From 5bf800a54247c5752053831e15f7b132bf9fddbf Mon Sep 17 00:00:00 2001
From: Aliaksey Kandratsenka <alk@tut.by>
Date: Sat, 14 Dec 2013 12:03:02 -0800
Subject: [PATCH] issue-586: detect main executable even if PIE is active

Previous logic of detecting main program addresses is to assume that
main executable is at least addressess. With PIE (active by default on
Ubuntus) it doesn't work.

In order to deal with that, we're attempting to find main executable
mapping in /proc/[pid]/maps. And old logic is preserved too just in
case.
---
 bin/jeprof.in | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/bin/jeprof.in b/bin/jeprof.in
index 42087fce..baa80a54 100644
--- a/bin/jeprof.in
+++ b/bin/jeprof.in
@@ -71,6 +71,7 @@
 use strict;
 use warnings;
 use Getopt::Long;
+use Cwd;
 
 my $JEPROF_VERSION = "@jemalloc_version@";
 my $PPROF_VERSION = "2.0";
@@ -4570,7 +4571,7 @@ sub ParseTextSectionHeader {
 # Split /proc/pid/maps dump into a list of libraries
 sub ParseLibraries {
   return if $main::use_symbol_page;  # We don't need libraries info.
-  my $prog = shift;
+  my $prog = Cwd::abs_path(shift);
   my $map = shift;
   my $pcs = shift;
 
@@ -4603,6 +4604,16 @@ sub ParseLibraries {
       $finish = HexExtend($2);
       $offset = $zero_offset;
       $lib = $3;
+    } elsif (($l =~ /^($h)-($h)\s+..x.\s+($h)\s+\S+:\S+\s+\d+\s+(\S+)$/i) && ($4 eq $prog)) {
+      # PIEs and address space randomization do not play well with our
+      # default assumption that main executable is at lowest
+      # addresses. So we're detecting main executable in
+      # /proc/self/maps as well.
+      $start = HexExtend($1);
+      $finish = HexExtend($2);
+      $offset = HexExtend($3);
+      $lib = $4;
+      $lib =~ s|\\|/|g;     # turn windows-style paths into unix-style paths
     }
     # FreeBSD 10.0 virtual memory map /proc/curproc/map as defined in
     # function procfs_doprocmap (sys/fs/procfs/procfs_map.c)