diff options
| author | Adin Scannell <ascannell@google.com> | 2018-07-16 22:02:03 -0700 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2018-07-16 22:02:58 -0700 |
| commit | 29e00c943a61dfcfd4ac8d3f6f526eab641c44a6 (patch) | |
| tree | f7cdb0c59c8363b3a4e5737e17b1b4e423bfc05a /pkg/sentry/platform/ptrace | |
| parent | 14d06064d26b1cd9e2ccad08ebe997e704092eb8 (diff) | |
Add CPUID faulting for ptrace and KVM.
PiperOrigin-RevId: 204858314
Change-Id: I8252bf8de3232a7a27af51076139b585e73276d4
Diffstat (limited to 'pkg/sentry/platform/ptrace')
| -rw-r--r-- | pkg/sentry/platform/ptrace/ptrace.go | 15 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/subprocess_linux.go | 5 |
2 files changed, 16 insertions, 4 deletions
diff --git a/pkg/sentry/platform/ptrace/ptrace.go b/pkg/sentry/platform/ptrace/ptrace.go index 05f8b1d05..a44f549a2 100644 --- a/pkg/sentry/platform/ptrace/ptrace.go +++ b/pkg/sentry/platform/ptrace/ptrace.go @@ -101,9 +101,11 @@ func (c *context) Switch(as platform.AddressSpace, ac arch.Context, cpu int32) ( s := as.(*subprocess) isSyscall := s.switchToApp(c, ac) - var faultSP *subprocess - var faultAddr usermem.Addr - var faultIP usermem.Addr + var ( + faultSP *subprocess + faultAddr usermem.Addr + faultIP usermem.Addr + ) if !isSyscall && linux.Signal(c.signalInfo.Signo) == linux.SIGSEGV { faultSP = s faultAddr = usermem.Addr(c.signalInfo.Addr()) @@ -161,7 +163,12 @@ func (c *context) Switch(as platform.AddressSpace, ac arch.Context, cpu int32) ( lastFaultIP == faultIP { at.Write = true } - return &c.signalInfo, at, platform.ErrContextSignal + + // Unfortunately, we have to unilaterally return ErrContextSignalCPUID + // here, in case this fault was generated by a CPUID exception. There + // is no way to distinguish between CPUID-generated faults and regular + // page faults. + return &c.signalInfo, at, platform.ErrContextSignalCPUID } // Interrupt interrupts the running guest application associated with this context. diff --git a/pkg/sentry/platform/ptrace/subprocess_linux.go b/pkg/sentry/platform/ptrace/subprocess_linux.go index b3f2ebb20..b212bbdfe 100644 --- a/pkg/sentry/platform/ptrace/subprocess_linux.go +++ b/pkg/sentry/platform/ptrace/subprocess_linux.go @@ -20,6 +20,7 @@ import ( "fmt" "syscall" + "gvisor.googlesource.com/gvisor/pkg/abi/linux" "gvisor.googlesource.com/gvisor/pkg/sentry/arch" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/procid" ) @@ -85,6 +86,10 @@ func createStub() (*thread, error) { syscall.RawSyscall(syscall.SYS_EXIT, uintptr(errno), 0, 0) } + // Enable cpuid-faulting; this may fail on older kernels or hardware, + // so we just disregard the result. Host CPUID will be enabled. + syscall.RawSyscall(syscall.SYS_ARCH_PRCTL, linux.ARCH_SET_CPUID, 0, 0) + // Call the stub; should not return. stubCall(stubStart, ppid) panic("unreachable") |