Fix crash in gdbpy_parse_register_id

I noticed that gdbpy_parse_register_id would assert if passed a Python
object of a type it was not expecting.  The included test case shows
this crash.  This patch fixes the problem and also changes
gdbpy_parse_register_id to be more "Python-like" -- it always ensures
the Python error is set when it fails, and the callers now simply
propagate the existing exception.

diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index 9a28c36c1cc5fefa895e72aafa04172936f3887c..8bd2e0bc6daa6b808d72042549fff8e92f0edb41 100644 (file)
--- a/gdb/python/py-frame.c
+++ b/gdb/python/py-frame.c
@@ -253,10 +253,7 @@ frapy_read_register (PyObject *self, PyObject *args)
 
       if (!gdbpy_parse_register_id (get_frame_arch (frame), pyo_reg_id,
                                    &regnum))
-       {
-         PyErr_SetString (PyExc_ValueError, "Bad register");
-         return NULL;
-       }
+       return nullptr;
 
       gdb_assert (regnum >= 0);
       val = value_of_register (regnum, frame);

diff --git a/gdb/python/py-registers.c b/gdb/python/py-registers.c
index f22575a28c250f7d97e55af9f14eedac00780c95..fe7481cea9e64f3ac92d7599dd5d846b5086af96 100644 (file)
--- a/gdb/python/py-registers.c
+++ b/gdb/python/py-registers.c
@@ -381,21 +381,27 @@ gdbpy_parse_register_id (struct gdbarch *gdbarch, PyObject *pyo_reg_id,
        {
          *reg_num = user_reg_map_name_to_regnum (gdbarch, reg_name.get (),
                                                  strlen (reg_name.get ()));
-         return *reg_num >= 0;
+         if (*reg_num >= 0)
+           return true;
+         PyErr_SetString (PyExc_ValueError, "Bad register");
        }
     }
   /* The register could be its internal GDB register number.  */
   else if (PyLong_Check (pyo_reg_id))
     {
       long value;
-      if (gdb_py_int_as_long (pyo_reg_id, &value) && (int) value == value)
+      if (gdb_py_int_as_long (pyo_reg_id, &value) == 0)
        {
-         if (user_reg_map_regnum_to_name (gdbarch, value) != NULL)
-           {
-             *reg_num = (int) value;
-             return true;
-           }
+         /* Nothing -- error.  */
        }
+      else if ((int) value == value
+              && user_reg_map_regnum_to_name (gdbarch, value) != NULL)
+       {
+         *reg_num = (int) value;
+         return true;
+       }
+      else
+       PyErr_SetString (PyExc_ValueError, "Bad register");
     }
   /* The register could be a gdb.RegisterDescriptor object.  */
   else if (PyObject_IsInstance (pyo_reg_id,
@@ -412,6 +418,8 @@ gdbpy_parse_register_id (struct gdbarch *gdbarch, PyObject *pyo_reg_id,
        PyErr_SetString (PyExc_ValueError,
                         _("Invalid Architecture in RegisterDescriptor"));
     }
+  else
+    PyErr_SetString (PyExc_TypeError, _("Invalid type for register"));
 
   gdb_assert (PyErr_Occurred ());
   return false;

diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c
index fb9466102c45c2e6447d76a48b0757f15a88c8ec..dcb1d7abbcf64547226db99b0ad1de4f3f2c3c2f 100644 (file)
--- a/gdb/python/py-unwind.c
+++ b/gdb/python/py-unwind.c
@@ -260,10 +260,7 @@ unwind_infopy_add_saved_register (PyObject *self, PyObject *args)
                          &pyo_reg_id, &pyo_reg_value))
     return NULL;
   if (!gdbpy_parse_register_id (pending_frame->gdbarch, pyo_reg_id, &regnum))
-    {
-      PyErr_SetString (PyExc_ValueError, "Bad register");
-      return NULL;
-    }
+    return nullptr;
 
   /* If REGNUM identifies a user register then *maybe* we can convert this
      to a real (i.e. non-user) register.  The maybe qualifier is because we
@@ -381,10 +378,7 @@ pending_framepy_read_register (PyObject *self, PyObject *args)
   if (!PyArg_UnpackTuple (args, "read_register", 1, 1, &pyo_reg_id))
     return NULL;
   if (!gdbpy_parse_register_id (pending_frame->gdbarch, pyo_reg_id, &regnum))
-    {
-      PyErr_SetString (PyExc_ValueError, "Bad register");
-      return NULL;
-    }
+    return nullptr;
 
   try
     {

diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 800b03a105c280d0de19b2cb6e60fc4d64629852..d624b23fdc5e537c68484e186c38fb17e724b1cc 100644 (file)
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -819,7 +819,8 @@ typedef std::unique_ptr<Py_buffer, Py_buffer_deleter> Py_buffer_up;
 
    If a register is parsed successfully then *REG_NUM will have been
    updated, and true is returned.  Otherwise the contents of *REG_NUM are
-   undefined, and false is returned.
+   undefined, and false is returned.  When false is returned, the
+   Python error is set.
 
