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2021-02-12Merge branch 'for-next/vdso' into for-next/coreWill Deacon
vDSO build improvements. * for-next/vdso: arm64: Support running gen_vdso_offsets.sh with BSD userland. arm64: do not descend to vdso directories twice
2021-02-09arm64: cpufeature: Add an early command-line cpufeature override facilityMarc Zyngier
In order to be able to override CPU features at boot time, let's add a command line parser that matches options of the form "cpureg.feature=value", and store the corresponding value into the override val/mask pair. No features are currently defined, so no expected change in functionality. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: David Brazdil <dbrazdil@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210208095732.3267263-14-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-01-20arm64: do not descend to vdso directories twiceMasahiro Yamada
arm64 descends into each vdso directory twice; first in vdso_prepare, second during the ordinary build process. PPC mimicked it and uncovered a problem [1]. In the first descend, Kbuild directly visits the vdso directories, therefore it does not inherit subdir-ccflags-y from upper directories. This means the command line parameters may differ between the two. If it happens, the offset values in the generated headers might be different from real offsets of vdso.so in the kernel. This potential danger should be avoided. The vdso directories are built in the vdso_prepare stage, so the second descend is unneeded. [1]: https://lore.kernel.org/linux-kbuild/CAK7LNARAkJ3_-4gX0VA2UkapbOftuzfSTVMBbgbw=HD8n7N+7w@mail.gmail.com/T/#ma10dcb961fda13f36d42d58fa6cb2da988b7e73a Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20201218024540.1102650-1-masahiroy@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-12-01arm64: scs: use vmapped IRQ and SDEI shadow stacksSami Tolvanen
Use scs_alloc() to allocate also IRQ and SDEI shadow stacks instead of using statically allocated stacks. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201130233442.2562064-3-samitolvanen@google.com [will: Move CONFIG_SHADOW_CALL_STACK check into init_irq_scs()] Signed-off-by: Will Deacon <will@kernel.org>
2020-10-02Merge branch 'for-next/mte' into for-next/coreWill Deacon
Add userspace support for the Memory Tagging Extension introduced by Armv8.5. (Catalin Marinas and others) * for-next/mte: (30 commits) arm64: mte: Fix typo in memory tagging ABI documentation arm64: mte: Add Memory Tagging Extension documentation arm64: mte: Kconfig entry arm64: mte: Save tags when hibernating arm64: mte: Enable swap of tagged pages mm: Add arch hooks for saving/restoring tags fs: Handle intra-page faults in copy_mount_options() arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks arm64: mte: Restore the GCR_EL1 register after a suspend arm64: mte: Allow user control of the generated random tags via prctl() arm64: mte: Allow user control of the tag check mode via prctl() mm: Allow arm64 mmap(PROT_MTE) on RAM-based files arm64: mte: Validate the PROT_MTE request via arch_validate_flags() mm: Introduce arch_validate_flags() arm64: mte: Add PROT_MTE support to mmap() and mprotect() mm: Introduce arch_calc_vm_flag_bits() arm64: mte: Tags-aware aware memcmp_pages() implementation arm64: Avoid unnecessary clear_user_page() indirection ...
2020-10-02Merge branch 'for-next/ghostbusters' into for-next/coreWill Deacon
Fix and subsequently rewrite Spectre mitigations, including the addition of support for PR_SPEC_DISABLE_NOEXEC. (Will Deacon and Marc Zyngier) * for-next/ghostbusters: (22 commits) arm64: Add support for PR_SPEC_DISABLE_NOEXEC prctl() option arm64: Pull in task_stack_page() to Spectre-v4 mitigation code KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabled arm64: Get rid of arm64_ssbd_state KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state() KVM: arm64: Get rid of kvm_arm_have_ssbd() KVM: arm64: Simplify handling of ARCH_WORKAROUND_2 arm64: Rewrite Spectre-v4 mitigation code arm64: Move SSBD prctl() handler alongside other spectre mitigation code arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4 arm64: Treat SSBS as a non-strict system feature arm64: Group start_thread() functions together KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2 arm64: Rewrite Spectre-v2 mitigation code arm64: Introduce separate file for spectre mitigations and reporting arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 KVM: arm64: Simplify install_bp_hardening_cb() KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE arm64: Remove Spectre-related CONFIG_* options arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUs ...
