGE_PAGE that can be used to tell if pmd_mkwrite() should be defined. Otherwise in the !HAS_HUGE_PAGE cases the compiler would not be able to find pmd_mkwrite_novma(). No functional change. Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/lkml/CAHk-=wiZjSu7c9sFYZb3q04108stgHff2wfbokGCCgW7riz+8Q@mail.gmail.com/ Link: https://lore.kernel.org/all/20230613001108.3040476-2-rick.p.edgecombe%40intel.com
* | Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of ↵Linus Torvalds2023-08-291-14/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - An extensive rework of kexec and crash Kconfig from Eric DeVolder ("refactor Kconfig to consolidate KEXEC and CRASH options") - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a couple of macros to args.h") - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper commands") - vsprintf inclusion rationalization from Andy Shevchenko ("lib/vsprintf: Rework header inclusions") - Switch the handling of kdump from a udev scheme to in-kernel handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory hot un/plug") - Many singleton patches to various parts of the tree * tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits) document while_each_thread(), change first_tid() to use for_each_thread() drivers/char/mem.c: shrink character device's devlist[] array x86/crash: optimize CPU changes crash: change crash_prepare_elf64_headers() to for_each_possible_cpu() crash: hotplug support for kexec_load() x86/crash: add x86 crash hotplug support crash: memory and CPU hotplug sysfs attributes kexec: exclude elfcorehdr from the segment digest crash: add generic infrastructure for crash hotplug support crash: move a few code bits to setup support of crash hotplug kstrtox: consistently use _tolower() kill do_each_thread() nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse scripts/bloat-o-meter: count weak symbol sizes treewide: drop CONFIG_EMBEDDED lockdep: fix static memory detection even more lib/vsprintf: declare no_hash_pointers in sprintf.h lib/vsprintf: split out sprintf() and friends kernel/fork: stop playing lockless games for exe_file replacement adfs: delete unused "union adfs_dirtail" definition ...
| * | arch: enable HAS_LTO_CLANG with KASAN and KCOVJakob Koschel2023-08-181-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both KASAN and KCOV had issues with LTO_CLANG if DEBUG_INFO is enabled. With LTO inlinable function calls are required to have debug info if they are inlined into a function that has debug info. Starting with LLVM 17 this will be fixed ([1],[2]) and enabling LTO with KASAN/KCOV and DEBUG_INFO doesn't cause linker errors anymore. Link: https://github.com/llvm/llvm-project/commit/913f7e93dac67ecff47bade862ba42f27cb68ca9 Link: https://github.com/llvm/llvm-project/commit/4a8b1249306ff11f229320abdeadf0c215a00400 Link: https://lkml.kernel.org/r/20230717-enable-kasan-lto1-v3-1-650e1efc19d1@gmail.com Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Jakob Koschel <jkl820.git@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Tom Rix <trix@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * | kexec: consolidate kexec and crash options into kernel/Kconfig.kexecEric DeVolder2023-08-181-13/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "refactor Kconfig to consolidate KEXEC and CRASH options", v6. The Kconfig is refactored to consolidate KEXEC and CRASH options from various arch/<arch>/Kconfig files into new file kernel/Kconfig.kexec. The Kconfig.kexec is now a submenu titled "Kexec and crash features" located under "General Setup". The following options are impacted: - KEXEC - KEXEC_FILE - KEXEC_SIG - KEXEC_SIG_FORCE - KEXEC_IMAGE_VERIFY_SIG - KEXEC_BZIMAGE_VERIFY_SIG - KEXEC_JUMP - CRASH_DUMP Over time, these options have been copied between Kconfig files and are very similar to one another, but with slight differences. The following architectures are impacted by the refactor (because of use of one or more KEXEC/CRASH options): - arm - arm64 - ia64 - loongarch - m68k - mips - parisc - powerpc - riscv - s390 - sh - x86 More information: In the patch series "crash: Kernel handling of CPU and memory hot un/plug" https://lore.kernel.org/lkml/20230503224145.7405-1-eric.devolder@oracle.com/ the new kernel feature introduces the config option CRASH_HOTPLUG. In reviewing, Thomas Gleixner requested that the new config option not be placed in x86 Kconfig. Rather the option needs a generic/common home. To Thomas' point, the KEXEC and CRASH options have largely been duplicated in the various arch/<arch>/Kconfig files, with minor differences. This kind of proliferation is to be avoid/stopped. https://lore.kernel.org/lkml/875y91yv63.ffs@tglx/ To that end, I have refactored the arch Kconfigs so as to consolidate the various KEXEC and CRASH options. Generally speaking, this work has the following themes: - KEXEC and CRASH options are moved into new file kernel/Kconfig.kexec - These items from arch/Kconfig: CRASH_CORE KEXEC_CORE KEXEC_ELF HAVE_IMA_KEXEC - These items from arch/x86/Kconfig form the common options: KEXEC KEXEC_FILE KEXEC_SIG KEXEC_SIG_FORCE KEXEC_BZIMAGE_VERIFY_SIG KEXEC_JUMP CRASH_DUMP - These items from arch/arm64/Kconfig form the common options: KEXEC_IMAGE_VERIFY_SIG - The crash hotplug series appends CRASH_HOTPLUG to Kconfig.kexec - The Kconfig.kexec is now a submenu titled "Kexec and crash features" and is now listed in "General Setup" submenu from init/Kconfig. - To control the common options, each has a new ARCH_SUPPORTS_<option> option. These gateway options determine whether the common options options are valid for the architecture. - To account for the slight differences in the original architecture coding of the common options, each now has a corresponding ARCH_SELECTS_<option> which are used to elicit the same side effects as the original arch/<arch>/Kconfig files for KEXEC and CRASH options. An example, 'make menuconfig' illustrating the submenu: > General setup > Kexec and crash features [*] Enable kexec system call [*] Enable kexec file based system call [*] Verify kernel signature during kexec_file_load() syscall [ ] Require a valid signature in kexec_file_load() syscall [ ] Enable bzImage signature verification support [*] kexec jump [*] kernel crash dumps [*] Update the crash elfcorehdr on system configuration changes In the process of consolidating the common options, I encountered slight differences in the coding of these options in several of the