Closes #22258: Fix the the internal function set_inheritable() on Illumos.
This platform exposes the function ioctl(FIOCLEX), but calling it fails with
errno is ENOTTY: "Inappropriate ioctl for device". set_inheritable() now falls
back to the slower fcntl() (F_GETFD and then F_SETFD).
diff --git a/Python/fileutils.c b/Python/fileutils.c
index a55064f..f5000e5 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -622,10 +622,12 @@
#ifdef MS_WINDOWS
HANDLE handle;
DWORD flags;
-#elif defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
+#else
+#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
+ static int ioctl_works = -1;
int request;
int err;
-#elif defined(HAVE_FCNTL_H)
+#endif
int flags;
int res;
#endif
@@ -671,20 +673,38 @@
}
return 0;
-#elif defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
- if (inheritable)
- request = FIONCLEX;
- else
- request = FIOCLEX;
- err = ioctl(fd, request, NULL);
- if (err) {
- if (raise)
- PyErr_SetFromErrno(PyExc_OSError);
- return -1;
- }
- return 0;
-
#else
+
+#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
+ if (ioctl_works != 0) {
+ /* fast-path: ioctl() only requires one syscall */
+ if (inheritable)
+ request = FIONCLEX;
+ else
+ request = FIOCLEX;
+ err = ioctl(fd, request, NULL);
+ if (!err) {
+ ioctl_works = 1;
+ return 0;
+ }
+
+ if (errno != ENOTTY) {
+ if (raise)
+ PyErr_SetFromErrno(PyExc_OSError);
+ return -1;
+ }
+ else {
+ /* 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. */
+ ioctl_works = 0;
+ }
+ /* fallback to fcntl() if ioctl() does not work */
+ }
+#endif
+
+ /* slow-path: fcntl() requires two syscalls */
flags = fcntl(fd, F_GETFD);
if (flags < 0) {
if (raise)