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/******************************************************************************
* Python Remote Debugging Module
*
* This module provides functionality to debug Python processes remotely by
* reading their memory and reconstructing stack traces and asyncio task states.
******************************************************************************/
#define _GNU_SOURCE
/* ============================================================================
* HEADERS AND INCLUDES
* ============================================================================ */
#ifndef Py_BUILD_CORE_BUILTIN
# define Py_BUILD_CORE_MODULE 1
#endif
#include "Python.h"
#include <internal/pycore_debug_offsets.h> // _Py_DebugOffsets
#include <internal/pycore_frame.h> // FRAME_SUSPENDED_YIELD_FROM
#include <internal/pycore_interpframe.h> // FRAME_OWNED_BY_CSTACK
#include <internal/pycore_llist.h> // struct llist_node
#include <internal/pycore_stackref.h> // Py_TAG_BITS
#include "../Python/remote_debug.h"
// gh-141784: Python.h header must be included first, before system headers.
// Otherwise, some types such as ino_t can be defined differently, causing ABI
// issues.
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef HAVE_PROCESS_VM_READV
# define HAVE_PROCESS_VM_READV 0
#endif
/* ============================================================================
* TYPE DEFINITIONS AND STRUCTURES
* ============================================================================ */
#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)
#define SIZEOF_CODE_OBJ sizeof(PyCodeObject)
#define SIZEOF_GEN_OBJ sizeof(PyGenObject)
#define SIZEOF_INTERP_FRAME sizeof(_PyInterpreterFrame)
#define SIZEOF_LLIST_NODE sizeof(struct llist_node)
#define SIZEOF_PAGE_CACHE_ENTRY sizeof(page_cache_entry_t)
#define SIZEOF_PYOBJECT sizeof(PyObject)
#define SIZEOF_SET_OBJ sizeof(PySetObject)
#define SIZEOF_TASK_OBJ 4096
#define SIZEOF_THREAD_STATE sizeof(PyThreadState)
#define SIZEOF_TYPE_OBJ sizeof(PyTypeObject)
#define SIZEOF_UNICODE_OBJ sizeof(PyUnicodeObject)
#define SIZEOF_LONG_OBJ sizeof(PyLongObject)
// Calculate the minimum buffer size needed to read interpreter state fields
// We need to read code_object_generation and potentially tlbc_generation
#ifndef MAX
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#endif
#ifdef Py_GIL_DISABLED
#define INTERP_STATE_MIN_SIZE MAX(MAX(MAX(offsetof(PyInterpreterState, _code_object_generation) + sizeof(uint64_t), \
offsetof(PyInterpreterState, tlbc_indices.tlbc_generation) + sizeof(uint32_t)), \
offsetof(PyInterpreterState, threads.head) + sizeof(void*)), \
offsetof(PyInterpreterState, _gil.last_holder) + sizeof(PyThreadState*))
#else
#define INTERP_STATE_MIN_SIZE MAX(MAX(offsetof(PyInterpreterState, _code_object_generation) + sizeof(uint64_t), \
offsetof(PyInterpreterState, threads.head) + sizeof(void*)), \
offsetof(PyInterpreterState, _gil.last_holder) + sizeof(PyThreadState*))
#endif
#define INTERP_STATE_BUFFER_SIZE MAX(INTERP_STATE_MIN_SIZE, 256)
#define MAX_STACK_CHUNK_SIZE (16 * 1024 * 1024) /* 16 MB max for stack chunks */
#define MAX_SET_TABLE_SIZE (1 << 20) /* 1 million entries max for set iteration */
#define MAX_LONG_DIGITS 64 /* Allows values up to ~2^1920 */
// Copied from Modules/_asynciomodule.c because it's not exported
struct _Py_AsyncioModuleDebugOffsets {
struct _asyncio_task_object {
uint64_t size;
uint64_t task_name;
uint64_t task_awaited_by;
uint64_t task_is_task;
uint64_t task_awaited_by_is_set;
uint64_t task_coro;
uint64_t task_node;
} asyncio_task_object;
struct _asyncio_interpreter_state {
uint64_t size;
uint64_t asyncio_tasks_head;
} asyncio_interpreter_state;
struct _asyncio_thread_state {