architectures. As a result, I settled on the following solution: - Each of the common options has a 'depends on ARCH_SUPPORTS_<option>' statement. For example, the KEXEC_FILE option has a 'depends on ARCH_SUPPORTS_KEXEC_FILE' statement. This approach is needed on all common options so as to prevent options from appearing for architectures which previously did not allow/enable them. For example, arm supports KEXEC but not KEXEC_FILE. The arch/arm/Kconfig does not provide ARCH_SUPPORTS_KEXEC_FILE and so KEXEC_FILE and related options are not available to arm. - The boolean ARCH_SUPPORTS_<option> in effect allows the arch to determine when the feature is allowed. Archs which don't have the feature simply do not provide the corresponding ARCH_SUPPORTS_<option>. For each arch, where there previously were KEXEC and/or CRASH options, these have been replaced with the corresponding boolean ARCH_SUPPORTS_<option>, and an appropriate def_bool statement. For example, if the arch supports KEXEC_FILE, then the ARCH_SUPPORTS_KEXEC_FILE simply has a 'def_bool y'. This permits the KEXEC_FILE option to be available. If the arch has a 'depends on' statement in its original coding of the option, then that expression becomes part of the def_bool expression. For example, arm64 had: config KEXEC depends on PM_SLEEP_SMP and in this solution, this converts to: config ARCH_SUPPORTS_KEXEC def_bool PM_SLEEP_SMP - In order to account for the architecture differences in the coding for the common options, the ARCH_SELECTS_<option> in the arch/<arch>/Kconfig is used. This option has a 'depends on <option>' statement to couple it to the main option, and from there can insert the differences from the common option and the arch original coding of that option. For example, a few archs enable CRYPTO and CRYTPO_SHA256 for KEXEC_FILE. These require a ARCH_SELECTS_KEXEC_FILE and 'select CRYPTO' and 'select CRYPTO_SHA256' statements. Illustrating the option relationships: For each of the common KEXEC and CRASH options: ARCH_SUPPORTS_<option> <- <option> <- ARCH_SELECTS_<option> <option> # in Kconfig.kexec ARCH_SUPPORTS_<option> # in arch/<arch>/Kconfig, as needed ARCH_SELECTS_<option> # in arch/<arch>/Kconfig, as needed For example, KEXEC: ARCH_SUPPORTS_KEXEC <- KEXEC <- ARCH_SELECTS_KEXEC KEXEC # in Kconfig.kexec ARCH_SUPPORTS_KEXEC # in arch/<arch>/Kconfig, as needed ARCH_SELECTS_KEXEC # in arch/<arch>/Kconfig, as needed To summarize, the ARCH_SUPPORTS_<option> permits the <option> to be enabled, and the ARCH_SELECTS_<option> handles side effects (ie. select statements). Examples: A few examples to show the new strategy in action: ===== x86 (minus the help section) ===== Original: config KEXEC bool "kexec system call" select KEXEC_CORE config KEXEC_FILE bool "kexec file based system call" select KEXEC_CORE select HAVE_IMA_KEXEC if IMA depends on X86_64 depends on CRYPTO=y depends on CRYPTO_SHA256=y config ARCH_HAS_KEXEC_PURGATORY def_bool KEXEC_FILE config KEXEC_SIG bool "Verify kernel signature during kexec_file_load() syscall" depends on KEXEC_FILE config KEXEC_SIG_FORCE bool "Require a valid signature in kexec_file_load() syscall" depends on KEXEC_SIG config KEXEC_BZIMAGE_VERIFY_SIG bool "Enable bzImage signature verification support" depends on KEXEC_SIG depends on SIGNED_PE_FILE_VERIFICATION select SYSTEM_TRUSTED_KEYRING config CRASH_DUMP bool "kernel crash dumps" depends on X86_64 || (X86_32 && HIGHMEM) config KEXEC_JUMP bool "kexec jump" depends on KEXEC && HIBERNATION help becomes... New: config ARCH_SUPPORTS_KEXEC def_bool y config ARCH_SUPPORTS_KEXEC_FILE def_bool X86_64 && CRYPTO && CRYPTO_SHA256 config ARCH_SELECTS_KEXEC_FILE def_bool y depends on KEXEC_FILE select HAVE_IMA_KEXEC if IMA config ARCH_SUPPORTS_KEXEC_PURGATORY def_bool KEXEC_FILE config ARCH_SUPPORTS_KEXEC_SIG def_bool y config ARCH_SUPPORTS_KEXEC_SIG_FORCE def_bool y config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG def_bool y config ARCH_SUPPORTS_KEXEC_JUMP def_bool y config ARCH_SUPPORTS_CRASH_DUMP def_bool X86_64 || (X86_32 && HIGHMEM) ===== powerpc (minus the help section) ===== Original: config KEXEC bool "kexec system call" depends on PPC_BOOK3S || PPC_E500 || (44x && !SMP) select KEXEC_CORE config KEXEC_FILE bool "kexec file based system call" select KEXEC_CORE select HAVE_IMA_KEXEC if IMA select KEXEC_ELF depends on PPC64 depends on CRYPTO=y depends on CRYPTO_SHA256=y config ARCH_HAS_KEXEC_PURGATORY def_bool KEXEC_FILE config CRASH_DUMP bool "Build a dump capture kernel" depends on PPC64 || PPC_BOOK3S_32 || PPC_85xx || (44x && !SMP) select RELOCATABLE if PPC64 || 44x || PPC_85xx becomes... New: config ARCH_SUPPORTS_KEXEC def_bool PPC_BOOK3S || PPC_E500 || (44x && !SMP) config ARCH_SUPPORTS_KEXEC_FILE def_bool PPC64 && CRYPTO=y && CRYPTO_SHA256=y config ARCH_SUPPORTS_KEXEC_PURGATORY def_bool KEXEC_FILE config ARCH_SELECTS_KEXEC_FILE def_bool y depends on KEXEC_FILE select KEXEC_ELF select HAVE_IMA_KEXEC if IMA config ARCH_SUPPORTS_CRASH_DUMP def_bool PPC64 || PPC_BOOK3S_32 || PPC_85xx || (44x && !SMP) config ARCH_SELECTS_CRASH_DUMP def_bool y depends on CRASH_DUMP select RELOCATABLE if PPC64 || 44x || PPC_85xx Testing Approach and Results There are 388 config files in the arch/<arch>/configs directories. For each of these config files, a .config is generated both before and after this Kconfig series, and checked for equivalence. This approach allows for a rather rapid check of all architectures and a wide variety of configs wrt/ KEXEC and CRASH, and avoids requiring compiling for all architectures and running kernels and run-time testing. For each config file, the olddefconfig, allnoconfig and allyesconfig targets are utilized. In testing the randconfig has revealed problems as well, but is not used in the before and after equivalence check since one can not generate the "same" .config for before and after, even if using the same KCONFIG_SEED since the option list is different. As such, the following script steps compare the before and after of 'make olddefconfig'. The new symbols introduced by this series are filtered out, but otherwise the config files are PASS only if they were equivalent, and FAIL otherwise. The script performs the test by doing the following: # Obtain the "golden" .config output for given config file # Reset test sandbox git checkout master git branch -D test_Kconfig git checkout -B test_Kconfig master make distclean # Write out updated config cp -f <config file> .config make