2020-09-29arm64: Move SSBD prctl() handler alongside other spectre mitigation codeWill Deacon
As part of the spectre consolidation effort to shift all of the ghosts into their own proton pack, move all of the horrible SSBD prctl() code out of its own 'ssbd.c' file. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Introduce separate file for spectre mitigations and reportingWill Deacon
The spectre mitigation code is spread over a few different files, which makes it both hard to follow, but also hard to remove it should we want to do that in future. Introduce a new file for housing the spectre mitigations, and populate it with the spectre-v1 reporting code to start with. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Remove Spectre-related CONFIG_* optionsWill Deacon
The spectre mitigations are too configurable for their own good, leading to confusing logic trying to figure out when we should mitigate and when we shouldn't. Although the plethora of command-line options need to stick around for backwards compatibility, the default-on CONFIG options that depend on EXPERT can be dropped, as the mitigations only do anything if the system is vulnerable, a mitigation is available and the command-line hasn't disabled it. Remove CONFIG_HARDEN_BRANCH_PREDICTOR and CONFIG_ARM64_SSBD in favour of enabling this code unconditionally. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-07arm64: get rid of TEXT_OFFSETArd Biesheuvel
TEXT_OFFSET serves no purpose, and for this reason, it was redefined as 0x0 in the v5.8 timeframe. Since this does not appear to have caused any issues that require us to revisit that decision, let's get rid of the macro entirely, along with any references to it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-04arm64: mte: Handle synchronous and asynchronous tag check faultsVincenzo Frascino
The Memory Tagging Extension has two modes of notifying a tag check fault at EL0, configurable through the SCTLR_EL1.TCF0 field: 1. Synchronous raising of a Data Abort exception with DFSC 17. 2. Asynchronous setting of a cumulative bit in TFSRE0_EL1. Add the exception handler for the synchronous exception and handling of the asynchronous TFSRE0_EL1.TF0 bit setting via a new TIF flag in do_notify_resume(). On a tag check failure in user-space, whether synchronous or asynchronous, a SIGSEGV will be raised on the faulting thread. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Co-developed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org>
2020-06-23arm64: compat: Allow 32-bit vdso and sigpage to co-existWill Deacon
In preparation for removing the signal trampoline from the compat vDSO, allow the sigpage and the compat vDSO to co-exist. For the moment the vDSO signal trampoline will still be used when built. Subsequent patches will move to the sigpage consistently. Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-05-15arm64: Implement Shadow Call StackSami Tolvanen
This change implements shadow stack switching, initial SCS set-up, and interrupt shadow stacks for arm64. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-03-09arm64: efi: add efi-entry.o to targets instead of extra-$(CONFIG_EFI)Masahiro Yamada
efi-entry.o is built on demand for efi-entry.stub.o, so you do not have to repeat $(CONFIG_EFI) here. Adding it to 'targets' is enough. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
2019-10-28arm64: entry: convert el1_sync to CMark Rutland
This patch converts the EL1 sync entry assembly logic to C code. Doing this will allow us to make changes in a slightly more readable way. A case in point is supporting kernel-first RAS. do_sea() should be called on the CPU that took the fault. Largely the assembly code is converted to C in a relatively straightforward manner. Since all sync sites share a common asm entry point, the ASM_BUG() instances are no longer required for effective backtraces back to assembly, and we don't need similar BUG() entries. The ESR_ELx.EC codes for all (supported) debug exceptions are now checked in the el1_sync_handler's switch statement, which renders the check in el1_dbg redundant. This both simplifies the el1_dbg handler, and makes the EL1 exception handling more robust to currently-unallocated ESR_ELx.EC encodings. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [split out of a bigger series, added nokprobes, moved prototypes] Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-22arm64: vdso: Enable vDSO compat supportVincenzo Frascino
