Parse /proc/self/maps lines better to handle variations between Linux kernels.

It seems noone has had time to file a bug on this.
Review URL: http://codereview.chromium.org/4210

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@360 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/platform-linux.cc

@@ -43,6 +43,7 @@
 #include <sys/fcntl.h>  // open
 #include <unistd.h>     // getpagesize
 #include <execinfo.h>   // backtrace, backtrace_symbols
+#include <strings.h>    // index
 #include <errno.h>
 #include <stdarg.h>
 
@@ -335,12 +336,13 @@ void OS::LogSharedLibraryAddresses() {
       if (result < 1) break;
     } while (buffer[bytes_read] != '\n');
     buffer[bytes_read] = 0;
-    // There are 56 chars to ignore at this point in the line.
-    if (bytes_read < 56) continue;
     // Ignore mappings that are not executable.
     if (buffer[3] != 'x') continue;
+    char* start_of_path = index(buffer, '/');
+    // There may be no filename in this line.  Skip to next.
+    if (start_of_path == NULL) continue;
     buffer[bytes_read] = 0;
-    LOG(SharedLibraryEvent(buffer + 56, start, end));
+    LOG(SharedLibraryEvent(start_of_path, start, end));
   }
   close(fd);
 #endif