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2020-11-30arm64: mark idle code as noinstrMark Rutland1-4/+4
Core code disables RCU when calling arch_cpu_idle(), so it's not safe for arch_cpu_idle() or its calees to be instrumented, as the instrumentation callbacks may attempt to use RCU or other features which are unsafe to use in this context. Mark them noinstr to prevent issues. The use of local_irq_enable() in arch_cpu_idle() is similarly problematic, and the "sched/idle: Fix arch_cpu_idle() vs tracing" patch queued in the tip tree addresses that case. Reported-by: Marco Elver <elver@google.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201130115950.22492-3-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-11-30arm64: syscall: exit userspace before unmasking exceptionsMark Rutland1-1/+1
In el0_svc_common() we unmask exceptions before we call user_exit(), and so there's a window where an IRQ or debug exception can be taken while RCU is not watching. In do_debug_exception() we account for this in via debug_exception_{enter,exit}(), but in the el1_irq asm we do not and we call trace functions which rely on RCU before we have a guarantee that RCU is watching. Let's avoid this by having el0_svc_common() exit userspace before unmasking exceptions, matching what we do for all other EL0 entry paths. We can use user_exit_irqoff() to avoid the pointless save/restore of IRQ flags while we're sure exceptions are masked in DAIF. The workaround for Cortex-A76 erratum 1463225 may trigger a debug exception before this point, but the debug code invoked in this case is safe even when RCU is not watching. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201130115950.22492-2-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-11-29Merge tag 'locking-urgent-2020-11-29' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "Two more places which invoke tracing from RCU disabled regions in the idle path. Similar to the entry path the low level idle functions have to be non-instrumentable" * tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: intel_idle: Fix intel_idle() vs tracing sched/idle: Fix arch_cpu_idle() vs tracing
2020-11-28arm64: Make the Meltdown mitigation state availableMarc Zyngier1-3/+17
Our Meltdown mitigation state isn't exposed outside of cpufeature.c, contrary to the rest of the Spectre mitigation state. As we are going to use it in KVM, expose a arm64_get_meltdown_state() helper which returns the same possible values as arm64_get_spectre_v?_state(). Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-27arm64: vmlinux.lds.S: Drop redundant *.init.rodata.*Youling Tang1-1/+1
We currently try to emit *.init.rodata.* twice, once in INIT_DATA, and once in the line immediately following it. As the two section definitions are identical, the latter is redundant and can be dropped. This patch drops the redundant *.init.rodata.* section definition. Signed-off-by: Youling Tang <tangyouling@loongson.cn> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/1605750340-910-1-git-send-email-tangyouling@loongson.cn Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-27arm64: Extend the kernel command line from the bootloaderTyler Hicks1-1/+8
Provide support for additional kernel command line parameters to be concatenated onto the end of the command line provided by the bootloader. Additional parameters are specified in the CONFIG_CMDLINE option when CONFIG_CMDLINE_EXTEND is selected, matching other architectures and leveraging existing support in the FDT and EFI stub code. Special care must be taken for the arch-specific nokaslr parsing. Search the bootargs FDT property and the CONFIG_CMDLINE when CONFIG_CMDLINE_EXTEND is in use. There are a couple of known use cases for this feature: 1) Switching between stable and development kernel versions, where one of the versions benefits from additional command line parameters, such as debugging options. 2) Specifying additional command line parameters, for additional tuning or debugging, when the bootloader does not offer an interactive mode. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Link: https://lore.kernel.org/r/20200921191557.350256-3-tyhicks@linux.microsoft.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-27arm64: kaslr: Refactor early init command line parsingTyler Hicks1-8/+11
Don't ask for *the* command line string to search for "nokaslr" in kaslr_early_init(). Instead, tell a helper function to search all the appropriate command line strings for "nokaslr" and return the result. This paves the way for searching multiple command line strings without having to concatenate the strings in early init. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Link: https://lore.kernel.org/r/20200921191557.350256-2-tyhicks@linux.microsoft.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-27Merge branch 'kvm-arm64/vector-rework' into kvmarm-master/nextMarc Zyngier2-64/+39
