1 files changed, 77 insertions, 0 deletions
diff --git a/runsc/boot/compat_amd64.go b/runsc/boot/compat_amd64.go
new file mode 100644
index 000000000..99df5e614
--- /dev/null
+++ b/runsc/boot/compat_amd64.go
@@ -0,0 +1,77 @@
+// Copyright 2018 The gVisor Authors.
+//
+// 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"
+)
+
+// reportLimit is the max number of events that should be reported per tracker.
+const reportLimit = 100
+
+// argsTracker reports only once for each different combination of arguments.
+// It's used for generic syscalls like ioctl to report once per 'cmd'.
+type argsTracker struct {
+	// argsIdx is the syscall arguments to use as unique ID.
+	argsIdx  []int
+	reported map[string]struct{}
+	count    int
+}
+
+func newArgsTracker(argIdx ...int) *argsTracker {
+	return &argsTracker{argsIdx: argIdx, reported: make(map[string]struct{})}
+}
+
+// cmd returns the command based on the syscall argument index.
+func (a *argsTracker) key(regs *rpb.AMD64Registers) string {
+	var rv string
+	for _, idx := range a.argsIdx {
+		rv += fmt.Sprintf("%d|", argVal(idx, regs))
+	}
+	return rv
+}
+
+func argVal(argIdx int, regs *rpb.AMD64Registers) uint32 {
+	switch argIdx {
+	case 0:
+		return uint32(regs.Rdi)
+	case 1:
+		return uint32(regs.Rsi)
+	case 2:
+		return uint32(regs.Rdx)
+	case 3:
+		return uint32(regs.R10)
+	case 4:
+		return uint32(regs.R8)
+	case 5:
+		return uint32(regs.R9)
+	}
+	panic(fmt.Sprintf("invalid syscall argument index %d", argIdx))
+}
+
+func (a *argsTracker) shouldReport(regs *rpb.AMD64Registers) bool {
+	if a.count >= reportLimit {
+		return false
+	}
+	_, ok := a.reported[a.key(regs)]
+	return !ok
+}
+
+func (a *argsTracker) onReported(regs *rpb.AMD64Registers) {
+	a.count++
+	a.reported[a.key(regs)] = struct{}{}
+}