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2021-04-26Merge tag 'docs-5.13' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "It's been a relatively busy cycle in docsland, though more than usually well contained to Documentation/ itself. Highlights include: - The Chinese translators have been busy and show no signs of stopping anytime soon. Italian has also caught up. - Aditya Srivastava has been working on improvements to the kernel-doc script. - Thorsten continues his work on reporting-issues.rst and related documentation around regression reporting. - Lots of documentation updates, typo fixes, etc. as usual" * tag 'docs-5.13' of git://git.lwn.net/linux: (139 commits) docs/zh_CN: add openrisc translation to zh_CN index docs/zh_CN: add openrisc index.rst translation docs/zh_CN: add openrisc todo.rst translation docs/zh_CN: add openrisc openrisc_port.rst translation docs/zh_CN: add core api translation to zh_CN index docs/zh_CN: add core-api index.rst translation docs/zh_CN: add core-api irq index.rst translation docs/zh_CN: add core-api irq irqflags-tracing.rst translation docs/zh_CN: add core-api irq irq-domain.rst translation docs/zh_CN: add core-api irq irq-affinity.rst translation docs/zh_CN: add core-api irq concepts.rst translation docs: sphinx-pre-install: don't barf on beta Sphinx releases scripts: kernel-doc: improve parsing for kernel-doc comments syntax docs/zh_CN: two minor fixes in zh_CN/doc-guide/ Documentation: dev-tools: Add Testing Overview docs/zh_CN: add translations in zh_CN/dev-tools/gcov docs: reporting-issues: make people CC the regressions list MAINTAINERS: add regressions mailing list doc:it_IT: align Italian documentation docs/zh_CN: sync reporting-issues.rst ...
2021-04-26Merge tag 'tty-5.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty and serial driver updates from Greg KH: "Here is the big set of tty and serial driver updates for 5.13-rc1. Actually busy this release, with a number of cleanups happening: - much needed core tty cleanups by Jiri Slaby - removal of unused and orphaned old-style serial drivers. If anyone shows up with this hardware, it is trivial to restore these but we really do not think they are in use anymore. - fixes and cleanups from Johan Hovold on a number of termios setting corner cases that loads of drivers got wrong as well as removing unneeded code due to tty core changes from long ago that were never propagated out to the drivers - loads of platform-specific serial port driver updates and fixes - coding style cleanups and other small fixes and updates all over the tty/serial tree. All of these have been in linux-next for a while now with no reported issues" * tag 'tty-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits) serial: extend compile-test coverage serial: stm32: add FIFO threshold configuration dt-bindings: serial: 8250: update TX FIFO trigger level dt-bindings: serial: stm32: override FIFO threshold properties dt-bindings: serial: add RX and TX FIFO properties serial: xilinx_uartps: drop low-latency workaround serial: vt8500: drop low-latency workaround serial: timbuart: drop low-latency workaround serial: sunsu: drop low-latency workaround serial: sifive: drop low-latency workaround serial: txx9: drop low-latency workaround serial: sa1100: drop low-latency workaround serial: rp2: drop low-latency workaround serial: rda: drop low-latency workaround serial: owl: drop low-latency workaround serial: msm_serial: drop low-latency workaround serial: mpc52xx_uart: drop low-latency workaround serial: meson: drop low-latency workaround serial: mcf: drop low-latency workaround serial: lpc32xx_hs: drop low-latency workaround ...
2021-04-26Merge tag 'platform-drivers-x86-v5.13-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 Pull x86 platform driver updates freom Hans de Goede: - lots of Microsoft Surface work - platform-profile support for HP and Microsoft Surface devices - new WMI Gigabyte motherboard temperature monitoring driver - Intel PMC improvements for Tiger Lake and Alder Lake - misc bugfixes, improvements and quirk additions all over * tag 'platform-drivers-x86-v5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (87 commits) platform/x86: gigabyte-wmi: add support for B550M AORUS PRO-P platform/x86: intel_pmc_core: Uninitialized data in pmc_core_lpm_latch_mode_write() platform/x86: intel_pmc_core: add ACPI dependency platform/surface: aggregator: fix a bit test platform/x86: intel_pmc_core: Fix "unsigned 'ret' is never less than zero" smatch warning platform/x86: touchscreen_dmi: Add info for the Teclast Tbook 11 tablet platform/x86: intel_pmc_core: Add support for Alder Lake PCH-P platform/x86: intel_pmc_core: Add LTR registers for Tiger Lake platform/x86: intel_pmc_core: Add option to set/clear LPM mode platform/x86: intel_pmc_core: Add requirements file to debugfs platform/x86: intel_pmc_core: Get LPM requirements for Tiger Lake platform/x86: intel_pmc_core: Show LPM residency in microseconds platform/x86: intel_pmc_core: Handle sub-states generically platform/x86: intel_pmc_core: Remove global struct pmc_dev platform/x86: intel_pmc_core: Don't use global pmcdev in quirks platform/x86: intel_chtdc_ti_pwrbtn: Fix missing IRQF_ONESHOT as only threaded handler platform/x86: gigabyte-wmi: add X570 AORUS ELITE platform/x86: thinkpad_acpi: Add labels to the first 2 temperature sensors platform/x86: pmc_atom: Match all Beckhoff Automation baytrail boards with critclk_systems DMI table platform/x86: add Gigabyte WMI temperature driver ...
