csource: use tmp dir only when necessary

3 files changed, 30 insertions, 15 deletions

diff --git a/csource/common.go b/csource/common.go
index 048df6f52..8fa531598 100644
--- a/csource/common.go
+++ b/csource/common.go
@@ -150,7 +150,9 @@ static void install_segv_handler()
 	sigaction(SIGBUS, &sa, NULL);
 }
 
-static void use_temporary_dir() {
+#if defined(SYZ_EXECUTOR) || defined(SYZ_USE_TMP_DIR)
+static void use_temporary_dir()
+{
 	char tmpdir_template[] = "./syzkaller.XXXXXX";
 	char* tmpdir = mkdtemp(tmpdir_template);
 	if (!tmpdir)
@@ -160,6 +162,7 @@ static void use_temporary_dir() {
 	if (chdir(tmpdir))
 		fail("failed to chdir");
 }
+#endif
 
 #define NONFAILING(...)                                              \
 	{                                                            \
diff --git a/csource/csource.go b/csource/csource.go
index b41c5ca11..bc50bf2ea 100644
--- a/csource/csource.go
+++ b/csource/csource.go
@@ -34,6 +34,7 @@ type Options struct {
 
 	// These options allow for a more fine-tuned control over the generated C code.
 	EnableTun bool
+	UseTmpDir bool
 
 	// Generate code for use with repro package to prints log messages,
 	// which allows to distinguish between a hang and an absent crash.
@@ -75,7 +76,9 @@ func Write(p *prog.Prog, opts Options) ([]byte, error) {
 
 		fmt.Fprint(w, "int main()\n{\n")
 		fmt.Fprintf(w, "\tinstall_segv_handler();\n")
-		fmt.Fprintf(w, "\tuse_temporary_dir();\n")
+		if opts.UseTmpDir {
+			fmt.Fprintf(w, "\tuse_temporary_dir();\n")
+		}
 		fmt.Fprintf(w, "\tint pid = do_sandbox_%v(0, %v);\n", opts.Sandbox, opts.EnableTun)
 		fmt.Fprint(w, "\tint status = 0;\n")
 		fmt.Fprint(w, "\twhile (waitpid(pid, &status, __WALL) != pid) {}\n")
@@ -85,7 +88,9 @@ func Write(p *prog.Prog, opts Options) ([]byte, error) {
 		if opts.Procs <= 1 {
 			fmt.Fprint(w, "int main()\n{\n")
 			fmt.Fprintf(w, "\tinstall_segv_handler();\n")
-			fmt.Fprintf(w, "\tuse_temporary_dir();\n")
+			if opts.UseTmpDir {
+				fmt.Fprintf(w, "\tuse_temporary_dir();\n")
+			}
 			fmt.Fprintf(w, "\tint pid = do_sandbox_%v(0, %v);\n", opts.Sandbox, opts.EnableTun)
 			fmt.Fprint(w, "\tint status = 0;\n")
 			fmt.Fprint(w, "\twhile (waitpid(pid, &status, __WALL) != pid) {}\n")
@@ -96,7 +101,9 @@ func Write(p *prog.Prog, opts Options) ([]byte, error) {
 			fmt.Fprintf(w, "\tfor (i = 0; i < %v; i++) {\n", opts.Procs)
 			fmt.Fprint(w, "\t\tif (fork() == 0) {\n")
 			fmt.Fprintf(w, "\t\t\tinstall_segv_handler();\n")
-			fmt.Fprintf(w, "\t\t\tuse_temporary_dir();\n")
+			if opts.UseTmpDir {
+				fmt.Fprintf(w, "\t\t\tuse_temporary_dir();\n")
+			}
 			fmt.Fprintf(w, "\t\t\tint pid = do_sandbox_%v(i, %v);\n", opts.Sandbox, opts.EnableTun)
 			fmt.Fprint(w, "\t\t\tint status = 0;\n")
 			fmt.Fprint(w, "\t\t\twhile (waitpid(pid, &status, __WALL) != pid) {}\n")
@@ -327,6 +334,9 @@ func preprocessCommonHeader(opts Options, handled map[string]int) (string, error
 	if opts.EnableTun {
 		defines = append(defines, "SYZ_TUN_ENABLE")
 	}
+	if opts.UseTmpDir {
+		defines = append(defines, "SYZ_USE_TMP_DIR")
+	}
 	for name, _ := range handled {
 		defines = append(defines, "__NR_"+name)
 	}
diff --git a/csource/csource_test.go b/csource/csource_test.go
index 8ca7bb5ce..3e09a3019 100644
--- a/csource/csource_test.go
+++ b/csource/csource_test.go
@@ -35,18 +35,20 @@ func allOptionsPermutations() []Options {
 				for _, opt.Procs = range []int{1, 4} {
 					for _, opt.Sandbox = range []string{"none", "setuid", "namespace"} {
 						for _, opt.Repro = range []bool{false, true} {
-							for _, opt.EnableTun = range []bool{false, true} {
-								for _, opt.Fault = range []bool{false, true} {
-									if opt.Collide && !opt.Threaded {
-										continue
+							for _, opt.Fault = range []bool{false, true} {
+								for _, opt.EnableTun = range []bool{false, true} {
+									for _, opt.UseTmpDir = range []bool{false, true} {
+										if opt.Collide && !opt.Threaded {
+											continue
+										}
+										if !opt.Repeat && opt.Procs != 1 {
+											continue
+										}
+										if testing.Short() && opt.Procs != 1 {
+											continue
+										}
+										options = append(options, opt)
 									}
-									if !opt.Repeat && opt.Procs != 1 {
-										continue
-									}
-									if testing.Short() && opt.Procs != 1 {
-										continue
-									}
-									options = append(options, opt)
 								}
 							}
 						}