ARCH=<arch> olddefconfig # Track each item in .config, LHSB is "golden" scoreboard .config # Obtain the "changed" .config output for given config file # Reset test sandbox make distclean # Apply this Kconfig series git am <this Kconfig series> # Write out updated config cp -f <config file> .config make ARCH=<arch> olddefconfig # Track each item in .config, RHSB is "changed" scoreboard .config # Determine test result # Filter-out new symbols introduced by this series # Filter-out symbol=n which not in either scoreboard # Compare LHSB "golden" and RHSB "changed" scoreboards and issue PASS/FAIL The script was instrumental during the refactoring of Kconfig as it continually revealed problems. The end result being that the solution presented in this series passes all configs as checked by the script, with the following exceptions: - arch/ia64/configs/zx1_config with olddefconfig This config file has: # CONFIG_KEXEC is not set CONFIG_CRASH_DUMP=y and this refactor now couples KEXEC to CRASH_DUMP, so it is not possible to enable CRASH_DUMP without KEXEC. - arch/sh/configs/* with allyesconfig The arch/sh/Kconfig codes CRASH_DUMP as dependent upon BROKEN_ON_MMU (which clearly is not meant to be set). This symbol is not provided but with the allyesconfig it is set to yes which enables CRASH_DUMP. But KEXEC is coded as dependent upon MMU, and is set to no in arch/sh/mm/Kconfig, so KEXEC is not enabled. This refactor now couples KEXEC to CRASH_DUMP, so it is not possible to enable CRASH_DUMP without KEXEC. While the above exceptions are not equivalent to their original, the config file produced is valid (and in fact better wrt/ CRASH_DUMP handling). This patch (of 14) The config options for kexec and crash features are consolidated into new file kernel/Kconfig.kexec. Under the "General Setup" submenu is a new submenu "Kexec and crash handling". All the kexec and crash options that were once in the arch-dependent submenu "Processor type and features" are now consolidated in the new submenu. The following options are impacted: - KEXEC - KEXEC_FILE - KEXEC_SIG - KEXEC_SIG_FORCE - KEXEC_BZIMAGE_VERIFY_SIG - KEXEC_JUMP - CRASH_DUMP The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP. Architectures specify support of certain KEXEC and CRASH features with similarly named new ARCH_SUPPORTS_<option> config options. Architectures can utilize the new ARCH_SELECTS_<option> config options to specify additional components when <option> is enabled. To summarize, the ARCH_SUPPORTS_<option> permits the <option> to be enabled, and the ARCH_SELECTS_<option> handles side effects (ie. select statements). Link: https://lkml.kernel.org/r/20230712161545.87870-1-eric.devolder@oracle.com Link: https://lkml.kernel.org/r/20230712161545.87870-2-eric.devolder@oracle.com Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Cc. "H. Peter Anvin" <hpa@zytor.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> # for x86 Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Juerg Haefliger <juerg.haefliger@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Marc Aurèle La France <tsi@tuyoix.net> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sebastian Reichel <sebastian.reichel@collabora.com> Cc: Sourabh Jain <sourabhjain@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: Xin Li <xin3.li@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Zhen Lei <thunder.leizhen@huawei.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* / cpu/SMT: Create topology_smt_thread_allowed()Michael Ellerman2023-07-281-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some architectures allows partial SMT states, i.e. when not all SMT threads are brought online. To support that, add an architecture helper which checks whether a given CPU is allowed to be brought online depending on how many SMT threads are currently enabled. Since this is only applicable to architecture supporting partial SMT, only these architectures should select the new configuration variable CONFIG_SMT_NUM_THREADS_DYNAMIC. For the other architectures, not supporting the partial SMT states, there is no need to define topology_cpu_smt_allowed(), the generic code assumed that all the threads are allowed or only the primary ones. Call the helper from cpu_smt_enable(), and cpu_smt_allowed() when SMT is enabled, to check if the particular thread should be onlined. Notably, also call it from cpu_smt_disable() if CPU_SMT_ENABLED, to allow offlining some threads to move from a higher to lower number of threads online. [ ldufour: Slightly reword the commit's description ] [ ldufour: Introduce CONFIG_SMT_NUM_THREADS_DYNAMIC ] Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20230705145143.40545-7-ldufour@linux.ibm.com
* Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of ↵Linus Torvalds2023-06-281-11/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-mm updates from Andrew Morton: - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level directories - Douglas Anderson has added a new "buddy" mode to the hardlockup detector. It permits the detector to work on architectures which cannot provide the required interrupts, by having CPUs periodically perform checks on other CPUs - Zhen Lei has enhanced kexec's ability to support two crash regions - Petr Mladek has done a lot of cleanup on the hard lockup detector's Kconfig entries - And the usual bunch of singleton patches in various places * tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) kernel/time/posix-stubs.c: remove duplicated include ocfs2: remove redundant assignment to variable bit_off watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h devres: show which resource was invalid in __devm_ioremap_resource() watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64 watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h watchdog/hardlockup: make the config checks more straightforward watchdog/hardlockup: sort hardlockup detector related config values a logical way watchdog/hardlockup: move SMP barriers from common code to buddy code watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY watchdog/buddy: don't copy the cpumask in watchdog_next_cpu() watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog() watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy() watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick() watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe() watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails ...
| * watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specificPetr Mladek2023-06-201-18/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several hardlockup detector implementations and several Kconfig values which allow selection and build of the preferred one. CONFIG_HARDLOCKUP_DETECTOR was introduced by the commit 23637d477c1f53acb ("lockup_detector: Introduce CONFIG_HARDLOCKUP_DETECTOR") in v2.6.36. It was a preparation step for introducing the new generic perf hardlockup detector. The existing arch-specific variants did not support the to-be-created generic build configurations, sysctl interface, etc. This distinction was made explicit by the commit 4a7863cc2eb5f98 ("x86, nmi_watchdog: Remove ARCH_HAS_NMI_WATCHDOG and rely on CONFIG_HARDLOCKUP_DETECTOR") in v2.6.38. CONFIG_HAVE_NMI_WATCHDOG was introduced by the commit d314d74c695f967e105 ("nmi watchdog: do not use cpp symbol in Kconfig") in v3.4-rc1. It replaced the above mentioned ARCH_HAS_NMI_WATCHDOG. At that time, it was still used by three architectures, namely blackfin, mn10300, and sparc. The support for blackfin and mn10300 architectures has been completely dropped some time ago. And sparc is the only architecture with the historic NMI watchdog at the moment. And the old sparc implementation is really special. It is always built on sparc64. It used to be always enabled until the commit 7a5c8b57cec93196b ("sparc: implement watchdog_nmi_enable and watchdog_nmi_disable") added in v4.10-rc1. There are only few locations where the sparc64 NMI watchdog interacts with the generic hardlockup detectors code: + implements arch_touch_nmi_watchdog() which is called from the generic touch_nmi_watchdog() + implements watchdog_hardlockup_enable()/disable() to support /proc/sys/kernel/nmi_watchdog + is always preferred over other generic watchdogs, see CONFIG_HARDLOCKUP_DETECTOR + includes asm/nmi.h into linux/nmi.h because some sparc-specific functions are needed in sparc-specific code which includes only linux/nmi.h. The situation became more complicated after the commit 05a4a95279311c3 ("kernel/watchdog: split up config options") and commit 2104180a53698df5 ("powerpc/64s: implement arch-specific hardlockup watchdog") in v4.13-rc1. They introduced HAVE_HARDLOCKUP_DETECTOR_ARCH. It was used for powerpc specific hardlockup detector. It was compatible with the perf one regarding the general boot, sysctl, and programming interfaces. HAVE_HARDLOCKUP_DETECTOR_ARCH was defined as a superset of HAVE_NMI_WATCHDOG. It made some sense because all arch-specific detectors had some common requirements, namely: + implemented arch_touch_nmi_watchdog() + included asm/nmi.h into linux/nmi.h + defined the default value for /proc/sys/kernel/nmi_watchdog But it actually has made things pretty complicated when the generic buddy hardlockup detector was added. Before the generic perf detector was newer supported together with an arch-specific one. But the buddy detector could work on any SMP system. It means that an architecture could support both the arch-specific and buddy detector. As a result, there are few tricky dependencies. For example, CONFIG_HARDLOCKUP_DETECTOR depends on: ((HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY) && !HAVE_NMI_WATCHDOG) || HAVE_HARDLOCKUP_DETECTOR_ARCH The problem is that the very special sparc implementation is defined as: HAVE_NMI_WATCHDOG && !HAVE_HARDLOCKUP_DETECTOR_ARCH Another problem is that the meaning of HAVE_NMI_WATCHDOG is far from clear without reading understanding the history. Make the logic less tricky and more self-explanatory by making HAVE_NMI_WATCHDOG specific for the sparc64 implementation. And rename it to HAVE_HARDLOCKUP_DETECTOR_SPARC64. Note that HARDLOCKUP_DETECTOR_PREFER_BUDDY, HARDLOCKUP_DETECTOR_PERF, and HARDLOCKUP_DETECTOR_BUDDY may conflict only with HAVE_HARDLOCKUP_DETECTOR_ARCH. They depend on HARDLOCKUP_DETECTOR and it is not longer enabled when HAVE_NMI_WATCHDOG is set. Link: https://lkml.kernel.org/r/20230616150618.6073-5-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * watchdog/hardlockup: make the config checks more straightforwardPetr Mladek2023-06-201-6/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are four possible variants of hardlockup detectors: + buddy: available when SMP is set. + perf: available when HAVE_HARDLOCKUP_DETECTOR_PERF is set. + arch-specific: available when HAVE_HARDLOCKUP_DETECTOR_ARCH is set. + sparc64 special variant: available when HAVE_NMI_WATCHDOG is set and HAVE_HARDLOCKUP_DETECTOR_ARCH is not set. The check for the sparc64 variant is more complicated because HAVE_NMI_WATCHDOG is used to #ifdef code used by both arch-specific and sparc64 specific variant. Therefore it is automatically selected with HAVE_HARDLOCKUP_DETECTOR_ARCH. This complexity is partly hidden in HAVE_HARDLOCKUP_DETECTOR_NON_ARCH. It reduces the size of some checks but it makes them harder to follow. Finally, the other temporary variable HARDLOCKUP_DETECTOR_NON_ARCH is used to re-compute HARDLOCKUP_DETECTOR_PERF/BUDDY when the global HARDLOCKUP_DETECTOR switch is enabled/disabled. Make the logic more straightforward by the following changes: + Better explain the role of HAVE_HARDLOCKUP_DETECTOR_ARCH and HAVE_NMI_WATCHDOG in comments. + Add HAVE_HARDLOCKUP_DETECTOR_BUDDY so that there is separate HAVE_* for all four hardlockup detector variants. Use it in the other conditions instead of SMP. It makes it clear that it is about the buddy detector. + Open code HAVE_HARDLOCKUP_DETECTOR_NON_ARCH in HARDLOCKUP_DETECTOR and HARDLOCKUP_DETECTOR_PREFER_BUDDY. It helps to understand the conditions between the four hardlockup detector variants. + Define the exact conditions when HARDLOCKUP_DETECTOR_PERF/BUDDY can be enabled. It explains the dependency on the other hardlockup detector variants. Also it allows to remove HARDLOCKUP_DETECTOR_NON_ARCH by using "imply". It triggers re-evaluating HARDLOCKUP_DETECTOR_PERF/BUDDY when the global HARDLOCKUP_DETECTOR switch is changed. + Add dependency on HARDLOCKUP_DETECTOR so that the affected variables disappear when the hardlockup detectors are disabled. Another nice side effect is that HARDLOCKUP_DETECTOR_PREFER_BUDDY value is not preserved when the global switch is disabled. The user has to make the decision again when it gets re-enabled. Link: https://lkml.kernel.org/r/20230616150618.6073-3-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement ↵Douglas Anderson2023-06-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | watchdog_hardlockup_probe() Right now there is one arch (sparc64) that selects HAVE_NMI_WATCHDOG without selecting HAVE_HARDLOCKUP_DETECTOR_ARCH. Because of that one architecture, we have some special case code in the watchdog core to handle the fact that watchdog_hardlockup_probe() isn't implemented. Let's implement watchdog_hardlockup_probe() for sparc64 and get rid of the special case. As a side effect of doing this, code inspection tells us that we could fix a minor bug where the system won't properly realize that NMI watchdogs are disabled. Specifically, on powerpc if CONFIG_PPC_WATCHDOG is turned off the arch might still select CONFIG_HAVE_HARDLOCKUP_DETECTOR_ARCH which selects CONFIG_HAVE_NMI_WATCHDOG. Since CONFIG_PPC_WATCHDOG was off then nothing will override the "weak" watchdog_hardlockup_probe() and we'll fallback to looking at CONFIG_HAVE_NMI_WATCHDOG. Link: https://lkml.kernel.org/r/20230526184139.2.Ic6ebbf307ca0efe91f08ce2c1eb4a037ba6b0700@changeid Signed-off-by: Douglas Anderson <dianders@chromium.org> Suggested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'landlock-6.5-rc1' of ↵Linus Torvalds2023-06-281-7/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux Pull landlock updates from Mickaël Salaün: "Add support for Landlock to UML. To do this, this fixes the way hostfs manages inodes according to the underlying filesystem [1]. They are now properly handled as for other filesystems, which enables Landlock support (and probably other features). This also extends Landlock's tests with 6 pseudo filesystems, including hostfs" [1] https://lore.kernel.org/all/20230612191430.339153-1-mic@digikod.net/ * tag 'landlock-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux: selftests/landlock: Add hostfs tests selftests/landlock: Add tests for pseudo filesystems selftests/landlock: Make mounts configurable selftests/landlock: Add supports_filesystem() helper selftests/landlock: Don't create useless file layouts hostfs: Fix ephemeral inodes