2021-04-26Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - MTE asynchronous support for KASan. Previously only synchronous (slower) mode was supported. Asynchronous is faster but does not allow precise identification of the illegal access. - Run kernel mode SIMD with softirqs disabled. This allows using NEON in softirq context for crypto performance improvements. The conditional yield support is modified to take softirqs into account and reduce the latency. - Preparatory patches for Apple M1: handle CPUs that only have the VHE mode available (host kernel running at EL2), add FIQ support. - arm64 perf updates: support for HiSilicon PA and SLLC PMU drivers, new functions for the HiSilicon HHA and L3C PMU, cleanups. - Re-introduce support for execute-only user permissions but only when the EPAN (Enhanced Privileged Access Never) architecture feature is available. - Disable fine-grained traps at boot and improve the documented boot requirements. - Support CONFIG_KASAN_VMALLOC on arm64 (only with KASAN_GENERIC). - Add hierarchical eXecute Never permissions for all page tables. - Add arm64 prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) allowing user programs to control which PAC keys are enabled in a particular task. - arm64 kselftests for BTI and some improvements to the MTE tests. - Minor improvements to the compat vdso and sigpage. - Miscellaneous cleanups. * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (86 commits) arm64/sve: Add compile time checks for SVE hooks in generic functions arm64/kernel/probes: Use BUG_ON instead of if condition followed by BUG. arm64: pac: Optimize kernel entry/exit key installation code paths arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) arm64: mte: make the per-task SCTLR_EL1 field usable elsewhere arm64/sve: Remove redundant system_supports_sve() tests arm64: fpsimd: run kernel mode NEON with softirqs disabled arm64: assembler: introduce wxN aliases for wN registers arm64: assembler: remove conditional NEON yield macros kasan, arm64: tests supports for HW_TAGS async mode arm64: mte: Report async tag faults before suspend arm64: mte: Enable async tag check fault arm64: mte: Conditionally compile mte_enable_kernel_*() arm64: mte: Enable TCO in functions that can read beyond buffer limits kasan: Add report for async mode arm64: mte: Drop arch_enable_tagging() kasan: Add KASAN mode kernel parameter arm64: mte: Add asynchronous mode support arm64: Get rid of CONFIG_ARM64_VHE arm64: Cope with CPUs stuck in VHE mode ...
2021-04-26Merge tag 'x86-splitlock-2021-04-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 bus lock detection updates from Thomas Gleixner: "Support for enhanced split lock detection: Newer CPUs provide a second mechanism to detect operations with lock prefix which go accross a cache line boundary. Such operations have to take bus lock which causes a system wide performance degradation when these operations happen frequently. The new mechanism is not using the #AC exception. It triggers #DB and is restricted to operations in user space. Kernel side split lock access can only be detected by the #AC based variant. Contrary to the #AC based mechanism the #DB based variant triggers _after_ the instruction was executed. The mechanism is CPUID enumerated and contrary to the #AC version which is based on the magic TEST_CTRL_MSR and model/family based enumeration on the way to become architectural" * tag 'x86-splitlock-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation/admin-guide: Change doc for split_lock_detect parameter x86/traps: Handle #DB for bus lock x86/cpufeatures: Enumerate #DB for bus lock detection
2021-04-26Merge tag 'x86-entry-2021-04-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull entry code update from Thomas Gleixner: "Provide support for randomized stack offsets per syscall to make stack-based attacks harder which rely on the deterministic stack layout. The feature is based on the original idea of PaX's RANDSTACK feature, but uses a significantly different implementation. The offset does not affect the pt_regs location on the task stack as this was agreed on to be of dubious value. The offset is applied before the actual syscall is invoked. The offset is stored per cpu and the randomization happens at the end of the syscall which is less predictable than on syscall entry. The mechanism to apply the offset is via alloca(), i.e. abusing the dispised VLAs. This comes with the drawback that stack-clash-protection has to be disabled for the affected compilation units and there is also a negative interaction with stack-protector. Those downsides are traded with the advantage that this approach does not require any intrusive changes to the low level assembly entry code, does not affect the unwinder and the correct stack alignment is handled automatically by the compiler. The feature is guarded with a static branch which avoids the overhead when disabled. Currently this is supported for X86 and ARM64" * tag 'x86-entry-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm64: entry: Enable random_kstack_offset support lkdtm: Add REPORT_STACK for checking stack offsets x86/entry: Enable random_kstack_offset support stack: Optionally randomize kernel stack offset each syscall init_on_alloc: Optimize static branches jump_label: Provide CONFIG-driven build state defaults
2021-04-25Documentation/admin-guide/cifs: document open_files and dfscacheAurelien Aptel
Add missing documentation for open_files and dfscache /proc files. Signed-off-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-04-17sched/debug: Rename the sched_debug parameter to sched_verbosePeter Zijlstra
CONFIG_SCHED_DEBUG is the build-time Kconfig knob, the boot param sched_debug and the /debug/sched/debug_enabled knobs control the sched_debug_enabled variable, but what they really do is make SCHED_DEBUG more verbose, so rename the lot. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-04-15Merge branches 'for-next/misc', 'for-next/kselftest', 'for-next/xntable', ↵Catalin Marinas
