pkg/ipc: consistently set ENOSYS for non-executed syscalls

Currently we set errno=999 in executor for non-finished syscalls,
but syscalls that were not even started still have errno=0.
They also don't have Executed flag, but it's still handy to have
a non-0 errno when the call is not successful.

2 files changed, 8 insertions, 1 deletions

diff --git a/executor/executor.cc b/executor/executor.cc
index c5bd43f7b..92b344e56 100644
--- a/executor/executor.cc
+++ b/executor/executor.cc
@@ -1114,7 +1114,7 @@ void copyout_call_results(thread_t* th)
 
 void write_call_output(thread_t* th, bool finished)
 {
-	uint32 reserrno = 999;
+	uint32 reserrno = ENOSYS;
 	const bool blocked = finished && th != last_scheduled;
 	uint32 call_flags = call_flag_executed | (blocked ? call_flag_blocked : 0);
 	if (finished) {
diff --git a/pkg/ipc/ipc.go b/pkg/ipc/ipc.go
index 818c88a84..6185a6181 100644
--- a/pkg/ipc/ipc.go
+++ b/pkg/ipc/ipc.go
@@ -12,6 +12,7 @@ import (
 	"slices"
 	"strings"
 	"sync"
+	"syscall"
 	"time"
 	"unsafe"
 
@@ -382,6 +383,12 @@ func (env *Env) parseOutput(opts *ExecOpts, ncalls int) (*ProgInfo, error) {
 		return nil, fmt.Errorf("failed to read number of calls")
 	}
 	info := &ProgInfo{Calls: make([]CallInfo, ncalls)}
+	for i := range info.Calls {
+		// Store some unsuccessful errno in the case we won't get any result.
+		// It also won't have CallExecuted flag, but it's handy to make it
+		// look failed based on errno as well.
+		info.Calls[i].Errno = int(syscall.ENOSYS)
+	}
 	extraParts := make([]CallInfo, 0)
 	for i := uint32(0); i < ncmd; i++ {
 		if len(out) < int(unsafe.Sizeof(callReply{})) {