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2019-05-01Merge branch 'for-next/timers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into for-next/coreWill Deacon2-20/+68
Conflicts: arch/arm64/Kconfig arch/arm64/include/asm/arch_timer.h
2019-05-01Merge branch 'for-next/mitigations' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into for-next/coreWill Deacon1-4/+0
2019-05-01Merge branch 'for-next/futex' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into for-next/coreWill Deacon1-24/+39
2019-04-30clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable countersMarc Zyngier1-2/+14
Instead of always going via arch_counter_get_cntvct_stable to access the counter workaround, let's have arch_timer_read_counter point to the right method. For that, we need to track whether any CPU in the system has a workaround for the counter. This is done by having an atomic variable tracking this. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30clocksource/arm_arch_timer: Remove use of workaround static keyMarc Zyngier1-4/+0
The use of a static key in a hotplug path has proved to be a real nightmare, and makes it impossible to have scream-free lockdep kernel. Let's remove the static key altogether, and focus on something saner. Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30clocksource/arm_arch_timer: Drop use of static key in arch_timer_reg_read_stableMarc Zyngier1-14/+28
Let's start with the removal of the arch_timer_read_ool_enabled static key in arch_timer_reg_read_stable. It is not a fast path, and we can simplify things a bit. Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30clocksource/arm_arch_timer: Direcly assign set_next_event workaroundMarc Zyngier1-0/+16
When a given timer is affected by an erratum and requires an alternative implementation of set_next_event, we do a rather complicated dance to detect and call the workaround on each set_next_event call. This is clearly idiotic, as we can perfectly detect whether this CPU requires a workaround while setting up the clock event device. This only requires the CPU-specific detection to be done a bit earlier, and we can then safely override the set_next_event pointer if we have a workaround associated to that CPU. Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by; Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30arm64: Add part number for Neoverse N1Marc Zyngier1-0/+2
New CPU, new part number. You know the drill. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30arm64: mm: Remove pte_unmap_nested()Qian Cai1-2/+0
As of commit ece0e2b6406a ("mm: remove pte_*map_nested()"), pte_unmap_nested() is no longer used and can be removed from the arm64 code. Signed-off-by: Qian Cai <cai@lca.pw> [will: also remove pte_offset_map_nested()] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variableQian Cai1-1/+2
When building with -Wunused-but-set-variable, the compiler shouts about a number of pte_unmap() users, since this expands to an empty macro on arm64: | mm/gup.c: In function 'gup_pte_range': | mm/gup.c:1727:16: warning: variable 'ptem' set but not used | [-Wunused-but-set-variable] | mm/gup.c: At top level: | mm/memory.c: In function 'copy_pte_range': | mm/memory.c:821:24: warning: variable 'orig_dst_pte' set but not used | [-Wunused-but-set-variable] | mm/memory.c:821:9: warning: variable 'orig_src_pte' set but not used | [-Wunused-but-set-variable] | mm/swap_state.c: In function 'swap_ra_info': | mm/swap_state.c:641:15: warning: variable 'orig_pte' set but not used | [-Wunused-but-set-variable] | mm/madvise.c: In function 'madvise_free_pte_range': | mm/madvise.c:318:9: warning: variable 'orig_pte' set but not used | [-Wunused-but-set-variable] Rewrite pte_unmap() as a static inline function, which silences the warnings. Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30arm64: compat: Reduce address limit for 64K pagesVincenzo Frascino1-1/+1
With the introduction of the config option that allows to enable kuser helpers, it is now possible to reduce TASK_SIZE_32 when these are disabled and 64K pages are enabled. This extends the compliance with the section 6.5.8 of the C standard (C99). Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30arm64: arch_timer: Ensure counter register reads occur with seqlock heldWill Deacon1-2/+31
When executing clock_gettime(), either in the vDSO or via a system call, we need to ensure that the read of the counter register occurs within the seqlock reader critical section. This ensures that updates to the clocksource parameters (e.g. the multiplier) are consistent with the counter value and therefore avoids the situation where time appears to go backwards across multiple reads. Extend the vDSO logic so that the seqlock critical section covers the read of the counter register as well as accesses to the data page. Since reads of the counter system registers are not ordered by memory barrier instructions, introduce dependency ordering from the counter read to a subsequent memory access so that the seqlock memory barriers apply to the counter access in both the vDSO and the system call paths. Cc: <stable@vger.kernel.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/linux-arm-kernel/alpine.DEB.2.21.1902081950260.1662@nanos.tec.linutronix.de/ Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-0/+8
Daniel Borkmann says: ==================== pull-request: bpf-next 2019-04-28 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Introduce BPF socket local storage map so that BPF programs can store private data they associate with a socket (instead of e.g. separate hash table), from Martin. 2) Add support for bpftool to dump BTF types. This is done through a new `bpftool btf dump` sub-command, from Andrii. 3) Enable BPF-based flow dissector for skb-less eth_get_headlen() calls which was currently not supported since skb was used to lookup netns, from Stanislav. 4) Add an opt-in interface for tracepoints to expose a writable context for attached BPF programs, used here for NBD sockets, from Matt. 5) BPF xadd related arm64 JIT fixes and scalability improvements, from Daniel. 6) Change the skb->protocol for bpf_skb_adjust_room() helper in order to support tunnels such as sit. Add selftests as well, from Willem. 7) Various smaller misc fixes. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26bpf, arm64: use more scalable stadd over ldxr / stxr loop in xaddDaniel Borkmann1-0/+8
Since ARMv8.1 supplement introduced LSE atomic instructions back in 2016, lets add support for STADD and use that in favor of LDXR / STXR loop for the XADD mapping if available. STADD is encoded as an alias for LDADD with XZR as the destination register, therefore add LDADD to the instruction encoder along with STADD as special case and use it in the JIT for CPUs that advertise LSE atomics in CPUID register. If immediate offset in the BPF XADD insn is 0, then use dst register directly instead of temporary one. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-26arm64: Always enable ssb vulnerability detectionJeremy Linton1-4/+0
Ensure we are always able to detect whether or not the CPU is affected by SSB, so that we can later advertise this to userspace. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> [will: Use IS_ENABLED instead of #ifdef] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26arm64: futex: Avoid copying out uninitialised stack in failed cmpxchg()Will Deacon1-1/+3
Returning an error code from futex_atomic_cmpxchg_inatomic() indicates that the caller should not make any use of *uval, and should instead act upon on the value of the error code. Although this is implemented correctly in our futex code, we needlessly copy uninitialised stack to *uval in the error case, which can easily be avoided. Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26arm64: futex: Bound number of LDXR/STXR loops in FUTEX_WAKE_OPWill Deacon1-21/+34
Our futex implementation makes use of LDXR/STXR loops to perform atomic updates to user memory from atomic context. This can lead to latency problems if we end up spinning around the LL/SC sequence at the expense of doing something useful. Rework our futex atomic operations so that we return -EAGAIN if we fail to update the futex word after 128 attempts. The core futex code will reschedule if necessary and we'll try again later. Cc: <stable@kernel.org> Fixes: 6170a97460db ("arm64: Atomic operations") Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-26arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result valueWill Deacon1-8/+8
Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't explicitly set the return value on the non-faulting path and instead leaves it holding the result of the underlying atomic operation. This means that any FUTEX_WAKE_OP atomic operation which computes a non-zero value will be reported as having failed. Regrettably, I wrote the buggy code back in 2011 and it was upstreamed as part of the initial arm64 support in 2012. The reasons we appear to get away with this are: 1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get exercised by futex() test applications 2. If the result of the atomic operation is zero, the system call behaves correctly 3. Prior to version 2.25, the only operation used by GLIBC set the futex to zero, and therefore worked as expected. From 2.25 onwards, FUTEX_WAKE_OP is not used by GLIBC at all. Fix the implementation by ensuring that the return value is either 0 to indicate that the atomic operation completed successfully, or -EFAULT if we encountered a fault when accessing the user mapping. Cc: <stable@kernel.org> Fixes: 6170a97460db ("arm64: Atomic operations") Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-25arm64: sysreg: Make mrs_s and msr_s macros work with Clang and LTOKees Cook3-19/+38