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-27Merge branch 'kvm-arm64/host-hvc-table' into kvmarm-master/nextMarc Zyngier1-3/+2
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-27KVM: arm64: Patch kimage_voffset instead of loading the EL1 valueMarc Zyngier1-3/+1
Directly using the kimage_voffset variable is fine for now, but will become more problematic as we start distrusting EL1. Instead, patch the kimage_voffset into the HYP text, ensuring we don't have to load an untrusted value later on. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-27Merge branch 'linus' into sched/core, to resolve semantic conflictIngo Molnar16-85/+104
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-11-25arm64: Enable perf events based hard lockup detectorSumit Garg1-2/+39
With the recent feature added to enable perf events to use pseudo NMIs as interrupts on platforms which support GICv3 or later, its now been possible to enable hard lockup detector (or NMI watchdog) on arm64 platforms. So enable corresponding support. One thing to note here is that normally lockup detector is initialized just after the early initcalls but PMU on arm64 comes up much later as device_initcall(). So we need to re-initialize lockup detection once PMU has been initialized. Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Acked-by: Alexandru Elisei <alexandru.elisei@arm.com> Link: https://lore.kernel.org/r/1602060704-10921-1-git-send-email-sumit.garg@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-24sched/idle: Fix arch_cpu_idle() vs tracingPeter Zijlstra1-1/+1
We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-23arm64: expose FAR_EL1 tag bits in siginfoPeter Collingbourne5-27/+21
The kernel currently clears the tag bits (i.e. bits 56-63) in the fault address exposed via siginfo.si_addr and sigcontext.fault_address. However, the tag bits may be needed by tools in order to accurately diagnose memory errors, such as HWASan [1] or future tools based on the Memory Tagging Extension (MTE). Expose these bits via the arch_untagged_si_addr mechanism, so that they are only exposed to signal handlers with the SA_EXPOSE_TAGBITS flag set. [1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://linux-review.googlesource.com/id/Ia8876bad8c798e0a32df7c2ce1256c4771c81446 Link: https://lore.kernel.org/r/0010296597784267472fa13b39f8238d87a72cf8.1605904350.git.pcc@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-19arm64: Rebuild sched domains on invariance status changesIonela Voinescu1-0/+10
Task scheduler behavior depends on frequency invariance (FI) support and the resulting invariant load tracking signals. For example, in order to make accurate predictions across CPUs for all performance states, Energy Aware Scheduling (EAS) needs frequency-invariant load tracking signals and therefore it has a direct dependency on FI. This dependency is known, but EAS enablement is not yet conditioned on the presence of FI during the built of the scheduling domain hierarchy. Before this is done, the following must be considered: while arch_scale_freq_invariant() will see changes in FI support and could be used to condition the use of EAS, it could return different values during system initialisation. For arm64, such a scenario will happen for a system that does not support cpufreq driven FI, but does support counter-driven FI. For such a system, arch_scale_freq_invariant() will return false if called before counter based FI initialisation, but change its status to true after it. If EAS becomes explicitly dependent on FI this would affect the task scheduler behavior which builds its scheduling domain hierarchy well before the late counter-based FI init. During that process, EAS would be disabled due to its dependency on FI. Two points of future early calls to arch_scale_freq_invariant() which would determine EAS enablement are: - (1) drivers/base/arch_topology.c:126 <<update_topology_flags_workfn>> rebuild_sched_domains(); This will happen after CPU capacity initialisation. - (2) kernel/sched/cpufreq_schedutil.c:917 <<rebuild_sd_workfn>> rebuild_sched_domains_energy(); -->rebuild_sched_domains(); This will happen during sched_cpufreq_governor_change() for the schedutil cpufreq governor. Therefore, before enforcing the presence of FI support for the use of EAS, ensure the following: if there is a change in FI support status after counter init, use the existing rebuild_sched_domains_energy() function to trigger a rebuild of the scheduling and performance domains that in turn will determine the enablement of EAS. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lkml.kernel.org/r/20201027180713.7642-3-ionela.voinescu@arm.com