Add vDSO compat support to the arm64 build system. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-16-vincenzo.frascino@arm.com
2019-04-23arm64: compat: Add KUSER_HELPERS config optionVincenzo Frascino
When kuser helpers are enabled the kernel maps the relative code at a fixed address (0xffff0000). Making configurable the option to disable them means that the kernel can remove this mapping and any access to this memory area results in a sigfault. Add a KUSER_HELPERS config option that can be used to disable the mapping when it is turned off. This option can be turned off if and only if the applications are designed specifically for the platform and they do not make use of the kuser helpers code. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [will: Use IS_ENABLED() instead of #ifdef] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23arm64: compat: Split kuser32Vincenzo Frascino
To make it possible to disable kuser helpers in aarch32 we need to divide the kuser and the sigreturn functionalities. Split the current version of kuser32 in kuser32 (for kuser helpers) and sigreturn32 (for sigreturn helpers). Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-09arm64: Makefile: Replace -pg with CC_FLAGS_FTRACETorsten Duwe
In preparation for arm64 supporting ftrace built on other compiler options, let's have the arm64 Makefiles remove the $(CC_FLAGS_FTRACE) flags, whatever these may be, rather than assuming '-pg'. There should be no functional change as a result of this patch. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-04arm64: replace arm64-obj-* in Makefile with obj-*Masahiro Yamada
Use the standard obj-$(CONFIG_...) syntex. The behavior is still the same. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: add prctl control for resetting ptrauth keysKristina Martsenko
Add an arm64-specific prctl to allow a thread to reinitialize its pointer authentication keys to random values. This can be useful when exec() is not used for starting new processes, to ensure that different processes still have different keys. Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10Merge branch 'for-next/kexec' into aarch64/for-next/coreWill Deacon
Merge in kexec_file_load() support from Akashi Takahiro.
2018-12-10arm64: remove arm64ksyms.cMark Rutland
Now that arm64ksyms.c has been reduced to a stub, let's remove it entirely. New exports should be associated with their function definition. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-06arm64: kexec_file: allow for loading Image-format kernelAKASHI Takahiro
This patch provides kexec_file_ops for "Image"-format kernel. In this implementation, a binary is always loaded with a fixed offset identified in text_offset field of its header. Regarding signature verification for trusted boot, this patch doesn't contains CONFIG_KEXEC_VERIFY_SIG support, which is to be added later in this series, but file-attribute-based verification is still a viable option by enabling IMA security subsystem. You can sign(label) a to-be-kexec'ed kernel image on target file system with: $ evmctl ima_sign --key /path/to/private_key.pem Image On live system, you must have IMA enforced with, at least, the following security policy: "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig" See more details about IMA here: https://sourceforge.net/p/linux-ima/wiki/Home/ Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-06arm64: enable KEXEC_FILE configAKASHI Takahiro
Modify arm64/Kconfig to enable kexec_file_load support. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Acked-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-09-11arm64: kernel: arch_crash_save_vmcoreinfo() should depend on CONFIG_CRASH_COREJames Morse
Since commit 23c85094fe18 ("proc/kcore: add vmcoreinfo note to /proc/kcore") the kernel has exported the vmcoreinfo PT_NOTE on /proc/kcore as well as /proc/vmcore. arm64 only exposes it's additional arch information via arch_crash_save_vmcoreinfo() if built with CONFIG_KEXEC, as kdump was previously the only user of vmcoreinfo. Move this weak function to a separate file that is built at the same time as its caller in kernel/crash_core.c. This ensures values like 'kimage_voffset' are always present in the vmcoreinfo PT_NOTE. CC: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-12arm64: convert compat wrappers to CMark Rutland
