[3.15] gh-156114: Fix crash in perf trampoline with unencodable code names (GH-156300) (#157773)

Author: miss-islington

Lib/test/test_perf_profiler.py

@@ -113,6 +113,16 @@ def baz():
                 "Address should contain only hex characters",
             )
 
+    @unittest.skipIf(support.check_bolt_optimized(), "fails on BOLT instrumented binaries")
+    def test_trampoline_with_unencodable_name(self):
+        code = """if 1:
+                import sys
+
+                sys.activate_stack_trampoline("perf")
+                eval(compile("pass", "bad\\ud800file", "exec"))
+                """
+        assert_python_ok("-c", code, PYTHON_JIT="0")
+
     @unittest.skipIf(support.check_bolt_optimized(), "fails on BOLT instrumented binaries")
     def test_trampoline_works_with_forks(self):
         code = """if 1:

Misc/NEWS.d/next/Core_and_Builtins/2026-08-23-12-00-00.gh-issue-156114.Kq7fXz.rst

@@ -0,0 +1,2 @@
+Fix a crash in the perf trampoline when a code object has a name or filename
+that cannot be encoded to UTF-8. Patched by Shamil Abdulaev.

Python/perf_jit_trampoline.c

@@ -749,9 +749,15 @@ static void perf_map_jit_write_entry(void *state, const void *code_addr,
     if (co != NULL) {
         if (co->co_qualname != NULL) {
             entry = PyUnicode_AsUTF8(co->co_qualname);
+            if (entry == NULL) {
+                PyErr_Clear();
+            }
         }
         if (co->co_filename != NULL) {
             filename = PyUnicode_AsUTF8(co->co_filename);
+            if (filename == NULL) {
+                PyErr_Clear();
+            }
         }
     }
     perf_map_jit_write_entry_with_name(state, code_addr, code_size,

Python/perf_trampoline.c

@@ -254,10 +254,18 @@ perf_map_write_entry(void *state, const void *code_addr,
     const char *entry = "";
     if (co->co_qualname != NULL) {
         entry = PyUnicode_AsUTF8(co->co_qualname);
+        if (entry == NULL) {
+            PyErr_Clear();
+            entry = "";
+        }
     }
     const char *filename = "";
     if (co->co_filename != NULL) {
         filename = PyUnicode_AsUTF8(co->co_filename);
+        if (filename == NULL) {
+            PyErr_Clear();
+            filename = "";
+        }
     }
     size_t perf_map_entry_size = snprintf(NULL, 0, "py::%s:%s", entry, filename) + 1;
     char* perf_map_entry = (char*) PyMem_RawMalloc(perf_map_entry_size);