From 57998018d9569be2f908faa034945db258577556 Mon Sep 17 00:00:00 2001
From: Antonio Gutierrez <chibby0ne@gmail.com>
Date: Sat, 20 Jul 2019 02:44:15 +0200
Subject: [PATCH 1/2] Use thread-safe functions instead of unsafe ones (crypt,
 ttyname)

* Use dynamically-allocated buffer for ttyname_r buffer
* In case there is an error with the crypt/crypt_r then raise the error,
instead of failing silently.
* Check for EINVAL (invalid argument) in errno when adding not supported
cryptographic methods, such as Blowfish in the case of glibc, but raise
other errors.
* Use _SC_TTY_MAX_LENGTH for TTY_NAME_MAX

Signed-off-by: Antonio Gutierrez <chibby0ne@gmail.com>
---
 .../2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst  |  1 +
 Modules/posixmodule.c                         | 19 +++++++++++++++----
 2 files changed, 16 insertions(+), 4 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst

diff --git a/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst b/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst
new file mode 100644
index 00000000000000..aa0884ee1bad3f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst
@@ -0,0 +1 @@
+Use ttyname_r instead of ttyname for thread safety
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 5664027b2d3a3e..aeb0e9ddb1953c 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2774,13 +2774,24 @@ static PyObject *
 os_ttyname_impl(PyObject *module, int fd)
 /*[clinic end generated code: output=c424d2e9d1cd636a input=9ff5a58b08115c55]*/
 {
-    char *ret;
 
-    ret = ttyname(fd);
-    if (ret == NULL) {
+    long size = sysconf(_SC_TTY_NAME_MAX);
+    if (size == -1) {
+        return posix_error();
+    }
+    char *buffer = (char *)PyMem_RawMalloc(size);
+    if (buffer == NULL) {
+        return PyErr_NoMemory();
+    }
+    int ret = ttyname_r(fd, buffer, size);
+    if (ret != 0) {
+        PyMem_RawFree(buffer);
+        errno = ret;
         return posix_error();
     }
-    return PyUnicode_DecodeFSDefault(ret);
+    PyObject *res = PyUnicode_DecodeFSDefault(buffer);
+    PyMem_RawFree(buffer);
+    return res;
 }
 #endif
 

From 1614f7d770a10b2434474dbc3df73df623a4a284 Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Tue, 8 Oct 2019 19:00:03 -0700
Subject: [PATCH 2/2] tweak NEWS

---
 .../next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst b/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst
index aa0884ee1bad3f..b31496c7017447 100644
--- a/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst
+++ b/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst
@@ -1 +1 @@
-Use ttyname_r instead of ttyname for thread safety
+In :mod:`posix`, use ``ttyname_r`` instead of ``ttyname`` for thread safety.