In preparation for converting to pt_regs syscall wrappers, convert our existing compat wrappers to C. This will allow the pt_regs wrappers to be automatically generated, and will allow for the compat register manipulation to be folded in with the pt_regs accesses. To avoid confusion with the upcoming pt_regs wrappers and existing compat wrappers provided by core code, the C wrappers are renamed to compat_sys_aarch32_<syscall>. With the assembly wrappers gone, we can get rid of entry32.S and the associated boilerplate. Note that these must call the ksys_* syscall entry points, as the usual sys_* entry points will be modified to take a single pt_regs pointer argument. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-12arm64: convert raw syscall invocation to CMark Rutland
As a first step towards invoking syscalls with a pt_regs argument, convert the raw syscall invocation logic to C. We end up with a bit more register shuffling, but the unified invocation logic means we can unify the tracing paths, too. Previously, assembly had to open-code calls to ni_sys() when the system call number was out-of-bounds for the relevant syscall table. This case is now handled by invoke_syscall(), and the assembly no longer need to handle this case explicitly. This allows the tracing paths to be simplified and unified, as we no longer need the __ni_sys_trace path and the __sys_trace_return label. This only converts the invocation of the syscall. The rest of the syscall triage and tracing is left in assembly for now, and will be converted in subsequent patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-05-31arm64: ssbd: Add prctl interface for per-thread mitigationMarc Zyngier
If running on a system that performs dynamic SSBD mitigation, allow userspace to request the mitigation for itself. This is implemented as a prctl call, allowing the mitigation to be enabled or disabled at will for this particular thread. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-04-11arm64: Move the content of bpi.S to hyp-entry.SMarc Zyngier
bpi.S was introduced as we were starting to build the Spectre v2 mitigation framework, and it was rather unclear that it would become strictly KVM specific. Now that the picture is a lot clearer, let's move the content of that file to hyp-entry.S, where it actually belong. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-09Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - VHE optimizations - EL2 address space randomization - speculative execution mitigations ("variant 3a", aka execution past invalid privilege register access) - bugfixes and cleanups PPC: - improvements for the radix page fault handler for HV KVM on POWER9 s390: - more kvm stat counters - virtio gpu plumbing - documentation - facilities improvements x86: - support for VMware magic I/O port and pseudo-PMCs - AMD pause loop exiting - support for AMD core performance extensions - support for synchronous register access - expose nVMX capabilities to userspace - support for Hyper-V signaling via eventfd - use Enlightened VMCS when running on Hyper-V - allow userspace to disable MWAIT/HLT/PAUSE vmexits - usual roundup of optimizations and nested virtualization bugfixes Generic: - API selftest infrastructure (though the only tests are for x86 as of now)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (174 commits) kvm: x86: fix a prototype warning kvm: selftests: add sync_regs_test kvm: selftests: add API testing infrastructure kvm: x86: fix a compile warning KVM: X86: Add Force Emulation Prefix for "emulate the next instruction" KVM: X86: Introduce handle_ud() KVM: vmx: unify adjacent #ifdefs x86: kvm: hide the unused 'cpu' variable KVM: VMX: remove bogus WARN_ON in handle_ept_misconfig Revert "KVM: X86: Fix SMRAM accessing even if VM is shutdown" kvm: Add emulation for movups/movupd KVM: VMX: raise internal error for exception during invalid protected mode state KVM: nVMX: Optimization: Dont set KVM_REQ_EVENT when VMExit with nested_run_pending KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event pending KVM: x86: Fix misleading comments on handling pending exceptions KVM: x86: Rename interrupt.pending to interrupt.injected KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interrupt x86/kvm: use Enlightened VMCS when running on Hyper-V x86/hyper-v: detect nested features x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits ...