uint64_t size;
uint64_t asyncio_running_loop;
uint64_t asyncio_running_task;
uint64_t asyncio_tasks_head;
} asyncio_thread_state;
};
/* ============================================================================
* STRUCTSEQ TYPE DEFINITIONS
* ============================================================================ */
// TaskInfo structseq type - replaces 4-tuple (task_id, task_name, coroutine_stack, awaited_by)
static PyStructSequence_Field TaskInfo_fields[] = {
{"task_id", "Task ID (memory address)"},
{"task_name", "Task name"},
{"coroutine_stack", "Coroutine call stack"},
{"awaited_by", "Tasks awaiting this task"},
{NULL}
};
static PyStructSequence_Desc TaskInfo_desc = {
"_remote_debugging.TaskInfo",
"Information about an asyncio task",
TaskInfo_fields,
4
};
// FrameInfo structseq type - replaces 3-tuple (filename, lineno, funcname)
static PyStructSequence_Field FrameInfo_fields[] = {
{"filename", "Source code filename"},
{"lineno", "Line number"},
{"funcname", "Function name"},
{NULL}
};
static PyStructSequence_Desc FrameInfo_desc = {
"_remote_debugging.FrameInfo",
"Information about a frame",
FrameInfo_fields,
3
};
// CoroInfo structseq type - replaces 2-tuple (call_stack, task_name)
static PyStructSequence_Field CoroInfo_fields[] = {
{"call_stack", "Coroutine call stack"},
{"task_name", "Task name"},
{NULL}
};
static PyStructSequence_Desc CoroInfo_desc = {
"_remote_debugging.CoroInfo",
"Information about a coroutine",
CoroInfo_fields,
2
};
// ThreadInfo structseq type - replaces 2-tuple (thread_id, frame_info)
static PyStructSequence_Field ThreadInfo_fields[] = {
{"thread_id", "Thread ID"},
{"frame_info", "Frame information"},
{NULL}
};
static PyStructSequence_Desc ThreadInfo_desc = {
"_remote_debugging.ThreadInfo",
"Information about a thread",
ThreadInfo_fields,
2
};
// AwaitedInfo structseq type - replaces 2-tuple (tid, awaited_by_list)
static PyStructSequence_Field AwaitedInfo_fields[] = {
{"thread_id", "Thread ID"},
{"awaited_by", "List of tasks awaited by this thread"},
{NULL}
};
static PyStructSequence_Desc AwaitedInfo_desc = {
"_remote_debugging.AwaitedInfo",
"Information about what a thread is awaiting",
AwaitedInfo_fields,
2
};
typedef struct {
PyObject *func_name;
PyObject *file_name;
int first_lineno;
PyObject *linetable; // bytes
uintptr_t addr_code_adaptive;
} CachedCodeMetadata;
typedef struct {
/* Types */
PyTypeObject *RemoteDebugging_Type;
PyTypeObject *TaskInfo_Type;
PyTypeObject *FrameInfo_Type;
PyTypeObject *CoroInfo_Type;
PyTypeObject *ThreadInfo_Type;
PyTypeObject *AwaitedInfo_Type;
} RemoteDebuggingState;
typedef struct {
PyObject_HEAD
proc_handle_t handle;
uintptr_t runtime_start_address;
struct _Py_DebugOffsets debug_offsets;
int async_debug_offsets_available;
struct _Py_AsyncioModuleDebugOffsets async_debug_offsets;
uintptr_t interpreter_addr;
uintptr_t tstate_addr;
uint64_t code_object_generation;
_Py_hashtable_t *code_object_cache;
int debug;
int only_active_thread;
RemoteDebuggingState *cached_state; // Cached module state
#ifdef Py_GIL_DISABLED
// TLBC cache invalidation tracking
uint32_t tlbc_generation; // Track TLBC index pool changes
_Py_hashtable_t *tlbc_cache; // Cache of TLBC arrays by code object address
#endif
} RemoteUnwinderObject;
#define RemoteUnwinder_CAST(op) ((RemoteUnwinderObject *)(op))
typedef struct
{
int lineno;
int end_lineno;
int column;
int end_column;
} LocationInfo;
typedef struct {
uintptr_t remote_addr;
size_t size;
void *local_copy;
} StackChunkInfo;
typedef struct {
StackChunkInfo *chunks;
size_t count;
} StackChunkList;
#include "clinic/_remote_debugging_module.c.h"
/*[clinic input]
module _remote_debugging
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=5f507d5b2e76a7f7]*/