| * | hostfs: Fix ephemeral inodesMickaël Salaün2023-06-121-7/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hostfs creates a new inode for each opened or created file, which created useless inode allocations and forbade identifying a host file with a kernel inode. Fix this uncommon filesystem behavior by tying kernel inodes to host file's inode and device IDs. Even if the host filesystem inodes may be recycled, this cannot happen while a file referencing it is opened, which is the case with hostfs. It should be noted that hostfs inode IDs may not be unique for the same hostfs superblock because multiple host's (backed) superblocks may be used. Delete inodes when dropping them to force backed host's file descriptors closing. This enables to entirely remove ARCH_EPHEMERAL_INODES, and then makes Landlock fully supported by UML. This is very useful for testing changes. These changes also factor out and simplify some helpers thanks to the new hostfs_inode_update() and the hostfs_iget() revamp: read_name(), hostfs_create(), hostfs_lookup(), hostfs_mknod(), and hostfs_fill_sb_common(). A following commit with new Landlock tests check this new hostfs inode consistency. Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Acked-by: Richard Weinberger <richard@nod.at> Link: https://lore.kernel.org/r/20230612191430.339153-2-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
* | Merge tag 'smp-core-2023-06-26' of ↵Linus Torvalds2023-06-261-0/+23
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP updates from Thomas Gleixner: "A large update for SMP management: - Parallel CPU bringup The reason why people are interested in parallel bringup is to shorten the (kexec) reboot time of cloud servers to reduce the downtime of the VM tenants. The current fully serialized bringup does the following per AP: 1) Prepare callbacks (allocate, intialize, create threads) 2) Kick the AP alive (e.g. INIT/SIPI on x86) 3) Wait for the AP to report alive state 4) Let the AP continue through the atomic bringup 5) Let the AP run the threaded bringup to full online state There are two significant delays: #3 The time for an AP to report alive state in start_secondary() on x86 has been measured in the range between 350us and 3.5ms depending on vendor and CPU type, BIOS microcode size etc. #4 The atomic bringup does the microcode update. This has been measured to take up to ~8ms on the primary threads depending on the microcode patch size to apply. On a two socket SKL server with 56 cores (112 threads) the boot CPU spends on current mainline about 800ms busy waiting for the APs to come up and apply microcode. That's more than 80% of the actual onlining procedure. This can be reduced significantly by splitting the bringup mechanism into two parts: 1) Run the prepare callbacks and kick the AP alive for each AP which needs to be brought up. The APs wake up, do their firmware initialization and run the low level kernel startup code including microcode loading in parallel up to the first synchronization point. (#1 and #2 above) 2) Run the rest of the bringup code strictly serialized per CPU (#3 - #5 above) as it's done today. Parallelizing that stage of the CPU bringup might be possible in theory, but it's questionable whether required surgery would be justified for a pretty small gain. If the system is large enough the first AP is already waiting at the first synchronization point when the boot CPU finished the wake-up of the last AP. That reduces the AP bringup time on that SKL from ~800ms to ~80ms, i.e. by a factor ~10x. The actual gain varies wildly depending on the system, CPU, microcode patch size and other factors. There are some opportunities to reduce the overhead further, but that needs some deep surgery in the x86 CPU bringup code. For now this is only enabled on x86, but the core functionality obviously works for all SMP capable architectures. - Enhancements for SMP function call tracing so it is possible to locate the scheduling and the actual execution points. That allows to measure IPI delivery time precisely" * tag 'smp-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits) trace,smp: Add tracepoints for scheduling remotelly called functions trace,smp: Add tracepoints around remotelly called functions MAINTAINERS: Add CPU HOTPLUG entry x86/smpboot: Fix the parallel bringup decision x86/realmode: Make stack lock work in trampoline_compat() x86/smp: Initialize cpu_primary_thread_mask late cpu/hotplug: Fix off by one in cpuhp_bringup_mask() x86/apic: Fix use of X{,2}APIC_ENABLE in asm with older binutils x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it x86/smpboot: Support parallel startup of secondary CPUs x86/smpboot: Implement a bit spinlock to protect the realmode stack x86/apic: Save the APIC virtual base address cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE x86/apic: Provide cpu_primary_thread mask x86/smpboot: Enable split CPU startup cpu/hotplug: Provide a split up CPUHP_BRINGUP mechanism cpu/hotplug: Reset task stack state in _cpu_up() cpu/hotplug: Remove unused state functions riscv: Switch to hotplug core state synchronization parisc: Switch to hotplug core state synchronization ...
| * | cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATEThomas Gleixner2023-05-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is often significant latency in the early stages of CPU bringup, and time is wasted by waking each CPU (e.g. with SIPI/INIT/INIT on x86) and then waiting for it to respond before moving on to the next. Allow a platform to enable parallel setup which brings all to be onlined CPUs up to the CPUHP_BP_KICK_AP state. While this state advancement on the control CPU (BP) is single-threaded the important part is the last state CPUHP_BP_KICK_AP which wakes the to be onlined CPUs up. This allows the CPUs to run up to the first sychronization point cpuhp_ap_sync_alive() where they wait for the control CPU to release them one by one for the full onlining procedure. This parallelism depends on the CPU hotplug core sync mechanism which ensures that the parallel brought up CPUs wait for release before touching any state which would make the CPU visible to anything outside the hotplug control mechanism. To handle the SMT constraints of X86 correctly the bringup happens in two iterations when CONFIG_HOTPLUG_SMT is enabled. The control CPU brings up the primary SMT threads of each core first, which can load the microcode without the need to rendevouz with the thread siblings. Once that's completed it brings up the secondary SMT threads. Co-developed-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Tested-by: Helge Deller <deller@gmx.de> # parisc Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck Link: https://lore.kernel.org/r/20230512205257.240231377@linutronix.de
| * | cpu/hotplug: Provide a split up CPUHP_BRINGUP mechanismThomas Gleixner2023-05-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bring up logic of a to be onlined CPU consists of several parts, which are considered to be a single hotplug state: 1) Control CPU issues the wake-up 2) To be onlined CPU starts up, does the minimal initialization, reports to be alive and waits for release into the complete bring-up. 3) Control CPU waits for the alive report and releases the upcoming CPU for the complete bring-up. Allow to split this into two states: 1) Control CPU issues the wake-up After that the to be onlined CPU starts up, does the minimal initialization, reports to be alive and waits for release into the full bring-up. As this can run after the control CPU dropped the hotplug locks the code which is executed on the AP before it reports alive has to be carefully audited to not violate any of the hotplug constraints, especially not modifying any of the various cpumasks. This is really only meant to avoid waiting for the AP to react on the wake-up. Of course an architecture can move strict CPU related setup functionality, e.g. microcode loading, with care before the synchronization point to save further pointless waiting time. 2) Control CPU waits for the alive report and releases the upcoming CPU for the complete bring-up. This allows that the two states can be split up to run all to be onlined CPUs up to state #1 on the control CPU and then at a later point run state #2. This spares some of the latencies of the full serialized per CPU bringup by avoiding the per CPU wakeup/wait serialization. The assumption is that the first AP already waits when the last AP has been woken up. This obvioulsy depends on the hardware latencies and depending on the timings this might still not completely eliminate all wait scenarios. This split is just a preparatory step for enabling the parallel bringup later. The boot time bringup is still fully serialized. It has a separate config switch so that architectures which want to support parallel bringup can test the split of the CPUHP_BRINGUG step separately. To enable this the architecture must support the CPU hotplug core sync mechanism and has to be audited that there are no implicit hotplug state dependencies which require a fully serialized bringup. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Tested-by: Helge Deller <deller@gmx.de> # parisc Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck Link: https://lore.kernel.org/r/20230512205257.080801387@linutronix.de
| * | cpu/hotplug: Add CPU state tracking and synchronizationThomas Gleixner2023-05-151-0/+15
