all: replace collide mode by `async` call property

Replace the currently existing straightforward approach to race triggering
(that was almost entirely implemented inside syz-executor) with a more
flexible one.

The `async` call property instructs syz-executor not to block until the
call has completed execution and proceed immediately to the next call.
The decision on what calls to mark with `async` is made by syz-fuzzer.

Ultimately this should let us implement more intelligent race provoking
strategies as well as make more fine-grained reproducers.

1 files changed, 11 insertions, 0 deletions

diff --git a/pkg/csource/csource.go b/pkg/csource/csource.go
index 68f961526..32e01ff1e 100644
--- a/pkg/csource/csource.go
+++ b/pkg/csource/csource.go
@@ -115,6 +115,17 @@ func (ctx *context) generateSource() ([]byte, error) {
 		}
 	}
 	replacements["CALL_TIMEOUT_MS"] = timeoutExpr
+	if ctx.p.RequiredFeatures().Async {
+		conditions := []string{}
+		for idx, call := range ctx.p.Calls {
+			if !call.Props.Async {
+				continue
+			}
+			conditions = append(conditions, fmt.Sprintf("call == %v", idx))
+		}
+		replacements["ASYNC_CONDITIONS"] = strings.Join(conditions, " || ")
+	}
+
 	result, err := createCommonHeader(ctx.p, mmapProg, replacements, ctx.opts)
 	if err != nil {
 		return nil, err