/* ============================================================================
* FORWARD DECLARATIONS
* ============================================================================ */
static inline int
is_frame_valid(
RemoteUnwinderObject *unwinder,
uintptr_t frame_addr,
uintptr_t code_object_addr
);
typedef int (*thread_processor_func)(
RemoteUnwinderObject *unwinder,
uintptr_t thread_state_addr,
unsigned long tid,
void *context
);
typedef int (*set_entry_processor_func)(
RemoteUnwinderObject *unwinder,
uintptr_t key_addr,
void *context
);
static int
parse_task(
RemoteUnwinderObject *unwinder,
uintptr_t task_address,
PyObject *render_to
);
static int
parse_coro_chain(
RemoteUnwinderObject *unwinder,
uintptr_t coro_address,
PyObject *render_to
);
/* Forward declarations for task parsing functions */
static int parse_frame_object(
RemoteUnwinderObject *unwinder,
PyObject** result,
uintptr_t address,
uintptr_t* address_of_code_object,
uintptr_t* previous_frame
);
static int
parse_async_frame_chain(
RemoteUnwinderObject *unwinder,
PyObject *calls,
uintptr_t address_of_thread,
uintptr_t running_task_code_obj
);
static int read_py_ptr(RemoteUnwinderObject *unwinder, uintptr_t address, uintptr_t *ptr_addr);
static int read_Py_ssize_t(RemoteUnwinderObject *unwinder, uintptr_t address, Py_ssize_t *size);
static int process_task_and_waiters(RemoteUnwinderObject *unwinder, uintptr_t task_addr, PyObject *result);
static int process_task_awaited_by(RemoteUnwinderObject *unwinder, uintptr_t task_address, set_entry_processor_func processor, void *context);
static int find_running_task_in_thread(RemoteUnwinderObject *unwinder, uintptr_t thread_state_addr, uintptr_t *running_task_addr);
static int get_task_code_object(RemoteUnwinderObject *unwinder, uintptr_t task_addr, uintptr_t *code_obj_addr);
static int append_awaited_by(RemoteUnwinderObject *unwinder, unsigned long tid, uintptr_t head_addr, PyObject *result);
/* ============================================================================
* UTILITY FUNCTIONS AND HELPERS
* ============================================================================ */
#define set_exception_cause(unwinder, exc_type, message) \
do { \
assert(PyErr_Occurred() && "function returned -1 without setting exception"); \
if (unwinder->debug) { \
_set_debug_exception_cause(exc_type, message); \
} \
} while (0)
static void
cached_code_metadata_destroy(void *ptr)
{
CachedCodeMetadata *meta = (CachedCodeMetadata *)ptr;
Py_DECREF(meta->func_name);
Py_DECREF(meta->file_name);
Py_DECREF(meta->linetable);
PyMem_RawFree(meta);
}
static inline RemoteDebuggingState *
RemoteDebugging_GetState(PyObject *module)
{
void *state = _PyModule_GetState(module);
assert(state != NULL);
return (RemoteDebuggingState *)state;
}
static inline RemoteDebuggingState *
RemoteDebugging_GetStateFromType(PyTypeObject *type)
{
PyObject *module = PyType_GetModule(type);
assert(module != NULL);
return RemoteDebugging_GetState(module);
}
static inline RemoteDebuggingState *
RemoteDebugging_GetStateFromObject(PyObject *obj)
{
RemoteUnwinderObject *unwinder = (RemoteUnwinderObject *)obj;
if (unwinder->cached_state == NULL) {
unwinder->cached_state = RemoteDebugging_GetStateFromType(Py_TYPE(obj));
}
return unwinder->cached_state;
}
static inline int
RemoteDebugging_InitState(RemoteDebuggingState *st)
{
return 0;
}
static int
is_prerelease_version(uint64_t version)
{
return (version & 0xF0) != 0xF0;
}
static inline int
validate_debug_offsets(struct _Py_DebugOffsets *debug_offsets)
{
if (memcmp(debug_offsets->cookie, _Py_Debug_Cookie, sizeof(debug_offsets->cookie)) != 0) {
// The remote is probably running a Python version predating debug offsets.
