gh-131338: Disable computed stack limit checks on non-glibc linux (#134336)

bitdancer · kumaraditya303 · vstinner · web-flow · commit 1e9b8f2f8512 · 2025-07-28T22:02:34.000+05:30
Co-authored-by: Kumar Aditya &lt;kumaraditya@python.org&gt;
Co-authored-by: Victor Stinner &lt;vstinner@python.org&gt;
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-07-25-22-31-52.gh-issue-131338.zJDCMp.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-25-22-31-52.gh-issue-131338.zJDCMp.rst
@@ -0,0 +1,2 @@
+Disable computed stack limit checks on non-glibc linux platforms to fix
+crashes on deep recursion.
diff --git a/Python/ceval.c b/Python/ceval.c
@@ -452,7 +452,11 @@ _Py_InitializeRecursionLimits(PyThreadState *tstate)
     _tstate->c_stack_soft_limit = _tstate->c_stack_hard_limit + _PyOS_STACK_MARGIN_BYTES;
 #else
     uintptr_t here_addr = _Py_get_machine_stack_pointer();
-#  if defined(HAVE_PTHREAD_GETATTR_NP) && !defined(_AIX) && !defined(__NetBSD__)
+/// XXX musl supports HAVE_PTHRED_GETATTR_NP, but the resulting stack size
+/// (on alpine at least) is much smaller than expected and imposes undue limits
+/// compared to the old stack size estimation.  (We assume musl is not glibc.)
+#  if defined(HAVE_PTHREAD_GETATTR_NP) && !defined(_AIX) && \
+        !defined(__NetBSD__) && (defined(__GLIBC__) || !defined(__linux__))
     size_t stack_size, guard_size;
     void *stack_addr;
     pthread_attr_t attr;

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Disable computed stack limit checks on non-glibc linux platforms to fix`
	`2`	`+crashes on deep recursion.`