From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Wed, 27 Aug 2025 18:05:36 +0000 (+0200)
Subject: [3.13] bpo-41839: Fix error checking in sched_get_priority_ functions (GH-22374)... 
X-Git-Tag: v3.13.8~144
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=502ca0d1adc98775a7b92b5259c275ea2051b475;p=thirdparty%2FPython%2Fcpython.git

[3.13] bpo-41839: Fix error checking in sched_get_priority_ functions (GH-22374) (GH-138202)

(cherry picked from commit bbcb75c986c47887e6c0757e63d59cd7af544f39)

Co-authored-by: Jakub Kulík <Kulikjak@gmail.com>
---

diff --git a/Misc/NEWS.d/next/Library/2020-09-23-11-54-17.bpo-41839.kU5Ywl.rst b/Misc/NEWS.d/next/Library/2020-09-23-11-54-17.bpo-41839.kU5Ywl.rst
new file mode 100644
index 000000000000..760660408100
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-09-23-11-54-17.bpo-41839.kU5Ywl.rst
@@ -0,0 +1,2 @@
+Allow negative priority values from :func:`os.sched_get_priority_min` and
+:func:`os.sched_get_priority_max` functions.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index f31659808d73..90d91c28fd28 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -8101,10 +8101,10 @@ static PyObject *
 os_sched_get_priority_max_impl(PyObject *module, int policy)
 /*[clinic end generated code: output=9e465c6e43130521 input=2097b7998eca6874]*/
 {
-    int max;
-
-    max = sched_get_priority_max(policy);
-    if (max < 0)
+    /* make sure that errno is cleared before the call */
+    errno = 0;
+    int max = sched_get_priority_max(policy);
+    if (max == -1 && errno)
         return posix_error();
     return PyLong_FromLong(max);
 }
@@ -8122,8 +8122,10 @@ static PyObject *
 os_sched_get_priority_min_impl(PyObject *module, int policy)
 /*[clinic end generated code: output=7595c1138cc47a6d input=21bc8fa0d70983bf]*/
 {
+    /* make sure that errno is cleared before the call */
+    errno = 0;
     int min = sched_get_priority_min(policy);
-    if (min < 0)
+    if (min == -1 && errno)
         return posix_error();
     return PyLong_FromLong(min);
 }