From: Tom Tromey <tom@tromey.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tom@tromey.com>
Subject: [PATCH] Fix crash in gdbpy_parse_register_id
Date: Wed, 27 Apr 2022 15:27:42 -0600 [thread overview]
Message-ID: <20220427212742.4003557-1-tom@tromey.com> (raw)
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.
---
gdb/python/py-frame.c | 5 +----
gdb/python/py-registers.c | 22 +++++++++++++++-------
gdb/python/py-unwind.c | 10 ++--------
gdb/python/python-internal.h | 3 ++-
gdb/testsuite/gdb.python/py-frame.exp | 5 +++++
5 files changed, 25 insertions(+), 20 deletions(-)
diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index d07158a5ec6..933bdc773eb 100644
--- 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,
®num))
- {
- PyErr_SetString (PyExc_ValueError, "Bad register");
- return NULL;
- }
+ return NULL;
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 bbb322f068c..c7ea529bdde 100644
--- a/gdb/python/py-registers.c
+++ b/gdb/python/py-registers.c
@@ -386,21 +386,27 @@ 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,
@@ -417,6 +423,8 @@ gdbpy_parse_register_id (struct gdbarch *gdbarch, PyObject *pyo_reg_id,
PyErr_SetString (PyExc_ValueError,
_("Invalid Architecture in RegisterDescriptor"));
}
+ else
+ PyErr_SetString (PyExc_ValueError, _("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 b2fd1402e93..e2cd67a0785 100644
--- a/gdb/python/py-unwind.c
+++ b/gdb/python/py-unwind.c
@@ -262,10 +262,7 @@ 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, ®num))
- {
- PyErr_SetString (PyExc_ValueError, "Bad register");
- return NULL;
- }
+ return NULL;
/* 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
@@ -383,10 +380,7 @@ 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, ®num))
- {
- PyErr_SetString (PyExc_ValueError, "Bad register");
- return NULL;
- }
+ PyErr_SetString (PyExc_ValueError, "Bad register");
try
{
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index d947b96033b..dffcd3f1b7f 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -799,7 +799,8 @@ 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 b91ffe62a83..881219342e3 100644
--- a/gdb/testsuite/gdb.python/py-frame.exp
+++ b/gdb/testsuite/gdb.python/py-frame.exp
@@ -128,3 +128,8 @@ if { $pc != "" } {
" = True" \
"test Frame.read_register($pc)"
}
+
+# This previously caused a crash.
+gdb_test "python print(gdb.selected_frame().read_register(list()))" \
+ ".*Invalid type for register.*" \
+ "test Frame.read_register with list"
--
2.34.1
next reply other threads:[~2022-04-27 21:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-27 21:27 Tom Tromey [this message]
2022-04-28 1:45 ` Simon Marchi
2022-04-28 2:11 ` Tom Tromey
2022-06-11 17:38 ` Tom Tromey
2022-08-21 14:01 ` Tom Tromey
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