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CPU state tracking and synchronization mechanism in smpboot.c is completely independent of the hotplug code and all logic around it is implemented in architecture specific code. Except for the state reporting of the AP there is absolutely nothing architecture specific and the sychronization and decision functions can be moved into the generic hotplug core code. Provide an integrated variant and add the core synchronization and decision points. This comes in two flavours: 1) DEAD state synchronization Updated by the architecture code once the AP reaches the point where it is ready to be torn down by the control CPU, e.g. by removing power or clocks or tear down via the hypervisor. The control CPU waits for this state to be reached with a timeout. If the state is reached an architecture specific cleanup function is invoked. 2) Full state synchronization This extends #1 with AP alive synchronization. This is new functionality, which allows to replace architecture specific wait mechanims, e.g. cpumasks, completely. It also prevents that an AP which is in a limbo state can be brought up again. This can happen when an AP failed to report dead state during a previous off-line operation. The dead synchronization is what most architectures use. Only x86 makes a bringup decision based on that state at the moment. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Tested-by: Helge Deller <deller@gmx.de> # parisc Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck Link: https://lore.kernel.org/r/20230512205256.476305035@linutronix.de
* / init: Provide arch_cpu_finalize_init()Thomas Gleixner2023-06-161-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | check_bugs() has become a dumping ground for all sorts of activities to finalize the CPU initialization before running the rest of the init code. Most are empty, a few do actual bug checks, some do alternative patching and some cobble a CPU advertisement string together.... Aside of that the current implementation requires duplicated function declaration and mostly empty header files for them. Provide a new function arch_cpu_finalize_init(). Provide a generic declaration if CONFIG_ARCH_HAS_CPU_FINALIZE_INIT is selected and a stub inline otherwise. This requires a temporary #ifdef in start_kernel() which will be removed along with check_bugs() once the architectures are converted over. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230613224544.957805717@linutronix.de
* lazy tlb: shoot lazies, non-refcounting lazy tlb mm reference handling schemeNicholas Piggin2023-03-291-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On big systems, the mm refcount can become highly contented when doing a lot of context switching with threaded applications. user<->idle switch is one of the important cases. Abandoning lazy tlb entirely slows this switching down quite a bit in the common uncontended case, so that is not viable. Implement a scheme where lazy tlb mm references do not contribute to the refcount, instead they get explicitly removed when the refcount reaches zero. The final mmdrop() sends IPIs to all CPUs in the mm_cpumask and they switch away from this mm to init_mm if it was being used as the lazy tlb mm. Enabling the shoot lazies option therefore requires that the arch ensures that mm_cpumask contains all CPUs that could possibly be using mm. A DEBUG_VM option IPIs every CPU in the system after this to ensure there are no references remaining before the mm is freed. Shootdown IPIs cost could be an issue, but they have not been observed to be a serious problem with this scheme, because short-lived processes tend not to migrate CPUs much, therefore they don't get much chance to leave lazy tlb mm references on remote CPUs. There are a lot of options to reduce them if necessary, described in comments. The near-worst-case can be benchmarked with will-it-scale: context_switch1_threads -t $(($(nproc) / 2)) This will create nproc threads (nproc / 2 switching pairs) all sharing the same mm that spread over all CPUs so each CPU does thread->idle->thread switching. [ Rik came up with basically the same idea a few years ago, so credit to him for that. ] Link: https://lore.kernel.org/linux-mm/20230118080011.2258375-1-npiggin@gmail.com/ Link: https://lore.kernel.org/all/20180728215357.3249-11-riel@surriel.com/ Link: https://lkml.kernel.org/r/20230203071837.1136453-5-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* lazy tlb: allow lazy tlb mm refcounting to be configurableNicholas Piggin2023-03-291-0/+17
| | | | | | | | | | | | | | | | | | | | | | Add CONFIG_MMU_TLB_REFCOUNT which enables refcounting of the lazy tlb mm when it is context switched. This can be disabled by architectures that don't require this refcounting if they clean up lazy tlb mms when the last refcount is dropped. Currently this is always enabled, so the patch introduces no functional change. Link: https://lkml.kernel.org/r/20230203071837.1136453-4-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* arch/Kconfig: fix indentationJuerg Haefliger2023-02-101-64/+64
| | | | | | | | | | | | | | | | | | | | | | | | The convention for indentation seems to be a single tab. Help text is further indented by an additional two whitespaces. Fix the lines that violate these rules. Link: https://lkml.kernel.org/r/20230201162435.218368-1-juerg.haefliger@canonical.com Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Dan Li <ashimida@linux.alibaba.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Juerg Haefliger <juerg.haefliger@canonical.com> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Tom Rix <trix@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'arm64-fixes' of ↵Linus Torvalds2022-12-161-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: - Fix Kconfig dependencies to re-allow the enabling of function graph tracer and shadow call stacks at the same time. - Revert the workaround for CPU erratum #2645198 since the CONFIG_ guards were incorrect and the code has therefore not seen any real exposure in -next. * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: Revert "arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption" ftrace: Allow WITH_ARGS flavour of graph tracer with shadow call stack
| * ftrace: Allow WITH_ARGS flavour of graph tracer with shadow call stackArd Biesheuvel2022-12-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent switch on arm64 from DYNAMIC_FTRACE_WITH_REGS to DYNAMIC_FTRACE_WITH_ARGS failed to take into account that we currently require the former in order to allow the function graph tracer to be enabled in combination with shadow call stacks. This means that this is no longer permitted at all, in spite of the fact that either flavour of ftrace works perfectly fine in this combination. So permit WITH_ARGS as well as WITH_REGS. Fixes: ddc9863e9e90 ("scs: Disable when function graph tracing is enabled") Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20221213132407.1485025-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
* | Merge tag 'x86_core_for_v6.2' of ↵Linus Torvalds2022-12-151-0/+24
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Add the call depth tracking mitigation for Retbleed which has been long in the making. It is a lighterweight software-only fix for Skylake-based cores where enabling IBRS is a big hammer and causes a significant performance impact. What it basically does is, it aligns all kernel functions to 16 bytes boundary and adds a 16-byte padding before the function, objtool collects all functions' locations and when the mitigation gets applied, it patches a call accounting thunk which is used to track the call depth of the stack at any time. When that call depth reaches a magical, microarchitecture-specific value for the Return Stack Buffer, the code stuffs that RSB and avoids its underflow which could otherwise lead to the Intel variant of Retbleed. This software-only solution brings a lot of the lost performance back, as benchmarks suggest: https://lore.kernel.org/all/20220915111039.092790446@infradead.org/ That page above also contains a lot more detailed explanation of the whole mechanism - Implement a new control flow integrity scheme called FineIBT which is based on the software kCFI implementation and uses hardware IBT support where present to annotate and track indirect branches using a hash to validate them - Other misc fixes and cleanups * tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits) x86/paravirt: Use common macro for creating simple asm paravirt functions x86/paravirt: Remove clobber bitmask from .parainstructions x86/debug: Include percpu.h in debugreg.h to get DECLARE_PER_CPU() et al x86/cpufeatures: Move X86_FEATURE_CALL_DEPTH from bit 18 to bit 19 of word 11, to leave space for WIP X86_FEATURE_SGX_EDECCSSA bit x86/Kconfig: Enable kernel IBT by default x86,pm: Force out-of-line memcpy() objtool: Fix weak hole vs prefix symbol objtool: Optimize elf_dirty_reloc_sym() x86/cfi: Add boot time hash randomization x86/cfi: Boot time selection of CFI scheme x86/ibt: Implement FineIBT objtool: Add --cfi to generate the .cfi_sites section x86: Add prefix symbols for function padding objtool: Add option to generate prefix symbols objtool: Avoid O(bloody terrible) behaviour -- an ode to libelf objtool: Slice up elf_create_section_symbol() kallsyms: Revert "Take callthunks into account" x86: Unconfuse CONFIG_ and X86_FEATURE_ namespaces x86/retpoline: Fix crash printing warning x86/paravirt: Fix a !PARAVIRT build warning ...
