Make some ptrace commands x86-only

Signed-off-by: Haibo Xu <haibo.xu@arm.com>
Change-Id: I9751f859332d433ca772d6b9733f5a5a64398ec7
PiperOrigin-RevId: 234877624

1 files changed, 89 insertions, 0 deletions

diff --git a/pkg/sentry/kernel/ptrace_amd64.go b/pkg/sentry/kernel/ptrace_amd64.go
new file mode 100644
index 000000000..1f88efca3
--- /dev/null
+++ b/pkg/sentry/kernel/ptrace_amd64.go
@@ -0,0 +1,89 @@
+// Copyright 2019 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build amd64
+
+package kernel
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+	"gvisor.googlesource.com/gvisor/pkg/syserror"
+)
+
+// ptraceArch implements arch-specific ptrace commands.
+func (t *Task) ptraceArch(target *Task, req int64, addr, data usermem.Addr) error {
+	switch req {
+	case linux.PTRACE_PEEKUSR: // aka PTRACE_PEEKUSER
+		n, err := target.Arch().PtracePeekUser(uintptr(addr))
+		if err != nil {
+			return err
+		}
+		_, err = t.CopyOut(data, n)
+		return err
+
+	case linux.PTRACE_POKEUSR: // aka PTRACE_POKEUSER
+		return target.Arch().PtracePokeUser(uintptr(addr), uintptr(data))
+
+	case linux.PTRACE_GETREGS:
+		// "Copy the tracee's general-purpose ... registers ... to the address
+		// data in the tracer. ... (addr is ignored.) Note that SPARC systems
+		// have the meaning of data and addr reversed ..."
+		_, err := target.Arch().PtraceGetRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	case linux.PTRACE_GETFPREGS:
+		_, err := target.Arch().PtraceGetFPRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	case linux.PTRACE_SETREGS:
+		_, err := target.Arch().PtraceSetRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	case linux.PTRACE_SETFPREGS:
+		_, err := target.Arch().PtraceSetFPRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	default:
+		return syserror.EIO
+	}
+}