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2024-03-11x86/rfds: Mitigate Register File Data Sampling (RFDS)Pawan Gupta1-0/+1
RFDS is a CPU vulnerability that may allow userspace to infer kernel stale data previously used in floating point registers, vector registers and integer registers. RFDS only affects certain Intel Atom processors. Intel released a microcode update that uses VERW instruction to clear the affected CPU buffers. Unlike MDS, none of the affected cores support SMT. Add RFDS bug infrastructure and enable the VERW based mitigation by default, that clears the affected buffers just before exiting to userspace. Also add sysfs reporting and cmdline parameter "reg_file_data_sampling" to control the mitigation. For details see: Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-09-11Documentation: Drop or replace remaining mentions of IA64Ard Biesheuvel1-3/+0
Drop or update mentions of IA64, as appropriate. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-08-30Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of ↵Linus Torvalds1-0/+8
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 ...
2023-08-29Merge tag 'smp-core-2023-08-28' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CPU hotplug updates from Thomas Gleixner: "Updates for the CPU hotplug core: - Support partial SMT enablement. So far the sysfs SMT control only allows to toggle between SMT on and off. That's sufficient for x86 which usually has at max two threads except for the Xeon PHI platform which has four threads per core Though PowerPC has up to 16 threads per core and so far it's only possible to control the number of enabled threads per core via a command line option. There is some way to control this at runtime, but that lacks enforcement and the usability is awkward This update expands the sysfs interface and the core infrastructure to accept numerical values so PowerPC can build SMT runtime control for partial SMT enablement on top The core support has also been provided to the PowerPC maintainers who added the PowerPC related changes on top - Minor cleanups and documentation updates" * tag 'smp-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation: core-api/cpuhotplug: Fix state names cpu/hotplug: Remove unused function declaration cpu_set_state_online() cpu/SMT: Fix cpu_smt_possible() comment cpu/SMT: Allow enabling partial SMT states via sysfs cpu/SMT: Create topology_smt_thread_allowed() cpu/SMT: Remove topology_smt_supported() cpu/SMT: Store the current/max number of threads cpu/SMT: Move smt/control simple exit cases earlier cpu/SMT: Move SMT prototypes into cpu_smt.h cpu/hotplug: Remove dependancy against cpu_primary_thread_mask
2023-08-25crash: memory and CPU hotplug sysfs attributesEric DeVolder1-0/+8
Introduce the crash_hotplug attribute for memory and CPUs for use by userspace. These attributes directly facilitate the udev rule for managing userspace re-loading of the crash kernel upon hot un/plug changes. For memory, expose the crash_hotplug attribute to the /sys/devices/system/memory directory. For example: # udevadm info --attribute-walk /sys/devices/system/memory/memory81 looking at device '/devices/system/memory/memory81': KERNEL=="memory81" SUBSYSTEM=="memory" DRIVER=="" ATTR{online}=="1" ATTR{phys_device}=="0" ATTR{phys_index}=="00000051" ATTR{removable}=="1" ATTR{state}=="online" ATTR{valid_zones}=="Movable" looking at parent device '/devices/system/memory': KERNELS=="memory" SUBSYSTEMS=="" DRIVERS=="" ATTRS{auto_online_blocks}=="offline" ATTRS{block_size_bytes}=="8000000" ATTRS{crash_hotplug}=="1" For CPUs, expose the crash_hotplug attribute to the /sys/devices/system/cpu directory. For example: # udevadm info --attribute-walk /sys/devices/system/cpu/cpu0 looking at device '/devices/system/cpu/cpu0': KERNEL=="cpu0" SUBSYSTEM=="cpu" DRIVER=="processor" ATTR{crash_notes}=="277c38600" ATTR{crash_notes_size}=="368" ATTR{online}=="1" looking at parent device '/devices/system/cpu': KERNELS=="cpu" SUBSYSTEMS=="" DRIVERS=="" ATTRS{crash_hotplug}=="1" ATTRS{isolated}=="" ATTRS{kernel_max}=="8191" ATTRS{nohz_full}==" (null)" ATTRS{offline}=="4-7" ATTRS{online}=="0-3" ATTRS{possible}=="0-7" ATTRS{present}=="0-3" With these sysfs attributes in place, it is possible to efficiently instruct the udev rule to skip crash kernel reloading for kernels configured with crash hotplug support. For example, the following is the proposed udev rule change for RHEL system 98-kexec.rules (as the first lines of the rule file): # The kernel updates the crash elfcorehdr for CPU and memory changes SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" When examined in the context of 98-kexec.rules, the above rules test if crash_hotplug is set, and if so, the userspace initiated unload-then-reload of the crash kernel is skipped. CPU and memory checks are separated in accordance with CONFIG_HOTPLUG_CPU and CONFIG_MEMORY_HOTPLUG kernel config options. If an architecture supports, for example, memory hotplug but not CPU hotplug, then the /sys/devices/system/memory/crash_hotplug attribute file is present, but the /sys/devices/system/cpu/crash_hotplug attribute file will NOT be present. Thus the udev rule skips userspace processing of memory hot un/plug events, but the udev rule will evaluate false for CPU events, thus allowing userspace to process CPU hot un/plug events (ie the unload-then-reload of the kdump capture kernel). Link: https://lkml.kernel.org/r/20230814214446.6659-5-eric.devolder@oracle.com Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Akhil Raj <lf32.dev@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-28cpu/SMT: Allow enabling partial SMT states via sysfsMichael Ellerman1-0/+1