PyErr_SetString(
PyExc_RuntimeError,
"Can't determine the Python version of the remote process");
return -1;
}
// Assume debug offsets could change from one pre-release version to another,
// or one minor version to another, but are stable across patch versions.
if (is_prerelease_version(Py_Version) && Py_Version != debug_offsets->version) {
PyErr_SetString(
PyExc_RuntimeError,
"Can't attach from a pre-release Python interpreter"
" to a process running a different Python version");
return -1;
}
if (is_prerelease_version(debug_offsets->version) && Py_Version != debug_offsets->version) {
PyErr_SetString(
PyExc_RuntimeError,
"Can't attach to a pre-release Python interpreter"
" from a process running a different Python version");
return -1;
}
unsigned int remote_major = (debug_offsets->version >> 24) & 0xFF;
unsigned int remote_minor = (debug_offsets->version >> 16) & 0xFF;
if (PY_MAJOR_VERSION != remote_major || PY_MINOR_VERSION != remote_minor) {
PyErr_Format(
PyExc_RuntimeError,
"Can't attach from a Python %d.%d process to a Python %d.%d process",
PY_MAJOR_VERSION, PY_MINOR_VERSION, remote_major, remote_minor);
return -1;
}
// The debug offsets differ between free threaded and non-free threaded builds.
if (_Py_Debug_Free_Threaded && !debug_offsets->free_threaded) {
PyErr_SetString(
PyExc_RuntimeError,
"Cannot attach from a free-threaded Python process"
" to a process running a non-free-threaded version");
return -1;
}
if (!_Py_Debug_Free_Threaded && debug_offsets->free_threaded) {
PyErr_SetString(
PyExc_RuntimeError,
"Cannot attach to a free-threaded Python process"
" from a process running a non-free-threaded version");
return -1;
}
return 0;
}
// Generic function to iterate through all threads
static int
iterate_threads(
RemoteUnwinderObject *unwinder,
thread_processor_func processor,
void *context
) {
uintptr_t thread_state_addr;
unsigned long tid = 0;
if (0 > _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
unwinder->interpreter_addr + (uintptr_t)unwinder->debug_offsets.interpreter_state.threads_main,
sizeof(void*),
&thread_state_addr))
{
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read main thread state");
return -1;
}
while (thread_state_addr != 0) {
if (0 > _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
thread_state_addr + (uintptr_t)unwinder->debug_offsets.thread_state.native_thread_id,
sizeof(tid),
&tid))
{
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read thread ID");
return -1;
}
// Call the processor function for this thread
if (processor(unwinder, thread_state_addr, tid, context) < 0) {
return -1;
}
// Move to next thread
if (0 > _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
thread_state_addr + (uintptr_t)unwinder->debug_offsets.thread_state.next,
sizeof(void*),
&thread_state_addr))
{
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read next thread state");
return -1;
}
}
return 0;
}
// Generic function to iterate through set entries
static int
iterate_set_entries(
RemoteUnwinderObject *unwinder,
uintptr_t set_addr,
set_entry_processor_func processor,
void *context
) {
char set_object[SIZEOF_SET_OBJ];
if (_Py_RemoteDebug_PagedReadRemoteMemory(&unwinder->handle, set_addr,
SIZEOF_SET_OBJ, set_object) < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read set object");
return -1;
}
Py_ssize_t num_els = GET_MEMBER(Py_ssize_t, set_object, unwinder->debug_offsets.set_object.used);
Py_ssize_t mask = GET_MEMBER(Py_ssize_t, set_object, unwinder->debug_offsets.set_object.mask);
