https://github.com/python/cpython/commit/b9a1b049820517d270f5019d5eb52c8e452eb33f
commit: b9a1b049820517d270f5019d5eb52c8e452eb33f
branch: main
author: Pablo Galindo Salgado <pablog...@gmail.com>
committer: pablogsal <pablog...@gmail.com>
date: 2025-06-15T18:32:32Z
summary:
gh-135371: Clean tags from pointers in all cases in remote debugging module
(#135534)
files:
M Modules/_remote_debugging_module.c
diff --git a/Modules/_remote_debugging_module.c
b/Modules/_remote_debugging_module.c
index 19f12c3b02e5a4..389889a2cf4c6c 100644
--- a/Modules/_remote_debugging_module.c
+++ b/Modules/_remote_debugging_module.c
@@ -39,6 +39,8 @@
*
============================================================================ */
#define GET_MEMBER(type, obj, offset) (*(type*)((char*)(obj) + (offset)))
+#define CLEAR_PTR_TAG(ptr) (((uintptr_t)(ptr) & ~Py_TAG_BITS))
+#define GET_MEMBER_NO_TAG(type, obj, offset)
(type)(CLEAR_PTR_TAG(*(type*)((char*)(obj) + (offset))))
/* Size macros for opaque buffers */
#define SIZEOF_BYTES_OBJ sizeof(PyBytesObject)
@@ -243,6 +245,13 @@ module _remote_debugging
* FORWARD DECLARATIONS
*
============================================================================ */
+static inline int
+is_frame_valid(
+ RemoteUnwinderObject *unwinder,
+ uintptr_t frame_addr,
+ uintptr_t code_object_addr
+);
+
static int
parse_tasks_in_set(
RemoteUnwinderObject *unwinder,
@@ -734,8 +743,7 @@ parse_task_name(
return NULL;
}
- uintptr_t task_name_addr = GET_MEMBER(uintptr_t, task_obj,
unwinder->async_debug_offsets.asyncio_task_object.task_name);
- task_name_addr &= ~Py_TAG_BITS;
+ uintptr_t task_name_addr = GET_MEMBER_NO_TAG(uintptr_t, task_obj,
unwinder->async_debug_offsets.asyncio_task_object.task_name);
// The task name can be a long or a string so we need to check the type
char task_name_obj[SIZEOF_PYOBJECT];
@@ -798,8 +806,7 @@ static int parse_task_awaited_by(
return -1;
}
- uintptr_t task_ab_addr = GET_MEMBER(uintptr_t, task_obj,
unwinder->async_debug_offsets.asyncio_task_object.task_awaited_by);
- task_ab_addr &= ~Py_TAG_BITS;
+ uintptr_t task_ab_addr = GET_MEMBER_NO_TAG(uintptr_t, task_obj,
unwinder->async_debug_offsets.asyncio_task_object.task_awaited_by);
if ((void*)task_ab_addr == NULL) {
return 0;
@@ -849,8 +856,7 @@ handle_yield_from_frame(
return -1;
}
- uintptr_t stackpointer_addr = GET_MEMBER(uintptr_t, iframe,
unwinder->debug_offsets.interpreter_frame.stackpointer);
- stackpointer_addr &= ~Py_TAG_BITS;
+ uintptr_t stackpointer_addr = GET_MEMBER_NO_TAG(uintptr_t, iframe,
unwinder->debug_offsets.interpreter_frame.stackpointer);
if ((void*)stackpointer_addr != NULL) {
uintptr_t gi_await_addr;
@@ -917,6 +923,11 @@ parse_coro_chain(
return -1;
}
+ int8_t frame_state = GET_MEMBER(int8_t, gen_object,
unwinder->debug_offsets.gen_object.gi_frame_state);
+ if (frame_state == FRAME_CLEARED) {
+ return 0;
+ }
+
uintptr_t gen_type_addr = GET_MEMBER(uintptr_t, gen_object,
unwinder->debug_offsets.pyobject.ob_type);
PyObject* name = NULL;
@@ -936,7 +947,7 @@ parse_coro_chain(
}
Py_DECREF(name);
- if (GET_MEMBER(int8_t, gen_object,
unwinder->debug_offsets.gen_object.gi_frame_state) ==
FRAME_SUSPENDED_YIELD_FROM) {
+ if (frame_state == FRAME_SUSPENDED_YIELD_FROM) {
return handle_yield_from_frame(unwinder, gi_iframe_addr,
gen_type_addr, render_to);
}
@@ -981,8 +992,7 @@ create_task_result(
goto error;
}
- coro_addr = GET_MEMBER(uintptr_t, task_obj,
unwinder->async_debug_offsets.asyncio_task_object.task_coro);
- coro_addr &= ~Py_TAG_BITS;
+ coro_addr = GET_MEMBER_NO_TAG(uintptr_t, task_obj,
unwinder->async_debug_offsets.asyncio_task_object.task_coro);
if ((void*)coro_addr != NULL) {
if (parse_coro_chain(unwinder, coro_addr, call_stack) < 0) {
@@ -1816,10 +1826,10 @@ parse_frame_from_chunks(
char *frame = (char *)frame_ptr;
*previous_frame = GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.previous);
-
- if (GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) >= FRAME_OWNED_BY_INTERPRETER
||
- !GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.executable)) {
- return 0;
+ uintptr_t code_object = GET_MEMBER_NO_TAG(uintptr_t, frame_ptr,
unwinder->debug_offsets.interpreter_frame.executable);