Add support to the /sys/devices/system/cpu/smt/control interface for enabling a specified number of SMT threads per core, including partial SMT states where not all threads are brought online. The current interface accepts "on" and "off", to enable either 1 or all SMT threads per core. This commit allows writing an integer, between 1 and the number of SMT threads supported by the machine. Writing 1 is a synonym for "off", 2 or more enables SMT with the specified number of threads. When reading the file, if all threads are online "on" is returned, to avoid changing behaviour for existing users. If some other number of threads is online then the integer value is returned. Architectures like x86 only supporting 1 thread or all threads, should not define CONFIG_SMT_NUM_THREADS_DYNAMIC. Architecture supporting partial SMT states, like PowerPC, should define it. [ ldufour: Slightly reword the commit's description ] [ ldufour: Remove switch() in __store_smt_control() ] [ ldufour: Rix build issue in control_show() ] Reported-by: kernel test robot <lkp@intel.com> 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/20230705145143.40545-8-ldufour@linux.ibm.com
2023-07-20x86/speculation: Add Gather Data Sampling mitigationDaniel Sneddon1-6/+7
Gather Data Sampling (GDS) is a hardware vulnerability which allows unprivileged speculative access to data which was previously stored in vector registers. Intel processors that support AVX2 and AVX512 have gather instructions that fetch non-contiguous data elements from memory. On vulnerable hardware, when a gather instruction is transiently executed and encounters a fault, stale data from architectural or internal vector registers may get transiently stored to the destination vector register allowing an attacker to infer the stale data using typical side channel techniques like cache timing attacks. This mitigation is different from many earlier ones for two reasons. First, it is enabled by default and a bit must be set to *DISABLE* it. This is the opposite of normal mitigation polarity. This means GDS can be mitigated simply by updating microcode and leaving the new control bit alone. Second, GDS has a "lock" bit. This lock bit is there because the mitigation affects the hardware security features KeyLocker and SGX. It needs to be enabled and *STAY* enabled for these features to be mitigated against GDS. The mitigation is enabled in the microcode by default. Disable it by setting gather_data_sampling=off or by disabling all mitigations with mitigations=off. The mitigation status can be checked by reading: /sys/devices/system/cpu/vulnerabilities/gather_data_sampling Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-21docs: arm64: Move arm64 documentation under Documentation/arch/Jonathan Corbet1-1/+1
Architecture-specific documentation is being moved into Documentation/arch/ as a way of cleaning up the top-level documentation directory and making the docs hierarchy more closely match the source hierarchy. Move Documentation/arm64 into arch/ (along with the Chinese equvalent translations) and fix up documentation references. Cc: Will Deacon <will@kernel.org> Cc: Alex Shi <alexs@kernel.org> Cc: Hu Haowen <src.res@email.cn> Cc: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Yantengsi <siyanteng@loongson.cn> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-10-03Merge tag 'docs-6.1' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "There's not a huge amount of activity in the docs tree this time around, but a few significant changes even so: - A complete rewriting of the top-level index.rst file, which mostly reflects itself in a redone top page in the HTML-rendered docs. The hope is that the new organization will be a friendlier starting point for both users and developers. - Some math-rendering improvements. - A coding-style.rst update on the use of BUG() and WARN() - A big maintainer-PHP guide update. - Some code-of-conduct updates - More Chinese translation work Plus the usual pile of typo fixes, corrections, and updates" * tag 'docs-6.1' of git://git.lwn.net/linux: (66 commits) checkpatch: warn on usage of VM_BUG_ON() and other BUG variants coding-style.rst: document BUG() and WARN() rules ("do not crash the kernel") Documentation: devres: add missing IO helper Documentation: devres: update IRQ helper Documentation/mm: modify page_referenced to folio_referenced Documentation/CoC: Reflect current CoC interpretation and practices docs/doc-guide: Add documentation on SPHINX_IMGMATH docs: process/5.Posting.rst: clarify use of Reported-by: tag docs, kprobes: Fix the wrong location of Kprobes docs: add a man-pages link to the front page docs: put atomic*.txt and memory-barriers.txt into the core-api book docs: move asm-annotations.rst into core-api docs: remove some index.rst cruft docs: reconfigure the HTML left column docs: Rewrite the front page docs: promote the title of process/index.rst Documentation: devres: add missing SPI helper Documentation: devres: add missing PINCTRL helpers docs: hugetlbpage.rst: fix a typo of hugepage size docs/zh_CN: Add new translation of admin-guide/bootconfig.rst ...
