1 files changed, 54 insertions, 0 deletions
diff --git a/runsc/boot/compat_amd64.go b/runsc/boot/compat_amd64.go
new file mode 100644
index 000000000..2bb769a49
--- /dev/null
+++ b/runsc/boot/compat_amd64.go
@@ -0,0 +1,54 @@
+// Copyright 2018 Google LLC
+//
+// 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.
+
+package boot
+
+import (
+	"fmt"
+
+	rpb "gvisor.googlesource.com/gvisor/pkg/sentry/arch/registers_go_proto"
+)
+
+// cmdTracker reports only a single time for each different command argument in
+// the syscall. It's used for generic syscalls like ioctl to report once per
+// 'cmd'
+type cmdTracker struct {
+	// argIdx is the syscall argument index where the command is located.
+	argIdx int
+	cmds   map[uint32]struct{}
+}
+
+func newCmdTracker(argIdx int) *cmdTracker {
+	return &cmdTracker{argIdx: argIdx, cmds: make(map[uint32]struct{})}
+}
+
+// cmd returns the command based on the syscall argument index.
+func (c *cmdTracker) cmd(regs *rpb.AMD64Registers) uint32 {
+	switch c.argIdx {
+	case 0:
+		return uint32(regs.Rdi)
+	case 1:
+		return uint32(regs.Rsi)
+	}
+	panic(fmt.Sprintf("unsupported syscall argument index %d", c.argIdx))
+}
+
+func (c *cmdTracker) shouldReport(regs *rpb.AMD64Registers) bool {
+	_, ok := c.cmds[c.cmd(regs)]
+	return !ok
+}
+
+func (c *cmdTracker) onReported(regs *rpb.AMD64Registers) {
+	c.cmds[c.cmd(regs)] = struct{}{}
+}