commit this WIP stuff to a feature branch

internal/mem/funcs.go

@@ -0,0 +1,81 @@
+package mem
+
+import (
+	"encoding/binary"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+func getStdRIP(r *unix.PtraceRegs) (rip uint64) {
+
+	return
+}
+
+func getRIP(r *unix.PtraceRegs) uint64 {
+	// amd64
+	if binary.Size(unix.PtraceRegs{}) == 216 {
+		return r.Rip
+	}
+	// arm64
+	type regsArm64 struct{ Regs [18]uint64 }
+	return (*regsArm64)(unsafe.Pointer(r)).Regs[16] // PC
+}
+
+func setRIP(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
+	if binary.Size(unix.PtraceRegs{}) == 216 {
+		r.Rip = v
+	} else {
+		type regsArm64 struct{ Regs [18]uint64 }
+		(*regsArm64)(unsafe.Pointer(r)).Regs[16] = v
+	}
+	return r
+}
+
+func getRSP(r *unix.PtraceRegs) uint64 {
+	if binary.Size(unix.PtraceRegs{}) == 216 {
+		return r.Rsp
+	}
+	type regsArm64 struct{ Regs [18]uint64 }
+	return (*regsArm64)(unsafe.Pointer(r)).Regs[17] // SP
+}
+
+func setRSP(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
+	if binary.Size(unix.PtraceRegs{}) == 216 {
+		r.Rsp = v
+	} else {
+		type regsArm64 struct{ Regs [18]uint64 }
+		(*regsArm64)(unsafe.Pointer(r)).Regs[17] = v
+	}
+	return r
+}
+
+func setArg0(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
+	if binary.Size(unix.PtraceRegs{}) == 216 {
+		r.Rdi = v
+	} else {
+		type regsArm64 struct{ Regs [18]uint64 }
+		(*regsArm64)(unsafe.Pointer(r)).Regs[0] = v // X0
+	}
+	return r
+}
+
+func setArg1(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
+	if binary.Size(unix.PtraceRegs{}) == 216 {
+		r.Rsi = v
+	} else {
+		type regsArm64 struct{ Regs [18]uint64 }
+		(*regsArm64)(unsafe.Pointer(r)).Regs[1] = v // X1
+	}
+	return r
+}
+
+func setArg2(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
+	if binary.Size(unix.PtraceRegs{}) == 216 {
+		r.Rdx = v
+	} else {
+		type regsArm64 struct{ Regs [18]uint64 }
+		(*regsArm64)(unsafe.Pointer(r)).Regs[2] = v // X2
+	}
+	return r
+}