From 653db9dcbe3cb2e7192eb01b22b906a015e3ddc1 Mon Sep 17 00:00:00 2001
From: Kevin Tew <tewk@racket-lang.org>
Date: Fri, 12 Dec 2008 19:35:29 +0000
Subject: [PATCH] Added SIGSEGV diagnostics with 3m

svn: r12806
---
 src/mzscheme/gc2/sighand.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/mzscheme/gc2/sighand.c b/src/mzscheme/gc2/sighand.c
index db9145ea54..cd4e8a8f28 100644
--- a/src/mzscheme/gc2/sighand.c
+++ b/src/mzscheme/gc2/sighand.c
@@ -17,8 +17,21 @@
 # include <signal.h>
 void fault_handler(int sn, struct siginfo *si, void *ctx)
 {
-  if (!designate_modified(si->si_addr))
+  void *p = si->si_addr;
+  if (si->si_code != SEGV_ACCERR) { /*SEGV_MAPERR*/
+    printf("SIGSEGV fault on %p\n", p);
     abort();
+  }
+
+  if (!designate_modified(p)) {
+    if (si->si_code == SEGV_ACCERR) {
+      printf("mprotect fault on %p\n", p);
+    }
+    else {
+      printf("?? %i fault on %p\n", si->si_code, p);
+    }
+    abort();
+  }
 #  define NEED_SIGACTION
 #  define USE_SIGACTON_SIGNAL_KIND SIGSEGV
 }