all: add the `rerun` call property

To be able to collide specific syscalls more precisely, we need to
repeat the process many times.

Introduce the `rerun` call property, which instructs `syz-executor` to
repeat the call the specified number of times. The intended use is:

call1() (rerun: 100, async)
call2() (rerun: 100)

For now, assign rerun values randomly to consecutive pairs of calls,
where the first one is async.

1 files changed, 9 insertions, 0 deletions

diff --git a/prog/minimization.go b/prog/minimization.go
index 89ed6e142..26a4dfc93 100644
--- a/prog/minimization.go
+++ b/prog/minimization.go
@@ -120,6 +120,15 @@ func minimizeCallProps(p0 *Prog, callIndex, callIndex0 int, pred func(*Prog, int
 		}
 	}
 
+	// Try to drop rerun.
+	if props.Rerun > 0 {
+		p := p0.Clone()
+		p.Calls[callIndex].Props.Rerun = 0
+		if pred(p, callIndex0) {
+			p0 = p
+		}
+	}
+
 	return p0
 }