pm24.git/arch, branch rust-6.14

Merge tag 'arc-6.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2024-12-15T23:38:12Z

Pull ARC fixes from Vineet Gupta: - Sundry build and misc fixes * tag 'arc-6.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: build: Try to guess GCC variant of cross compiler ARC: bpf: Correct conditional check in 'check_jmp_32' ARC: dts: Replace deprecated snps,nr-gpios property for snps,dw-apb-gpio-port devices ARC: build: Use __force to suppress per-CPU cmpxchg warnings ARC: fix reference of dependency for PAE40 config ARC: build: disallow invalid PAE40 + 4K page config arc: rename aux.h to arc_aux.h

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2024-12-15T17:26:13Z

Pull kvm fixes from Paolo Bonzini: "ARM64: - Fix confusion with implicitly-shifted MDCR_EL2 masks breaking SPE/TRBE initialization - Align nested page table walker with the intended memory attribute combining rules of the architecture - Prevent userspace from constraining the advertised ASID width, avoiding horrors of guest TLBIs not matching the intended context in hardware - Don't leak references on LPIs when insertion into the translation cache fails RISC-V: - Replace csr_write() with csr_set() for HVIEN PMU overflow bit x86: - Cache CPUID.0xD XSTATE offsets+sizes during module init On Intel's Emerald Rapids CPUID costs hundreds of cycles and there are a lot of leaves under 0xD. Getting rid of the CPUIDs during nested VM-Enter and VM-Exit is planned for the next release, for now just cache them: even on Skylake that is 40% faster" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Cache CPUID.0xD XSTATE offsets+sizes during module init RISC-V: KVM: Fix csr_write -> csr_set for HVIEN PMU overflow bit KVM: arm64: vgic-its: Add error handling in vgic_its_cache_translation KVM: arm64: Do not allow ID_AA64MMFR0_EL1.ASIDbits to be overridden KVM: arm64: Fix S1/S2 combination when FWB==1 and S2 has Device memory type arm64: Fix usage of new shifted MDCR_EL2 values

ARC: build: Try to guess GCC variant of cross compiler

2024-12-13T22:39:24Z

ARC GCC compiler is packaged starting from Fedora 39i and the GCC variant of cross compile tools has arc-linux-gnu- prefix and not arc-linux-. This is causing that CROSS_COMPILE variable is left unset. This change allows builds without need to supply CROSS_COMPILE argument if distro package is used. Before this change: $ make -j 128 ARCH=arc W=1 drivers/infiniband/hw/mlx4/ gcc: warning: ‘-mcpu=’ is deprecated; use ‘-mtune=’ or ‘-march=’ instead gcc: error: unrecognized command-line option ‘-mmedium-calls’ gcc: error: unrecognized command-line option ‘-mlock’ gcc: error: unrecognized command-line option ‘-munaligned-access’ [1] https://packages.fedoraproject.org/pkgs/cross-gcc/gcc-arc-linux-gnu/index.html Signed-off-by: Leon Romanovsky Signed-off-by: Vineet Gupta

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2024-12-13T22:23:09Z

Pull arm64 fixes from Catalin Marinas: - arm64 stacktrace: address some fallout from the recent changes to unwinding across exception boundaries - Ensure the arm64 signal delivery failure is recoverable - only override the return registers after all the user accesses took place - Fix the arm64 kselftest access to SVCR - only when SME is detected * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: kselftest/arm64: abi: fix SVCR detection arm64: signal: Ensure signal delivery failure is recoverable arm64: stacktrace: Don't WARN when unwinding other tasks arm64: stacktrace: Skip reporting LR at exception boundaries

Merge tag 'riscv-for-linus-6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2024-12-13T22:18:18Z

Pull RISC-V fixes from Palmer Dabbelt: - avoid taking a mutex while resolving jump_labels in the mutex implementation - avoid trying to resolve the early boot DT pointer via the linear map - avoid trying to IPI kfence TLB flushes, as kfence might flush with IRQs disabled - avoid calling PMD destructors on PMDs that were never constructed * tag 'riscv-for-linus-6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: mm: Do not call pmd dtor on vmemmap page table teardown riscv: Fix IPIs usage in kfence_protect_page() riscv: Fix wrong usage of __pa() on a fixmap address riscv: Fixup boot failure when CONFIG_DEBUG_RT_MUTEXES=y

Merge tag 'kvm-riscv-fixes-6.13-1' of https://github.com/kvm-riscv/linux into HEAD