2022-09-27Documentation/ABI: correct possessive "its" typosRandy Dunlap1-1/+1
Correct all uses of "it's" that are meant to be possessive "its". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220801025207.29971-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-08-25Documentation/ABI: Mention retbleed vulnerability info file for sysfsSalvatore Bonaccorso1-0/+1
While reporting for the AMD retbleed vulnerability was added in 6b80b59b3555 ("x86/bugs: Report AMD retbleed vulnerability") the new sysfs file was not mentioned so far in the ABI documentation for sysfs-devices-system-cpu. Fix that. Fixes: 6b80b59b3555 ("x86/bugs: Report AMD retbleed vulnerability") Signed-off-by: Salvatore Bonaccorso <carnil@debian.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220801091529.325327-1-carnil@debian.org
2022-08-04Merge tag 'driver-core-6.0-rc1' of ↵Linus Torvalds1-6/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core / kernfs updates from Greg KH: "Here is the set of driver core and kernfs changes for 6.0-rc1. The "biggest" thing in here is some scalability improvements for kernfs for large systems. Other than that, included in here are: - arch topology and cache info changes that have been reviewed and discussed a lot. - potential error path cleanup fixes - deferred driver probe cleanups - firmware loader cleanups and tweaks - documentation updates - other small things All of these have been in the linux-next tree for a while with no reported problems" * tag 'driver-core-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (63 commits) docs: embargoed-hardware-issues: fix invalid AMD contact email firmware_loader: Replace kmap() with kmap_local_page() sysfs docs: ABI: Fix typo in comment kobject: fix Kconfig.debug "its" grammar kernfs: Fix typo 'the the' in comment docs: driver-api: firmware: add driver firmware guidelines. (v3) arch_topology: Fix cache attributes detection in the CPU hotplug path ACPI: PPTT: Leave the table mapped for the runtime usage cacheinfo: Use atomic allocation for percpu cache attributes drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist MAINTAINERS: Change mentions of mpm to olivia docs: ABI: sysfs-devices-soc: Update Lee Jones' email address docs: ABI: sysfs-class-pwm: Update Lee Jones' email address Documentation/process: Add embargoed HW contact for LLVM Revert "kernfs: Change kernfs_notify_list to llist." ACPI: Remove the unused find_acpi_cpu_cache_topology() arch_topology: Warn that topology for nested clusters is not supported arch_topology: Add support for parsing sockets in /cpu-map arch_topology: Set cluster identifier in each core/thread from /cpu-map arch_topology: Limit span of cpu_clustergroup_mask() ...
2022-06-27ABI: testing/sysfs-devices-system-cpu: remove duplicated core_idMauro Carvalho Chehab1-6/+1
This was already defined at stable/sysfs-devices-system-cpu with the same description, as pointed by get_abi.pl: Warning: /sys/devices/system/cpu/cpuX/topology/core_id is defined 2 times: Documentation/ABI/stable/sysfs-devices-system-cpu:38 Documentation/ABI/testing/sysfs-devices-system-cpu:69 Remove the duplicated one. Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> Link: https://lore.kernel.org/r/1e92337c1ef74f5eb9e1c1871e20b858b490d269.1656235926.git.mchehab@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-23arm64/sme: Expose SMIDR through sysfsMark Brown1-1/+2
We currently expose MIDR and REVID to userspace through sysfs to enable it to make decisions based on the specific implementation. Since SME supports implementations where streaming mode is provided by a separate hardware unit called a SMCU it provides a similar ID register SMIDR. Expose it to userspace via sysfs when the system supports SME along with the other ID registers. Since we disable the SME priority mapping feature if it is supported by hardware we currently mask out the SMPS bit which reports that it is supported. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220607132857.1358361-1-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-05-21x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale DataPawan Gupta1-0/+1
Add the sysfs reporting file for Processor MMIO Stale Data vulnerability. It exposes the vulnerability and mitigation state similar to the existing files for the other hardware vulnerabilities. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-03-21Merge tag 'x86_cpu_for_v5.18_rc1' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu feature updates from Borislav Petkov: - Merge the AMD and Intel PPIN code into a shared one by both vendors. Add the PPIN number to sysfs so that sockets can be identified when replacement is needed - Minor fixes and cleanups * tag 'x86_cpu_for_v5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Clear SME feature flag when not in use x86/cpufeatures: Put the AMX macros in the word 18 block topology/sysfs: Add PPIN in sysfs under cpu topology topology/sysfs: Add format parameter to macro defining "show" functions for proc x86/cpu: Read/save PPIN MSR during initialization x86/cpu: X86_FEATURE_INTEL_PPIN finally has a CPUID bit x86/cpu: Merge Intel and AMD ppin_init() functions x86/CPU/AMD: Use default_groups in kobj_type
2022-03-10docs: sysfs-devices-system-cpu: document "asymm" value for mte_tcf_preferredEvgenii Stepanov1-0/+1
It was added in commit 766121ba5de3 ("arm64/mte: Add userspace interface for enabling asymmetric mode"). Signed-off-by: Evgenii Stepanov <eugenis@google.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220309215943.87831-1-eugenis@google.com Signed-off-by: Will Deacon <will@kernel.org>
2022-02-01topology/sysfs: Add PPIN in sysfs under cpu topologyTony Luck1-0/+6