uintptr_t table_ptr = GET_MEMBER(uintptr_t, set_object, unwinder->debug_offsets.set_object.table);
if (mask < 0 || mask >= MAX_SET_TABLE_SIZE || num_els < 0 || num_els > mask + 1) {
PyErr_SetString(PyExc_RuntimeError, "Invalid set object (corrupted remote memory)");
set_exception_cause(unwinder, PyExc_RuntimeError,
"Invalid set object (corrupted remote memory)");
return -1;
}
Py_ssize_t set_len = mask + 1;
Py_ssize_t i = 0;
Py_ssize_t els = 0;
while (i < set_len && els < num_els) {
uintptr_t key_addr;
if (read_py_ptr(unwinder, table_ptr, &key_addr) < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read set entry key");
return -1;
}
if ((void*)key_addr != NULL) {
Py_ssize_t ref_cnt;
if (read_Py_ssize_t(unwinder, table_ptr, &ref_cnt) < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read set entry ref count");
return -1;
}
if (ref_cnt) {
// Process this valid set entry
if (processor(unwinder, key_addr, context) < 0) {
return -1;
}
els++;
}
}
table_ptr += sizeof(void*) * 2;
i++;
}
return 0;
}
// Processor function for task waiters
static int
process_waiter_task(
RemoteUnwinderObject *unwinder,
uintptr_t key_addr,
void *context
) {
PyObject *result = (PyObject *)context;
return process_task_and_waiters(unwinder, key_addr, result);
}
// Processor function for parsing tasks in sets
static int
process_task_parser(
RemoteUnwinderObject *unwinder,
uintptr_t key_addr,
void *context
) {
PyObject *awaited_by = (PyObject *)context;
return parse_task(unwinder, key_addr, awaited_by);
}
/* ============================================================================
* MEMORY READING FUNCTIONS
* ============================================================================ */
#define DEFINE_MEMORY_READER(type_name, c_type, error_msg) \
static inline int \
read_##type_name(RemoteUnwinderObject *unwinder, uintptr_t address, c_type *result) \
{ \
int res = _Py_RemoteDebug_PagedReadRemoteMemory(&unwinder->handle, address, sizeof(c_type), result); \
if (res < 0) { \
set_exception_cause(unwinder, PyExc_RuntimeError, error_msg); \
return -1; \
} \
return 0; \
}
DEFINE_MEMORY_READER(ptr, uintptr_t, "Failed to read pointer from remote memory")
DEFINE_MEMORY_READER(Py_ssize_t, Py_ssize_t, "Failed to read Py_ssize_t from remote memory")
DEFINE_MEMORY_READER(char, char, "Failed to read char from remote memory")
static int
read_py_ptr(RemoteUnwinderObject *unwinder, uintptr_t address, uintptr_t *ptr_addr)
{
if (read_ptr(unwinder, address, ptr_addr)) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read Python pointer");
return -1;
}
*ptr_addr &= ~Py_TAG_BITS;
return 0;
}
/* ============================================================================
* PYTHON OBJECT READING FUNCTIONS
* ============================================================================ */
static PyObject *
read_py_str(
RemoteUnwinderObject *unwinder,
uintptr_t address,
Py_ssize_t max_len
) {
PyObject *result = NULL;
char *buf = NULL;
// Read the entire PyUnicodeObject at once
char unicode_obj[SIZEOF_UNICODE_OBJ];
int res = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
address,
SIZEOF_UNICODE_OBJ,
unicode_obj
);
if (res < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read PyUnicodeObject");
goto err;
}
Py_ssize_t len = GET_MEMBER(Py_ssize_t, unicode_obj, unwinder->debug_offsets.unicode_object.length);
if (len < 0 || len > max_len) {
PyErr_Format(PyExc_RuntimeError,
"Invalid string length (%zd) at 0x%lx", len, address);