2024-12-13T18:59:20Z

KVM/riscv fixes for 6.13, take #1 - Replace csr_write() with csr_set() for HVIEN PMU overflow bit

KVM: x86: Cache CPUID.0xD XSTATE offsets+sizes during module init

2024-12-13T18:58:10Z

Snapshot the output of CPUID.0xD.[1..n] during kvm.ko initiliaization to avoid the overead of CPUID during runtime. The offset, size, and metadata for CPUID.0xD.[1..n] sub-leaves does not depend on XCR0 or XSS values, i.e. is constant for a given CPU, and thus can be cached during module load. On Intel's Emerald Rapids, CPUID is *wildly* expensive, to the point where recomputing XSAVE offsets and sizes results in a 4x increase in latency of nested VM-Enter and VM-Exit (nested transitions can trigger xstate_required_size() multiple times per transition), relative to using cached values. The issue is easily visible by running `perf top` while triggering nested transitions: kvm_update_cpuid_runtime() shows up at a whopping 50%. As measured via RDTSC from L2 (using KVM-Unit-Test's CPUID VM-Exit test and a slightly modified L1 KVM to handle CPUID in the fastpath), a nested roundtrip to emulate CPUID on Skylake (SKX), Icelake (ICX), and Emerald Rapids (EMR) takes: SKX 11650 ICX 22350 EMR 28850 Using cached values, the latency drops to: SKX 6850 ICX 9000 EMR 7900 The underlying issue is that CPUID itself is slow on ICX, and comically slow on EMR. The problem is exacerbated on CPUs which support XSAVES and/or XSAVEC, as KVM invokes xstate_required_size() twice on each runtime CPUID update, and because there are more supported XSAVE features (CPUID for supported XSAVE feature sub-leafs is significantly slower). SKX: CPUID.0xD.2 = 348 cycles CPUID.0xD.3 = 400 cycles CPUID.0xD.4 = 276 cycles CPUID.0xD.5 = 236 cycles EMR: CPUID.0xD.2 = 1138 cycles CPUID.0xD.3 = 1362 cycles CPUID.0xD.4 = 1068 cycles CPUID.0xD.5 = 910 cycles CPUID.0xD.6 = 914 cycles CPUID.0xD.7 = 1350 cycles CPUID.0xD.8 = 734 cycles CPUID.0xD.9 = 766 cycles CPUID.0xD.10 = 732 cycles CPUID.0xD.11 = 718 cycles CPUID.0xD.12 = 734 cycles CPUID.0xD.13 = 1700 cycles CPUID.0xD.14 = 1126 cycles CPUID.0xD.15 = 898 cycles CPUID.0xD.16 = 716 cycles CPUID.0xD.17 = 748 cycles CPUID.0xD.18 = 776 cycles Note, updating runtime CPUID information multiple times per nested transition is itself a flaw, especially since CPUID is a mandotory intercept on both Intel and AMD. E.g. KVM doesn't need to ensure emulated CPUID state is up-to-date while running L2. That flaw will be fixed in a future patch, as deferring runtime CPUID updates is more subtle than it appears at first glance, the benefits aren't super critical to have once the XSAVE issue is resolved, and caching CPUID output is desirable even if KVM's updates are deferred. Cc: Jim Mattson Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Message-ID: <20241211013302.1347853-2-seanjc@google.com> Signed-off-by: Paolo Bonzini

arm64: signal: Ensure signal delivery failure is recoverable

2024-12-13T14:13:27Z

Commit eaf62ce1563b ("arm64/signal: Set up and restore the GCS context for signal handlers") introduced a potential failure point at the end of setup_return(). This is unfortunate as it is too late to deliver a SIGSEGV: if that SIGSEGV is handled, the subsequent sigreturn will end up returning to the original handler, which is not the intention (since we failed to deliver that signal). Make sure this does not happen by calling gcs_signal_entry() at the very beginning of setup_return(), and add a comment just after to discourage error cases being introduced from that point onwards. While at it, also take care of copy_siginfo_to_user(): since it may fail, we shouldn't be calling it after setup_return() either. Call it before setup_return() instead, and move the setting of X1/X2 inside setup_return() where it belongs (after the "point of no failure"). Background: the first part of setup_rt_frame(), including setup_sigframe(), has no impact on the execution of the interrupted thread. The signal frame is written to the stack, but the stack pointer remains unchanged. Failure at this stage can be recovered by a SIGSEGV handler, and sigreturn will restore the original context, at the point where the original signal occurred. On the other hand, once setup_return() has updated registers including SP, the thread's control flow has been modified and we must deliver the original signal. Fixes: eaf62ce1563b ("arm64/signal: Set up and restore the GCS context for signal handlers") Signed-off-by: Kevin Brodsky Reviewed-by: Dave Martin Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20241210160940.2031997-1-kevin.brodsky@arm.com Signed-off-by: Catalin Marinas

