From 91f1ac731933ac1fe0f9ef30f4c9d06fa4031021 Mon Sep 17 00:00:00 2001 From: Michael Pratt Date: Tue, 17 Dec 2019 13:57:39 -0800 Subject: Mark enableCpuidFault nosplit This is called after fork, so it must be nosplit. Updates #1408 PiperOrigin-RevId: 286053054 --- pkg/sentry/platform/ptrace/subprocess_amd64.go | 10 ++++++++-- pkg/sentry/platform/ptrace/subprocess_arm64.go | 2 ++ 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/pkg/sentry/platform/ptrace/subprocess_amd64.go b/pkg/sentry/platform/ptrace/subprocess_amd64.go index a55cff507..606dc2b1d 100644 --- a/pkg/sentry/platform/ptrace/subprocess_amd64.go +++ b/pkg/sentry/platform/ptrace/subprocess_amd64.go @@ -167,8 +167,14 @@ func patchSignalInfo(regs *syscall.PtraceRegs, signalInfo *arch.SignalInfo) { } } -// enableCpuidFault enable cpuid-faulting; this may fail on older kernels or hardware, -// so we just disregard the result. Host CPUID will be enabled. +// enableCpuidFault enables cpuid-faulting. +// +// This may fail on older kernels or hardware, so we just disregard the result. +// Host CPUID will be enabled. +// +// This is safe to call in an afterFork context. +// +//go:nosplit func enableCpuidFault() { syscall.RawSyscall6(syscall.SYS_ARCH_PRCTL, linux.ARCH_SET_CPUID, 0, 0, 0, 0, 0) } diff --git a/pkg/sentry/platform/ptrace/subprocess_arm64.go b/pkg/sentry/platform/ptrace/subprocess_arm64.go index aed34e7ee..62a686ee7 100644 --- a/pkg/sentry/platform/ptrace/subprocess_arm64.go +++ b/pkg/sentry/platform/ptrace/subprocess_arm64.go @@ -151,6 +151,8 @@ func patchSignalInfo(regs *syscall.PtraceRegs, signalInfo *arch.SignalInfo) { } // Noop on arm64. +// +//go:nosplit func enableCpuidFault() { } -- cgit v1.2.3