Clang's integrated assembler does not allow assembly macros defined in one inline asm block using the .macro directive to be used across separate asm blocks. LLVM developers consider this a feature and not a bug, recommending code refactoring: https://bugs.llvm.org/show_bug.cgi?id=19749 As binutils doesn't allow macros to be redefined, this change uses UNDEFINE_MRS_S and UNDEFINE_MSR_S to define corresponding macros in-place and workaround gcc and clang limitations on redefining macros across different assembler blocks. Specifically, the current state after preprocessing looks like this: asm volatile(".macro mXX_s ... .endm"); void f() { asm volatile("mXX_s a, b"); } With GCC, it gives macro redefinition error because sysreg.h is included in multiple source files, and assembler code for all of them is later combined for LTO (I've seen an intermediate file with hundreds of identical definitions). With clang, it gives macro undefined error because clang doesn't allow sharing macros between inline asm statements. I also seem to remember catching another sort of undefined error with GCC due to reordering of macro definition asm statement and generated asm code for function that uses the macro. The solution with defining and undefining for each use, while certainly not elegant, satisfies both GCC and clang, LTO and non-LTO. Co-developed-by: Alex Matveev <alxmtvv@gmail.com> Co-developed-by: Yury Norov <ynorov@caviumnetworks.com> Co-developed-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-24arm64: KVM: Enable VHE support for :G/:H perf event modifiersAndrew Murray1-1/+4
With VHE different exception levels are used between the host (EL2) and guest (EL1) with a shared exception level for userpace (EL0). We can take advantage of this and use the PMU's exception level filtering to avoid enabling/disabling counters in the world-switch code. Instead we just modify the counter type to include or exclude EL0 at vcpu_{load,put} time. We also ensure that trapped PMU system register writes do not re-enable EL0 when reconfiguring the backing perf events. This approach completely avoids blackout windows seen with !VHE. Suggested-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Andrew Murray <andrew.murray@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24arm64: KVM: Enable !VHE support for :G/:H perf event modifiersAndrew Murray1-0/+3
Enable/disable event counters as appropriate when entering and exiting the guest to enable support for guest or host only event counting. For both VHE and non-VHE we switch the counters between host/guest at EL2. The PMU may be on when we change which counters are enabled however we avoid adding an isb as we instead rely on existing context synchronisation events: the eret to enter the guest (__guest_enter) and eret in kvm_call_hyp for __kvm_vcpu_run_nvhe on returning. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24arm64: KVM: Add accessors to track guest/host only countersAndrew Murray1-0/+17
In order to effeciently switch events_{guest,host} perf counters at guest entry/exit we add bitfields to kvm_cpu_context for guest and host events as well as accessors for updating them. A function is also provided which allows the PMU driver to determine if a counter should start counting when it is enabled. With exclude_host, we may only start counting when entering the guest. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_dataAndrew Murray2-7/+12
The virt/arm core allocates a kvm_cpu_context_t percpu, at present this is a typedef to kvm_cpu_context and is used to store host cpu context. The kvm_cpu_context structure is also used elsewhere to hold vcpu context. In order to use the percpu to hold additional future host information we encapsulate kvm_cpu_context in a new structure and rename the typedef and percpu to match. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24KVM: arm64: Add userspace flag to enable pointer authenticationAmit Daniel Kachhap1-1/+1
