On Tue, Jul 16, 2019 at 1:15 AM Sasha Levin <sas...@kernel.org> wrote: > > From: "Eric W. Biederman" <ebied...@xmission.com> > > [ Upstream commit 72abe3bcf0911d69b46c1e8bdb5612675e0ac42c ] > > The locking in force_sig_info is not prepared to deal with a task that > exits or execs (as sighand may change). The is not a locking problem > in force_sig as force_sig is only built to handle synchronous > exceptions. > > Further the function force_sig_info changes the signal state if the > signal is ignored, or blocked or if SIGNAL_UNKILLABLE will prevent the > delivery of the signal. The signal SIGKILL can not be ignored and can > not be blocked and SIGNAL_UNKILLABLE won't prevent it from being > delivered. > > So using force_sig rather than send_sig for SIGKILL is confusing > and pointless. > > Because it won't impact the sending of the signal and and because > using force_sig is wrong, replace force_sig with send_sig.
I think this patch broke the cifs module. The issue is that the use count is now not updated properly and thus it is no longer possible to rmmod the module. > > Cc: Namjae Jeon <namjae.j...@samsung.com> > Cc: Jeff Layton <jlay...@primarydata.com> > Cc: Steve French <smfre...@gmail.com> > Fixes: a5c3e1c725af ("Revert "cifs: No need to send SIGKILL to demux_thread > during umount"") > Fixes: e7ddee9037e7 ("cifs: disable sharing session and tcon and add new TCP > sharing code") > Signed-off-by: "Eric W. Biederman" <ebied...@xmission.com> > Signed-off-by: Sasha Levin <sas...@kernel.org> > --- > fs/cifs/connect.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > index 8dd6637a3cbb..714a359c7c8d 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -2631,7 +2631,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, > int from_reconnect) > > task = xchg(&server->tsk, NULL); > if (task) > - force_sig(SIGKILL, task); > + send_sig(SIGKILL, task, 1); > } > > static struct TCP_Server_Info * > -- > 2.20.1 >