Add configurable gdbinit (#1007)

* fix typo in comment

* new config option: context.gdbinit

This allows setting the default gdbinit for GDB, which is helpful when you want
to enable some GDB extension only when using pwntools and not by default.

pwnlib/context/__init__.py

@@ -150,7 +150,7 @@ class _Tls_DictStack(threading.local, _DictStack):
 
 def _validator(validator):
     """
-    Validator that tis tightly coupled to the implementation
+    Validator that is tightly coupled to the implementation
     of the classes here.
 
     This expects that the object has a ._tls property which
@@ -340,6 +340,7 @@ class ContextType(object):
         'delete_corefiles': False,
         'device': os.getenv('ANDROID_SERIAL', None) or None,
         'endian': 'little',
+        'gdbinit': "",
         'kernel': None,
         'log_level': logging.INFO,
         'log_file': _devnull(),
@@ -1231,6 +1232,23 @@ def rename_corefiles(self, v):
         """
         return bool(v)
 
+
+    @_validator
+    def gdbinit(self, value):
+        """Path to the gdbinit that is used when running GDB locally.
+
+        This is useful if you want pwntools-launched GDB to include some additional modules,
+        like PEDA but you do not want to have GDB include them by default.
+
+        The setting will only apply when GDB is launched locally since remote hosts may not have
+        the necessary requirements for the gdbinit.
+
+        If set to an empty string, GDB will use the default `~/.gdbinit`.
+
+        Default value is ``""``.
+        """
+        return str(value)
+
     #*************************************************************************
     #                               ALIASES
     #*************************************************************************

pwnlib/gdb.py

@@ -646,6 +646,10 @@ def findexe():
         cmd += ' '
         cmd += ' '.join(gdb_args)
 
+    if context.gdbinit:
+        cmd += ' -nh '                     # ignore ~/.gdbinit
+        cmd += ' -x %s ' % context.gdbinit # load custom gdbinit
+
     cmd += ' -q '
 
     if exe and context.native: