pkg/runtest: fixes for fuchsia

Add simple fuchsia program, the one that is run during image testing.
Fix csource errno printing for fuchsia.
Fix creation of executable files (chmod is not implemented on fuchsia).
Check that we get signal/coverage from all syscalls.

1 files changed, 7 insertions, 1 deletions

diff --git a/pkg/csource/csource.go b/pkg/csource/csource.go
index 69be3ff2a..49431f655 100644
--- a/pkg/csource/csource.go
+++ b/pkg/csource/csource.go
@@ -247,7 +247,13 @@ func (ctx *context) emitCall(w *bytes.Buffer, call prog.ExecCall, ci int, haveCo
 	}
 	fmt.Fprintf(w, ");\n")
 	if trace {
-		fmt.Fprintf(w, "\tprintf(\"### call=%v errno=%%u\\n\", res == -1 ? errno : 0);\n", ci)
+		cast := ""
+		if !native && !strings.HasPrefix(callName, "syz_") {
+			// Potentially we casted a function returning int to a function returning long.
+			// So instead of long -1 we can get 0x00000000ffffffff. Sign extend it to long.
+			cast = "(long)(int)"
+		}
+		fmt.Fprintf(w, "\tprintf(\"### call=%v errno=%%u\\n\", %vres == -1 ? errno : 0);\n", ci, cast)
 	}
 }