executor: Protect the coverage buffer

Add functions to protect and unprotect the coverage buffer. The buffer is
protected from being written to while tracing. When the trace data is
sorted we need to make it read/write, but can return it to read only after
this has completed.

Leave the first page as read/write as we need to clear the length field.

1 files changed, 8 insertions, 0 deletions

diff --git a/executor/nocover.h b/executor/nocover.h
index 3b23f66ab..e23d69162 100644
--- a/executor/nocover.h
+++ b/executor/nocover.h
@@ -17,7 +17,15 @@ static void cover_collect(cover_t* cov)
 {
 }
 
+static void cover_protect(cover_t* cov)
+{
+}
+
 #if SYZ_EXECUTOR_USES_SHMEM
+static void cover_unprotect(cover_t* cov)
+{
+}
+
 static bool cover_check(uint32 pc)
 {
 	return true;