Now that the building blocks of pointer authentication are present, lets add userspace flags KVM_ARM_VCPU_PTRAUTH_ADDRESS and KVM_ARM_VCPU_PTRAUTH_GENERIC. These flags will enable pointer authentication for the KVM guest on a per-vcpu basis through the ioctl KVM_ARM_VCPU_INIT. This features will allow the KVM guest to allow the handling of pointer authentication instructions or to treat them as undefined if not set. Necessary documentations are added to reflect the changes done. Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24KVM: arm/arm64: Context-switch ptrauth registersMark Rutland3-0/+141
When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-23Merge tag 'syscalls-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-genericLinus Torvalds2-1/+9
Pull syscall numbering updates from Arnd Bergmann: "arch: add pidfd and io_uring syscalls everywhere This comes a bit late, but should be in 5.1 anyway: we want the newly added system calls to be synchronized across all architectures in the release. I hope that in the future, any newly added system calls can be added to all architectures at the same time, and tested there while they are in linux-next, avoiding dependencies between the architecture maintainer trees and the tree that contains the new system call" * tag 'syscalls-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: arch: add pidfd and io_uring syscalls everywhere
2019-04-23arch: mostly remove <asm/segment.h>Christoph Hellwig1-1/+0
A few architectures use <asm/segment.h> internally, but nothing in common code does. Remove all the empty or almost empty versions of it, including the asm-generic one. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-04-23arm64: Expose SVE2 features for userspaceDave Martin2-0/+20
This patch provides support for reporting the presence of SVE2 and its optional features to userspace. This will also enable visibility of SVE2 for guests, when KVM support for SVE-enabled guests is available. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23arm64: compat: Alloc separate pages for vectors and sigpageVincenzo Frascino2-5/+3
For AArch32 tasks, we install a special "[vectors]" page that contains the sigreturn trampolines and kuser helpers, which is mapped at a fixed address specified by the kuser helpers ABI. Having the sigreturn trampolines in the same page as the kuser helpers makes it impossible to disable the kuser helpers independently. Follow the Arm implementation, by moving the signal trampolines out of the "[vectors]" page and into their own "[sigpage]". 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: tweaked comments and fixed sparse warning] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23KVM: arm64: Add a vcpu flag to control ptrauth for guestAmit Daniel Kachhap1-0/+5
A per vcpu flag is added to check if pointer authentication is enabled for the vcpu or not. This flag may be enabled according to the necessary user policies and host capabilities. This patch also adds a helper to check the flag. Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18arm64: futex: Restore oldval initialization to work around buggy compilersNathan Chancellor1-1/+1
Commit 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value") removed oldval's zero initialization in arch_futex_atomic_op_inuser because it is not necessary. Unfortunately, Android's arm64 GCC 4.9.4 [1] does not agree: ../kernel/futex.c: In function 'do_futex': ../kernel/futex.c:1658:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized] return oldval == cmparg; ^ In file included from ../kernel/futex.c:73:0: ../arch/arm64/include/asm/futex.h:53:6: note: 'oldval' was declared here int oldval, ret, tmp; ^ GCC fails to follow that when ret is non-zero, futex_atomic_op_inuser returns right away, avoiding the uninitialized use that it claims. Restoring the zero initialization works around this issue. [1]: https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/ Cc: stable@vger.kernel.org Fixes: 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-04-18KVM: arm/arm64: Clean up vcpu finalization function parameter namingDave Martin1-1/+1
Currently, the internal vcpu finalization functions use a different name ("what") for the feature parameter than the name ("feature") used in the documentation. To avoid future confusion, this patch converts everything to use the name "feature" consistently. No functional change. Suggested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18KVM: arm/arm64: Demote kvm_arm_init_arch_resources() to just set up SVEDave Martin1-1/+1