2018-03-19arm64: KVM: Move BP hardening vectors into .hyp.text sectionMarc Zyngier
There is no reason why the BP hardening vectors shouldn't be part of the HYP text at compile time, rather than being mapped at runtime. Also introduce a new config symbol that controls the compilation of bpi.S. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-09efi/arm64: Check whether x18 is preserved by runtime services callsArd Biesheuvel
Whether or not we will ever decide to start using x18 as a platform register in Linux is uncertain, but by that time, we will need to ensure that UEFI runtime services calls don't corrupt it. So let's start issuing warnings now for this, and increase the likelihood that these firmware images have all been replaced by that time. This has been fixed on the EDK2 side in commit: 6d73863b5464 ("BaseTools/tools_def AARCH64: mark register x18 as reserved") dated July 13, 2017. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180308080020.22828-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-13arm64: kernel: Add arch-specific SDEI entry code and CPU maskingJames Morse
The Software Delegated Exception Interface (SDEI) is an ARM standard for registering callbacks from the platform firmware into the OS. This is typically used to implement RAS notifications. Such notifications enter the kernel at the registered entry-point with the register values of the interrupted CPU context. Because this is not a CPU exception, it cannot reuse the existing entry code. (crucially we don't implicitly know which exception level we interrupted), Add the entry point to entry.S to set us up for calling into C code. If the event interrupted code that had interrupts masked, we always return to that location. Otherwise we pretend this was an IRQ, and use SDEI's complete_and_resume call to return to vbar_el1 + offset. This allows the kernel to deliver signals to user space processes. For KVM this triggers the world switch, a quick spin round vcpu_run, then back into the guest, unless there are pending signals. Add sdei_mask_local_cpu() calls to the smp_send_stop() code, this covers the panic() code-path, which doesn't invoke cpuhotplug notifiers. Because we can interrupt entry-from/exit-to another EL, we can't trust the value in sp_el0 or x29, even if we interrupted the kernel, in this case the code in entry.S will save/restore sp_el0 and use the value in __entry_task. When we have VMAP stacks we can interrupt the stack-overflow test, which stirs x0 into sp, meaning we have to have our own VMAP stacks. For now these are allocated when we probe the interface. Future patches will add refcounting hooks to allow the arch code to allocate them lazily. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08arm64: Add skeleton to harden the branch predictor against aliasing attacksWill Deacon
Aliasing attacks against CPU branch predictors can allow an attacker to redirect speculative control flow on some CPUs and potentially divulge information from one context to another. This patch adds initial skeleton code behind a new Kconfig option to enable implementation-specific mitigations against these attacks for CPUs that are affected. Co-developed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-01arm64: ftrace: emit ftrace-mod.o contents through codeArd Biesheuvel
When building the arm64 kernel with both CONFIG_ARM64_MODULE_PLTS and CONFIG_DYNAMIC_FTRACE enabled, the ftrace-mod.o object file is built with the kernel and contains a trampoline that is linked into each module, so that modules can be loaded far away from the kernel and still reach the ftrace entry point in the core kernel with an ordinary relative branch, as is emitted by the compiler instrumentation code dynamic ftrace relies on. In order to be able to build out of tree modules, this object file needs to be included into the linux-headers or linux-devel packages, which is undesirable, as it makes arm64 a special case (although a precedent does exist for 32-bit PPC). Given that the trampoline essentially consists of a PLT entry, let's not bother with a source or object file for it, and simply patch it in whenever the trampoline is being populated, using the existing PLT support routines. Cc: <stable@vger.kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-15Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "The big highlight is support for the Scalable Vector Extension (SVE) which required