PPIN is the Protected Processor Identification Number. This is used to identify the socket as a Field Replaceable Unit (FRU). Existing code only displays this when reporting errors. But this makes it inconvenient for large clusters to use it for its intended purpose of inventory control. Add ppin to /sys/devices/system/cpu/cpu*/topology to make what is already available using RDMSR more easily accessible. Make the file read only for root in case there are still people concerned about making a unique system "serial number" available. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220131230111.2004669-6-tony.luck@intel.com
2021-12-03docs: document the sysfs ABI for "isolated"Kohei Tarumizu1-0/+8
Add missing documentation of sysfs ABI for "isolated". It was added by commit 59f30abe94bf("show isolated cpus in sysfs"). However, there is no documentation for these interface. Signed-off-by: Kohei Tarumizu <tarumizu.kohei@fujitsu.com> Link: https://lore.kernel.org/r/20211201115957.254224-3-tarumizu.kohei@fujitsu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-03docs: document the sysfs ABI for "nohz_full"Kohei Tarumizu1-0/+7
Add missing documentation of sysfs ABI for "nohz_full". It was added by commit 6570a9a1ce3a("show nohz_full cpus in sysfs"). However, there is no documentation for these interface. Signed-off-by: Kohei Tarumizu <tarumizu.kohei@fujitsu.com> Link: https://lore.kernel.org/r/20211201115957.254224-2-tarumizu.kohei@fujitsu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-05ABI: sysfs-devices-system-cpu: use cpuX instead of cpu#Mauro Carvalho Chehab1-26/+26
Some What entries here use cpu# as a wildcard, while others use, instead, cpuX. As scripts/get_abi.pl doesn't consider "#" as a wildcard, replace: cpu# -> cpuX inside the file. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/60b1a79189d1a9d9f1c9c9c299770e69b18972fd.1632994837.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-21ABI: sysfs-devices-system-cpu: use wildcards on What definitionsMauro Carvalho Chehab1-8/+8
An "N" upper letter is not a wildcard, nor can easily be identified by script, specially since the USB sysfs define things like. bNumInterfaces. Use, instead, <N>, in order to let script/get_abi.pl to convert it into a Regex. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/d18385a391b6797373a5d1382ea024857fb29987.1631782432.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-31Merge remote-tracking branch 'tip/sched/arm64' into for-next/coreCatalin Marinas1-0/+9
* tip/sched/arm64: (785 commits) Documentation: arm64: describe asymmetric 32-bit support arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 arm64: Advertise CPUs capable of running 32-bit applications in sysfs arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 arm64: Implement task_cpu_possible_mask() sched: Introduce dl_task_check_affinity() to check proposed affinity sched: Allow task CPU affinity to be restricted on asymmetric systems sched: Split the guts of sched_setaffinity() into a helper function sched: Introduce task_struct::user_cpus_ptr to track requested affinity sched: Reject CPU affinity changes based on task_cpu_possible_mask() cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq() cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 sched: Introduce task_cpu_possible_mask() to limit fallback rq selection sched: Cgroup SCHED_IDLE support sched/topology: Skip updating masks for non-online nodes Linux 5.14-rc6 lib: use PFN_PHYS() in devmem_is_allowed() ...
2021-08-20arm64: Advertise CPUs capable of running 32-bit applications in sysfsWill Deacon1-0/+9
Since 32-bit applications will be killed if they are caught trying to execute on a 64-bit-only CPU in a mismatched system, advertise the set of 32-bit capable CPUs to userspace in sysfs. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210730112443.23245-14-will@kernel.org
2021-07-28Documentation: document the preferred tag checking mode featurePeter Collingbourne1-0/+17
Document the functionality added in the previous patches. Link: https://linux-review.googlesource.com/id/I48217cc3e8b8da33abc08cbaddc11cf4360a1b86 Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210727205300.2554659-6-pcc@google.com Acked-by: Will Deacon <will@kernel.org> [catalin.marinas@arm.com: clarify that the change happens on task scheduling] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-05-13docs: typo fixes in Documentation/ABI/Carlos Bilbao1-5/+5
Fix the following typos in the Documentation/ABI/ directory: - In file obsolete/sysfs-cpuidle, change "obselete" for "obsolete". - In file removed/sysfs-kernel-uids, change "propotional" for "proportional". - In directory stable/, fix the following words: "associtated" for "associated", "hexidecimal" for "hexadecimal", "vlue" for "value", "csed" for "caused" and "wrtie" for "write". This updates a total of five files. - In directory testing/, fix the following words: "subystem" for "subsystem", "isochrnous" for "isochronous", "Desctiptors" for "Descriptors", "picutre" for "picture", "capture" for "capture", "occured" for "ocurred", "connnected" for "connected","agressively" for "aggressively","manufacturee" for "manufacturer" and "transaction" for "transaction", "malformatted" for "incorrectly formated" ,"internel" for "internal", "writtento" for "written to", "specificed" for "specified", "beyound" for "beyond", "Symetric" for "Symmetric". This updates a total of eleven files. Signed-off-by: Carlos Bilbao <bilbao@vt.edu> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5710038.lOV4Wx5bFT@iron-maiden Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-05-04docs: correct URL to bios and kernel developer's guideAnatoly Pugachev1-1/+1