'for-next/vdso', 'for-next/fiq', 'for-next/epan', 'for-next/kasan-vmalloc', 'for-next/fgt-boot-init', 'for-next/vhe-only' and 'for-next/neon-softirqs-disabled', remote-tracking branch 'arm64/for-next/perf' into for-next/core * for-next/misc: : Miscellaneous patches arm64/sve: Add compile time checks for SVE hooks in generic functions arm64/kernel/probes: Use BUG_ON instead of if condition followed by BUG. arm64/sve: Remove redundant system_supports_sve() tests arm64: mte: Remove unused mte_assign_mem_tag_range() arm64: Add __init section marker to some functions arm64/sve: Rework SVE access trap to convert state in registers docs: arm64: Fix a grammar error arm64: smp: Add missing prototype for some smp.c functions arm64: setup: name `tcr` register arm64: setup: name `mair` register arm64: stacktrace: Move start_backtrace() out of the header arm64: barrier: Remove spec_bar() macro arm64: entry: remove test_irqs_unmasked macro ARM64: enable GENERIC_FIND_FIRST_BIT arm64: defconfig: Use DEBUG_INFO_REDUCED * for-next/kselftest: : Various kselftests for arm64 kselftest: arm64: Add BTI tests kselftest/arm64: mte: Report filename on failing temp file creation kselftest/arm64: mte: Fix clang warning kselftest/arm64: mte: Makefile: Fix clang compilation kselftest/arm64: mte: Output warning about failing compiler kselftest/arm64: mte: Use cross-compiler if specified kselftest/arm64: mte: Fix MTE feature detection kselftest/arm64: mte: common: Fix write() warnings kselftest/arm64: mte: user_mem: Fix write() warning kselftest/arm64: mte: ksm_options: Fix fscanf warning kselftest/arm64: mte: Fix pthread linking kselftest/arm64: mte: Fix compilation with native compiler * for-next/xntable: : Add hierarchical XN permissions for all page tables arm64: mm: use XN table mapping attributes for user/kernel mappings arm64: mm: use XN table mapping attributes for the linear region arm64: mm: add missing P4D definitions and use them consistently * for-next/vdso: : Minor improvements to the compat vdso and sigpage arm64: compat: Poison the compat sigpage arm64: vdso: Avoid ISB after reading from cntvct_el0 arm64: compat: Allow signal page to be remapped arm64: vdso: Remove redundant calls to flush_dcache_page() arm64: vdso: Use GFP_KERNEL for allocating compat vdso and signal pages * for-next/fiq: : Support arm64 FIQ controller registration arm64: irq: allow FIQs to be handled arm64: Always keep DAIF.[IF] in sync arm64: entry: factor irq triage logic into macros arm64: irq: rework root IRQ handler registration arm64: don't use GENERIC_IRQ_MULTI_HANDLER genirq: Allow architectures to override set_handle_irq() fallback * for-next/epan: : Support for Enhanced PAN (execute-only permissions) arm64: Support execute-only permissions with Enhanced PAN * for-next/kasan-vmalloc: : Support CONFIG_KASAN_VMALLOC on arm64 arm64: Kconfig: select KASAN_VMALLOC if KANSAN_GENERIC is enabled arm64: kaslr: support randomized module area with KASAN_VMALLOC arm64: Kconfig: support CONFIG_KASAN_VMALLOC arm64: kasan: abstract _text and _end to KERNEL_START/END arm64: kasan: don't populate vmalloc area for CONFIG_KASAN_VMALLOC * for-next/fgt-boot-init: : Booting clarifications and fine grained traps setup arm64: Require that system registers at all visible ELs be initialized arm64: Disable fine grained traps on boot arm64: Document requirements for fine grained traps at boot * for-next/vhe-only: : Dealing with VHE-only CPUs (a.k.a. M1) arm64: Get rid of CONFIG_ARM64_VHE arm64: Cope with CPUs stuck in VHE mode arm64: cpufeature: Allow early filtering of feature override * arm64/for-next/perf: arm64: perf: Remove redundant initialization in perf_event.c perf/arm_pmu_platform: Clean up with dev_printk perf/arm_pmu_platform: Fix error handling perf/arm_pmu_platform: Use dev_err_probe() for IRQ errors docs: perf: Address some html build warnings docs: perf: Add new description on HiSilicon uncore PMU v2 drivers/perf: hisi: Add support for HiSilicon PA PMU driver drivers/perf: hisi: Add support for HiSilicon SLLC PMU driver drivers/perf: hisi: Update DDRC PMU for programmable counter drivers/perf: hisi: Add new functions for HHA PMU drivers/perf: hisi: Add new functions for L3C PMU drivers/perf: hisi: Add PMU version for uncore PMU drivers. drivers/perf: hisi: Refactor code for more uncore PMUs drivers/perf: hisi: Remove unnecessary check of counter index drivers/perf: Simplify the SMMUv3 PMU event attributes drivers/perf: convert sysfs sprintf family to sysfs_emit drivers/perf: convert sysfs scnprintf family to sysfs_emit_at() and sysfs_emit() drivers/perf: convert sysfs snprintf family to sysfs_emit * for-next/neon-softirqs-disabled: : Run kernel mode SIMD with softirqs disabled arm64: fpsimd: run kernel mode NEON with softirqs disabled arm64: assembler: introduce wxN aliases for wN registers arm64: assembler: remove conditional NEON yield macros
2021-04-14KEYS: trusted: Add generic trusted keys frameworkSumit Garg
Current trusted keys framework is tightly coupled to use TPM device as an underlying implementation which makes it difficult for implementations like Trusted Execution Environment (TEE) etc. to provide trusted keys support in case platform doesn't posses a TPM device. Add a generic trusted keys framework where underlying implementations can be easily plugged in. Create struct trusted_key_ops to achieve this, which contains necessary functions of a backend. Also, define a module parameter in order to select a particular trust source in case a platform support multiple trust sources. In case its not specified then implementation itetrates through trust sources list starting with TPM and assign the first trust source as a backend which has initiazed successfully during iteration. Note that current implementation only supports a single trust source at runtime which is either selectable at compile time or during boot via aforementioned module parameter. Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2021-04-13docs: reporting-issues: make people CC the regressions listThorsten Leemhuis
Make people CC the recently created mailing list dedicated to Linux kernel regressions when reporting one. Some paragraphs had to be reshuffled and slightly rewritten during the process, as the text otherwise would have gotten unnecessarily hard to follow. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/ac28089d710d5d41f295221bc726555ba32f4984.1617967127.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-04-08arm64: Get rid of CONFIG_ARM64_VHEMarc Zyngier
CONFIG_ARM64_VHE was introduced with ARMv8.1 (some 7 years ago), and has been enabled by default for almost all that time. Given that newer systems that are VHE capable are finally becoming available, and that some systems are even incapable of not running VHE, drop the configuration altogether. Anyone willing to stick to non-VHE on VHE hardware for obscure reasons should use the 'kvm-arm.mode=nvhe' command-line option. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210408131010.1109027-4-maz@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-08stack: Optionally randomize kernel stack offset each syscallKees Cook
This provides the ability for architectures to enable kernel stack base address offset randomization. This feature is controlled by the boot param "randomize_kstack_offset=on/off", with its default value set by CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT. This feature is based on the original idea from the last public release of PaX's RANDKSTACK feature: https://pax.grsecurity.net/docs/randkstack.txt All the credit for the original idea goes to the PaX team. Note that the design and implementation of this upstream randomize_kstack_offset feature differs greatly from the RANDKSTACK feature (see below). Reasoning for the feature: This feature aims to make harder the various stack-based attacks that rely on deterministic stack structure. We have had many such attacks in past (just to name few): https://jon.oberheide.org/files/infiltrate12-thestackisback.pdf https://jon.oberheide.org/files/stackjacking-infiltrate11.pdf https://googleprojectzero.blogspot.com/2016/06/exploiting-recursion-in-linux-kernel_20.html As Linux kernel stack protections have been constantly improving (vmap-based stack allocation with guard pages, removal of thread_info, STACKLEAK), attackers have had to find new ways for their exploits to work. They have done so, continuing to rely on the kernel's stack determinism, in situations where VMAP_STACK and THREAD_INFO_IN_TASK_STRUCT were not relevant. For example, the following recent attacks would have been hampered if the stack offset was non-deterministic between syscalls: https://repositorio-aberto.up.pt/bitstream/10216/125357/2/374717.pdf (page 70: targeting the pt_regs copy with linear stack overflow) https://a13xp0p0v.github.io/2020/02/15/CVE-2019-18683.html (leaked stack address from one syscall as a target during next syscall) The main idea is that since the stack offset is randomized on each system call, it is harder for an attack to reliably land in any particular place on the thread stack, even with address exposures, as the stack base will change on the next syscall. Also, since randomization is performed after placing pt_regs, the ptrace-based approach[1] to discover the randomized offset during a long-running syscall should not be possible. Design description: During most of the kernel's execution, it runs on the "thread stack", which is pretty deterministic in its structure: it is fixed in size, and on every entry from userspace to kernel on a syscall the thread stack starts construction from an address fetched from the per-cpu cpu_current_top_of_stack variable. The first element to be pushed to the thread stack is the pt_regs struct that stores all required CPU registers and syscall parameters. Finally the specific syscall function is called, with the stack being used as the kernel executes the resulting request. The goal of randomize_kstack_offset feature is to add a random offset after the pt_regs has been pushed to the stack and before the rest of the thread stack is used during the syscall processing, and to change it every time a process issues a syscall. The source of randomness is currently architecture-defined (but x86 is using the low byte of rdtsc()). Future improvements for different entropy sources is possible, but out of scope for this patch. Further more, to add more unpredictability, new offsets are chosen at the end of syscalls (the timing of which should be less easy to measure from userspace than at syscall entry time), and stored in a per-CPU variable, so that the life of the value does not stay explicitly tied to a single task. As suggested by Andy Lutomirski, the offset is added using alloca() and an empty asm() statement with an output constraint, since it avoids changes to assembly syscall entry code, to the unwinder, and provides correct stack alignment as defined by the compiler. In order to make this available by default with zero performance impact for those that don't want it, it is boot-time selectable with static branches. This way, if the overhead is not wanted, it can just be left turned off with no performance impact. The generated assembly for x86_64 with GCC looks like this: ... ffffffff81003977: 65 8b 05 02 ea 00 7f mov %gs:0x7f00ea02(%rip),%eax # 12380 <kstack_offset> ffffffff8100397e: 25 ff 03 00 00 and $0x3ff,%eax ffffffff81003983: 48 83 c0 0f add $0xf,%rax ffffffff81003987: 25 f8 07 00 00 and $0x7f8,%eax ffffffff8100398c: 48 29 c4 sub %rax,%rsp ffffffff8100398f: 48 8d 44 24 0f lea 0xf(%rsp),%rax ffffffff81003994: 48 83 e0 f0 and $0xfffffffffffffff0,%rax ... As a result of the above stack alignment, this patch introduces about 5 bits of randomness after pt_regs is spilled to the thread stack on x86_64, and 6 bits on x86_32 (since its has 1 fewer bit required for stack alignment). The amount of entropy could be adjusted based on how much of the stack space we wish to trade for security. My measure of syscall performance overhead (on x86_64): lmbench: /usr/lib/lmbench/bin/x86_64-linux-gnu/lat_syscall -N 10000 null randomize_kstack_offset=y Simple syscall: 0.7082 microseconds randomize_kstack_offset=n Simple syscall: 0.7016 microseconds So, roughly 0.9% overhead growth for a no-op syscall, which is very manageable. And for people that don't want this, it's off by default. There are two gotchas with using the alloca() trick. First, compilers that have Stack Clash protection (-fstack-clash-protection) enabled by default (e.g. Ubuntu[3]) add pagesize stack probes to any dynamic stack allocations. While the randomization offset is always less than a page, the resulting assembly would still contain (unreachable!) probing routines, bloating the resulting assembly. To avoid this, -fno-stack-clash-protection is unconditionally added to the kernel Makefile since this is the only dynamic stack allocation in the kernel (now that VLAs have been removed) and it is provably safe from Stack Clash style attacks. The second gotcha with alloca() is a negative interaction with -fstack-protector*, in that it sees the alloca() as an array allocation, which triggers the unconditional addition of the stack canary function pre/post-amble which slows down syscalls regardless of the static branch. In order to avoid adding this unneeded check and its associated performance impact, architectures need to carefully remove uses of -fstack-protector-strong (or -fstack-protector) in the compilation units that use the add_random_kstack() macro and to audit the resulting stack mitigation coverage (to make sure no desired coverage disappears). No change is visible for this on x86 because the stack protector is already unconditionally disabled for the compilation unit, but the change is required on arm64. There is, unfortunately, no attribute that can be used to disable stack protector for specific functions. Comparison to PaX RANDKSTACK feature: The RANDKSTACK feature randomizes the location of the stack start (cpu_current_top_of_stack), i.e. including the location of pt_regs structure itself on the stack. Initially this patch followed the same approach, but during the recent discussions[2], it has been determined to be of a little value since, if ptrace functionality is available for an attacker, they can use PTRACE_PEEKUSR/PTRACE_POKEUSR to read/write different offsets in the pt_regs struct, observe the cache behavior of the pt_regs accesses, and figure out the random stack offset. Another difference is that the random offset is stored in a per-cpu variable, rather than having it be per-thread. As a result, these implementations differ a fair bit in their implementation details and results, though obviously the intent is similar. [1] https://lore.kernel.org/kernel-hardening/2236FBA76BA1254E88B949DDB74E612BA4BC57C1@IRSMSX102.ger.corp.intel.com/ [2] https://lore.kernel.org/kernel-hardening/20190329081358.30497-1-elena.reshetova@intel.com/ [3] https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040741.html Co-developed-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210401232347.2791257-4-keescook@chromium.org
2021-04-06pata_legacy: Add `probe_mask' parameter like with ide-genericMaciej W. Rozycki
Carry the `probe_mask' parameter over from ide-generic to pata_legacy so that there is a way to prevent random poking at ISA port I/O locations in attempt to discover adapter option cards with libata like with the old IDE driver. By default all enabled locations are tried, however it may interfere with a different kind of hardware responding there. For example with a plain (E)ISA system the driver tries all the six possible locations: scsi host0: pata_legacy ata1: PATA max PIO4 cmd 0x1f0 ctl 0x3f6 irq 14 ata1.00: ATA-4: ST310211A, 3.54, max UDMA/100 ata1.00: 19541088 sectors, multi 16: LBA ata1.00: configured for PIO scsi 0:0:0:0: Direct-Access ATA ST310211A 3.54 PQ: 0 ANSI: 5 scsi 0:0:0:0: Attached scsi generic sg0 type 0 sd 0:0:0:0: [sda] 19541088 512-byte logical blocks: (10.0 GB/9.32 GiB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sda: sda1 sda2 sda3 sd 0:0:0:0: [sda] Attached SCSI disk scsi host1: pata_legacy ata2: PATA max PIO4 cmd 0x170 ctl 0x376 irq 15 scsi host1: pata_legacy ata3: PATA max PIO4 cmd 0x1e8 ctl 0x3ee irq 11 scsi host1: pata_legacy ata4: PATA max PIO4 cmd 0x168 ctl 0x36e irq 10 scsi host1: pata_legacy ata5: PATA max PIO4 cmd 0x1e0 ctl 0x3e6 irq 8 scsi host1: pata_legacy ata6: PATA max PIO4 cmd 0x160 ctl 0x366 irq 12 however giving the kernel "pata_legacy.probe_mask=21" makes it try every other location only: scsi host0: pata_legacy ata1: PATA max PIO4 cmd 0x1f0 ctl 0x3f6 irq 14 ata1.00: ATA-4: ST310211A, 3.54, max UDMA/100 ata1.00: 19541088 sectors, multi 16: LBA ata1.00: configured for PIO scsi 0:0:0:0: Direct-Access ATA ST310211A 3.54 PQ: 0 ANSI: 5 scsi 0:0:0:0: Attached scsi generic sg0 type 0 sd 0:0:0:0: [sda] 19541088 512-byte logical blocks: (10.0 GB/9.32 GiB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sda: sda1 sda2 sda3 sd 0:0:0:0: [sda] Attached SCSI disk scsi host1: pata_legacy ata2: PATA max PIO4 cmd 0x1e8 ctl 0x3ee irq 11 scsi host1: pata_legacy ata3: PATA max PIO4 cmd 0x1e0 ctl 0x3e6 irq 8 Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2103211800110.21463@angie.orcam.me.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-06pata_platform: Document `pio_mask' module parameterMaciej W. Rozycki
Add MODULE_PARM_DESC documentation and a kernel-parameters.txt entry. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2103212023190.21463@angie.orcam.me.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-06pata_legacy: Properly document module parametersMaciej W. Rozycki
Most pata_legacy module parameters lack MODULE_PARM_DESC documentation and none is described in kernel-parameters.txt. Also several comments are inaccurate or wrong. Add the missing documentation pieces then and reorder parameters into a consistent block. Remove inaccuracies as follows: - `all' affects primary and secondary port ranges only rather than all, - `probe_all' affects tertiary and further port ranges rather than all, - `ht6560b' is for HT 6560B rather than HT 6560A. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2103211909560.21463@angie.orcam.me.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-04cgroup: Miscellaneous cgroup documentation.Vipin Sharma
Documentation of miscellaneous cgroup controller. This new controller is used to track and limit the usage of scalar resources. Signed-off-by: Vipin Sharma <vipinsh@google.com> Reviewed-by: David Rientjes <rientjes@google.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2021-04-03powerpc/bpf: Implement extended BPF on PPC32Christophe Leroy
Implement Extended Berkeley Packet Filter on Powerpc 32 Test result with test_bpf module: test_bpf: Summary: 378 PASSED, 0 FAILED, [354/366 JIT'ed] Registers mapping: [BPF_REG_0] = r11-r12 /* function arguments */ [BPF_REG_1] = r3-r4 [BPF_REG_2] = r5-r6 [BPF_REG_3] = r7-r8 [BPF_REG_4] = r9-r10 [BPF_REG_5] = r21-r22 (Args 9 and 10 come in via the stack) /* non volatile registers */ [BPF_REG_6] = r23-r24 [BPF_REG_7] = r25-r26 [BPF_REG_8] = r27-r28 [BPF_REG_9] = r29-r30 /* frame pointer aka BPF_REG_10 */ [BPF_REG_FP] = r17-r18 /* eBPF jit internal registers */ [BPF_REG_AX] = r19-r20 [TMP_REG] = r31 As PPC32 doesn't have a redzone in the stack, a stack frame must always be set in order to host at least the tail count counter. The stack frame remains for tail calls, it is set by the first callee and freed by the last callee. r0 is used as temporary register as much as possible. It is referenced directly in the code in order to avoid misusing it, because some instructions interpret it as value 0 instead of register r0 (ex: addi, addis, stw, lwz, ...) The following operations are not implemented: case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */ The following operations are only implemented for power of two constants: case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/61d8b149176ddf99e7d5cef0b6dc1598583ca202.1616430991.git.christophe.leroy@csgroup.eu
2021-03-31docs: reporting-issues: Remove reference to oldnoconfigIsmael Luceno
Replace it with olddefconfig. oldnoconfig didn't do what the document suggests (it aliased to olddefconfig), and isn't available since 4.19. Ref: 04c459d20448 ("kconfig: remove oldnoconfig target") Ref: 312ee68752fa ("kconfig: announce removal of oldnoconfig if used") Signed-off-by: Ismael Luceno <ismael@iodev.co.uk> Link: https://lore.kernel.org/r/20210331163541.28356-1-ismael@iodev.co.uk Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31doc: admin-guide: remove explanation of "watchdog/%u"Wang Qing
"watchdog/%u" threads has be replaced by cpu_stop_work, which will mislead the reader. Signed-off-by: Wang Qing <wangqing@vivo.com> Link: https://lore.kernel.org/r/1615801744-31548-1-git-send-email-wangqing@vivo.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31Documentation: Add leading slash to some pathsMark O'Donovan
Change multiple sys/xyz to /sys/xyz Signed-off-by: Mark O'Donovan <shiftee@posteo.net> Link: https://lore.kernel.org/r/20210328152837.73347-1-shiftee@posteo.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31docs: reporting-issues: reduce quoting and assorted fixesThorsten Leemhuis
A pile of small fixes: - don't quote terms like vanilla, mainline, and stable, unless in they occur in places where readers new to the kernel might see them for the first time - make people rule out that vendor patches are interfering if they face a regression in a stable or longterm kernel they saw in a vendor kernel for the first time - s/bugs/issues/ in a selected spots - exchange two headlines that got mixed up somehow - add a few links to some of the steps in the guide - Greg mentioned sending reports to the stable mailing list is sufficient, so remove the "CC stable maintainers" bits - fix a few typos and mistakes in the text, with a few very small improvements along the way Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Link: https://lore.kernel.org/r/07bca15d8465b8e234537feb8841dd2ff20243bc.1617113469.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31docs: reporting-issues.rst: reshuffle and improve TLDRThorsten Leemhuis
Make the TLDR a bit shorter while improving it at the same time by going straight to the aspects readers are more interested it. The change makes the process especially more straight-forward for people that hit a regression in a stable or longterm kernel. Due to the changes the TLDR now also matches the step by step guide better. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Link: https://lore.kernel.org/r/762ccd7735315d2fdaa79612fccc1f474881118b.1617113469.git.linux@leemhuis.info [ jc: fixed transposed _` as noted by Thorsten ] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31docs: make reporting-issues.rst official and delete reporting-bugs.rstThorsten Leemhuis
Remove the WIP and two FIXME notes in the text to make it official, as it's now considered fully ready for consumption. To make sure this step is okay for people the intent of this change and the latest version of the text were posted to ksummit-discuss; nobody complained, thus lets move ahead. Add a footer to point out people can contact Thorsten directly in case they find something to improve in the text. Dear reporting-bugs.rst, I'm sorry to tell you, but that makes you fully obsolete and we thus have to let you go now. Thank you very much for your service, you in one form or another have been around for a long time. I'm sure over the years you got read a lot and helped quite a few people. But it's time to retire now. Rest in peace. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Harry Wei <harryxiyou@gmail.com> CC: Alex Shi <alex.shi@linux.alibaba.com> CC: Federico Vaga <federico.vaga@vaga.pv.it> CC: Greg KH <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/49c674c2d304d87e6259063580fda05267e8c348.1617113469.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31pstore: Add mem_type property DT parsing supportMukesh Ojha
There could be a scenario where we define some region in normal memory and use them store to logs which is later retrieved by bootloader during warm reset. In this scenario, we wanted to treat this memory as normal cacheable memory instead of default behaviour which is an overhead. Making it cacheable could improve performance. This commit gives control to change mem_type from Device tree, and also documents the value for normal memory. Signed-off-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/1616438537-13719-1-git-send-email-mojha@codeaurora.org
2021-03-30docs: perf: Address some html build warningsQi Liu