set_exception_cause(unwinder, PyExc_RuntimeError, "Invalid string length in remote Unicode object");
return NULL;
}
buf = (char *)PyMem_RawMalloc(len+1);
if (buf == NULL) {
PyErr_NoMemory();
set_exception_cause(unwinder, PyExc_MemoryError, "Failed to allocate buffer for string reading");
return NULL;
}
size_t offset = (size_t)unwinder->debug_offsets.unicode_object.asciiobject_size;
res = _Py_RemoteDebug_PagedReadRemoteMemory(&unwinder->handle, address + offset, len, buf);
if (res < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read string data from remote memory");
goto err;
}
buf[len] = '\0';
result = PyUnicode_FromStringAndSize(buf, len);
if (result == NULL) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to create PyUnicode from remote string data");
goto err;
}
PyMem_RawFree(buf);
assert(result != NULL);
return result;
err:
if (buf != NULL) {
PyMem_RawFree(buf);
}
return NULL;
}
static PyObject *
read_py_bytes(
RemoteUnwinderObject *unwinder,
uintptr_t address,
Py_ssize_t max_len
) {
PyObject *result = NULL;
char *buf = NULL;
// Read the entire PyBytesObject at once
char bytes_obj[SIZEOF_BYTES_OBJ];
int res = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
address,
SIZEOF_BYTES_OBJ,
bytes_obj
);
if (res < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read PyBytesObject");
goto err;
}
Py_ssize_t len = GET_MEMBER(Py_ssize_t, bytes_obj, unwinder->debug_offsets.bytes_object.ob_size);
if (len < 0 || len > max_len) {
PyErr_Format(PyExc_RuntimeError,
"Invalid bytes length (%zd) at 0x%lx", len, address);
set_exception_cause(unwinder, PyExc_RuntimeError, "Invalid bytes length in remote bytes object");
return NULL;
}
buf = (char *)PyMem_RawMalloc(len+1);
if (buf == NULL) {
PyErr_NoMemory();
set_exception_cause(unwinder, PyExc_MemoryError, "Failed to allocate buffer for bytes reading");
return NULL;
}
size_t offset = (size_t)unwinder->debug_offsets.bytes_object.ob_sval;
res = _Py_RemoteDebug_PagedReadRemoteMemory(&unwinder->handle, address + offset, len, buf);
if (res < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read bytes data from remote memory");
goto err;
}
buf[len] = '\0';
result = PyBytes_FromStringAndSize(buf, len);
if (result == NULL) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to create PyBytes from remote bytes data");
goto err;
}
PyMem_RawFree(buf);
assert(result != NULL);
return result;
err:
if (buf != NULL) {
PyMem_RawFree(buf);
}
return NULL;
}
static long
read_py_long(
RemoteUnwinderObject *unwinder,
uintptr_t address
)
{
unsigned int shift = PYLONG_BITS_IN_DIGIT;
// Read the entire PyLongObject at once
char long_obj[SIZEOF_LONG_OBJ];
int bytes_read = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
address,
(size_t)unwinder->debug_offsets.long_object.size,
long_obj);
if (bytes_read < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read PyLongObject");
return -1;
}
uintptr_t lv_tag = GET_MEMBER(uintptr_t, long_obj, unwinder->debug_offsets.long_object.lv_tag);
int negative = (lv_tag & 3) == 2;
Py_ssize_t size = lv_tag >> 3;
if (size == 0) {
return 0;
}
if (size < 0 || size > MAX_LONG_DIGITS) {
PyErr_Format(PyExc_RuntimeError,
"Invalid PyLong digit count: %zd (expected 0-%d)",
size, MAX_LONG_DIGITS);
set_exception_cause(unwinder, PyExc_RuntimeError,
"Invalid PyLong size (corrupted remote memory)");
return -1;
}
// If the long object has inline digits, use them directly
digit *digits;
if (size <= _PY_NSMALLNEGINTS + _PY_NSMALLPOSINTS) {