| * | arch: Introduce CONFIG_FUNCTION_ALIGNMENTPeter Zijlstra2022-10-171-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generic function-alignment infrastructure. Architectures can select FUNCTION_ALIGNMENT_xxB symbols; the FUNCTION_ALIGNMENT symbol is then set to the largest such selected size, 0 otherwise. From this the -falign-functions compiler argument and __ALIGN macro are set. This incorporates the DEBUG_FORCE_FUNCTION_ALIGN_64B knob and future alignment requirements for x86_64 (later in this series) into a single place. NOTE: also removes the 0x90 filler byte from the generic __ALIGN primitive, that value makes no sense outside of x86. NOTE: .balign 0 reverts to a no-op. Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111143.719248727@infradead.org
* | | Merge tag 'arm64-upstream' of ↵Linus Torvalds2022-12-121-0/+7
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "The highlights this time are support for dynamically enabling and disabling Clang's Shadow Call Stack at boot and a long-awaited optimisation to the way in which we handle the SVE register state on system call entry to avoid taking unnecessary traps from userspace. Summary: ACPI: - Enable FPDT support for boot-time profiling - Fix CPU PMU probing to work better with PREEMPT_RT - Update SMMUv3 MSI DeviceID parsing to latest IORT spec - APMT support for probing Arm CoreSight PMU devices CPU features: - Advertise new SVE instructions (v2.1) - Advertise range prefetch instruction - Advertise CSSC ("Common Short Sequence Compression") scalar instructions, adding things like min, max, abs, popcount - Enable DIT (Data Independent Timing) when running in the kernel - More conversion of system register fields over to the generated header CPU misfeatures: - Workaround for Cortex-A715 erratum #2645198 Dynamic SCS: - Support for dynamic shadow call stacks to allow switching at runtime between Clang's SCS implementation and the CPU's pointer authentication feature when it is supported (complete with scary DWARF parser!) Tracing and debug: - Remove static ftrace in favour of, err, dynamic ftrace! - Seperate 'struct ftrace_regs' from 'struct pt_regs' in core ftrace and existing arch code - Introduce and implement FTRACE_WITH_ARGS on arm64 to replace the old FTRACE_WITH_REGS - Extend 'crashkernel=' parameter with default value and fallback to placement above 4G physical if initial (low) allocation fails SVE: - Optimisation to avoid disabling SVE unconditionally on syscall entry and just zeroing the non-shared state on return instead Exceptions: - Rework of undefined instruction handling to avoid serialisation on global lock (this includes emulation of user accesses to the ID registers) Perf and PMU: - Support for TLP filters in Hisilicon's PCIe PMU device - Support for the DDR PMU present in Amlogic Meson G12 SoCs - Support for the terribly-named "CoreSight PMU" architecture from Arm (and Nvidia's implementation of said architecture) Misc: - Tighten up our boot protocol for systems with memory above 52 bits physical - Const-ify static keys to satisty jump label asm constraints - Trivial FFA driver cleanups in preparation for v1.1 support - Export the kernel_neon_* APIs as GPL symbols - Harden our instruction generation routines against instrumentation - A bunch of robustness improvements to our arch-specific selftests - Minor cleanups and fixes all over (kbuild, kprobes, kfence, PMU, ...)" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (151 commits) arm64: kprobes: Return DBG_HOOK_ERROR if kprobes can not handle a BRK arm64: kprobes: Let arch do_page_fault() fix up page fault in user handler arm64: Prohibit instrumentation on arch_stack_walk() arm64:uprobe fix the uprobe SWBP_INSN in big-endian arm64: alternatives: add __init/__initconst to some functions/variables arm_pmu: Drop redundant armpmu->map_event() in armpmu_event_init() kselftest/arm64: Allow epoll_wait() to return more than one result kselftest/arm64: Don't drain output while spawning children kselftest/arm64: Hold fp-stress children until they're all spawned arm64/sysreg: Remove duplicate definitions from asm/sysreg.h arm64/sysreg: Convert ID_DFR1_EL1 to automatic generation arm64/sysreg: Convert ID_DFR0_EL1 to automatic generation arm64/sysreg: Convert ID_AFR0_EL1 to automatic generation arm64/sysreg: Convert ID_MMFR5_EL1 to automatic generation arm64/sysreg: Convert MVFR2_EL1 to automatic generation arm64/sysreg: Convert MVFR1_EL1 to automatic generation arm64/sysreg: Convert MVFR0_EL1 to automatic generation arm64/sysreg: Convert ID_PFR2_EL1 to automatic generation arm64/sysreg: Convert ID_PFR1_EL1 to automatic generation arm64/sysreg: Convert ID_PFR0_EL1 to automatic generation ...
