support cgroup2

* only shim v2 runc v2 ("io.containerd.runc.v2") is supported
* only PID metrics is implemented. Others should be implemented in separate PRs.
* lots of code duplication in v1 metrics and v2 metrics. Dedupe should be separate PR.

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

vendor/github.com/cilium/ebpf/asm/jump.go

@@ -0,0 +1,109 @@
+package asm
+
+//go:generate stringer -output jump_string.go -type=JumpOp
+
+// JumpOp affect control flow.
+//
+//    msb      lsb
+//    +----+-+---+
+//    |OP  |s|cls|
+//    +----+-+---+
+type JumpOp uint8
+
+const jumpMask OpCode = aluMask
+
+const (
+	// InvalidJumpOp is returned by getters when invoked
+	// on non branch OpCodes
+	InvalidJumpOp JumpOp = 0xff
+	// Ja jumps by offset unconditionally
+	Ja JumpOp = 0x00
+	// JEq jumps by offset if r == imm
+	JEq JumpOp = 0x10
+	// JGT jumps by offset if r > imm
+	JGT JumpOp = 0x20
+	// JGE jumps by offset if r >= imm
+	JGE JumpOp = 0x30
+	// JSet jumps by offset if r & imm
+	JSet JumpOp = 0x40
+	// JNE jumps by offset if r != imm
+	JNE JumpOp = 0x50
+	// JSGT jumps by offset if signed r > signed imm
+	JSGT JumpOp = 0x60
+	// JSGE jumps by offset if signed r >= signed imm
+	JSGE JumpOp = 0x70
+	// Call builtin or user defined function from imm
+	Call JumpOp = 0x80
+	// Exit ends execution, with value in r0
+	Exit JumpOp = 0x90
+	// JLT jumps by offset if r < imm
+	JLT JumpOp = 0xa0
+	// JLE jumps by offset if r <= imm
+	JLE JumpOp = 0xb0
+	// JSLT jumps by offset if signed r < signed imm
+	JSLT JumpOp = 0xc0
+	// JSLE jumps by offset if signed r <= signed imm
+	JSLE JumpOp = 0xd0
+)
+
+// Return emits an exit instruction.
+//
+// Requires a return value in R0.
+func Return() Instruction {
+	return Instruction{
+		OpCode: OpCode(JumpClass).SetJumpOp(Exit),
+	}
+}
+
+// Op returns the OpCode for a given jump source.
+func (op JumpOp) Op(source Source) OpCode {
+	return OpCode(JumpClass).SetJumpOp(op).SetSource(source)
+}
+
+// Imm compares dst to value, and adjusts PC by offset if the condition is fulfilled.
+func (op JumpOp) Imm(dst Register, value int32, label string) Instruction {
+	if op == Exit || op == Call || op == Ja {
+		return Instruction{OpCode: InvalidOpCode}
+	}
+
+	return Instruction{
+		OpCode:    OpCode(JumpClass).SetJumpOp(op).SetSource(ImmSource),
+		Dst:       dst,
+		Offset:    -1,
+		Constant:  int64(value),
+		Reference: label,
+	}
+}
+
+// Reg compares dst to src, and adjusts PC by offset if the condition is fulfilled.
+func (op JumpOp) Reg(dst, src Register, label string) Instruction {
+	if op == Exit || op == Call || op == Ja {
+		return Instruction{OpCode: InvalidOpCode}
+	}
+
+	return Instruction{
+		OpCode:    OpCode(JumpClass).SetJumpOp(op).SetSource(RegSource),
+		Dst:       dst,
+		Src:       src,
+		Offset:    -1,
+		Reference: label,
+	}
+}
+
+// Label adjusts PC to the address of the label.
+func (op JumpOp) Label(label string) Instruction {
+	if op == Call {
+		return Instruction{
+			OpCode:    OpCode(JumpClass).SetJumpOp(Call),
+			Src:       R1,
+			Constant:  -1,
+			Reference: label,
+		}
+	}
+
+	return Instruction{
+		OpCode:    OpCode(JumpClass).SetJumpOp(op),
+		Offset:    -1,
+		Reference: label,
+	}
+}