correct URL to bios and kernel developer's guide on amd.com site Signed-off-by: Anatoly Pugachev <matorola@gmail.com> Link: https://lore.kernel.org/r/20210428104851.GA10572@u164.east.ru [jc: fixed resulting sphinx warning] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-15cppc_cpufreq: expose information on frequency domainsIonela Voinescu1-1/+2
Use the existing sysfs attribute "freqdomain_cpus" to expose information to userspace about CPUs in the same frequency domain. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-30docs: ABI: cleanup several ABI documentsMauro Carvalho Chehab1-2/+2
There are some ABI documents that, while they don't generate any warnings, they have issues when parsed by get_abi.pl script on its output result. Address them, in order to provide a clean output. Reviewed-by: Tom Rix <trix@redhat.com> # for fpga-manager Reviewed-By: Kajol Jain<kjain@linux.ibm.com> # for sysfs-bus-event_source-devices-hv_gpci and sysfs-bus-event_source-devices-hv_24x7 Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for IIO Acked-by: Oded Gabbay <oded.gabbay@gmail.com> # for Habanalabs Acked-by: Vaibhav Jain <vaibhav@linux.ibm.com> # for sysfs-bus-papr-pmem Acked-by: Cezary Rojewski <cezary.rojewski@intel.com> # for catpt Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Ilya Dryomov <idryomov@gmail.com> # for rbd Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/5bc78e5b68ed1e9e39135173857cb2e753be868f.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-30docs: ABI: testing: make the files compatible with ReST outputMauro Carvalho Chehab1-37/+62
Some files over there won't parse well by Sphinx. Fix them. Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-09Merge branch 'x86/srbds' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 srbds fixes from Thomas Gleixner: "The 9th episode of the dime novel "The performance killer" with the subtitle "Slow Randomizing Boosts Denial of Service". SRBDS is an MDS-like speculative side channel that can leak bits from the random number generator (RNG) across cores and threads. New microcode serializes the processor access during the execution of RDRAND and RDSEED. This ensures that the shared buffer is overwritten before it is released for reuse. This is equivalent to a full bus lock, which means that many threads running the RNG instructions in parallel have the same effect as the same amount of threads issuing a locked instruction targeting an address which requires locking of two cachelines at once. The mitigation support comes with the usual pile of unpleasant ingredients: - command line options - sysfs file - microcode checks - a list of vulnerable CPUs identified by model and stepping this time which requires stepping match support for the cpu match logic. - the inevitable slowdown of affected CPUs" * branch 'x86/srbds' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation: Add Ivy Bridge to affected list x86/speculation: Add SRBDS vulnerability and mitigation documentation x86/speculation: Add Special Register Buffer Data Sampling (SRBDS) mitigation x86/cpu: Add 'table' argument to cpu_matches()
2020-06-05Merge tag 'powerpc-5.8-1' of ↵Linus Torvalds1-0/+39
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Support for userspace to send requests directly to the on-chip GZIP accelerator on Power9. - Rework of our lockless page table walking (__find_linux_pte()) to make it safe against parallel page table manipulations without relying on an IPI for serialisation. - A series of fixes & enhancements to make our machine check handling more robust. - Lots of plumbing to add support for "prefixed" (64-bit) instructions on Power10. - Support for using huge pages for the linear mapping on 8xx (32-bit). - Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound driver. - Removal of some obsolete 40x platforms and associated cruft. - Initial support for booting on Power10. - Lots of other small features, cleanups & fixes. Thanks to: Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Andrey Abramov, Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent Abali, Cédric Le Goater, Chen Zhou, Christian Zigotzky, Christophe JAILLET, Christophe Leroy, Dmitry Torokhov, Emmanuel Nicolet, Erhard F., Gautham R. Shenoy, Geoff Levand, George Spelvin, Greg Kurz, Gustavo A. R. Silva, Gustavo Walbon, Haren Myneni, Hari Bathini, Joel Stanley, Jordan Niethe, Kajol Jain, Kees Cook, Leonardo Bras, Madhavan Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Michal Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram Pai, Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler, Wolfram Sang, Xiongfeng Wang. * tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (299 commits) powerpc/pseries: Make vio and ibmebus initcalls pseries specific cxl: Remove dead Kconfig options powerpc: Add POWER10 architected mode powerpc/dt_cpu_ftrs: Add MMA feature powerpc/dt_cpu_ftrs: Enable Prefixed Instructions powerpc/dt_cpu_ftrs: Advertise support for ISA v3.1 if selected powerpc: Add support for ISA v3.1 powerpc: Add new HWCAP bits powerpc/64s: Don't set FSCR bits in INIT_THREAD powerpc/64s: Save FSCR to init_task.thread.fscr after feature init powerpc/64s: Don't let DT CPU features set FSCR_DSCR powerpc/64s: Don't init FSCR_DSCR in __init_FSCR() powerpc/32s: Fix another build failure with CONFIG_PPC_KUAP_DEBUG powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations powerpc/module_64: Consolidate ftrace code powerpc/32: Disable KASAN with pages bigger than 16k powerpc/uaccess: Don't set KUEP by default on book3s/32 powerpc/uaccess: Don't set KUAP by default on book3s/32 powerpc/8xx: Reduce time spent in allow_user_access() and friends ...