extensive ABI work to ensure we don't break existing applications by blowing away their signal stack with the rather large new vector context (<= 2 kbit per vector register). There's further work to be done optimising things like exception return, but the ABI is solid now. Much of the line count comes from some new PMU drivers we have, but they're pretty self-contained and I suspect we'll have more of them in future. Plenty of acronym soup here: - initial support for the Scalable Vector Extension (SVE) - improved handling for SError interrupts (required to handle RAS events) - enable GCC support for 128-bit integer types - remove kernel text addresses from backtraces and register dumps - use of WFE to implement long delay()s - ACPI IORT updates from Lorenzo Pieralisi - perf PMU driver for the Statistical Profiling Extension (SPE) - perf PMU driver for Hisilicon's system PMUs - misc cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits) arm64: Make ARMV8_DEPRECATED depend on SYSCTL arm64: Implement __lshrti3 library function arm64: support __int128 on gcc 5+ arm64/sve: Add documentation arm64/sve: Detect SVE and activate runtime support arm64/sve: KVM: Hide SVE from CPU features exposed to guests arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Prevent guests from using SVE arm64/sve: Add sysctl to set the default vector length for new processes arm64/sve: Add prctl controls for userspace vector length management arm64/sve: ptrace and ELF coredump support arm64/sve: Preserve SVE registers around EFI runtime service calls arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Probe SVE capabilities and usable vector lengths arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Backend logic for setting the vector length arm64/sve: Signal handling support arm64/sve: Support vector length resetting for new processes arm64/sve: Core task context handling arm64/sve: Low-level CPU setup ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-02arm64: remove unneeded copy to init_utsname()->machineMasahiro Yamada
As you see in init/version.c, init_uts_ns.name.machine is initially set to UTS_MACHINE. There is no point to copy the same string. I dug the git history to figure out why this line is here. My best guess is like this: - This line has been around here since the initial support of arm64 by commit 9703d9d7f77c ("arm64: Kernel booting and initialisation"). If ARCH (=arm64) and UTS_MACHINE (=aarch64) do not match, arch/$(ARCH)/Makefile is supposed to override UTS_MACHINE, but the initial version of arch/arm64/Makefile missed to do that. Instead, the boot code copied "aarch64" to init_utsname()->machine. - Commit 94ed1f2cb5d4 ("arm64: setup: report ELF_PLATFORM as the machine for utsname") replaced "aarch64" with ELF_PLATFORM to make "uname" to reflect the endianness. - ELF_PLATFORM does not help to provide the UTS machine name to rpm target, so commit cfa88c79462d ("arm64: Set UTS_MACHINE in the Makefile") fixed it. The commit simply replaced ELF_PLATFORM with UTS_MACHINE, but missed the fact the string copy itself is no longer needed. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-07arm64: ftrace: add support for far branches to dynamic ftraceArd Biesheuvel
Currently, dynamic ftrace support in the arm64 kernel assumes that all core kernel code is within range of ordinary branch instructions that occur in module code, which is usually the case, but is no longer guaranteed now that we have support for module PLTs and address space randomization. Since on arm64, all patching of branch instructions involves function calls to the same entry point [ftrace_caller()], we can emit the modules with a trampoline that has unlimited range, and patch both the trampoline itself and the branch instruction to redirect the call via the trampoline. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: minor clarification to smp_wmb() comment] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-04-05arm64: kdump: provide /proc/vmcore fileAKASHI Takahiro