2020-11-18arm64: mte: optimize asynchronous tag check fault flag checkPeter Collingbourne1-1/+1
We don't need to check for MTE support before checking the flag because it can only be set if the hardware supports MTE. As a result we can unconditionally check the flag bit which is expected to be in a register and therefore the check can be done in a single instruction instead of first needing to load the hwcaps. On a DragonBoard 845c with a kernel built with CONFIG_ARM64_MTE=y with the powersave governor this reduces the cost of a kernel entry/exit (invalid syscall) from 465.1ns to 463.8ns. Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/If4dc3501fd4e4f287322f17805509613cfe47d24 Link: https://lore.kernel.org/r/20201118032051.1405907-1-pcc@google.com [catalin.marinas@arm.com: remove IS_ENABLED(CONFIG_ARM64_MTE)] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-17arm64: head: tidy up the Image header definitionArd Biesheuvel2-27/+35
Even though support for EFI boot remains entirely optional for arm64, it is unlikely that we will ever be able to repurpose the image header fields that the EFI loader relies on, i.e., the magic NOP at offset 0x0 and the PE header address at offset 0x3c. So let's factor out the differences into a 'efi_signature_nop' macro and a local symbol representing the PE header address, and move the conditional definitions into efi-header.S, taking into account whether CONFIG_EFI is enabled or not. While at it, switch to a signature NOP that behaves more like a NOP, i.e., one that only clobbers the flags. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201117124729.12642-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-17arm64/head: avoid symbol names pointing into first 64 KB of kernel imageArd Biesheuvel1-24/+22
We no longer map the first 64 KB of the kernel image, as there is nothing there that we ever need to refer back to once the kernel has booted. Even though facilities like kallsyms are very careful to only refer to the region that starts at _stext when mapping virtual addresses to symbol names, let's avoid any confusion by switching to local .L prefixed symbol names for the EFI header, as none of them have any significance to the rest of the kernel. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201117124729.12642-3-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-17arm64: omit [_text, _stext) from permanent kernel mappingArd Biesheuvel3-10/+3
In a previous patch, we increased the size of the EFI PE/COFF header to 64 KB, which resulted in the _stext symbol to appear at a fixed offset of 64 KB into the image. Since 64 KB is also the largest page size we support, this completely removes the need to map the first 64 KB of the kernel image, given that it only contains the arm64 Image header and the EFI header, neither of which we ever access again after booting the kernel. More importantly, we should avoid an executable mapping of non-executable and not entirely predictable data, to deal with the unlikely event that we inadvertently emitted something that looks like an opcode that could be used as a gadget for speculative execution. So let's limit the kernel mapping of .text to the [_stext, _etext) region, which matches the view of generic code (such as kallsyms) when it reasons about the boundaries of the kernel's .text section. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201117124729.12642-2-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-16arm64: spectre: Consolidate spectre-v3a detectionWill Deacon2-11/+14
The spectre-v3a mitigation is split between cpu_errata.c and spectre.c, with the former handling detection of the problem and the latter handling enabling of the workaround. Move the detection logic alongside the enabling logic, like we do for the other spectre mitigations. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20201113113847.21619-10-will@kernel.org
2020-11-16arm64: spectre: Rename ARM64_HARDEN_EL2_VECTORS to ARM64_SPECTRE_V3AWill Deacon2-6/+13
Since ARM64_HARDEN_EL2_VECTORS is really a mitigation for Spectre-v3a, rename it accordingly for consistency with the v2 and v4 mitigation. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20201113113847.21619-9-will@kernel.org
2020-11-16KVM: arm64: Allocate hyp vectors staticallyWill Deacon2-50/+15