The introduction of kvm_arm_init_arch_resources() looks like premature factoring, since nothing else uses this hook yet and it is not clear what will use it in the future. For now, let's not pretend that this is a general thing: This patch simply renames the function to kvm_arm_init_sve(), retaining the arm stub version under the new name. Suggested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-18arm64/sve: Clarify vq map semanticsDave Martin1-4/+0
Currently the meanings of sve_vq_map and the ancillary helpers __bit_to_vq() and __vq_to_bit() are not clearly explained. This patch makes the explanatory comment clearer, and removes the duplicate comment from fpsimd.h. The WARN_ON() currently present in __bit_to_vq() confuses the intended use of this helper. Since these are low-level helpers not intended for general-purpose use anyway, it is better not to make guesses about how these functions will be used: rather, this patch removes the WARN_ON() and relies on callers to use the helpers sensibly. Suggested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-16arm64: vdso: Fix clock_getres() for CLOCK_REALTIMEVincenzo Frascino1-0/+1
clock_getres() in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; where 'hrtimer_resolution' depends on whether or not high resolution timers are enabled, which is a runtime decision. The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this by exposing 'hrtimer_resolution' in the vDSO datapage and returning that instead. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> [will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: Use the correct style for SPDX License IdentifierNishad Kamdar3-3/+3
This patch corrects the SPDX License Identifier style in the arm64 Hardware Architecture related files. Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: instrument smp_{load_acquire,store_release}Mark Rutland1-9/+15
Our __smp_store_release() and __smp_load_acquire() macros use inline assembly, which is opaque to kasan. This means that kasan can't catch erroneous use of these. This patch adds kasan instrumentation to both. Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> [will: consistently use *p as argument to sizeof] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: mm: check virtual addr in virt_to_page() if CONFIG_DEBUG_VIRTUAL=yMiles Chen1-1/+1
This change uses the original virt_to_page() (the one with __pa()) to check the given virtual address if CONFIG_DEBUG_VIRTUAL=y. Recently, I worked on a bug: a driver passes a symbol address to dma_map_single() and the virt_to_page() (called by dma_map_single()) does not work for non-linear addresses after commit 9f2875912dac ("arm64: mm: restrict virt_to_page() to the linear mapping"). I tried to trap the bug by enabling CONFIG_DEBUG_VIRTUAL but it did not work - bacause the commit removes the __pa() from virt_to_page() but CONFIG_DEBUG_VIRTUAL checks the virtual address in __pa()/__virt_to_phys(). A simple solution is to use the original virt_to_page() (the one with__pa()) if CONFIG_DEBUG_VIRTUAL=y. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: Advertise ARM64_HAS_DCPODP cpu featureAndrew Murray1-1/+2
Advertise ARM64_HAS_DCPODP when both DC CVAP and DC CVADP are supported. Even though we don't use this feature now, we provide it for consistency with DCPOP and anticipate it being used in the future. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: add CVADP support to the cache maintenance helperAndrew Murray1-0/+4
Allow users of dcache_by_line_op to specify cvadp as an op. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: Expose DC CVADP to userspaceAndrew Murray1-0/+1
ARMv8.5 builds upon the ARMv8.2 DC CVAP instruction by introducing a DC CVADP instruction which cleans the data cache to the point of deep persistence. Let's expose this support via the arm64 ELF hwcaps. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: Handle trapped DC CVADPAndrew Murray1-1/+2
The ARMv8.5 DC CVADP instruction may be trapped to EL1 via SCTLR_EL1.UCI therefore let's provide a handler for it. Just like the CVAP instruction we use a 'sys' instruction instead of the 'dc' alias to avoid build issues with older toolchains. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: HWCAP: encapsulate elf_hwcapAndrew Murray2-15/+7
The introduction of AT_HWCAP2 introduced accessors which ensure that hwcap features are set and tested appropriately. Let's now mandate access to elf_hwcap via these accessors by making elf_hwcap static within cpufeature.c. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: HWCAP: add support for AT_HWCAP2Andrew Murray2-11/+63
