Don't use logging in signal handler

PowerDNS · Feb 7, 2025 · 450db0b · 450db0b
1 parent 9088fb2
commit 450db0b
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Showing 2 changed files with 4 additions and 7 deletions.
diff --git a/pdns/recursordist/rec-main.cc b/pdns/recursordist/rec-main.cc
@@ -3329,15 +3329,12 @@ int main(int argc, char** argv)
     }
 
     ret = serviceMain(startupLog);
-    cerr << "serviceMain done" << endl;
     {
       std::lock_guard lock(g_doneRunning.mutex);
       g_doneRunning.done = true;
       g_doneRunning.condVar.notify_one();
     }
-    cerr << "g_doneRunning notify done" << endl;
     RecThreadInfo::joinThread0();
-    cerr << "joinThread0 done" << endl;
   }
   catch (const PDNSException& ae) {
     SLOG(g_log << Logger::Error << "Exception: " << ae.reason << endl,

diff --git a/pdns/recursordist/rec_channel_rec.cc b/pdns/recursordist/rec_channel_rec.cc
@@ -1378,21 +1378,21 @@ void doExitGeneric(bool nicely)
 #if defined(__SANITIZE_THREAD__)
   _exit(0); // regression test check for exit 0
 #endif
-  g_slog->withName("runtime")->info(Logr::Notice, "Exiting on user request");
+  // Not safe from a signal handler!
+  // g_slog->withName("runtime")->info(Logr::Notice, "Exiting on user request")
+  static const string msg("Exiting on user request\n");
+  (void)write(STDERR_FILENO, msg.data(), msg.size());
 
   if (!g_pidfname.empty()) {
     unlink(g_pidfname.c_str()); // we can at least try..
   }
 
   if (nicely) {
     RecursorControlChannel::stop = true;
-    cerr << "locking g_doneRunning.mutex" << endl;
     {
       std::unique_lock lock(g_doneRunning.mutex);
-      cerr << "locked g_doneRunning.mutex" << endl;
       g_doneRunning.condVar.wait(lock, [] { return g_doneRunning.done.load(); });
     }
-    cerr << "done locking g_doneRunning.mutex" << endl;
     // g_rcc.~RecursorControlChannel() do not call, caller still needs it!
   }
   else {