Fix following html build warnings: Documentation/admin-guide/perf/hisi-pmu.rst:61: WARNING: Unexpected indentation. Documentation/admin-guide/perf/hisi-pmu.rst:62: WARNING: Block quote ends without a blank line; unexpected unindent. Documentation/admin-guide/perf/hisi-pmu.rst:69: WARNING: Unexpected indentation. Documentation/admin-guide/perf/hisi-pmu.rst:70: WARNING: Block quote ends without a blank line; unexpected unindent. Documentation/admin-guide/perf/hisi-pmu.rst:83: WARNING: Unexpected indentation. Fixes: 9b86b1b41e0f ("docs: perf: Add new description on HiSilicon uncore PMU v2") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Qi Liu <liuqi115@huawei.com> Link: https://lore.kernel.org/r/1617021121-31450-1-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
2021-03-28Documentation/admin-guide: Change doc for split_lock_detect parameterFenghua Yu
Since #DB for bus lock detect changes the split_lock_detect parameter, update the documentation for the changes. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20210322135325.682257-4-fenghua.yu@intel.com
2021-03-26gpio: mockup: Adjust documentation to the codeAndy Shevchenko
First of all one of the parameter missed 'mockup' in its name, Second, the semantics of the integer pairs depends on the sign of the base (the first value in the pair). Update documentation to reflect the real code behaviour. Fixes: 2fd1abe99e5f ("Documentation: gpio: add documentation for gpio-mockup") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-03-25net: change netdev_unregister_timeout_secs min value to 1Dmitry Vyukov
netdev_unregister_timeout_secs=0 can lead to printing the "waiting for dev to become free" message every jiffy. This is too frequent and unnecessary. Set the min value to 1 second. Also fix the merge issue introduced by "net: make unregister netdev warning timeout configurable": it changed "refcnt != 1" to "refcnt". Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Suggested-by: Eric Dumazet <edumazet@google.com> Fixes: 5aa3afe107d9 ("net: make unregister netdev warning timeout configurable") Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-25xfs: rename the blockgc workqueueDarrick J. Wong
Since we're about to start using the blockgc workqueue to dispose of inactivated inodes, strip the "block" prefix from the name; now it's merely the general garbage collection (gc) workqueue. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2021-03-25docs: reporting-issues.rst: improved process esp. for stable regressionsThorsten Leemhuis
Provide a shorter and easier process for users that deal with regressions in stable and longterm kernels, as those should be reported quickly. To realize this in the least-confusing way and without having steps multiple times in different places, split the 'search for existing reports' into two. That has the additinal benefit that users will search for them quickly when going through the step by step guide and thus will save them trouble if the find reports. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> CC: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/d934c15e536bceeff5c40a126930ddf803548e08.1616181657.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25docs: reporting-issues.rst: duplicate sections for reviewing purposesThorsten Leemhuis
This duplicates two section to make the diff in the next patch a bit easier to gasp for humans. Straight copy, no content changes. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Link: https://lore.kernel.org/r/ef85edc8466f035eb243dd6629429ad4fd0565d8.1616181657.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25docs: reporting-issues.rst: reorder some stepsThorsten Leemhuis
Reorder some steps where the order in which the readers perform them is not crucial. This is a preparation for a later change that would make the text much more complex otherwise. Content just moved, not changed at all in the process. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Link: https://lore.kernel.org/r/8dfc58efde25a05ccf9bf85929826c4b1b9e09c5.1616181657.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25docs: reporting-issues.rst: tone down 'test vanilla mainline' a littleThorsten Leemhuis
Tell users that reporting bugs with vendor kernels which are only slightly patched can be okay in some situations, but point out there's a risk in doing so. Adjust some related sections to make them compatible and a bit clearer. At the same time make them less daunting: we want users to report bugs, even if they can't test vanilla mainline kernel. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> CC: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/652ee20eb36228f5d7ca842299faa4cb472feedb.1616181657.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25docs: reporting-issues.rst: fix small typos and style issuesThorsten Leemhuis
Fix a typo and change "head over" to "scroll down", as suggested by Jon when reviewing another patch that used the phrase the same way. Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Link: https://lore.kernel.org/r/fb845d2f1db6138337203bbfac419c04b5f28053.1616181657.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25docs: perf: Add new description on HiSilicon uncore PMU v2Shaokun Zhang
Some news functions are added on HiSilicon uncore PMUs. Document them to provide guidance on how to use them. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: John Garry <john.garry@huawei.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: John Garry <john.garry@huawei.com> Co-developed-by: Qi Liu <liuqi115@huawei.com> Signed-off-by: Qi Liu <liuqi115@huawei.com> Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Link: https://lore.kernel.org/r/1615186237-22263-10-git-send-email-zhangshaokun@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>
2021-03-24Merge branches 'bitmaprange.2021.03.08a', 'fixes.2021.03.15a', ↵Paul E. McKenney
'kvfree_rcu.2021.03.08a', 'mmdumpobj.2021.03.08a', 'nocb.2021.03.15a', 'poll.2021.03.24a', 'rt.2021.03.08a', 'tasks.2021.03.08a', 'torture.2021.03.08a' and 'torturescript.2021.03.22a' into HEAD bitmaprange.2021.03.08a: Allow 3-N for bitmap ranges. fixes.2021.03.15a: Miscellaneous fixes. kvfree_rcu.2021.03.08a: kvfree_rcu() updates. mmdumpobj.2021.03.08a: mem_dump_obj() updates. nocb.2021.03.15a: RCU NOCB CPU updates, including limited deoffloading. poll.2021.03.24a: Polling grace-period interfaces for RCU. rt.2021.03.08a: Realtime-related RCU changes. tasks.2021.03.08a: Tasks-RCU updates. torture.2021.03.08a: Torture-test updates. torturescript.2021.03.22a: Torture-test scripting updates.