2020-05-19Documentation: cpuidle: update the documentHanjun Guo1-15/+9
Update the document after the remove of cpuidle_sysfs_switch. Signed-off-by: Hanjun Guo <guohanjun@huawei.com> Reviewed-by: Doug Smythies <dsmythies@telus.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-04-30Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurrGautham R. Shenoy1-0/+39
Add documentation for the following sysfs interfaces: /sys/devices/system/cpu/cpuX/purr /sys/devices/system/cpu/cpuX/spurr /sys/devices/system/cpu/cpuX/idle_purr /sys/devices/system/cpu/cpuX/idle_spurr Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1586249263-14048-6-git-send-email-ego@linux.vnet.ibm.com
2020-04-20x86/speculation: Add Special Register Buffer Data Sampling (SRBDS) mitigationMark Gross1-0/+1
SRBDS is an MDS-like speculative side channel that can leak bits from the random number generator (RNG) across cores and threads. New microcode serializes the processor access during the execution of RDRAND and RDSEED. This ensures that the shared buffer is overwritten before it is released for reuse. While it is present on all affected CPU models, the microcode mitigation is not needed on models that enumerate ARCH_CAPABILITIES[MDS_NO] in the cases where TSX is not supported or has been disabled with TSX_CTRL. The mitigation is activated by default on affected processors and it increases latency for RDRAND and RDSEED instructions. Among other effects this will reduce throughput from /dev/urandom. * Enable administrator to configure the mitigation off when desired using either mitigations=off or srbds=off. * Export vulnerability status via sysfs * Rename file-scoped macros to apply for non-whitelist table initializations. [ bp: Massage, - s/VULNBL_INTEL_STEPPING/VULNBL_INTEL_STEPPINGS/g, - do not read arch cap MSR a second time in tsx_fused_off() - just pass it in, - flip check in cpu_set_bug_bits() to save an indentation level, - reflow comments. jpoimboe: s/Mitigated/Mitigation/ in user-visible strings tglx: Dropped the fused off magic for now ] Signed-off-by: Mark Gross <mgross@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
2019-12-27cpuidle: Allow idle states to be disabled by defaultRafael J. Wysocki1-0/+6
In certain situations it may be useful to prevent some idle states from being used by default while allowing user space to enable them later on. For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to mark idle states that should be disabled by default, make the core set CPUIDLE_STATE_DISABLED_BY_USER for those states at the initialization time and add a new state attribute in sysfs, "default_status", to inform user space of the initial status of the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it, "enabled" otherwise). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-04x86/bugs: Add ITLB_MULTIHIT bug infrastructureVineela Tummalapalli1-0/+1
Some processors may incur a machine check error possibly resulting in an unrecoverable CPU lockup when an instruction fetch encounters a TLB multi-hit in the instruction TLB. This can occur when the page size is changed along with either the physical address or cache type. The relevant erratum can be found here: https://bugzilla.kernel.org/show_bug.cgi?id=205195 There are other processors affected for which the erratum does not fully disclose the impact. This issue affects both bare-metal x86 page tables and EPT. It can be mitigated by either eliminating the use of large pages or by using careful TLB invalidations when changing the page size in the page tables. Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which are mitigated against this issue. Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com> Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-10-28x86/speculation/taa: Add documentation for TSX Async AbortPawan Gupta1-0/+1
Add the documenation for TSX Async Abort. Include the description of the issue, how to check the mitigation state, control the mitigation, guidance for system administrators. [ bp: Add proper SPDX tags, touch ups by Josh and me. ] Co-developed-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mark Gross <mgross@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
2019-08-30powerpc/pseries/svm: Export guest SVM status to user space via sysfsRyan Grimm1-0/+10
User space might want to know it's running in a secure VM. It can't do a mfmsr because mfmsr is a privileged instruction. The solution here is to create a cpu attribute: /sys/devices/system/cpu/svm which will read 0 or 1 based on the S bit of the current CPU. Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820021326.6884-12-bauerman@linux.ibm.com
2019-07-15docs: admin-guide: add a series of orphaned documentsMauro Carvalho Chehab1-2/+2
There are lots of documents that belong to the admin-guide but are on random places (most under Documentation root dir). Move them to the admin guide. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2019-07-09Merge tag 'docs-5.3' of git://git.lwn.net/linuxLinus Torvalds1-1/+2
Pull Documentation updates from Jonathan Corbet: "It's been a relatively busy cycle for docs: - A fair pile of RST conversions, many from Mauro. These create more than the usual number of simple but annoying merge conflicts with other trees, unfortunately. He has a lot more of these waiting on the wings that, I think, will go to you directly later on. - A new document on how to use merges and rebases in kernel repos, and one on Spectre vulnerabilities. - Various improvements to the build system, including automatic markup of function() references because some people, for reasons I will never understand, were of the opinion that :c:func:``function()`` is unattractive and not fun to type. - We now recommend using sphinx 1.7, but still support back to 1.4. - Lots of smaller improvements, warning fixes, typo fixes, etc" * tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits) docs: automarkup.py: ignore exceptions when seeking for xrefs docs: Move binderfs to admin-guide Disable Sphinx SmartyPants in HTML output doc: RCU callback locks need only _bh, not necessarily _irq docs: format kernel-parameters -- as code Doc : doc-guide : Fix a typo platform: x86: get rid of a non-existent document Add the RCU docs to the core-api manual Documentation: RCU: Add TOC tree hooks Documentation: RCU: Rename txt files to rst Documentation: RCU: Convert RCU UP systems to reST Documentation: RCU: Convert RCU linked list to reST Documentation: RCU: Convert RCU basic concepts to reST docs: filesystems: Remove uneeded .rst extension on toctables scripts/sphinx-pre-install: fix out-of-tree build docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/ Documentation: PGP: update for newer HW devices Documentation: Add section about CPU vulnerabilities for Spectre Documentation: platform: Delete x86-laptop-drivers.txt docs: Note that :c:func: should no longer be used ...