The EL2 vectors installed when a guest is running point at one of the following configurations for a given CPU: - Straight at __kvm_hyp_vector - A trampoline containing an SMC sequence to mitigate Spectre-v2 and then a direct branch to __kvm_hyp_vector - A dynamically-allocated trampoline which has an indirect branch to __kvm_hyp_vector - A dynamically-allocated trampoline containing an SMC sequence to mitigate Spectre-v2 and then an indirect branch to __kvm_hyp_vector The indirect branches mean that VA randomization at EL2 isn't trivially bypassable using Spectre-v3a (where the vector base is readable by the guest). Rather than populate these vectors dynamically, configure everything statically and use an enumerated type to identify the vector "slot" corresponding to one of the configurations above. This both simplifies the code, but also makes it much easier to implement at EL2 later on. Signed-off-by: Will Deacon <will@kernel.org> [maz: fixed double call to kvm_init_vector_slots() on nVHE] Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20201113113847.21619-8-will@kernel.org
2020-11-15Merge tag 'perf-urgent-2020-11-15' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A set of fixes for perf: - A set of commits which reduce the stack usage of various perf event handling functions which allocated large data structs on stack causing stack overflows in the worst case - Use the proper mechanism for detecting soft interrupts in the recursion protection - Make the resursion protection simpler and more robust - Simplify the scheduling of event groups to make the code more robust and prepare for fixing the issues vs. scheduling of exclusive event groups - Prevent event multiplexing and rotation for exclusive event groups - Correct the perf event attribute exclusive semantics to take pinned events, e.g. the PMU watchdog, into account - Make the anythread filtering conditional for Intel's generic PMU counters as it is not longer guaranteed to be supported on newer CPUs. Check the corresponding CPUID leaf to make sure - Fixup a duplicate initialization in an array which was probably caused by the usual 'copy & paste - forgot to edit' mishap" * tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Fix Add BW copypasta perf/x86/intel: Make anythread filter support conditional perf: Tweak perf_event_attr::exclusive semantics perf: Fix event multiplexing for exclusive groups perf: Simplify group_sched_in() perf: Simplify group_sched_out() perf/x86: Make dummy_iregs static perf/arch: Remove perf_sample_data::regs_user_copy perf: Optimize get_recursion_context() perf: Fix get_recursion_context() perf/x86: Reduce stack usage for x86_pmu::drain_pebs() perf: Reduce stack usage of perf_output_begin()
2020-11-13arm64: abort counter_read_on_cpu() when irqs_disabled()Ionela Voinescu1-0/+7
Given that smp_call_function_single() can deadlock when interrupts are disabled, abort the SMP call if irqs_disabled(). This scenario is currently not possible given the function's uses, but safeguard this for potential future uses. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Cc: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20201113155328.4194-1-ionela.voinescu@arm.com [catalin.marinas@arm.com: modified following Mark's comment] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-13arm64: implement CPPC FFH support using AMUsIonela Voinescu2-0/+74
If Activity Monitors (AMUs) are present, two of the counters can be used to implement support for CPPC's (Collaborative Processor Performance Control) delivered and reference performance monitoring functionality using FFH (Functional Fixed Hardware). Given that counters for a certain CPU can only be read from that CPU, while FFH operations can be called from any CPU for any of the CPUs, use smp_call_function_single() to provide the requested values. Therefore, depending on the register addresses, the following values are returned: - 0x0 (DeliveredPerformanceCounterRegister): AMU core counter - 0x1 (ReferencePerformanceCounterRegister): AMU constant counter The use of Activity Monitors is hidden behind the generic cpu_read_{corecnt,constcnt}() functions. Read functionality for these two registers represents the only current FFH support for CPPC. Read operations for other register values or write operation for all registers are unsupported. Therefore, keep CPPC's FFH unsupported if no CPUs have valid AMU frequency counters. For this purpose, the get_cpu_with_amu_feat() is introduced. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201106125334.21570-4-ionela.voinescu@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-13arm64: split counter validation functionIonela Voinescu1-18/+26
In order for the counter validation function to be reused, split validate_cpu_freq_invariance_counters() into: - freq_counters_valid(cpu) - check cpu for valid cycle counters - freq_inv_set_max_ratio(int cpu, u64 max_rate, u64 ref_rate) - generic function that sets the normalization ratio used by topology_scale_freq_tick() Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201106125334.21570-3-ionela.voinescu@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-13arm64: wrap and generalise counter read functionsIonela Voinescu2-13/+15
