mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-29 05:05:03 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8

bpo-45915: use fcntl(fd, F_GETFD) in is_valid_fd() (GH-29821)

Browse source
This commit is contained in:
Christian Heimes 2021-11-28 20:40:27 +02:00 • committed by GitHub
parent aaf42222cf
commit f87ea03502
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 16 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

18
Python/pylifecycle.c
View file

@ -30,6 +30,10 @@
# include <langinfo.h> // nl_langinfo(CODESET)
#endif
#ifdef HAVE_FCNTL_H
# include <fcntl.h> // F_GETFD
#endif
#ifdef MS_WINDOWS
# undef BYTE
# include "windows.h"
@ -2129,18 +2133,26 @@ is_valid_fd(int fd)
startup. Problem: dup() doesn't check if the file descriptor is valid on
some platforms.
fcntl(fd, F_GETFD) is even faster, because it only checks the process table.
bpo-30225: On macOS Tiger, when stdout is redirected to a pipe and the other
side of the pipe is closed, dup(1) succeed, whereas fstat(1, &st) fails with
EBADF. FreeBSD has similar issue (bpo-32849).
Only use dup() on platforms where dup() is enough to detect invalid FD in
corner cases: on Linux and Windows (bpo-32849). */
#if defined(__linux__) || defined(MS_WINDOWS)
corner cases: on Linux and Windows (bpo-32849).
*/
if (fd < 0) {
return 0;
}
#if defined(F_GETFD) && (defined(__linux__) || defined(__APPLE__) || defined(MS_WINDOWS))
int res;
_Py_BEGIN_SUPPRESS_IPH
res = fcntl(fd, F_GETFD);
_Py_END_SUPPRESS_IPH
return res >= 0;
#elif defined(__linux__) || defined(MS_WINDOWS)
int fd2;
_Py_BEGIN_SUPPRESS_IPH
fd2 = dup(fd);
if (fd2 >= 0) {