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| author | Andrew Burgess <aburgess@redhat.com> | 2025-04-22 21:43:43 +0100 |
|---|---|---|
| committer | Andrew Burgess <aburgess@redhat.com> | 2025-04-23 23:50:22 +0100 |
| commit | 1fc2d1491c0d512c61303f71d2ba420dd389da0f (patch) | |
| tree | be071aadd6c894b1ffe68ba48c39d521710ddc87 | |
| parent | f17820ec6e4326447e1de02b5211793290cd32ef (diff) | |
| download | binutils-1fc2d1491c0d512c61303f71d2ba420dd389da0f.zip binutils-1fc2d1491c0d512c61303f71d2ba420dd389da0f.tar.gz binutils-1fc2d1491c0d512c61303f71d2ba420dd389da0f.tar.bz2 | |
gdb/python: don't use PyObject_IsInstance in py-registers.c
In python/py-registers.c we make use of PyObject_IsInstance. The
PyObject_IsInstance can return -1 for an error, 0 for false, or 1 for
true.
In py-registers.c we treat the return value from PyObject_IsInstance
as a boolean, which means both -1 and 1 will be treated as true.
If PyObject_IsInstance returns -1 for an error, this will be treated
as true, we will then invoke undefined behaviour as the pyo_reg_id
object will be treated as a gdb.RegisterDescriptor, even though it
might not be.
I noticed that the gdb.RegisterDescriptor class does not have the
Py_TPFLAGS_BASETYPE flag, and therefore cannot be inherited from. As
such, using PyObject_IsInstance is not necessary, we can use
PyObject_TypeCheck instead. The PyObject_TypeCheck function only
returns 0 or 1, so we don't need to worry about the error case.
Approved-By: Tom Tromey <tom@tromey.com>
| -rw-r--r-- | gdb/python/py-registers.c | 3 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.python/py-frame.exp | 15 |
2 files changed, 16 insertions, 2 deletions
diff --git a/gdb/python/py-registers.c b/gdb/python/py-registers.c index 78a806c..9be2e3c 100644 --- a/gdb/python/py-registers.c +++ b/gdb/python/py-registers.c @@ -403,8 +403,7 @@ gdbpy_parse_register_id (struct gdbarch *gdbarch, PyObject *pyo_reg_id, PyErr_SetString (PyExc_ValueError, "Bad register"); } /* The register could be a gdb.RegisterDescriptor object. */ - else if (PyObject_IsInstance (pyo_reg_id, - (PyObject *) ®ister_descriptor_object_type)) + else if (PyObject_TypeCheck (pyo_reg_id, ®ister_descriptor_object_type)) { register_descriptor_object *reg = (register_descriptor_object *) pyo_reg_id; diff --git a/gdb/testsuite/gdb.python/py-frame.exp b/gdb/testsuite/gdb.python/py-frame.exp index 5668807..c1e3e33 100644 --- a/gdb/testsuite/gdb.python/py-frame.exp +++ b/gdb/testsuite/gdb.python/py-frame.exp @@ -188,6 +188,21 @@ gdb_test "python print(gdb.selected_frame().read_register(list()))" \ ".*Invalid type for register.*" \ "test Frame.read_register with list" +gdb_test_multiline "setup a bad object" \ + "python" "" \ + "class bad_type:" "" \ + " def __init__ (self):" "" \ + " pass" "" \ + " @property" "" \ + " def __class__(self):" "" \ + " raise RuntimeError('error from __class in bad_type')" "" \ + "bad_object = bad_type()" "" \ + "end" "" + +gdb_test "python print(gdb.selected_frame().read_register(bad_object))" \ + ".*Invalid type for register.*" \ + "test Frame.read_register with bad_type object" + # Compile again without debug info. gdb_exit if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile} {}] } { |