In preparation for other uses of Activity Monitors (AMU) cycle counters, place counter read functionality in generic functions that can reused: read_corecnt() and read_constcnt(). As a result, implement update_freq_counters_refs() to replace init_cpu_freq_invariance_counters() and both initialise and update the per-cpu reference variables. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201106125334.21570-2-ionela.voinescu@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-13Merge tag 'arm64-fixes' of ↵Linus Torvalds7-8/+10
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: - Spectre/Meltdown safelisting for some Qualcomm KRYO cores - Fix RCU splat when failing to online a CPU due to a feature mismatch - Fix a recently introduced sparse warning in kexec() - Fix handling of CPU erratum 1418040 for late CPUs - Ensure hot-added memory falls within linear-mapped region * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX Silver arm64: proton-pack: Add KRYO2XX silver CPUs to spectre-v2 safe-list arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelist arm64: Add MIDR value for KRYO2XX gold/silver CPU cores arm64/mm: Validate hotplug range before creating linear mapping arm64: smp: Tell RCU about CPUs that fail to come online arm64: psci: Avoid printing in cpu_psci_cpu_die() arm64: kexec_file: Fix sparse warning arm64: errata: Fix handling of 1418040 with late CPU onlining
2020-11-13arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX SilverKonrad Dybcio1-0/+2
QCOM KRYO2XX Silver cores are Cortex-A53 based and are susceptible to the 845719 erratum. Add them to the lookup list to apply the erratum. Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org> Link: https://lore.kernel.org/r/20201104232218.198800-5-konrad.dybcio@somainline.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-13arm64: proton-pack: Add KRYO2XX silver CPUs to spectre-v2 safe-listKonrad Dybcio1-0/+1
KRYO2XX silver (LITTLE) CPUs are based on Cortex-A53 and they are not affected by spectre-v2. Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org> Link: https://lore.kernel.org/r/20201104232218.198800-4-konrad.dybcio@somainline.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-13arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelistKonrad Dybcio1-0/+2
QCOM KRYO2XX gold (big) silver (LITTLE) CPU cores are based on Cortex-A73 and Cortex-A53 respectively and are meltdown safe, hence add them to kpti_safe_list[]. Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org> Link: https://lore.kernel.org/r/20201104232218.198800-3-konrad.dybcio@somainline.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64/smp: Drop the macro S(x,s)Anshuman Khandual1-8/+7
Mapping between IPI type index and its string is direct without requiring an additional offset. Hence the existing macro S(x, s) is now redundant and can just be dropped. This also makes the code clean and simple. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/1604921916-23368-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-10arm64: consistently use reserved_pg_dirMark Rutland3-8/+8
Depending on configuration options and specific code paths, we either use the empty_zero_page or the configuration-dependent reserved_ttbr0 as a reserved value for TTBR{0,1}_EL1. To simplify this code, let's always allocate and use the same reserved_pg_dir, replacing reserved_ttbr0. Note that this is allocated (and hence pre-zeroed), and is also marked as read-only in the kernel Image mapping. Keeping this separate from the empty_zero_page potentially helps with robustness as the empty_zero_page is used in a number of cases where a failure to map it read-only could allow it to become corrupted. The (presently unused) swapper_pg_end symbol is also removed, and comments are added wherever we rely on the offsets between the pre-allocated pg_dirs to keep these cases easily identifiable. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201103102229.8542-1-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-10arm64: kprobes: Remove redundant kprobe_step_ctxMasami Hiramatsu1-41/+12
The kprobe_step_ctx (kcb->ss_ctx) has ss_pending and match_addr, but those are redundant because those can be replaced by KPROBE_HIT_SS and &cur_kprobe->ainsn.api.insn[1] respectively. To simplify the code, remove the kprobe_step_ctx. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201103134900.337243-2-jean-philippe@linaro.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-11-10arm64: smp: Tell RCU about CPUs that fail to come onlineWill Deacon1-0/+1