| * | scs: add support for dynamic shadow call stacksArd Biesheuvel2022-11-091-0/+7
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to allow arches to use code patching to conditionally emit the shadow stack pushes and pops, rather than always taking the performance hit even on CPUs that implement alternatives such as stack pointer authentication on arm64, add a Kconfig symbol that can be set by the arch to omit the SCS codegen itself, without otherwise affecting how support code for SCS and compiler options (for register reservation, for instance) are emitted. Also, add a static key and some plumbing to omit the allocation of shadow call stack for dynamic SCS configurations if SCS is disabled at runtime. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20221027155908.1940624-3-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
* / srcu: Create an srcu_read_lock_nmisafe() and srcu_read_unlock_nmisafe()Paul E. McKenney2022-10-201-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On strict load-store architectures, the use of this_cpu_inc() by srcu_read_lock() and srcu_read_unlock() is not NMI-safe in TREE SRCU. To see this suppose that an NMI arrives in the middle of srcu_read_lock(), just after it has read ->srcu_lock_count, but before it has written the incremented value back to memory. If that NMI handler also does srcu_read_lock() and srcu_read_lock() on that same srcu_struct structure, then upon return from that NMI handler, the interrupted srcu_read_lock() will overwrite the NMI handler's update to ->srcu_lock_count, but leave unchanged the NMI handler's update by srcu_read_unlock() to ->srcu_unlock_count. This can result in a too-short SRCU grace period, which can in turn result in arbitrary memory corruption. If the NMI handler instead interrupts the srcu_read_unlock(), this can result in eternal SRCU grace periods, which is not much better. This commit therefore creates a pair of new srcu_read_lock_nmisafe() and srcu_read_unlock_nmisafe() functions, which allow SRCU readers in both NMI handlers and in process and IRQ context. It is bad practice to mix the existing and the new _nmisafe() primitives on the same srcu_struct structure. Use one set or the other, not both. Just to underline that "bad practice" point, using srcu_read_lock() at process level and srcu_read_lock_nmisafe() in your NMI handler will not, repeat NOT, work. If you do not immediately understand why this is the case, please review the earlier paragraphs in this commit log. [ paulmck: Apply kernel test robot feedback. ] [ paulmck: Apply feedback from Randy Dunlap. ] [ paulmck: Apply feedback from John Ogness. ] [ paulmck: Apply feedback from Frederic Weisbecker. ] Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/ Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Ogness <john.ogness@linutronix.de> Cc: Petr Mladek <pmladek@suse.com>
* Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds2022-10-111-0/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
| * mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNGYu Zhao2022-09-271-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some architectures support the accessed bit in non-leaf PMD entries, e.g., x86 sets the accessed bit in a non-leaf PMD entry when using it as part of linear address translation [1]. Page table walkers that clear the accessed bit may use this capability to reduce their search space. Note that: 1. Although an inline function is preferable, this capability is added as a configuration option for consistency with the existing macros. 2. Due to the little interest in other varieties, this capability was only tested on Intel and AMD CPUs. Thanks to the following developers for their efforts [2][3]. Randy Dunlap <rdunlap@infradead.org> Stephen Rothwell <sfr@canb.auug.org.au> [1]: Intel 64 and IA-32 Architectures Software Developer's Manual Volume 3 (June 2021), section 4.8 [2] https://lore.kernel.org/r/bfdcc7c8-922f-61a9-aa15-7e7250f04af7@infradead.org/ [3] https://lore.kernel.org/r/20220413151513.5a0d7a7e@canb.auug.org.au/ Link: https://lkml.kernel.org/r/20220918080010.2920238-3-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Barry Song <baohua@kernel.org> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'kcfi-v6.1-rc1' of ↵Linus Torvalds2022-10-041-13/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull kcfi updates from Kees Cook: "This replaces the prior support for Clang's standard Control Flow Integrity (CFI) instrumentation, which has required a lot of special conditions (e.g. LTO) and work-arounds. The new implementation ("Kernel CFI") is specific to C, directly designed for the Linux kernel, and takes advantage of architectural features like x86's IBT. This series retains arm64 support and adds x86 support. GCC support is expected in the future[1], and additional "generic" architectural support is expected soon[2]. Summary: - treewide: Remove old CFI support details - arm64: Replace Clang CFI support with Clang KCFI support - x86: Introduce Clang KCFI support" Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107048 [1] Link: https://github.com/samitolvanen/llvm-project/commits/kcfi_generic [2] * tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits) x86: Add support for CONFIG_CFI_CLANG x86/purgatory: Disable CFI x86: Add types to indirectly called assembly functions x86/tools/relocs: Ignore __kcfi_typeid_ relocations kallsyms: Drop CONFIG_CFI_CLANG workarounds objtool: Disable CFI warnings objtool: Preserve special st_shndx indexes in elf_update_symbol treewide: Drop __cficanonical treewide: Drop WARN_ON_FUNCTION_MISMATCH treewide: Drop function_nocfi init: Drop __nocfi from __init arm64: Drop unneeded __nocfi attributes arm64: Add CFI error handling arm64: Add types to indirect called assembly functions psci: Fix the function type for psci_initcall_t lkdtm: Emit an indirect call for CFI tests cfi: Add type helper macros cfi: Switch to -fsanitize=kcfi cfi: Drop __CFI_ADDRESSABLE cfi: Remove CONFIG_CFI_CLANG_SHADOW ...
| * | cfi: Switch to -fsanitize=kcfiSami Tolvanen2022-09-261-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch from Clang's original forward-edge control-flow integrity implementation to -fsanitize=kcfi, which is better suited for the kernel, as it doesn't require LTO, doesn't use a jump table that requires altering function references, and won't break cross-module function address equality. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-6-samitolvanen@google.com
| * | cfi: Remove CONFIG_CFI_CLANG_SHADOWSami Tolvanen2022-09-261-10/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation to switching to -fsanitize=kcfi, remove support for the CFI module shadow that will no longer be needed. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-4-samitolvanen@google.com
* | Kbuild: add Rust supportMiguel Ojeda2022-09-281-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Having most of the new files in place, we now enable Rust support in the build system, including `Kconfig` entries related to Rust, the Rust configuration printer and a few other bits. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Finn Behrens <me@kloenk.de> Signed-off-by: Finn Behrens <me@kloenk.de> Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Co-developed-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de> Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de> Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Douglas Su <d0u9.su@outlook.com> Signed-off-by: Douglas Su <d0u9.su@outlook.com> Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl> Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl> Co-developed-by: Antonio Terceiro <antonio.terceiro@linaro.org> Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org> Co-developed-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Co-developed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
* | asm-generic: Conditionally enable do_softirq_own_stack() via Kconfig.Sebastian Andrzej Siewior2022-09-051-0/+3
|/ | | | | | | | | | | | | | Remove the CONFIG_PREEMPT_RT symbol from the ifdef around do_softirq_own_stack() and move it to Kconfig instead. Enable softirq stacks based on SOFTIRQ_ON_OWN_STACK which depends on HAVE_SOFTIRQ_ON_OWN_STACK and its default value is set to !PREEMPT_RT. This ensures that softirq stacks are not used on PREEMPT_RT and avoids a 'select' statement on an option which has a 'depends' statement. Link: https://lore.kernel.org/YvN5E%2FPrHfUhggr7@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>