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Leverage new debug offsets added in 3.13rc2
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Some offsets that we previously needed to infer or make assumptions
about are now provided by the interpreter itself. Start using them.

Signed-off-by: Matt Wozniski <[email protected]>
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@godlygeek @pablogsal
godlygeek authored and pablogsal committed Sep 11, 2024
1 parent 5942474 commit c77eb4f
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Showing 3 changed files with 111 additions and 61 deletions.
127 changes: 66 additions & 61 deletions src/pystack/_pystack/process.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -839,9 +839,31 @@ AbstractProcessManager::warnIfOffsetsAreMismatched(remote_addr_t runtime_addr) c

compare_size(&py_runtime_v::o_dbg_off_type_object_struct_size, py_type);
compare_offset(&py_runtime_v::o_dbg_off_type_object_tp_name, py_type.o_tp_name);
compare_offset(&py_runtime_v::o_dbg_off_type_object_tp_repr, py_type.o_tp_repr);
compare_offset(&py_runtime_v::o_dbg_off_type_object_tp_flags, py_type.o_tp_flags);

compare_size(&py_runtime_v::o_dbg_off_tuple_object_struct_size, py_tuple);
compare_offset(&py_runtime_v::o_dbg_off_tuple_object_ob_item, py_tuple.o_ob_item);
compare_offset(&py_runtime_v::o_dbg_off_tuple_object_ob_size, py_tuple.o_ob_size);

compare_size(&py_runtime_v::o_dbg_off_list_object_struct_size, py_list);
compare_offset(&py_runtime_v::o_dbg_off_list_object_ob_item, py_list.o_ob_item);
compare_offset(&py_runtime_v::o_dbg_off_list_object_ob_size, py_list.o_ob_size);

compare_size(&py_runtime_v::o_dbg_off_dict_object_struct_size, py_dict);
compare_offset(&py_runtime_v::o_dbg_off_dict_object_ma_keys, py_dict.o_ma_keys);
compare_offset(&py_runtime_v::o_dbg_off_dict_object_ma_values, py_dict.o_ma_values);

compare_size(&py_runtime_v::o_dbg_off_float_object_struct_size, py_float);
compare_offset(&py_runtime_v::o_dbg_off_float_object_ob_fval, py_float.o_ob_fval);

compare_size(&py_runtime_v::o_dbg_off_long_object_struct_size, py_long);
compare_offset(&py_runtime_v::o_dbg_off_long_object_lv_tag, py_long.o_ob_size);
compare_offset(&py_runtime_v::o_dbg_off_long_object_ob_digit, py_long.o_ob_digit);

compare_size(&py_runtime_v::o_dbg_off_bytes_object_struct_size, py_bytes);
compare_offset(&py_runtime_v::o_dbg_off_bytes_object_ob_size, py_bytes.o_ob_size);
compare_offset(&py_runtime_v::o_dbg_off_bytes_object_ob_sval, py_bytes.o_ob_sval);

compare_size(&py_runtime_v::o_dbg_off_unicode_object_struct_size, py_unicode);
compare_offset(&py_runtime_v::o_dbg_off_unicode_object_state, py_unicode.o_state);
Expand Down Expand Up @@ -896,12 +918,8 @@ bool
AbstractProcessManager::copyDebugOffsets(Structure<py_runtime_v>& py_runtime, python_v& debug_offsets)
const
{
// Fill in a temporary python_v with the offsets from the remote.
// For fields that aren't in _Py_DebugOffsets, make some assumptions, based
// in part on the size delta between the sizeof(PyObject) baked into our
// static offsets and the sizeof(PyObject) in the remote process/core.
Py_ssize_t new_pyobject_size = py_runtime.getField(&py_runtime_v::o_dbg_off_pyobject_struct_size);
Py_ssize_t pyobject_size_delta = -d_py_v->py_object.size + new_pyobject_size;
// Fill in a temporary python_v with the offsets from the remote. For fields
// that aren't in _Py_DebugOffsets, assume our static offsets are correct.

#define set_size(pystack_struct, size_offset) \
debug_offsets.pystack_struct.size = py_runtime.getField(size_offset)
Expand Down Expand Up @@ -951,19 +969,35 @@ AbstractProcessManager::copyDebugOffsets(Structure<py_runtime_v>& py_runtime, py

set_size(py_type, &py_runtime_v::o_dbg_off_type_object_struct_size);
set_offset(py_type.o_tp_name, &py_runtime_v::o_dbg_off_type_object_tp_name);
// Assume our static offsets are correct about the distance from tp_name to the other fields
debug_offsets.py_type.o_tp_repr = {
d_py_v->py_type.o_tp_repr.offset - d_py_v->py_type.o_tp_name.offset
+ debug_offsets.py_type.o_tp_name.offset};
debug_offsets.py_type.o_tp_flags = {
d_py_v->py_type.o_tp_flags.offset - d_py_v->py_type.o_tp_name.offset
+ debug_offsets.py_type.o_tp_name.offset};
set_offset(py_type.o_tp_repr, &py_runtime_v::o_dbg_off_type_object_tp_repr);
set_offset(py_type.o_tp_flags, &py_runtime_v::o_dbg_off_type_object_tp_flags);

set_size(py_tuple, &py_runtime_v::o_dbg_off_tuple_object_struct_size);
// Assume ob_base is the first field of PyVarObject and ob_size is the second
static_assert(sizeof(PyTupleObject::ob_base.ob_base) == offsetof(PyTupleObject, ob_base.ob_size));
debug_offsets.py_tuple.o_ob_size = {(offset_t)new_pyobject_size};
set_offset(py_tuple.o_ob_item, &py_runtime_v::o_dbg_off_tuple_object_ob_item);
set_offset(py_tuple.o_ob_size, &py_runtime_v::o_dbg_off_tuple_object_ob_size);

set_size(py_list, &py_runtime_v::o_dbg_off_list_object_struct_size);
set_offset(py_list.o_ob_item, &py_runtime_v::o_dbg_off_list_object_ob_item);
set_offset(py_list.o_ob_size, &py_runtime_v::o_dbg_off_list_object_ob_size);

set_size(py_dict, &py_runtime_v::o_dbg_off_dict_object_struct_size);
set_offset(py_dict.o_ma_keys, &py_runtime_v::o_dbg_off_dict_object_ma_keys);
set_offset(py_dict.o_ma_values, &py_runtime_v::o_dbg_off_dict_object_ma_values);

// Assume our static offsets for dict keys and values are correct
debug_offsets.py_dictkeys = d_py_v->py_dictkeys;
debug_offsets.py_dictvalues = d_py_v->py_dictvalues;

set_size(py_float, &py_runtime_v::o_dbg_off_float_object_struct_size);
set_offset(py_float.o_ob_fval, &py_runtime_v::o_dbg_off_float_object_ob_fval);

set_size(py_long, &py_runtime_v::o_dbg_off_long_object_struct_size);
set_offset(py_long.o_ob_size, &py_runtime_v::o_dbg_off_long_object_lv_tag);
set_offset(py_long.o_ob_digit, &py_runtime_v::o_dbg_off_long_object_ob_digit);

set_size(py_bytes, &py_runtime_v::o_dbg_off_bytes_object_struct_size);
set_offset(py_bytes.o_ob_size, &py_runtime_v::o_dbg_off_bytes_object_ob_size);
set_offset(py_bytes.o_ob_sval, &py_runtime_v::o_dbg_off_bytes_object_ob_sval);

set_size(py_unicode, &py_runtime_v::o_dbg_off_unicode_object_struct_size);
set_offset(py_unicode.o_state, &py_runtime_v::o_dbg_off_unicode_object_state);
Expand All @@ -973,54 +1007,25 @@ AbstractProcessManager::copyDebugOffsets(Structure<py_runtime_v>& py_runtime, py
set_size(py_gc, &py_runtime_v::o_dbg_off_gc_struct_size);
set_offset(py_gc.o_collecting, &py_runtime_v::o_dbg_off_gc_collecting);

// Assume ob_size and ob_item are at the same location for list as for tuple
static_assert(
offsetof(PyListObject, ob_item) + sizeof(PyListObject::ob_item) <= sizeof(PyTupleObject));
debug_offsets.py_list.size = debug_offsets.py_tuple.size;

static_assert(offsetof(PyListObject, ob_base.ob_size) == offsetof(PyTupleObject, ob_base.ob_size));
debug_offsets.py_list.o_ob_size = debug_offsets.py_tuple.o_ob_size;

static_assert(offsetof(PyListObject, ob_item) == offsetof(PyTupleObject, ob_item));
debug_offsets.py_list.o_ob_item = {debug_offsets.py_tuple.o_ob_item.offset};

// Assume our static offsets for dict are correct save possibly for sizeof(PyObject) changing
debug_offsets.py_dictkeys = d_py_v->py_dictkeys;
debug_offsets.py_dictvalues = d_py_v->py_dictvalues;
debug_offsets.py_dict = d_py_v->py_dict;
debug_offsets.py_dict.size += pyobject_size_delta;
debug_offsets.py_dict.o_ma_keys.offset += pyobject_size_delta;
debug_offsets.py_dict.o_ma_values.offset += pyobject_size_delta;

// Assume our static offsets for float are correct save possibly for sizeof(PyObject) changing
debug_offsets.py_float = d_py_v->py_float;
debug_offsets.py_float.size += pyobject_size_delta;
debug_offsets.py_float.o_ob_fval.offset += pyobject_size_delta;

// Assume our static offsets for long are correct save possibly for sizeof(PyObject) changing
debug_offsets.py_long = d_py_v->py_long;
debug_offsets.py_long.size += pyobject_size_delta;
debug_offsets.py_long.o_ob_size.offset += pyobject_size_delta;
debug_offsets.py_long.o_ob_digit.offset += pyobject_size_delta;

// Assume our static offsets for bytes are correct save possibly for sizeof(PyObject) changing
debug_offsets.py_bytes = d_py_v->py_bytes;
debug_offsets.py_bytes.size += pyobject_size_delta;
debug_offsets.py_bytes.o_ob_size.offset += pyobject_size_delta;
debug_offsets.py_bytes.o_ob_sval.offset += pyobject_size_delta;

// Assume our static offsets for cframe are all correct
debug_offsets.py_cframe = d_py_v->py_cframe;

// Assume our static offsets for gilruntimestate are off by 8 bytes in a free-threading build.
// This is quite a hack...
debug_offsets.py_gilruntimestate = d_py_v->py_gilruntimestate;
bool is_free_threading = static_cast<size_t>(debug_offsets.py_object.size) > 2 * sizeof(void*);
if (is_free_threading) {
debug_offsets.py_gilruntimestate.size += 8;
debug_offsets.py_gilruntimestate.o_last_holder.offset += 8;
debug_offsets.py_gilruntimestate.o_locked.offset += 8;
}
size_t gilruntimestate_start =
py_runtime.getField(&py_runtime_v::o_dbg_off_interpreter_state_gil_runtime_state);

size_t gilruntimestate_locked_offset =
py_runtime.getField(&py_runtime_v::o_dbg_off_interpreter_state_gil_runtime_state_locked)
- gilruntimestate_start;
size_t gilruntimestate_holder_offset =
py_runtime.getField(&py_runtime_v::o_dbg_off_interpreter_state_gil_runtime_state_holder)
- gilruntimestate_start;

debug_offsets.py_gilruntimestate.size = std::max(
{gilruntimestate_locked_offset + sizeof(decltype(py_gilruntimestate_v::o_locked)::Type),
gilruntimestate_holder_offset
+ sizeof(decltype(py_gilruntimestate_v::o_last_holder)::Type)});
debug_offsets.py_gilruntimestate.o_locked.offset = gilruntimestate_locked_offset;
debug_offsets.py_gilruntimestate.o_last_holder.offset = gilruntimestate_holder_offset;

#undef set_size
#undef set_offset
Expand Down
20 changes: 20 additions & 0 deletions src/pystack/_pystack/version.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -239,6 +239,7 @@ py_runtimev313()
{},
offsetof(T, debug_offsets.cookie),
offsetof(T, debug_offsets.version),
offsetof(T, debug_offsets.free_threaded),
offsetof(T, debug_offsets.runtime_state.size),
offsetof(T, debug_offsets.runtime_state.finalizing),
offsetof(T, debug_offsets.runtime_state.interpreters_head),
Expand All @@ -251,6 +252,8 @@ py_runtimev313()
offsetof(T, debug_offsets.interpreter_state.sysdict),
offsetof(T, debug_offsets.interpreter_state.builtins),
offsetof(T, debug_offsets.interpreter_state.ceval_gil),
offsetof(T, debug_offsets.interpreter_state.gil_runtime_state),
offsetof(T, debug_offsets.interpreter_state.gil_runtime_state_enabled),
offsetof(T, debug_offsets.interpreter_state.gil_runtime_state_locked),
offsetof(T, debug_offsets.interpreter_state.gil_runtime_state_holder),
offsetof(T, debug_offsets.thread_state.size),
Expand Down Expand Up @@ -282,8 +285,25 @@ py_runtimev313()
offsetof(T, debug_offsets.pyobject.ob_type),
offsetof(T, debug_offsets.type_object.size),
offsetof(T, debug_offsets.type_object.tp_name),
offsetof(T, debug_offsets.type_object.tp_repr),
offsetof(T, debug_offsets.type_object.tp_flags),
offsetof(T, debug_offsets.tuple_object.size),
offsetof(T, debug_offsets.tuple_object.ob_item),
offsetof(T, debug_offsets.tuple_object.ob_size),
offsetof(T, debug_offsets.list_object.size),
offsetof(T, debug_offsets.list_object.ob_item),
offsetof(T, debug_offsets.list_object.ob_size),
offsetof(T, debug_offsets.dict_object.size),
offsetof(T, debug_offsets.dict_object.ma_keys),
offsetof(T, debug_offsets.dict_object.ma_values),
offsetof(T, debug_offsets.float_object.size),
offsetof(T, debug_offsets.float_object.ob_fval),
offsetof(T, debug_offsets.long_object.size),
offsetof(T, debug_offsets.long_object.lv_tag),
offsetof(T, debug_offsets.long_object.ob_digit),
offsetof(T, debug_offsets.bytes_object.size),
offsetof(T, debug_offsets.bytes_object.ob_size),
offsetof(T, debug_offsets.bytes_object.ob_sval),
offsetof(T, debug_offsets.unicode_object.size),
offsetof(T, debug_offsets.unicode_object.state),
offsetof(T, debug_offsets.unicode_object.length),
Expand Down
25 changes: 25 additions & 0 deletions src/pystack/_pystack/version.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -134,6 +134,7 @@ struct py_runtime_v

FieldOffset<char[8]> o_dbg_off_cookie;
FieldOffset<uint64_t> o_dbg_off_py_version_hex;
FieldOffset<uint64_t> o_dbg_off_free_threaded;

FieldOffset<uint64_t> o_dbg_off_runtime_state_struct_size;
FieldOffset<uint64_t> o_dbg_off_runtime_state_finalizing;
Expand All @@ -148,6 +149,8 @@ struct py_runtime_v
FieldOffset<uint64_t> o_dbg_off_interpreter_state_sysdict;
FieldOffset<uint64_t> o_dbg_off_interpreter_state_builtins;
FieldOffset<uint64_t> o_dbg_off_interpreter_state_ceval_gil;
FieldOffset<uint64_t> o_dbg_off_interpreter_state_gil_runtime_state;
FieldOffset<uint64_t> o_dbg_off_interpreter_state_gil_runtime_state_enabled;
FieldOffset<uint64_t> o_dbg_off_interpreter_state_gil_runtime_state_locked;
FieldOffset<uint64_t> o_dbg_off_interpreter_state_gil_runtime_state_holder;

Expand Down Expand Up @@ -184,9 +187,31 @@ struct py_runtime_v

FieldOffset<uint64_t> o_dbg_off_type_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_type_object_tp_name;
FieldOffset<uint64_t> o_dbg_off_type_object_tp_repr;
FieldOffset<uint64_t> o_dbg_off_type_object_tp_flags;

FieldOffset<uint64_t> o_dbg_off_tuple_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_tuple_object_ob_item;
FieldOffset<uint64_t> o_dbg_off_tuple_object_ob_size;

FieldOffset<uint64_t> o_dbg_off_list_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_list_object_ob_item;
FieldOffset<uint64_t> o_dbg_off_list_object_ob_size;

FieldOffset<uint64_t> o_dbg_off_dict_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_dict_object_ma_keys;
FieldOffset<uint64_t> o_dbg_off_dict_object_ma_values;

FieldOffset<uint64_t> o_dbg_off_float_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_float_object_ob_fval;

FieldOffset<uint64_t> o_dbg_off_long_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_long_object_lv_tag;
FieldOffset<uint64_t> o_dbg_off_long_object_ob_digit;

FieldOffset<uint64_t> o_dbg_off_bytes_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_bytes_object_ob_size;
FieldOffset<uint64_t> o_dbg_off_bytes_object_ob_sval;

FieldOffset<uint64_t> o_dbg_off_unicode_object_struct_size;
FieldOffset<uint64_t> o_dbg_off_unicode_object_state;
Expand Down

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