Fix os.set_inheritable() on Android

Issue #27057: Fix os.set_inheritable() on Android, ioctl() is blocked by
SELinux and fails with EACCESS. The function now falls back to fcntl().

Patch written by Michał Bednarski.

1 files changed, 7 insertions, 2 deletions

diff --git a/Python/fileutils.c b/Python/fileutils.c
index 06d632a..8987ce5 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -856,7 +856,7 @@ set_inheritable(int fd, int inheritable, int raise, int *atomic_flag_works)
             return 0;
         }
 
-        if (errno != ENOTTY) {
+        if (errno != ENOTTY && errno != EACCES) {
             if (raise)
                 PyErr_SetFromErrno(PyExc_OSError);
             return -1;
@@ -865,7 +865,12 @@ set_inheritable(int fd, int inheritable, int raise, int *atomic_flag_works)
             /* Issue #22258: Here, ENOTTY means "Inappropriate ioctl for
                device". The ioctl is declared but not supported by the kernel.
                Remember that ioctl() doesn't work. It is the case on
-               Illumos-based OS for example. */
+               Illumos-based OS for example.
+
+               Issue #27057: When SELinux policy disallows ioctl it will fail
+               with EACCES. While FIOCLEX is safe operation it may be
+               unavailable because ioctl was denied altogether.
+               This can be the case on Android. */
             ioctl_works = 0;
         }
         /* fallback to fcntl() if ioctl() does not work */