2019-06-24Documentation/ABI: Document umwait control sysfs interfacesFenghua Yu1-0/+23
Since two new sysfs interface files are created for umwait control, add an ABI document entry for the files: /sys/devices/system/cpu/umwait_control/enable_c02 /sys/devices/system/cpu/umwait_control/max_time [ tglx: Made the write value instructions readable ] Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ashok Raj <ashok.raj@intel.com> Cc: "Borislav Petkov" <bp@alien8.de> Cc: "H Peter Anvin" <hpa@zytor.com> Cc: "Andy Lutomirski" <luto@kernel.org> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Tony Luck" <tony.luck@intel.com> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Link: https://lkml.kernel.org/r/1560994438-235698-6-git-send-email-fenghua.yu@intel.com
2019-06-08ABI: sysfs-devices-system-cpu: point to the right docsMauro Carvalho Chehab1-1/+2
The cpuidle doc was split on two, one at the admin guide and another one at the driver API guide. Instead of pointing to a non-existent file, point to both (admin guide being the first one). Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-14Merge branch 'x86-mds-for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 MDS mitigations from Thomas Gleixner: "Microarchitectural Data Sampling (MDS) is a hardware vulnerability which allows unprivileged speculative access to data which is available in various CPU internal buffers. This new set of misfeatures has the following CVEs assigned: CVE-2018-12126 MSBDS Microarchitectural Store Buffer Data Sampling CVE-2018-12130 MFBDS Microarchitectural Fill Buffer Data Sampling CVE-2018-12127 MLPDS Microarchitectural Load Port Data Sampling CVE-2019-11091 MDSUM Microarchitectural Data Sampling Uncacheable Memory MDS attacks target microarchitectural buffers which speculatively forward data under certain conditions. Disclosure gadgets can expose this data via cache side channels. Contrary to other speculation based vulnerabilities the MDS vulnerability does not allow the attacker to control the memory target address. As a consequence the attacks are purely sampling based, but as demonstrated with the TLBleed attack samples can be postprocessed successfully. The mitigation is to flush the microarchitectural buffers on return to user space and before entering a VM. It's bolted on the VERW instruction and requires a microcode update. As some of the attacks exploit data structures shared between hyperthreads, full protection requires to disable hyperthreading. The kernel does not do that by default to avoid breaking unattended updates. The mitigation set comes with documentation for administrators and a deeper technical view" * 'x86-mds-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/speculation/mds: Fix documentation typo Documentation: Correct the possible MDS sysfs values x86/mds: Add MDSUM variant to the MDS documentation x86/speculation/mds: Add 'mitigations=' support for MDS x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off x86/speculation/mds: Fix comment x86/speculation/mds: Add SMT warning message x86/speculation: Move arch_smt_update() call to after mitigation decisions x86/speculation/mds: Add mds=full,nosmt cmdline option Documentation: Add MDS vulnerability documentation Documentation: Move L1TF to separate directory x86/speculation/mds: Add mitigation mode VMWERV x86/speculation/mds: Add sysfs reporting for MDS x86/speculation/mds: Add mitigation control for MDS x86/speculation/mds: Conditionally clear CPU buffers on idle entry x86/kvm/vmx: Add MDS protection when L1D Flush is not active x86/speculation/mds: Clear CPU buffers on exit to user x86/speculation/mds: Add mds_clear_cpu_buffers() x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests x86/speculation/mds: Add BUG_MSBDS_ONLY ...