+ int frame_valid = is_frame_valid(unwinder, (uintptr_t)frame, code_object);
+ if (frame_valid != 1) {
+ return frame_valid;
}
uintptr_t instruction_pointer = GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.instr_ptr);
@@ -1832,9 +1842,7 @@ parse_frame_from_chunks(
}
#endif
- return parse_code_object(
- unwinder, result, GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.executable),
- instruction_pointer, previous_frame, tlbc_index);
+ return parse_code_object(unwinder, result, code_object,
instruction_pointer, previous_frame, tlbc_index);
}
/* ============================================================================
@@ -2077,6 +2085,33 @@ find_running_task_and_coro(
* FRAME PARSING FUNCTIONS
*
============================================================================ */
+static inline int
+is_frame_valid(
+ RemoteUnwinderObject *unwinder,
+ uintptr_t frame_addr,
+ uintptr_t code_object_addr
+) {
+ if ((void*)code_object_addr == NULL) {
+ return 0;
+ }
+
+ void* frame = (void*)frame_addr;
+
+ if (GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) == FRAME_OWNED_BY_CSTACK ||
+ GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) == FRAME_OWNED_BY_INTERPRETER)
{
+ return 0; // C frame
+ }
+
+ if (GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) != FRAME_OWNED_BY_GENERATOR
+ && GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) != FRAME_OWNED_BY_THREAD) {
+ PyErr_Format(PyExc_RuntimeError, "Unhandled frame owner %d.\n",
+ GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner));
+ set_exception_cause(unwinder, PyExc_RuntimeError, "Unhandled frame
owner type in async frame");
+ return -1;
+ }
+ return 1;
+}
+
static int
parse_frame_object(
RemoteUnwinderObject *unwinder,
@@ -2098,13 +2133,10 @@ parse_frame_object(
}
*previous_frame = GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.previous);
-
- if (GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) >= FRAME_OWNED_BY_INTERPRETER)
{
- return 0;
- }
-
- if ((void*)GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.executable) == NULL) {
- return 0;
+ uintptr_t code_object = GET_MEMBER_NO_TAG(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.executable);
+ int frame_valid = is_frame_valid(unwinder, (uintptr_t)frame, code_object);
+ if (frame_valid != 1) {
+ return frame_valid;
}
uintptr_t instruction_pointer = GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.instr_ptr);
@@ -2117,9 +2149,7 @@ parse_frame_object(
}
#endif
- return parse_code_object(
- unwinder, result, GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.executable),
- instruction_pointer, previous_frame, tlbc_index);
+ return parse_code_object(unwinder, result,
code_object,instruction_pointer, previous_frame, tlbc_index);
}
static int
@@ -2144,26 +2174,10 @@ parse_async_frame_object(
}
*previous_frame = GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.previous);
-
- *code_object = GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.executable);
- // Strip tag bits for consistent comparison
- *code_object &= ~Py_TAG_BITS;
- assert(code_object != NULL);
- if ((void*)*code_object == NULL) {
- return 0;
- }
-
- if (GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) == FRAME_OWNED_BY_CSTACK ||
- GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) == FRAME_OWNED_BY_INTERPRETER)
{
- return 0; // C frame
- }
-
- if (GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) != FRAME_OWNED_BY_GENERATOR
- && GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner) != FRAME_OWNED_BY_THREAD) {
- PyErr_Format(PyExc_RuntimeError, "Unhandled frame owner %d.\n",
- GET_MEMBER(char, frame,
unwinder->debug_offsets.interpreter_frame.owner));
- set_exception_cause(unwinder, PyExc_RuntimeError, "Unhandled frame
owner type in async frame");
- return -1;
+ *code_object = GET_MEMBER_NO_TAG(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.executable);
+ int frame_valid = is_frame_valid(unwinder, (uintptr_t)frame, *code_object);
+ if (frame_valid != 1) {
+ return frame_valid;
}
uintptr_t instruction_pointer = GET_MEMBER(uintptr_t, frame,
unwinder->debug_offsets.interpreter_frame.instr_ptr);
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