pkg/csource: refactor generateCalls

Move call generation into a separate function.

Update #538

1 files changed, 48 insertions, 42 deletions

diff --git a/pkg/csource/csource.go b/pkg/csource/csource.go
index 51234fb2d..06bfd5d40 100644
--- a/pkg/csource/csource.go
+++ b/pkg/csource/csource.go
@@ -173,59 +173,22 @@ func (ctx *context) generateCalls(p prog.ExecProg, trace bool) ([]string, []uint
 			ctx.copyin(w, &csumSeq, copyin)
 		}
 
-		// Call itself.
 		if ctx.opts.Fault && ctx.opts.FaultCall == ci {
 			fmt.Fprintf(w, "\twrite_file(\"/sys/kernel/debug/failslab/ignore-gfp-wait\", \"N\");\n")
 			fmt.Fprintf(w, "\twrite_file(\"/sys/kernel/debug/fail_futex/ignore-private\", \"N\");\n")
 			fmt.Fprintf(w, "\tinject_fault(%v);\n", ctx.opts.FaultNth)
 		}
+		// Call itself.
 		callName := call.Meta.CallName
 		resCopyout := call.Index != prog.ExecNoCopyout
 		argCopyout := len(call.Copyout) != 0
-		emitCall := ctx.opts.EnableTun || callName != "syz_emit_ethernet" &&
-			callName != "syz_extract_tcp_res"
+		emitCall := ctx.opts.EnableTun ||
+			callName != "syz_emit_ethernet" &&
+				callName != "syz_extract_tcp_res"
 		// TODO: if we don't emit the call we must also not emit copyin, copyout and fault injection.
 		// However, simply skipping whole iteration breaks tests due to unused static functions.
 		if emitCall {
-			native := ctx.sysTarget.SyscallNumbers && !strings.HasPrefix(callName, "syz_")
-			fmt.Fprintf(w, "\t")
-			if resCopyout || argCopyout || trace {
-				fmt.Fprintf(w, "res = ")
-			}
-			if native {
-				fmt.Fprintf(w, "syscall(%v%v", ctx.sysTarget.SyscallPrefix, callName)
-			} else if strings.HasPrefix(callName, "syz_") {
-				fmt.Fprintf(w, "%v(", callName)
-			} else {
-				args := strings.Repeat(",long", len(call.Args))
-				if args != "" {
-					args = args[1:]
-				}
-				fmt.Fprintf(w, "((long(*)(%v))%v)(", args, callName)
-			}
-			for ai, arg := range call.Args {
-				if native || ai > 0 {
-					fmt.Fprintf(w, ", ")
-				}
-				switch arg := arg.(type) {
-				case prog.ExecArgConst:
-					if arg.Format != prog.FormatNative && arg.Format != prog.FormatBigEndian {
-						panic("sring format in syscall argument")
-					}
-					fmt.Fprintf(w, "%v", ctx.constArgToStr(arg))
-				case prog.ExecArgResult:
-					if arg.Format != prog.FormatNative && arg.Format != prog.FormatBigEndian {
-						panic("sring format in syscall argument")
-					}
-					fmt.Fprintf(w, "%v", ctx.resultArgToStr(arg))
-				default:
-					panic(fmt.Sprintf("unknown arg type: %+v", arg))
-				}
-			}
-			fmt.Fprintf(w, ");\n")
-			if trace {
-				fmt.Fprintf(w, "\tprintf(\"### call=%v errno=%%d\\n\", res == -1 ? errno : 0);\n", ci)
-			}
+			ctx.emitCall(w, call, ci, resCopyout || argCopyout, trace)
 		}
 
 		// Copyout.
@@ -237,6 +200,49 @@ func (ctx *context) generateCalls(p prog.ExecProg, trace bool) ([]string, []uint
 	return calls, p.Vars
 }
 
+func (ctx *context) emitCall(w *bytes.Buffer, call prog.ExecCall, ci int, haveCopyout, trace bool) {
+	callName := call.Meta.CallName
+	native := ctx.sysTarget.SyscallNumbers && !strings.HasPrefix(callName, "syz_")
+	fmt.Fprintf(w, "\t")
+	if haveCopyout || trace {
+		fmt.Fprintf(w, "res = ")
+	}
+	if native {
+		fmt.Fprintf(w, "syscall(%v%v", ctx.sysTarget.SyscallPrefix, callName)
+	} else if strings.HasPrefix(callName, "syz_") {
+		fmt.Fprintf(w, "%v(", callName)
+	} else {
+		args := strings.Repeat(",long", len(call.Args))
+		if args != "" {
+			args = args[1:]
+		}
+		fmt.Fprintf(w, "((long(*)(%v))%v)(", args, callName)
+	}
+	for ai, arg := range call.Args {
+		if native || ai > 0 {
+			fmt.Fprintf(w, ", ")
+		}
+		switch arg := arg.(type) {
+		case prog.ExecArgConst:
+			if arg.Format != prog.FormatNative && arg.Format != prog.FormatBigEndian {
+				panic("sring format in syscall argument")
+			}
+			fmt.Fprintf(w, "%v", ctx.constArgToStr(arg))
+		case prog.ExecArgResult:
+			if arg.Format != prog.FormatNative && arg.Format != prog.FormatBigEndian {
+				panic("sring format in syscall argument")
+			}
+			fmt.Fprintf(w, "%v", ctx.resultArgToStr(arg))
+		default:
+			panic(fmt.Sprintf("unknown arg type: %+v", arg))
+		}
+	}
+	fmt.Fprintf(w, ");\n")
+	if trace {
+		fmt.Fprintf(w, "\tprintf(\"### call=%v errno=%%d\\n\", res == -1 ? errno : 0);\n", ci)
+	}
+}
+
 func (ctx *context) generateCsumInet(w *bytes.Buffer, addr uint64, arg prog.ExecArgCsum, csumSeq int) {
 	fmt.Fprintf(w, "\tstruct csum_inet csum_%d;\n", csumSeq)
 	fmt.Fprintf(w, "\tcsum_inet_init(&csum_%d);\n", csumSeq)