closes bpo-36161: Use thread-safe ttyname_r instead of ttyname. (GH-14868)
Signed-off-by: Antonio Gutierrez <chibby0ne@gmail.com>
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 0000000..b31496c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-07-20-01-17-43.bpo-36161.Fzf-f9.rst
@@ -0,0 +1 @@
+In :mod:`posix`, use ``ttyname_r`` instead of ``ttyname`` for thread safety.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 5664027..aeb0e9d 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2774,13 +2774,24 @@
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();
}
- return PyUnicode_DecodeFSDefault(ret);
+ 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();
+ }
+ PyObject *res = PyUnicode_DecodeFSDefault(buffer);
+ PyMem_RawFree(buffer);
+ return res;
}
#endif