2021-03-23net: make unregister netdev warning timeout configurableDmitry Vyukov
netdev_wait_allrefs() issues a warning if refcount does not drop to 0 after 10 seconds. While 10 second wait generally should not happen under normal workload in normal environment, it seems to fire falsely very often during fuzzing and/or in qemu emulation (~10x slower). At least it's not possible to understand if it's really a false positive or not. Automated testing generally bumps all timeouts to very high values to avoid flake failures. Add net.core.netdev_unregister_timeout_secs sysctl to make the timeout configurable for automated testing systems. Lowering the timeout may also be useful for e.g. manual bisection. The default value matches the current behavior. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=211877 Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-21platform/x86: thinkpad_acpi: sysfs interface to get wwan antenna typeNitin Joshi
On some newer Thinkpads we need to set SAR value based on antenna type. This patch provides a sysfs interface that userspace can use to get antenna type and set corresponding SAR value, as is required for FCC certification. Reviewed-by: Mark Pearson <markpearson@lenovo.com> Signed-off-by: Nitin Joshi <njoshi1@lenovo.com> Link: https://lore.kernel.org/r/20210317024636.356175-1-njoshi1@lenovo.com Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2021-03-18iommu/dma: Resurrect the "forcedac" optionRobin Murphy
In converting intel-iommu over to the common IOMMU DMA ops, it quietly lost the functionality of its "forcedac" option. Since this is a handy thing both for testing and for performance optimisation on certain platforms, reimplement it under the common IOMMU parameter namespace. For the sake of fixing the inadvertent breakage of the Intel-specific parameter, remove the dmar_forcedac remnants and hook it up as an alias while documenting the transition to the new common parameter. Fixes: c588072bba6b ("iommu/vt-d: Convert intel iommu driver to the iommu ops") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/7eece8e0ea7bfbe2cd0e30789e0d46df573af9b0.1614961776.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-15Documentation: sysrq: update description about sysrq crashGao Xiang
After commit 8341f2f222d7 ("sysrq: Use panic() to force a crash"), a crash was not generated by dereferencing a NULL pointer anymore. Let's update documentation as well to make it less misleading. Signed-off-by: Gao Xiang <hsiangkao@redhat.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Zefan Li <lizefan.x@bytedance.com> Link: https://lore.kernel.org/r/20210309191550.3955601-1-hsiangkao@redhat.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-15security/loadpin: Update the changing interface in the source code.Jiele zhao
Loadpin cmdline interface "enabled" has been renamed to "enforce" for a long time, but the User Description Document was not updated. (Meaning unchanged) And kernel_read_file* were moved from linux/fs.h to its own linux/kernel_read_file.h include file. So update that change here. Signed-off-by: Jiele zhao <unclexiaole@gmail.com> Link: https://lore.kernel.org/r/20210308020358.102836-1-unclexiaole@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-15docs: admin-guide: cgroup-v1: Fix typos in the file memory.rstBhaskar Chowdhury
s/overcommited/overcommitted/ s/Overcommiting/Overcommitting/ Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20210313061029.28024-1-unixbhaskar@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-10tty: isicom, remove this orphanJiri Slaby
The Isicom driver was orphaned by commit d86b3001a1a6 (MAINTAINERS: orphan isicom) 10 years ago. Noone stepped up to take care of them and to fix all the issues the driver has. So it's time to drop the driver with all its traces. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10tty: cyclades, remove this orphanJiri Slaby
The Cyclades driver was orphaned by commit d459883e6c54 (MAINTAINERS: remove two dead e-mail) 13 years ago. Noone stepped up to take care of them and to fix all the issues the driver has. On the top of that, there is no way to obtain the firmware for Z cards from the vendor as cyclades.com ceased to exist. So it's time to drop the driver with all its traces. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-09riscv: Add support for memtestKefeng Wang
The riscv [rv32_]defconfig enabled CONFIG_MEMTEST, but memtest feature is not supported in RISCV. Add early_memtest() to support for memtest. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-08Documentation/admin-guide: kernel-parameters: correct the architectures for ↵Barry Song
numa_balancing X86 isn't the only architecture supporting NUMA_BALANCING. ARM64, PPC, S390 and RISCV also support it: arch$ git grep NUMA_BALANCING arm64/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING arm64/configs/defconfig:CONFIG_NUMA_BALANCING=y arm64/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/configs/powernv_defconfig:CONFIG_NUMA_BALANCING=y powerpc/configs/ppc64_defconfig:CONFIG_NUMA_BALANCING=y powerpc/configs/pseries_defconfig:CONFIG_NUMA_BALANCING=y powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/book3s/64/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/book3s/64/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ powerpc/include/asm/nohash/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/nohash/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ powerpc/platforms/Kconfig.cputype: select ARCH_SUPPORTS_NUMA_BALANCING riscv/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING riscv/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING s390/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING s390/configs/debug_defconfig:CONFIG_NUMA_BALANCING=y s390/configs/defconfig:CONFIG_NUMA_BALANCING=y s390/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING x86/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 x86/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING x86/include/asm/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ On the other hand, setup_numabalancing() is implemented in mm/mempolicy.c which doesn't depend on architectures. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210302084159.33688-1-song.bao.hua@hisilicon.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-08Documentation: dynamic-debug-howto: fix exampleMartin Kepplinger
dynamic debug is "expecting pairs of match-spec <value>" so the example for all files of which the paths include "usb" there is "file" missing. Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm> Link: https://lore.kernel.org/r/20210303091646.773111-1-martin.kepplinger@puri.sm Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-08rcuscale: Add kfree_rcu() single-argument scale testUladzislau Rezki (Sony)
The single-argument variant of kfree_rcu() is currently not tested by any member of the rcutoture test suite. This commit therefore adds rcuscale code to test it. This testing is controlled by two new boolean module parameters, kfree_rcu_test_single and kfree_rcu_test_double. If one is set and the other not, only the corresponding variant is tested, otherwise both are tested, with the variant to be tested determined randomly on each invocation. Both of these module parameters are initialized to false, so setting either to true will test only that variant. Suggested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08rcu: deprecate "all" option to rcu_nocbs=Paul Gortmaker
With the core bitmap support now accepting "N" as a placeholder for the end of the bitmap, "all" can be represented as "0-N" and has the advantage of not being specific to RCU (or any other subsystem). So deprecate the use of "all" by removing documentation references to it. The support itself needs to remain for now, since we don't know how many people out there are using it currently, but since it is in an __init area anyway, it isn't worth losing sleep over. Cc: Yury Norov <yury.norov@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Acked-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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