Alexey Izbyshev <izbys...@ispras.ru> added the comment: OK, never mind with the test. I've finally got to a FreeBSD box and reproduced the problem. It has to do with 'revoke' feature of *BSD. When revoke is called on a terminal device (as part of logout process, for example), all descriptors associated with it are invalidated. They can be dup'ed, but any I/O (including fstat) will fail with EBADF. The attached 'repro.c' demonstrates the same behavior as Python in your ktrace log.
# sleep 5; ./repro >&err.txt & # exit (login again) # cat err.txt isatty: Inappropriate ioctl for device dup ok: 3 fstat: Bad file descriptor So it seems that in your case the parent of your Python processes passed a descriptor referring to the terminal as fd 0, and then terminal got revoked at some point. People have stumbled on that, for example, https://bitbucket.org/tildeslash/monit/issues/649/init_env-fails-if-open-2-returns-an As for Python, it seems OK to fix it as in #30225 since the fd is unusable for I/O anyway. I think that we can even drop dup-based validation from is_valid_fd() since there is a corner case for Linux too: if a descriptor opened with O_PATH inherited as a standard one, dup() will succeed but fstat() will fail in kernels before 3.6. And we do fstat() almost immediately after is_valid_fd() to get blksize, so the dup-based optimization doesn't seem worth the trouble. Victor, do you have an opinion on that? ---------- components: +FreeBSD, IO nosy: +koobs versions: +Python 3.7 Added file: https://bugs.python.org/file47452/repro.c _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32849> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
