Use SA_SIGINFO to report pc in error messages. Copied from Linux.

1 files changed, 34 insertions, 28 deletions

diff --git a/emu/NetBSD/os.c b/emu/NetBSD/os.c
index 34526088..3aa95975 100644
--- a/emu/NetBSD/os.c
+++ b/emu/NetBSD/os.c
@@ -13,6 +13,8 @@
 #include	"fns.h"
 #include	"error.h"
 
+#include	"raise.h"
+
 /* For dynamic linking init/fini code that needs malloc */
 void (*coherence)(void) = nofence;
 
@@ -31,50 +33,49 @@ int	gidnobody = -1;
 int	uidnobody = -1;
 static struct 	termios tinit;
 
-/*
- * TO DO:
- * To get pc on trap, use sigaction instead of signal and
- * examine its siginfo structure
- */
-
-/*
 static void
-diserr(char *s, int pc)
+sysfault(char *what, void *addr)
 {
-	char buf[ERRMAX];
+	char buf[64];
 
-	snprint(buf, sizeof(buf), "%s: pc=0x%lux", s, pc);
+	snprint(buf, sizeof(buf), "sys: %s%#p", what, addr);
 	disfault(nil, buf);
 }
-*/
 
 static void
-trapILL(int signo)
+trapILL(int signo, siginfo_t *si, void *a)
 {
 	USED(signo);
-	disfault(nil, "Illegal instruction");
+	USED(a);
+	sysfault("illegal instruction pc=", si->si_addr);
 }
 
-static void
-trapBUS(int signo)
+static int
+isnilref(siginfo_t *si)
 {
-	USED(signo);
-	disfault(nil, "Bus error");
+	return si != 0 && (si->si_addr == (void*)~(uintptr_t)0 || (uintptr_t)si->si_addr < 512);
 }
 
 static void
-trapSEGV(int signo)
+trapmemref(int signo, siginfo_t *si, void *a)
 {
-	USED(signo);
-	disfault(nil, "Segmentation violation");
+	USED(a);	/* ucontext_t*, could fetch pc in machine-dependent way */
+	if(isnilref(si))
+		disfault(nil, exNilref);
+	else if(signo == SIGBUS)
+		sysfault("bad address addr=", si->si_addr);	/* eg, misaligned */
+	else
+		sysfault("segmentation violation addr=", si->si_addr);
 }
 
 static void
-trapFPE(int signo)
+trapFPE(int signo, siginfo_t *si, void *a)
 {
 	char buf[64];
+
 	USED(signo);
-	snprint(buf, sizeof(buf), "sys: fp: exception status=%.4lux", getfsr());
+	USED(a);
+	snprint(buf, sizeof(buf), "sys: fp: exception status=%.4lux pc=%#p", getfsr(), si->si_addr);
 	disfault(nil, buf);
 }
 
@@ -187,14 +188,19 @@ libinit(char *imod)
 		signal(SIGINT, cleanexit);
 
 	if(sflag == 0) {
-		act.sa_handler = trapBUS;
-		sigaction(SIGBUS, &act, nil);
-		act.sa_handler = trapILL;
+		act.sa_flags = SA_SIGINFO;
+
+		act.sa_sigaction = trapILL;
 		sigaction(SIGILL, &act, nil);
-		act.sa_handler = trapSEGV;
-		sigaction(SIGSEGV, &act, nil);
-		act.sa_handler = trapFPE;
+
+		act.sa_sigaction = trapFPE;
 		sigaction(SIGFPE, &act, nil);
+
+		act.sa_sigaction = trapmemref;
+		sigaction(SIGBUS, &act, nil);
+		sigaction(SIGSEGV, &act, nil);
+
+		act.sa_flags = 0;
 	}
 
 	p = newproc();