// For small integers, digits are inline in the long_value.ob_digit array
digits = (digit *)PyMem_RawMalloc(size * sizeof(digit));
if (!digits) {
PyErr_NoMemory();
set_exception_cause(unwinder, PyExc_MemoryError, "Failed to allocate digits for small PyLong");
return -1;
}
memcpy(digits, long_obj + unwinder->debug_offsets.long_object.ob_digit, size * sizeof(digit));
} else {
// For larger integers, we need to read the digits separately
digits = (digit *)PyMem_RawMalloc(size * sizeof(digit));
if (!digits) {
PyErr_NoMemory();
set_exception_cause(unwinder, PyExc_MemoryError, "Failed to allocate digits for large PyLong");
return -1;
}
bytes_read = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
address + (uintptr_t)unwinder->debug_offsets.long_object.ob_digit,
sizeof(digit) * size,
digits
);
if (bytes_read < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read PyLong digits from remote memory");
goto error;
}
}
long long value = 0;
// In theory this can overflow, but because of llvm/llvm-project#16778
// we can't use __builtin_mul_overflow because it fails to link with
// __muloti4 on aarch64. In practice this is fine because all we're
// testing here are task numbers that would fit in a single byte.
for (Py_ssize_t i = 0; i < size; ++i) {
long long factor = digits[i] * (1UL << (Py_ssize_t)(shift * i));
value += factor;
}
PyMem_RawFree(digits);
if (negative) {
value *= -1;
}
return (long)value;
error:
PyMem_RawFree(digits);
return -1;
}
/* ============================================================================
* ASYNCIO DEBUG FUNCTIONS
* ============================================================================ */
// Get the PyAsyncioDebug section address for any platform
static uintptr_t
_Py_RemoteDebug_GetAsyncioDebugAddress(proc_handle_t* handle)
{
uintptr_t address;
#ifdef MS_WINDOWS
// On Windows, search for asyncio debug in executable or DLL
address = search_windows_map_for_section(handle, "AsyncioD", L"_asyncio", NULL);
if (address == 0) {
// Error out: 'python' substring covers both executable and DLL
PyObject *exc = PyErr_GetRaisedException();
PyErr_SetString(PyExc_RuntimeError, "Failed to find the AsyncioDebug section in the process.");
_PyErr_ChainExceptions1(exc);
}
#elif defined(__linux__)
// On Linux, search for asyncio debug in executable or DLL
address = search_linux_map_for_section(handle, "AsyncioDebug", "_asyncio.cpython", NULL);
if (address == 0) {
// Error out: 'python' substring covers both executable and DLL
PyObject *exc = PyErr_GetRaisedException();
PyErr_SetString(PyExc_RuntimeError, "Failed to find the AsyncioDebug section in the process.");
_PyErr_ChainExceptions1(exc);
}
#elif defined(__APPLE__) && TARGET_OS_OSX
// On macOS, try libpython first, then fall back to python
address = search_map_for_section(handle, "AsyncioDebug", "_asyncio.cpython", NULL);
if (address == 0) {
PyErr_Clear();
address = search_map_for_section(handle, "AsyncioDebug", "_asyncio.cpython", NULL);
}
if (address == 0) {
// Error out: 'python' substring covers both executable and DLL
PyObject *exc = PyErr_GetRaisedException();
PyErr_SetString(PyExc_RuntimeError, "Failed to find the AsyncioDebug section in the process.");
_PyErr_ChainExceptions1(exc);
}
#else
Py_UNREACHABLE();
#endif
return address;
}
static int
read_async_debug(
RemoteUnwinderObject *unwinder
) {
uintptr_t async_debug_addr = _Py_RemoteDebug_GetAsyncioDebugAddress(&unwinder->handle);
if (!async_debug_addr) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to get AsyncioDebug address");
return -1;
}
size_t size = sizeof(struct _Py_AsyncioModuleDebugOffsets);
int result = _Py_RemoteDebug_PagedReadRemoteMemory(&unwinder->handle, async_debug_addr, size, &unwinder->async_debug_offsets);
if (result < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read AsyncioDebug offsets");
}
return result;
}
/* ============================================================================
* ASYNCIO TASK PARSING FUNCTIONS
* ============================================================================ */
static PyObject *
parse_task_name(
RemoteUnwinderObject *unwinder,
uintptr_t task_address
) {
// Read the entire TaskObj at once
char task_obj[SIZEOF_TASK_OBJ];
int err = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
task_address,
(size_t)unwinder->async_debug_offsets.asyncio_task_object.size,
task_obj);
if (err < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read task object");
return NULL;
}
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];
err = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
task_name_addr,
SIZEOF_PYOBJECT,
task_name_obj);
if (err < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read task name object");
return NULL;
}
// Now read the type object to get the flags
char type_obj[SIZEOF_TYPE_OBJ];
err = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
GET_MEMBER(uintptr_t, task_name_obj, unwinder->debug_offsets.pyobject.ob_type),
SIZEOF_TYPE_OBJ,
type_obj);
if (err < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read task name type object");
return NULL;
}
if ((GET_MEMBER(unsigned long, type_obj, unwinder->debug_offsets.type_object.tp_flags) & Py_TPFLAGS_LONG_SUBCLASS)) {
long res = read_py_long(unwinder, task_name_addr);
if (res == -1) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Task name PyLong parsing failed");
return NULL;
}
return PyUnicode_FromFormat("Task-%ld", res);
}
if(!(GET_MEMBER(unsigned long, type_obj, unwinder->debug_offsets.type_object.tp_flags) & Py_TPFLAGS_UNICODE_SUBCLASS)) {
PyErr_SetString(PyExc_RuntimeError, "Invalid task name object");
set_exception_cause(unwinder, PyExc_RuntimeError, "Task name object is neither long nor unicode");
return NULL;
}
return read_py_str(
unwinder,
task_name_addr,
255
);
}
static int parse_task_awaited_by(
RemoteUnwinderObject *unwinder,
uintptr_t task_address,
PyObject *awaited_by
) {
return process_task_awaited_by(unwinder, task_address, process_task_parser, awaited_by);
}
static int
handle_yield_from_frame(
RemoteUnwinderObject *unwinder,
uintptr_t gi_iframe_addr,
uintptr_t gen_type_addr,
PyObject *render_to
) {
// Read the entire interpreter frame at once
char iframe[SIZEOF_INTERP_FRAME];
int err = _Py_RemoteDebug_PagedReadRemoteMemory(
&unwinder->handle,
gi_iframe_addr,
SIZEOF_INTERP_FRAME,
iframe);
if (err < 0) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read interpreter frame in yield_from handler");
return -1;
}
if (GET_MEMBER(char, iframe, unwinder->debug_offsets.interpreter_frame.owner) != FRAME_OWNED_BY_GENERATOR) {
PyErr_SetString(
PyExc_RuntimeError,
"generator doesn't own its frame \\_o_/");
set_exception_cause(unwinder, PyExc_RuntimeError, "Frame ownership mismatch in yield_from");
return -1;
}
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;
err = read_py_ptr(
unwinder,
stackpointer_addr - sizeof(void*),
&gi_await_addr);
if (err) {
set_exception_cause(unwinder, PyExc_RuntimeError, "Failed to read gi_await address");
return -1;
}