Changeset 7775

Timestamp:

Dec 17, 2010, 2:22:00 PM (14 years ago)

Author:

scheusso

Message:

this should reenable the SignalHandler's backtrace for more restrictive environments (e.g. Ubuntu 10.10)

File:

• code/branches/network5/src/libraries/util/SignalHandler.cc (modified) (2 diffs)

code/branches/network5/src/libraries/util/SignalHandler.cc

@@ -37 +37 @@
 #include <cstdlib>
 #include <cstring>
+#include <sys/prctl.h>
 
 #include "Debug.h"
@@ -137 +138 @@
       COUT(0) << "Received signal " << sigName.c_str() << std::endl << "Try to write backtrace to file orxonox_crash.log" << std::endl;
 
-      int sigPipe[2];
-      if ( pipe(sigPipe) == -1 )
-      {
-        perror("pipe failed!\n");
-        exit(EXIT_FAILURE);
-      }
-
-      int sigPid = fork();
-
-      if ( sigPid == -1 )
-      {
-        perror("fork failed!\n");
-        exit(EXIT_FAILURE);
-      }
-
-      // gdb will be attached to this process
-      if ( sigPid == 0 )
-      {
-        getInstance().dontCatch();
-        // wait for message from parent when it has attached gdb
-        int someData;
-
-        read( sigPipe[0], &someData, sizeof(someData) );
-
-        if ( someData != 0x12345678 )
-        {
-          COUT(0) << "something went wrong :(" << std::endl;
-        }
-
-        return;
-      }
-
+      
+      // First start GDB which will be attached to this process later on
+      
       int gdbIn[2];
       int gdbOut[2];
       int gdbErr[2];
-
+      
       if ( pipe(gdbIn) == -1 || pipe(gdbOut) == -1 || pipe(gdbErr) == -1 )
       {
         perror("pipe failed!\n");
-        kill( sigPid, SIGTERM );
-        waitpid( sigPid, NULL, 0 );
         exit(EXIT_FAILURE);
       }
-
+      
       int gdbPid = fork();
       // this process will run gdb
-
+      
       if ( gdbPid == -1 )
       {
         perror("fork failed\n");
-        kill( sigPid, SIGTERM );
-        waitpid( sigPid, NULL, 0 );
         exit(EXIT_FAILURE);
       }
-
+      
       if ( gdbPid == 0 )
       {
         // start gdb
-
+        
         close(gdbIn[1]);
         close(gdbOut[0]);
         close(gdbErr[0]);
-
+        
         dup2( gdbIn[0], STDIN_FILENO );
         dup2( gdbOut[1], STDOUT_FILENO );
         dup2( gdbErr[1], STDERR_FILENO );
-
+        
         execlp( "sh", "sh", "-c", "gdb", static_cast<void*>(NULL));
+      }
+      
+      
+      // Now start a fork of this process on which GDB will be attached on
+      
+      int sigPipe[2];
+      if ( pipe(sigPipe) == -1 )
+      {
+        perror("pipe failed!\n");
+        kill( gdbPid, SIGTERM );
+        waitpid( gdbPid, NULL, 0 );
+        exit(EXIT_FAILURE);
+      }
+
+      int sigPid = fork();
+
+      if ( sigPid == -1 )
+      {
+        perror("fork failed!\n");
+        kill( gdbPid, SIGTERM );
+        waitpid( gdbPid, NULL, 0 );
+        exit(EXIT_FAILURE);
+      }
+
+      // gdb will be attached to this process
+      if ( sigPid == 0 )
+      {
+        getInstance().dontCatch();
+        
+        // make sure gdb is allowed to attach to our PID even if there are some system restrictions
+        if( prctl(PR_SET_PTRACER, gdbPid, 0, 0, 0) == -1 )
+          COUT(0) << "could not set proper permissions for GDB to attach to process..." << endl;
+        
+        // wait for message from parent when it has attached gdb
+        int someData;
+
+        if( read( sigPipe[0], &someData, sizeof(someData) ) != sizeof(someData) )
+          COUT(0) << "something went wrong :(" << std::endl;
+
+        if ( someData != 0x12345678 )
+        {
+          COUT(0) << "something went wrong :(" << std::endl;
+        }
+
+        return;
       }