Commit ce3d31ad3cac ("arm64/smp: Move rcu_cpu_starting() earlier") ensured that RCU is informed early about incoming CPUs that might end up calling into printk() before they are online. However, if such a CPU fails the early CPU feature compatibility checks in check_local_cpu_capabilities(), then it will be powered off or parked without informing RCU, leading to an endless stream of stalls: | rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: | rcu: 2-O...: (0 ticks this GP) idle=002/1/0x4000000000000000 softirq=0/0 fqs=2593 | (detected by 0, t=5252 jiffies, g=9317, q=136) | Task dump for CPU 2: | task:swapper/2 state:R running task stack: 0 pid: 0 ppid: 1 flags:0x00000028 | Call trace: | ret_from_fork+0x0/0x30 Ensure that the dying CPU invokes rcu_report_dead() prior to being powered off or parked. Cc: Qian Cai <cai@redhat.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Suggested-by: Qian Cai <cai@redhat.com> Link: https://lore.kernel.org/r/20201105222242.GA8842@willie-the-truck Link: https://lore.kernel.org/r/20201106103602.9849-3-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64: psci: Avoid printing in cpu_psci_cpu_die()Will Deacon1-4/+1
cpu_psci_cpu_die() is called in the context of the dying CPU, which will no longer be online or tracked by RCU. It is therefore not generally safe to call printk() if the PSCI "cpu off" request fails, so remove the pr_crit() invocation. Cc: Qian Cai <cai@redhat.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20201106103602.9849-2-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64: kexec_file: Fix sparse warningWill Deacon1-1/+1
Sparse gets cross about us returning 0 from image_load(), which has a return type of 'void *': >> arch/arm64/kernel/kexec_image.c:130:16: sparse: sparse: Using plain integer as NULL pointer Return NULL instead, as we don't use the return value for anything if it does not indicate an error. Cc: Benjamin Gwin <bgwin@google.com> Reported-by: kernel test robot <lkp@intel.com> Fixes: 108aa503657e ("arm64: kexec_file: try more regions if loading segments fails") Link: https://lore.kernel.org/r/202011091736.T0zH8kaC-lkp@intel.com Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64: errata: Fix handling of 1418040 with late CPU onliningWill Deacon1-3/+2
In a surprising turn of events, it transpires that CPU capabilities configured as ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE are never set as the result of late-onlining. Therefore our handling of erratum 1418040 does not get activated if it is not required by any of the boot CPUs, even though we allow late-onlining of an affected CPU. In order to get things working again, replace the cpus_have_const_cap() invocation with an explicit check for the current CPU using this_cpu_has_cap(). Cc: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201106114952.10032-1-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=yWill Deacon3-3/+3
When building with LTO, there is an increased risk of the compiler converting an address dependency headed by a READ_ONCE() invocation into a control dependency and consequently allowing for harmful reordering by the CPU. Ensure that such transformations are harmless by overriding the generic READ_ONCE() definition with one that provides acquire semantics when building with LTO. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64: alternatives: Remove READ_ONCE() usage during patch operationWill Deacon1-3/+4
In preparation for patching the internals of READ_ONCE() itself, replace its usage on the alternatives patching patch with a volatile variable instead. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64: cpufeatures: Add capability for LDAPR instructionWill Deacon1-0/+10
Armv8.3 introduced the LDAPR instruction, which provides weaker memory ordering semantics than LDARi (RCpc vs RCsc). Generally, we provide an RCsc implementation when implementing the Linux memory model, but LDAPR can be used as a useful alternative to dependency ordering, particularly when the compiler is capable of breaking the dependencies. Since LDAPR is not available on all CPUs, add a cpufeature to detect it at runtime and allow the instruction to be used with alternative code patching. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10arm64: alternatives: Split up alternative.hWill Deacon1-0/+1
asm/alternative.h contains both the macros needed to use alternatives, as well the type definitions and function prototypes for applying them. Split the header in two, so that alternatives can be used from core header files such as linux/compiler.h without the risk of circular includes Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-11-09perf/arch: Remove perf_sample_data::regs_user_copyPeter Zijlstra1-2/+1
struct perf_sample_data lives on-stack, we should be careful about it's size. Furthermore, the pt_regs copy in there is only because x86_64 is a trainwreck, solve it differently. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Steven Rostedt <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
2020-11-09KVM: arm64: Turn host HVC handling into a dispatch tableMarc Zyngier1-0/+1
Now that we can use function pointer, use a dispatch table to call the individual HVC handlers, leading to more maintainable code. Further improvements include helpers to declare the mapping of local variables to values passed in the host context. Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-09arm64: add support for TIF_NOTIFY_SIGNALJens Axboe1-1/+1
Wire up TIF_NOTIFY_SIGNAL handling for arm64. Cc: linux-arm-kernel@lists.infradead.org Acked-by: Will Deacon <will@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-06Merge tag 'arm64-fixes' of ↵Linus Torvalds3-57/+62
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "Here's the weekly batch of fixes for arm64. Not an awful lot here, but there are still a few unresolved issues relating to CPU hotplug, RCU and IRQ tracing that I hope to queue fixes for next week. Summary: - Fix early use of kprobes - Fix kernel placement in kexec_file_load() - Bump maximum number of NUMA nodes" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kexec_file: try more regions if loading segments fails arm64: kprobes: Use BRK instead of single-step when executing instructions out-of-line arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4
2020-11-06arm64: kexec_file: try more regions if loading segments failsBenjamin Gwin2-11/+39
It's possible that the first region picked for the new kernel will make it impossible to fit the other segments in the required 32GB window, especially if we have a very large initrd. Instead of giving up, we can keep testing other regions for the kernel until we find one that works. Suggested-by: Ryan O'Leary <ryanoleary@google.com> Signed-off-by: Benjamin Gwin <bgwin@google.com> Link: https://lore.kernel.org/r/20201103201106.2397844-1-bgwin@google.com Signed-off-by: Will Deacon <will@kernel.org>
2020-11-03arm64: kprobes: Use BRK instead of single-step when executing instructions ↵Jean-Philippe Brucker1-46/+23
out-of-line Commit 36dadef23fcc ("kprobes: Init kprobes in early_initcall") enabled using kprobes from early_initcall. Unfortunately at this point the hardware debug infrastructure is not operational. The OS lock may still be locked, and the hardware watchpoints may have unknown values when kprobe enables debug monitors to single-step instructions. Rather than using hardware single-step, append a BRK instruction after the instruction to be executed out-of-line. Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall") Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20201103134900.337243-1-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-11-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-1/+0
Pull kvm fixes from Paolo Bonzini: "ARM: - selftest fix - force PTE mapping on device pages provided via VFIO - fix detection of cacheable mapping at S2 - fallback to PMD/PTE mappings for composite huge pages - fix accounting of Stage-2 PGD allocation - fix AArch32 handling of some of the debug registers - simplify host HYP entry - fix stray pointer conversion on nVHE TLB invalidation - fix initialization of the nVHE code - simplify handling of capabilities exposed to HYP - nuke VCPUs caught using a forbidden AArch32 EL0 x86: - new nested virtualization selftest - miscellaneous fixes - make W=1 fixes - reserve new CPUID bit in the KVM leaves" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: vmx: remove unused variable KVM: selftests: Don't require THP to run tests KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work again KVM: selftests: test behavior of unmapped L2 APIC-access address KVM: x86: Fix NULL dereference at kvm_msr_ignored_check() KVM: x86: replace static const variables with macros KVM: arm64: Handle Asymmetric AArch32 systems arm64: cpufeature: upgrade hyp caps to final arm64: cpufeature: reorder cpus_have_{const, final}_cap() KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code() KVM: arm64: Force PTE mapping on fault resulting in a device mapping KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes KVM: arm64: Fix masks in stage2_pte_cacheable() KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR KVM: arm64: Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation KVM: arm64: Don't corrupt tpidr_el2 on failed HVC call x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_ID
2020-10-30Merge tag 'kvmarm-fixes-5.10-1' of ↵Paolo Bonzini1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.10, take #1 - Force PTE mapping on device pages provided via VFIO - Fix detection of cacheable mapping at S2 - Fallback to PMD/PTE mappings for composite huge pages - Fix accounting of Stage-2 PGD allocation - Fix AArch32 handling of some of the debug registers - Simplify host HYP entry - Fix stray pointer conversion on nVHE TLB invalidation - Fix initialization of the nVHE code - Simplify handling of capabilities exposed to HYP - Nuke VCPUs caught using a forbidden AArch32 EL0