snapshot-interface: replace Subramanian's /proc/*/maps checking

Subramanian's code needed rewriting. It didn't actual snapshot any globals, and
it was also written so that it would never snapshot libmodel.so. I rewrite this
code and fix these problems, after Brian Demsky has fixed the problem with
dynamic linking of the HandlePF() code.

diff --git a/snapshot-interface.cc b/snapshot-interface.cc
index 2ef7e4ba94f9ef88b250b9dce1d5d3b3ff551efd..4def5c88c56d7baa2e1f44bec06c9680671a4779 100644 (file)
--- a/snapshot-interface.cc
+++ b/snapshot-interface.cc
@@ -10,73 +10,41 @@
 #include <cassert>
 #include <vector>
 #include <utility>
+#include <inttypes.h>
+
+#include "common.h"
 
 #define MYBINARYNAME "model"
 #define MYLIBRARYNAME "libmodel.so"
-#define PROCNAME      "/proc/*/maps"
-#define REPLACEPOS             6
-
-typedef std::basic_string<char, std::char_traits<char>, MyAlloc<char> > MyString;
+#define MAPFILE_FORMAT "/proc/%d/maps"
 
 SnapshotStack * snapshotObject;
 
-/*This looks like it might leak memory...  Subramanian should fix this. */
+void SnapshotGlobalSegments(){
+       int pid = getpid();
+       char buf[9000], filename[100];
+       FILE *map;
 
-typedef std::basic_stringstream< char, std::char_traits< char >, MyAlloc< char > > MyStringStream;
-std::vector< MyString, MyAlloc< MyString> > splitString( MyString input, char delim ){
-       std::vector< MyString, MyAlloc< MyString > > splits;
-       MyStringStream ss( input );     
-       MyString item;
-       while( std::getline( ss, item, delim ) ){
-               splits.push_back( item );       
+       sprintf(filename, MAPFILE_FORMAT, pid);
+       map = fopen(filename, "r");
+       if (!map) {
+               perror("fopen");
+               exit(EXIT_FAILURE);
        }
-       return splits;
-}
+       while (fgets(buf, sizeof(buf), map)) {
+               char regionname[200] = "";
+               char r, w, x, p;
+               void *begin, *end;
 
-bool checkPermissions( MyString permStr ){
-       return permStr.find("w") != MyString::npos;
-}
-static void takeSegmentSnapshot( const MyString & lineText ){
-       std::vector< MyString, MyAlloc< MyString > > firstSplit = splitString( lineText, ' ' );
-       if( checkPermissions( firstSplit[ 1 ] ) ){
-               std::vector< MyString, MyAlloc< MyString > > secondSplit = splitString( firstSplit[ 0 ], '-' );    
-               size_t val1 = 0, val2 = 0;
-               sscanf( secondSplit[ 0 ].c_str(), "%zx", &val1 );
-               sscanf( secondSplit[ 1 ].c_str(), "%zx", &val2 );
-               size_t len = ( val2 - val1 ) / PAGESIZE;    
-               if( 0 != len ){
-                       addMemoryRegionToSnapShot( ( void * )val1, len );        
+               sscanf(buf, "%p-%p %c%c%c%c %*x %*x:%*x %*u %200s\n", &begin, &end, &r, &w, &x, &p, regionname);
+               if (w == 'w' && (strstr(regionname, MYBINARYNAME) || strstr(regionname, MYLIBRARYNAME))) {
+                       size_t len = ((uintptr_t)end - (uintptr_t)begin) / PAGESIZE;
+                       if (len != 0)
+                               addMemoryRegionToSnapShot(begin, len);
+                       DEBUG("%45s: %18p - %18p\t%c%c%c%c\n", regionname, begin, end, r, w, x, p);
                }
        }
-}
-void SnapshotGlobalSegments(){
-       MyString fn = PROCNAME;
-       static char sProcessSize[ 12 ] = { 0 };
-       std::pair< const char *, bool > dataSect[ 2 ];
-       dataSect[ 0 ] = std::make_pair( MYBINARYNAME, false );
-       dataSect[ 1 ] = std::make_pair( MYLIBRARYNAME, false );
-       static pid_t sProcID = 0;
-       if( 0 == sProcID ) {
-               sProcID = getpid();     
-               sprintf( sProcessSize, "%d", sProcID );
-       }
-       fn.replace( REPLACEPOS, 1, sProcessSize );
-       std::ifstream procName( fn.c_str() );
-       if( procName.is_open() ){
-               MyString line;
-               while( procName.good() ){
-                       getline( procName, line );
-                       int i;
-                       for( i = 0; i < 2; ++i ){
-                               if( MyString::npos != line.find( dataSect[ i ].first ) ) break;                 
-                       }
-                       if( i >= 2 || dataSect[ i ].second == true ) continue;
-                       dataSect[ i ].second = true;
-                       if( !procName.good() )return;
-                       getline( procName, line );
-                       takeSegmentSnapshot( line );    
-               }       
-       }
+       fclose(map);
 }
 
 //class definition of SnapshotStack.....
@@ -85,10 +53,10 @@ SnapshotStack::SnapshotStack(){
        SnapshotGlobalSegments();
        stack=NULL;
 }
-       
+
 SnapshotStack::~SnapshotStack(){
 }
-       
+
 int SnapshotStack::backTrackBeforeStep(int seqindex) {
        while(true) {
                if (stack->index<=seqindex) {