2019-05-07Merge tag 'pm-5.2-rc1' of ↵Linus Torvalds1-0/+18
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These fix the (Intel-specific) Performance and Energy Bias Hint (EPB) handling and expose it to user space via sysfs, fix and clean up several cpufreq drivers, add support for two new chips to the qoriq cpufreq driver, fix, simplify and clean up the cpufreq core and the schedutil governor, add support for "CPU" domains to the generic power domains (genpd) framework and provide low-level PSCI firmware support for that feature, fix the exynos cpuidle driver and fix a couple of issues in the devfreq subsystem and clean it up. Specifics: - Fix the handling of Performance and Energy Bias Hint (EPB) on Intel processors and expose it to user space via sysfs to avoid having to access it through the generic MSR I/F (Rafael Wysocki). - Improve the handling of global turbo changes made by the platform firmware in the intel_pstate driver (Rafael Wysocki). - Convert some slow-path static_cpu_has() callers to boot_cpu_has() in cpufreq (Borislav Petkov). - Fix the frequency calculation loop in the armada-37xx cpufreq driver (Gregory CLEMENT). - Fix possible object reference leaks in multuple cpufreq drivers (Wen Yang). - Fix kerneldoc comment in the centrino cpufreq driver (dongjian). - Clean up the ACPI and maple cpufreq drivers (Viresh Kumar, Mohan Kumar). - Add support for lx2160a and ls1028a to the qoriq cpufreq driver (Vabhav Sharma, Yuantian Tang). - Fix kobject memory leak in the cpufreq core (Viresh Kumar). - Simplify the IOwait boosting in the schedutil cpufreq governor and rework the TSC cpufreq notifier on x86 (Rafael Wysocki). - Clean up the cpufreq core and statistics code (Yue Hu, Kyle Lin). - Improve the cpufreq documentation, add SPDX license tags to some PM documentation files and unify copyright notices in them (Rafael Wysocki). - Add support for "CPU" domains to the generic power domains (genpd) framework and provide low-level PSCI firmware support for that feature (Ulf Hansson). - Rearrange the PSCI firmware support code and add support for SYSTEM_RESET2 to it (Ulf Hansson, Sudeep Holla). - Improve genpd support for devices in multiple power domains (Ulf Hansson). - Unify target residency for the AFTR and coupled AFTR states in the exynos cpuidle driver (Marek Szyprowski). - Introduce new helper routine in the operating performance points (OPP) framework (Andrew-sh.Cheng). - Add support for passing on-die termination (ODT) and auto power down parameters from the kernel to Trusted Firmware-A (TF-A) to the rk3399_dmc devfreq driver (Enric Balletbo i Serra). - Add tracing to devfreq (Lukasz Luba). - Make the exynos-bus devfreq driver suspend all devices on system shutdown (Marek Szyprowski). - Fix a few minor issues in the devfreq subsystem and clean it up somewhat (Enric Balletbo i Serra, MyungJoo Ham, Rob Herring, Saravana Kannan, Yangtao Li). - Improve system wakeup diagnostics (Stephen Boyd). - Rework filesystem sync messages emitted during system suspend and hibernation (Harry Pan)" * tag 'pm-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (72 commits) cpufreq: Fix kobject memleak cpufreq: armada-37xx: fix frequency calculation for opp cpufreq: centrino: Fix centrino_setpolicy() kerneldoc comment cpufreq: qoriq: add support for lx2160a x86: tsc: Rework time_cpufreq_notifier() PM / Domains: Allow to attach a CPU via genpd_dev_pm_attach_by_id|name() PM / Domains: Search for the CPU device outside the genpd lock PM / Domains: Drop unused in-parameter to some genpd functions PM / Domains: Use the base device for driver_deferred_probe_check_state() cpufreq: qoriq: Add ls1028a chip support PM / Domains: Enable genpd_dev_pm_attach_by_id|name() for single PM domain PM / Domains: Allow OF lookup for multi PM domain case from ->attach_dev() PM / Domains: Don't kfree() the virtual device in the error path cpufreq: Move ->get callback check outside of __cpufreq_get() PM / Domains: remove unnecessary unlikely() cpufreq: Remove needless bios_limit check in show_bios_limit() drivers/cpufreq/acpi-cpufreq.c: This fixes the following checkpatch warning firmware/psci: add support for SYSTEM_RESET2 PM / devfreq: add tracing for scheduling work trace: events: add devfreq trace event file ...
2019-04-07PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interfaceRafael J. Wysocki1-0/+18
The Performance and Energy Bias Hint (EPB) is expected to be set by user space through the generic MSR interface, but that interface is not particularly nice and there are security concerns regarding it, so it is not always available. For this reason, add a sysfs interface for reading and updating the EPB, in the form of a new attribute, energy_perf_bias, located under /sys/devices/system/cpu/cpu#/power/ for online CPUs that support the EPB feature. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Borislav Petkov <bp@suse.de>
2019-04-02cpu/hotplug: Create SMT sysfs interface for all archesJosh Poimboeuf1-4/+6
Make the /sys/devices/system/cpu/smt/* files available on all arches, so user space has a consistent way to detect whether SMT is enabled. The 'control' file now shows 'notimplemented' for architectures which don't yet have CONFIG_HOTPLUG_SMT. [ tglx: Make notimplemented a real state ] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <longman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jikos@kernel.org> Link: https://lkml.kernel.org/r/469c2b98055f2c41e75748e06447d592a64080c9.1553635520.git.jpoimboe@redhat.com
2019-03-06Documentation: Add MDS vulnerability documentationThomas Gleixner1-2/+1
Add the initial MDS vulnerability documentation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jon Masters <jcm@redhat.com>
2019-03-06Documentation: Move L1TF to separate directoryThomas Gleixner1-1/+1
Move L!TF to a separate directory so the MDS stuff can be added at the side. Otherwise the all hardware vulnerabilites have their own top level entry. Should have done that right away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add sysfs reporting for MDSThomas Gleixner1-0/+1
Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>