From 87b2adb6a1fa69b5d0b92a9437dd08ea990ee30d Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Thu, 12 Nov 2020 18:49:49 -0500
Subject: [PATCH] With --debug, turn off address space layout randomization.

---
 bin/verilator | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/bin/verilator b/bin/verilator
index 3f921dc02..213d90e34 100755
--- a/bin/verilator
+++ b/bin/verilator
@@ -76,7 +76,8 @@ if ($opt_gdbbt && !gdb_works()) {
 my @quoted_sw = map {sh_escape($_)} @Opt_Verilator_Sw;
 if ($opt_gdb) {
     # Generic GDB interactive
-    run (($ENV{VERILATOR_GDB}||"gdb")
+    run (aslr_off()
+         .($ENV{VERILATOR_GDB}||"gdb")
          ." ".verilator_bin()
          # Note, uncomment to set breakpoints before running:
          #  ." -ex 'break main'"
@@ -91,16 +92,22 @@ if ($opt_gdb) {
          ." -ex 'bt'");
 } elsif ($opt_rr) {
     # Record with rr
-    run ("rr record ".verilator_bin()
+    run (aslr_off()
+         ."rr record ".verilator_bin()
          ." ".join(' ', @quoted_sw));
 } elsif ($opt_gdbbt && $Debug) {
     # Run under GDB to get gdbbt
-    run ("gdb"
+    run (aslr_off()
+         ."gdb"
          ." ".verilator_bin()
          ." --batch --quiet --return-child-result"
          ." -ex \"run ".join(' ', @quoted_sw)."\""
          ." -ex 'set width 0'"
          ." -ex 'bt' -ex 'quit'");
+} elsif ($Debug) {
+    # Debug
+    run(aslr_off()
+        .verilator_bin()." ".join(' ',@quoted_sw));
 } else {
     # Normal, non gdb
     run(verilator_bin()." ".join(' ',@quoted_sw));
@@ -165,6 +172,15 @@ sub gdb_works {
     return $status==0;
 }
 
+sub aslr_off {
+    my $ok = `setarch --addr-no-randomize echo ok 2>/dev/null` || "";
+    if ($ok =~ /ok/) {
+        return "setarch --addr-no-randomize ";
+    } else {
+        return "";
+    }
+}
+
 sub run {
     # Run command, check errors
     my $command = shift;