Merge tag 'for-linus' of https://github.com/openrisc/linux

2024-12-12T21:20:53Z

Pull OpenRISC fixes from Stafford Horne: - Fix from Masahiro Yamada to fix 6.13 OpenRISC boot issues after vmlinux.lds.h symbol ordering was changed - Code formatting fixups from Geert * tag 'for-linus' of https://github.com/openrisc/linux: openrisc: Fix misalignments in head.S openrisc: place exception table at the head of vmlinux

arm64: stacktrace: Don't WARN when unwinding other tasks

2024-12-12T16:23:15Z

The arm64 stacktrace code has a few error conditions where a WARN_ON_ONCE() is triggered before the stacktrace is terminated and an error is returned to the caller. The conditions shouldn't be triggered when unwinding the current task, but it is possible to trigger these when unwinding another task which is not blocked, as the stack of that task is concurrently modified. Kent reports that these warnings can be triggered while running filesystem tests on bcachefs, which calls the stacktrace code directly. To produce a meaningful stacktrace of another task, the task in question should be blocked, but the stacktrace code is expected to be robust to cases where it is not blocked. Note that this is purely about not unuduly scaring the user and/or crashing the kernel; stacktraces in such cases are meaningless and may leak kernel secrets from the stack of the task being unwound. Ideally we'd pin the task in a blocked state during the unwind, as we do for /proc/${PID}/wchan since commit: 42a20f86dc19f928 ("sched: Add wrapper for get_wchan() to keep task blocked") ... but a bunch of places don't do that, notably /proc/${PID}/stack, where we don't pin the task in a blocked state, but do restrict the output to privileged users since commit: f8a00cef17206ecd ("proc: restrict kernel stack dumps to root") ... and so it's possible to trigger these warnings accidentally, e.g. by reading /proc/*/stack (as root): | for n in $(seq 1 10); do | while true; do cat /proc/*/stack > /dev/null 2>&1; done & | done | ------------[ cut here ]------------ | WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370 | Modules linked in: | CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2 | Hardware name: linux,dummy-virt (DT) | pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) | pc : arch_stack_walk+0x1c8/0x370 | lr : arch_stack_walk+0x1b0/0x370 | sp : ffff800080773890 | x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038 | x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000 | x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0 | x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000 | x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 | x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 | x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 | x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818 | x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0 | x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000 | Call trace: | arch_stack_walk+0x1c8/0x370 (P) | stack_trace_save_tsk+0x8c/0x108 | proc_pid_stack+0xb0/0x134 | proc_single_show+0x60/0x120 | seq_read_iter+0x104/0x438 | seq_read+0xf8/0x140 | vfs_read+0xc4/0x31c | ksys_read+0x70/0x108 | __arm64_sys_read+0x1c/0x28 | invoke_syscall+0x48/0x104 | el0_svc_common.constprop.0+0x40/0xe0 | do_el0_svc+0x1c/0x28 | el0_svc+0x30/0xcc | el0t_64_sync_handler+0x10c/0x138 | el0t_64_sync+0x198/0x19c | ---[ end trace 0000000000000000 ]--- Fix this by only warning when unwinding the current task. When unwinding another task the error conditions will be handled by returning an error without producing a warning. The two warnings in kunwind_next_frame_record_meta() were added recently as part of commit: c2c6b27b5aa14fa2 ("arm64: stacktrace: unwind exception boundaries") The warning when recovering the fgraph return address has changed form many times, but was originally introduced back in commit: 9f416319f40cd857 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing") Fixes: c2c6b27b5aa1 ("arm64: stacktrace: unwind exception boundaries") Fixes: 9f416319f40c ("arm64: fix unwind_frame() for filtered out fn for function graph tracing") Signed-off-by: Mark Rutland Reported-by: Kent Overstreet Cc: Kees Cook Cc: Peter Zijlstra Cc: Will Deacon Link: https://lore.kernel.org/r/20241211140704.2498712-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas