FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

GH-137573: Check C stack depth before stack allocating JIT optimizer struct by markshannon · Pull Request #137676 · python/cpython · GitHub

/ cpython Public

GH-137573: Check C stack depth before stack allocating JIT optimizer struct #137676

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
markshannon wants to merge 4 commits into from
+45 −1
Conversation 7 Commits 4 Checks 57 Files changed 4
Closed

GH-137573: Check C stack depth before stack allocating JIT optimizer struct #137676

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
a2c2a78
Check C stack depth before stack allocating JIT optimizer struct
markshannon Aug 12, 2025
ef27395
Add news
markshannon Aug 12, 2025
0a889df
Update Lib/test/test_call.py
markshannon Aug 13, 2025
be99bd4
Account for trace buffer as well
markshannon Aug 13, 2025
File filter

Filter by extension

Filter by extension .c  (2) .py  (1) .rst  (1) All 3 file types selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
34 changes: 33 additions & 1 deletion Lib/test/test_capi/test_opt.py
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -10,11 +10,12 @@

from test.support import (script_helper, requires_specialization,
import_helper, Py_GIL_DISABLED, requires_jit_enabled,
reset_code)
reset_code, infinite_recursion)

_testinternalcapi = import_helper.import_module("_testinternalcapi")

from _testinternalcapi import TIER2_THRESHOLD
from _testcapi import pyobject_vectorcall


@contextlib.contextmanager
Expand Down Expand Up @@ -2502,6 +2503,37 @@ def testfunc(n):
self.assertIn("_BINARY_OP", uops)


@requires_jit_enabled
class TestStackUse(unittest.TestCase):

def test_jit_at_depth(self):

def run_at_depth(n, func):
if n:
pyobject_vectorcall(run_at_depth, (n-1, func), None)
else:
func()

def find_stack_limit():
nonlocal depth
depth += 1
pyobject_vectorcall(find_stack_limit, (), None)

with infinite_recursion():
depth = 0
try:
find_stack_limit()
except RecursionError:
pass

def loop_func():
r = 0
for i in range(TIER2_THRESHOLD):
r += i
return r
run_at_depth(depth-1, loop_func)


def global_identity(x):
return x

Expand Down
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2025-08-12-15-02-24.gh-issue-137573.9J6xfX.rst
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Guard against C stack overflow when JIT compiling.
6 changes: 6 additions & 0 deletions Python/optimizer.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -114,6 +114,12 @@ _PyOptimizer_Optimize(
_PyInterpreterFrame *frame, _Py_CODEUNIT *start,
_PyExecutorObject **executor_ptr, int chain_depth)
{
/* Make sure we have enough C stack space for the buffer */
int margin = 1 + sizeof(_PyUOpInstruction) * UOP_MAX_TRACE_LENGTH / _PyOS_STACK_MARGIN_BYTES;
if (_Py_ReachedRecursionLimitWithMargin(_PyThreadState_GET(), margin)) {
return 0;
}

_PyStackRef *stack_pointer = frame->stackpointer;
assert(_PyInterpreterState_GET()->jit);
// The first executor in a chain and the MAX_CHAIN_DEPTH'th executor *must*
Expand Down
5 changes: 5 additions & 0 deletions Python/optimizer_analysis.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -695,6 +695,11 @@ _Py_uop_analyze_and_optimize(
)
{
OPT_STAT_INC(optimizer_attempts);
/* Make sure we have enough C stack space for the optimizer */
int margin = 1 + sizeof(JitOptContext)/_PyOS_STACK_MARGIN_BYTES;
if (_Py_ReachedRecursionLimitWithMargin(_PyThreadState_GET(), margin)) {

Fidget-Spinner Aug 14, 2025

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

To work properly, the optimize_uops function or this function must be marked Py_NO_INLINE as well.

Otherwise, the compiler can just inline the functions and hoist the alloca above the check, making the check useless.
return 0;
}

int err = remove_globals(frame, buffer, length, dependencies);
if (err <= 0) {
Expand Down
Loading
Back | FazBrowse Home | New Git URL