| Message ID | 20210105160021.160108-1-vmojzis@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | python/semanage: empty stdout before exiting on BrokenPipeError | expand |
On Tue, Jan 5, 2021 at 5:03 PM Vit Mojzis <vmojzis@redhat.com> wrote: > > Empty stdout buffer before exiting when BrokenPipeError is > encountered. Otherwise python will flush the bufer during exit, which > may trigger the exception again. > https://docs.python.org/3/library/signal.html#note-on-sigpipe > > Fixes: > #semanage fcontext -l | egrep -q -e '^/home' > BrokenPipeError: [Errno 32] Broken pipe > Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'> > BrokenPipeError: [Errno 32] Broken pipe > > Note that the error above only appears occasionally (usually only the > first line is printed). > > Signed-off-by: Vit Mojzis <vmojzis@redhat.com> > --- > python/semanage/semanage | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/python/semanage/semanage b/python/semanage/semanage > index b2fabea6..ce15983b 100644 > --- a/python/semanage/semanage > +++ b/python/semanage/semanage > @@ -27,6 +27,7 @@ import traceback > import argparse > import seobject > import sys > +import os Hello, It would be nicer if the imports were imported in alphabetical order (also moving "import traceback" after "import sys"). But there also is an "import re" in the middle of the file, and while at it the Python2-compatibility layer in the gettext things could be dropped... so this should be done in other patches anyway. No need to change this patch. > PROGNAME = "policycoreutils" > try: > import gettext > @@ -945,6 +946,13 @@ def do_parser(): > args = commandParser.parse_args(make_args(sys.argv)) > args.func(args) > sys.exit(0) > + except BrokenPipeError as e: > + sys.stderr.write("%s: %s\n" % (e.__class__.__name__, str(e))) > + # Python flushes standard streams on exit; redirect remaining output > + # to devnull to avoid another BrokenPipeError at shutdown > + devnull = os.open(os.devnull, os.O_WRONLY) > + os.dup2(devnull, sys.stdout.fileno()) > + sys.exit(1) > except IOError as e: > sys.stderr.write("%s: %s\n" % (e.__class__.__name__, str(e))) > sys.exit(1) > -- > 2.29.2 Doing open(os.devnull) + dup2 seems strange, but as this is precisely what is documented in the official Python documentation that you linked in the commit description, I am fine with this. Acked-by: Nicolas Iooss <nicolas.iooss@m4x.org> Thanks! Nicolas
diff --git a/python/semanage/semanage b/python/semanage/semanage index b2fabea6..ce15983b 100644 --- a/python/semanage/semanage +++ b/python/semanage/semanage @@ -27,6 +27,7 @@ import traceback import argparse import seobject import sys +import os PROGNAME = "policycoreutils" try: import gettext @@ -945,6 +946,13 @@ def do_parser(): args = commandParser.parse_args(make_args(sys.argv)) args.func(args) sys.exit(0) + except BrokenPipeError as e: + sys.stderr.write("%s: %s\n" % (e.__class__.__name__, str(e))) + # Python flushes standard streams on exit; redirect remaining output + # to devnull to avoid another BrokenPipeError at shutdown + devnull = os.open(os.devnull, os.O_WRONLY) + os.dup2(devnull, sys.stdout.fileno()) + sys.exit(1) except IOError as e: sys.stderr.write("%s: %s\n" % (e.__class__.__name__, str(e))) sys.exit(1)
Empty stdout buffer before exiting when BrokenPipeError is encountered. Otherwise python will flush the bufer during exit, which may trigger the exception again. https://docs.python.org/3/library/signal.html#note-on-sigpipe Fixes: #semanage fcontext -l | egrep -q -e '^/home' BrokenPipeError: [Errno 32] Broken pipe Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'> BrokenPipeError: [Errno 32] Broken pipe Note that the error above only appears occasionally (usually only the first line is printed). Signed-off-by: Vit Mojzis <vmojzis@redhat.com> --- python/semanage/semanage | 8 ++++++++ 1 file changed, 8 insertions(+)