    The PYO_REG_ID object can be a string, the name of the register.  This
    is the slowest approach as GDB has to map the name to a number for each

diff --git a/gdb/testsuite/gdb.python/py-frame.exp b/gdb/testsuite/gdb.python/py-frame.exp
index 4991e8a0c5db1113a78038b34a3df3f0619e9ca1..56e1ecdcedd54764139ab1d7dff841db6e635b8d 100644 (file)
--- a/gdb/testsuite/gdb.python/py-frame.exp
+++ b/gdb/testsuite/gdb.python/py-frame.exp
@@ -134,3 +134,9 @@ gdb_test "python print(gdb.selected_frame().language())" "c"
 gdb_test "set language ada"
 gdb_test "python print(gdb.selected_frame().language())" "c" \
     "frame language is not affected by global language"
+
+# This previously caused a crash -- the implementation was missing the
+# case where a register had an unexpected type.
+gdb_test "python print(gdb.selected_frame().read_register(list()))" \
+    ".*Invalid type for register.*" \
+    "test Frame.read_register with list"

diff --git a/gdb/testsuite/gdb.python/py-unwind.exp b/gdb/testsuite/gdb.python/py-unwind.exp
index cdf9034b1bd0e589a89d61a85db5ec9da07b7a2b..798e76525dbcc4dc477efb5f2e2dda4b8978449e 100644 (file)
--- a/gdb/testsuite/gdb.python/py-unwind.exp
+++ b/gdb/testsuite/gdb.python/py-unwind.exp
@@ -57,3 +57,9 @@ gdb_test_sequence "where"  "Backtrace restored by unwinder" {
 
 # Check that the Python unwinder frames can be flushed / released.
 gdb_test "maint flush register-cache" "Register cache flushed\\." "flush frames"
+
+# Check that invalid register names cause errors.
+gdb_test "python print(add_saved_register_error)" "True" \
+    "add_saved_register error"
+gdb_test "python print(read_register_error)" "True" \
+    "read_register error"

diff --git a/gdb/testsuite/gdb.python/py-unwind.py b/gdb/testsuite/gdb.python/py-unwind.py
index 15dba59f6245dbf8aefcd20228e5e2b1468ec29f..319bb630c1c64f86ead847f02f7d28b00c4ca135 100644 (file)
--- a/gdb/testsuite/gdb.python/py-unwind.py
+++ b/gdb/testsuite/gdb.python/py-unwind.py
@@ -17,6 +17,11 @@ import gdb
 from gdb.unwinder import Unwinder
 
 
+# These are set to test whether invalid register names cause an error.
+add_saved_register_error = False
+read_register_error = False
+
+
 class FrameId(object):
     def __init__(self, sp, pc):
         self._sp = sp
@@ -101,6 +106,12 @@ class TestUnwinder(Unwinder):
             previous_ip = self._read_word(bp + 8)
             previous_sp = bp + 16
 
+            try:
+                pending_frame.read_register("nosuchregister")
+            except ValueError:
+                global read_register_error
+                read_register_error = True
+
             frame_id = FrameId(
                 pending_frame.read_register(TestUnwinder.AMD64_RSP),
                 pending_frame.read_register(TestUnwinder.AMD64_RIP),
@@ -109,6 +120,11 @@ class TestUnwinder(Unwinder):
             unwind_info.add_saved_register(TestUnwinder.AMD64_RBP, previous_bp)
             unwind_info.add_saved_register("rip", previous_ip)
             unwind_info.add_saved_register("rsp", previous_sp)
+            try:
+                unwind_info.add_saved_register("nosuchregister", previous_sp)
+            except ValueError:
+                global add_saved_register_error
+                add_saved_register_error = True
             return unwind_info
         except (gdb.error, RuntimeError):
             return None