Arch-specific functions are added to allow for implementing a crash dump file interface, /proc/vmcore, which can be viewed as a ELF file. A user space tool, like kexec-tools, is responsible for allocating a separate region for the core's ELF header within crash kdump kernel memory and filling it in when executing kexec_load(). Then, its location will be advertised to crash dump kernel via a new device-tree property, "linux,elfcorehdr", and crash dump kernel preserves the region for later use with reserve_elfcorehdr() at boot time. On crash dump kernel, /proc/vmcore will access the primary kernel's memory with copy_oldmem_page(), which feeds the data page-by-page by ioremap'ing it since it does not reside in linear mapping on crash dump kernel. Meanwhile, elfcorehdr_read() is simple as the region is always mapped. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-04arm64: relocation testing moduleArd Biesheuvel
This module tests the module loader's ELF relocation processing routines. When loaded, it logs output like below. Relocation test: ------------------------------------------------------- R_AARCH64_ABS64 0xffff880000cccccc pass R_AARCH64_ABS32 0x00000000f800cccc pass R_AARCH64_ABS16 0x000000000000f8cc pass R_AARCH64_MOVW_SABS_Gn 0xffff880000cccccc pass R_AARCH64_MOVW_UABS_Gn 0xffff880000cccccc pass R_AARCH64_ADR_PREL_LO21 0xffffff9cf4d1a400 pass R_AARCH64_PREL64 0xffffff9cf4d1a400 pass R_AARCH64_PREL32 0xffffff9cf4d1a400 pass R_AARCH64_PREL16 0xffffff9cf4d1a400 pass Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-02-03efi: arm64: Add vmlinux debug link to the Image binaryArd Biesheuvel
When building with debugging symbols, take the absolute path to the vmlinux binary and add it to the special PE/COFF debug table entry. This allows a debug EFI build to find the vmlinux binary, which is very helpful in debugging, given that the offset where the Image is first loaded by EFI is highly unpredictable. On implementations of UEFI that choose to implement it, this information is exposed via the EFI debug support table, which is a UEFI configuration table that is accessible both by the firmware at boot time and by the OS at runtime, and lists all PE/COFF images loaded by the system. The format of the NB10 Codeview entry is based on the definition used by EDK2, which is our primary reference when it comes to the use of PE/COFF in the context of UEFI firmware. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: use realpath instead of shell invocation, as discussed on list] Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31arm64: Set UTS_MACHINE in the MakefileMichal Marek
The make rpm target depends on proper UTS_MACHINE definition. Also, use the variable in arch/arm64/kernel/setup.c, so that it's not accidentally removed in the future. Reported-and-tested-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-07-27Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - Kexec support for arm64 - Kprobes support - Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs - Trapping of user space cache maintenance operations and emulation in the kernel (CPU errata workaround) - Clean-up of the early page tables creation (kernel linear mapping, EFI run-time maps) to avoid splitting larger blocks (e.g. pmds) into smaller ones (e.g. ptes) - VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime() - ARCH_HAS_KCOV enabled for arm64 - Optimise IP checksum helpers - SWIOTLB optimisation to only allocate/initialise the buffer if the available RAM is beyond the 32-bit mask - Properly handle the "nosmp" command line argument - Fix for the initialisation of the CPU debug state during early boot - vdso-offsets.h build dependency workaround - Build fix when RANDOMIZE_BASE is enabled with MODULES off * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits) arm64: arm: Fix-up the removal of the arm64 regs_query_register_name() prototype arm64: Only select ARM64_MODULE_PLTS if MODULES=y arm64: mm: run pgtable_page_ctor() on non-swapper translation table pages arm64: mm: make create_mapping_late() non-allocating arm64: Honor nosmp kernel command line option arm64: Fix incorrect per-cpu usage for boot CPU arm64: kprobes: Add KASAN instrumentation around stack accesses arm64: kprobes: Cleanup jprobe_return arm64: kprobes: Fix overflow when saving stack arm64: kprobes: WARN if attempting to step with PSTATE.D=1 arm64: debug: remove unused local_dbg_{enable, disable} macros arm64: debug: remove redundant spsr manipulation arm64: debug: unmask PSTATE.D earlier arm64: localise Image objcopy flags arm64: ptrace: remove extra define for CPSR's E bit kprobes: Add arm64 case in kprobe example module arm64: Add kernel return probes support (kretprobes) arm64: Add trampoline code for kretprobes arm64: kprobes instruction simulation support arm64: Treat all entry code as non-kprobe-able ...
2016-07-21Merge branch 'for-next/kprobes' into for-next/coreCatalin Marinas
* kprobes: arm64: kprobes: Add KASAN instrumentation around stack accesses arm64: kprobes: Cleanup jprobe_return arm64: kprobes: Fix overflow when saving stack arm64: kprobes: WARN if attempting to step with PSTATE.D=1 kprobes: Add arm64 case in kprobe example module arm64: Add kernel return probes support (kretprobes) arm64: Add trampoline code for kretprobes arm64: kprobes instruction simulation support arm64: Treat all entry code as non-kprobe-able arm64: Blacklist non-kprobe-able symbol arm64: Kprobes with single stepping support arm64: add conditional instruction simulation support arm64: Add more test functions to insn.c arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature
2016-07-19arm64: Kprobes with single stepping supportSandeepa Prabhu
Add support for basic kernel probes(kprobes) and jump probes (jprobes) for ARM64. Kprobes utilizes software breakpoint and single step debug exceptions supported on ARM v8. A software breakpoint is placed at the probe address to trap the kernel execution into the kprobe handler. ARM v8 supports enabling single stepping before the break exception return (ERET), with next PC in exception return address (ELR_EL1). The kprobe handler prepares an executable memory slot for out-of-line execution with a copy of the original instruction being probed, and enables single stepping. The PC is set to the out-of-line slot address before the ERET. With this scheme, the instruction is executed with the exact same register context except for the PC (and DAIF) registers. Debug mask (PSTATE.D) is enabled only when single stepping a recursive kprobe, e.g.: during kprobes reenter so that probed instruction can be single stepped within the kprobe handler -exception- context. The recursion depth of kprobe is always 2, i.e. upon probe re-entry, any further re-entry is prevented by not calling handlers and the case counted as a missed kprobe). Single stepping from the x-o-l slot has a drawback for PC-relative accesses like branching and symbolic literals access as the offset from the new PC (slot address) may not be ensured to fit in the immediate value of the opcode. Such instructions need simulation, so reject probing them. Instructions generating exceptions or cpu mode change are rejected for probing. Exclusive load/store instructions are rejected too. Additionally, the code is checked to see if it is inside an exclusive load/store sequence (code from Pratyush). System instructions are mostly enabled for stepping, except MSR/MRS accesses to "DAIF" flags in PSTATE, which are not safe for probing. This also changes arch/arm64/include/asm/ptrace.h to use include/asm-generic/ptrace.h. Thanks to Steve Capper and Pratyush Anand for several suggested Changes. Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Pratyush Anand <panand@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-19arm64: add conditional instruction simulation supportDavid A. Long
Cease using the arm32 arm_check_condition() function and replace it with a local version for use in deprecated instruction support on arm64. Also make the function table used by this available for future use by kprobes and/or uprobes. This function is derived from code written by Sandeepa Prabhu. Signed-off-by: Sandeepa Prabhu <sandeepa.s.prabhu@gmail.com> Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-11arm64: fix vdso-offsets.h dependencyKevin Brodsky
arm64/kernel/{vdso,signal}.c include vdso-offsets.h, as well as any file that includes asm/vdso.h. Therefore, vdso-offsets.h must be generated before these files are compiled. The current rules in arm64/kernel/Makefile do not actually enforce this, because even though $(obj)/vdso is listed as a prerequisite for vdso-offsets.h, this does not result in the intended effect of building the vdso subdirectory (before all the other objects). As a consequence, depending on the order in which the rules are followed, vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o are built. The current rules also impose an unnecessary dependency on vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary rebuilds. This is made obvious when using make -j: touch arch/arm64/kernel/vdso/gettimeofday.S && make -j$NCPUS arch/arm64/kernel will sometimes result in none of arm64/kernel/*.o being rebuilt, sometimes all of them, or even just some of them. It is quite difficult to ensure that a header is generated before it is used with recursive Makefiles by using normal rules. Instead, arch-specific generated headers are normally built in the archprepare recipe in the arch Makefile (see for instance arch/ia64/Makefile). Unfortunately, asm-offsets.h is included in gettimeofday.S, and must therefore be generated before vdso-offsets.h, which is not the case if archprepare is used. For this reason, a rule run after archprepare has to be used. This commit adds rules in arm64/Makefile to build vdso-offsets.h during the prepare step, ensuring that vdso-offsets.h is generated before building anything. It also removes the now-unnecessary dependencies on vdso-offsets.h in arm64/kernel/Makefile. Finally, it removes the duplication of asm-offsets.h between arm64/kernel/vdso/ and include/generated/ and makes include/generated/vdso-offsets.h a target in arm64/kernel/vdso/Makefile. Cc: Will Deacon <will.deacon@arm.com> Cc: Michal Marek <mmarek@suse.com> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-11Revert "arm64: Fix vdso-offsets.h dependency"Catalin Marinas
This reverts commit 90f777beb788d08300f4a1482cb4fd37a401b472. While this commit was aimed at fixing the dependencies, with a large make -j the vdso-offsets.h file is not generated, leading to build failures. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>