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This patch uses the sigaction interface to gain access to the PC value
so that it can be printed out when a fatal signal occurs.
--- m3/m3core/src/runtime/FreeBSD2/RTSignal.m3.orig Mon Nov 21 10:31:19 1994
+++ m3/m3core/src/runtime/FreeBSD2/RTSignal.m3 Thu Jul 10 14:24:59 1997
@@ -7,18 +7,21 @@
UNSAFE MODULE RTSignal;
-IMPORT RTMisc, RTProcess, Csignal, Usignal, Uprocess;
+IMPORT RTMisc, RTProcess, Usignal, Uprocess;
FROM Ctypes IMPORT int;
+TYPE
+ SigInfo = UNTRACED REF Usignal.struct_sigcontext;
+
VAR
- DefaultHandler : Csignal.Handler;
- IgnoreSignal : Csignal.Handler;
- initial_handlers : ARRAY [0..5] OF Csignal.Handler;
+ DefaultHandler : Usignal.SignalHandler;
+ IgnoreSignal : Usignal.SignalHandler;
+ initial_handlers : ARRAY [0..5] OF Usignal.struct_sigaction;
PROCEDURE InstallHandlers () =
BEGIN
- DefaultHandler := LOOPHOLE (0, Csignal.Handler);
- IgnoreSignal := LOOPHOLE (1, Csignal.Handler);
+ DefaultHandler := LOOPHOLE (0, Usignal.SignalHandler);
+ IgnoreSignal := LOOPHOLE (1, Usignal.SignalHandler);
SetHandler (0, Usignal.SIGHUP, Shutdown);
SetHandler (1, Usignal.SIGINT, Interrupt);
@@ -28,13 +31,18 @@
SetHandler (5, Usignal.SIGTERM, Shutdown);
END InstallHandlers;
-PROCEDURE SetHandler (id: INTEGER; sig: int; handler: Csignal.Handler) =
- VAR old := Csignal.signal (sig, handler);
- BEGIN
- initial_handlers[id] := old;
- IF (old # DefaultHandler) THEN
+PROCEDURE SetHandler (id: INTEGER; sig: int; handler: Usignal.SignalHandler) =
+ (* Note: we use the LOOPHOLE to prevent the runtime check for
+ nested procedure. The runtime check crashes when
+ handler = IgnoreSignal = 1. *)
+ VAR new: Usignal.struct_sigaction;
+ BEGIN
+ new.sa_handler := LOOPHOLE (handler, Usignal.SignalHandler);
+ new.sa_flags := 0;
+ EVAL Usignal.sigaction (sig, ADR(new), ADR(initial_handlers[id]));
+ IF (initial_handlers[id].sa_handler # DefaultHandler) THEN
(* don't override inherited, non-default handlers *)
- EVAL Csignal.signal (sig, old);
+ EVAL Usignal.sigaction (sig, ADR(initial_handlers[id]), ADR(new));
END;
END SetHandler;
@@ -50,36 +58,43 @@
PROCEDURE RestoreHandler (id: INTEGER; sig: int) =
BEGIN
- EVAL Csignal.signal (sig, initial_handlers[id]);
+ EVAL Usignal.sigaction (sig, ADR(initial_handlers[id]), NIL);
END RestoreHandler;
-PROCEDURE Shutdown (sig: int) =
+PROCEDURE Shutdown (sig: int; <*UNUSED*> code: int; <*UNUSED*> scp: SigInfo) =
+ VAR new, old: Usignal.struct_sigaction;
BEGIN
+ new.sa_handler := DefaultHandler;
+ new.sa_flags := 0;
RTProcess.InvokeExitors (); (* flush stdio... *)
- EVAL Csignal.signal (sig, DefaultHandler); (* restore default handler *)
+ EVAL Usignal.sigaction (sig, ADR(new), ADR(old)); (* restore default handler *)
EVAL Usignal.kill (Uprocess.getpid (), sig); (* and resend the signal *)
END Shutdown;
-PROCEDURE Interrupt (sig: int) =
+PROCEDURE Interrupt (sig: int; code: int; scp: SigInfo) =
VAR h := RTProcess.OnInterrupt (NIL);
BEGIN
IF (h = NIL) THEN
- Shutdown (sig);
+ Shutdown (sig, code, scp);
ELSE
EVAL RTProcess.OnInterrupt (h); (* reinstall the handler *)
h ();
END;
END Interrupt;
-PROCEDURE Quit (<*UNUSED*> sig: int) =
+PROCEDURE Quit (<*UNUSED*> sig, code: int; scp: SigInfo) =
+ VAR pc := 0;
BEGIN
- RTMisc.FatalErrorI ("aborted", 0);
+ IF (scp # NIL) THEN pc := scp.sc_eip END;
+ RTMisc.FatalErrorPC (pc, "aborted");
END Quit;
-PROCEDURE SegV (<*UNUSED*> sig: int) =
+PROCEDURE SegV (<*UNUSED*> sig, code: int; scp: SigInfo) =
+ VAR pc := 0;
BEGIN
- RTMisc.FatalErrorI (
- "Segmentation violation - possible attempt to dereference NIL", 0);
+ IF (scp # NIL) THEN pc := scp.sc_eip END;
+ RTMisc.FatalErrorPC (pc,
+ "Segmentation violation - possible attempt to dereference NIL");
END SegV;
BEGIN
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