As we will exhaust the first 32 bits of AT_HWCAP let's start exposing AT_HWCAP2 to userspace to give us up to 64 caps. Whilst it's possible to use the remaining 32 bits of AT_HWCAP, we prefer to expand into AT_HWCAP2 in order to provide a consistent view to userspace between ILP32 and LP64. However internal to the kernel we prefer to continue to use the full space of elf_hwcap. To reduce complexity and allow for future expansion, we now represent hwcaps in the kernel as ordinals and use a KERNEL_HWCAP_ prefix. This allows us to support automatic feature based module loading for all our hwcaps. We introduce cpu_set_feature to set hwcaps which complements the existing cpu_have_feature helper. These helpers allow us to clean up existing direct uses of elf_hwcap and reduce any future effort required to move beyond 64 caps. For convenience we also introduce cpu_{have,set}_named_feature which makes use of the cpu_feature macro to allow providing a hwcap name without a {KERNEL_}HWCAP_ prefix. Signed-off-by: Andrew Murray <andrew.murray@arm.com> [will: use const_ilog2() and tweak documentation] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-15arch: add pidfd and io_uring syscalls everywhereArnd Bergmann2-1/+9
Add the io_uring and pidfd_send_signal system calls to all architectures. These system calls are designed to handle both native and compat tasks, so all entries are the same across architectures, only arm-compat and the generic tale still use an old format. Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> (s390) Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-04-12arm64: ptrace: Add function argument access APIMasami Hiramatsu1-0/+22
Add regs_get_argument() which returns N th argument of the function call. On arm64, it supports up to 8th argument. Note that this chooses most probably assignment, in some case it can be incorrect (e.g. passing data structure or floating point etc.) This enables ftrace kprobe events to access kernel function arguments via $argN syntax. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> [will: tidied up the comment a bit] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-12arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result valueWill Deacon1-8/+8
Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't explicitly set the return value on the non-faulting path and instead leaves it holding the result of the underlying atomic operation. This means that any FUTEX_WAKE_OP atomic operation which computes a non-zero value will be reported as having failed. Regrettably, I wrote the buggy code back in 2011 and it was upstreamed as part of the initial arm64 support in 2012. The reasons we appear to get away with this are: 1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get exercised by futex() test applications 2. If the result of the atomic operation is zero, the system call behaves correctly 3. Prior to version 2.25, the only operation used by GLIBC set the futex to zero, and therefore worked as expected. From 2.25 onwards, FUTEX_WAKE_OP is not used by GLIBC at all. Fix the implementation by ensuring that the return value is either 0 to indicate that the atomic operation completed successfully, or -EFAULT if we encountered a fault when accessing the user mapping. Cc: <stable@kernel.org> Fixes: 6170a97460db ("arm64: Atomic operations") Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-10arm64: compat: Reduce address limitVincenzo Frascino1-0/+8
Currently, compat tasks running on arm64 can allocate memory up to TASK_SIZE_32 (UL(0x100000000)). This means that mmap() allocations, if we treat them as returning an array, are not compliant with the sections 6.5.8 of the C standard (C99) which states that: "If the expression P points to an element of an array object and the expression Q points to the last element of the same array object, the pointer expression Q+1 compares greater than P". Redefine TASK_SIZE_32 to address the issue. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> [will: fixed typo in comment] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-10Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar1-36/+6
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-09arm64: mm: enable per pmd page table lockYu Zhao2-2/+15
Switch from per mm_struct to per pmd page table lock by enabling ARCH_ENABLE_SPLIT_PMD_PTLOCK. This provides better granularity for large system. I'm not sure if there is contention on mm->page_table_lock. Given the option comes at no cost (apart from initializing more spin locks), why not enable it now. We only do so when pmd is not folded, so we don't mistakenly call pgtable_pmd_page_ctor() on pud or p4d in pgd_pgtable_alloc(). Signed-off-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Will Deacon <will.deacon@arm.com>