From: Eric Wong <e@80x24.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Deepa Dinamani <deepa.kernel@gmail.com>,
linux-kernel@vger.kernel.org, arnd@arndb.de, dbueso@suse.de,
axboe@kernel.dk, dave@stgolabs.net, jbaron@akamai.com,
linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
omar.kilani@gmail.com, tglx@linutronix.de,
stable@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Laight <David.Laight@ACULAB.COM>
Subject: Re: [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask()
Date: Tue, 4 Jun 2019 18:35:23 +0000 [thread overview]
Message-ID: <20190604183523.kkruvskcgbli2fpu@dcvr> (raw)
In-Reply-To: <20190604134117.GA29963@redhat.com>
Oleg Nesterov <oleg@redhat.com> wrote:
> This is the minimal fix for stable, I'll send cleanups later.
>
> The commit 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add
> restore_user_sigmask()") introduced the visible change which breaks
> user-space: a signal temporary unblocked by set_user_sigmask() can
> be delivered even if the caller returns success or timeout.
>
> Change restore_user_sigmask() to accept the additional "interrupted"
> argument which should be used instead of signal_pending() check, and
> update the callers.
>
> Reported-by: Eric Wong <e@80x24.org>
> Fixes: 854a6ed56839a40f6b5d02a2962f48841482eec4 ("signal: Add restore_user_sigmask()")
> cc: stable@vger.kernel.org (v5.0+)
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Thanks, for epoll_pwait on top of Linux v5.1.7 and cmogstored v1.7.0:
Tested-by: Eric Wong <e@80x24.org>
(cmogstored v1.7.1 already works around this when it sees a 0
return value (but not >0, yet...))
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 0fbb486..1147c5d 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2201,11 +2201,12 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
> }
>
> ret = wait_event_interruptible(ctx->wait, io_cqring_events(ring) >= min_events);
> - if (ret == -ERESTARTSYS)
> - ret = -EINTR;
>
> if (sig)
> - restore_user_sigmask(sig, &sigsaved);
> + restore_user_sigmask(sig, &sigsaved, ret == -ERESTARTSYS);
> +
> + if (ret == -ERESTARTSYS)
> + ret = -EINTR;
>
> return READ_ONCE(ring->r.head) == READ_ONCE(ring->r.tail) ? ret : 0;
> }
That io_uring bit didn't apply cleanly to stable,
since stable is missing fdb288a679cdf6a71f3c1ae6f348ba4dae742681
("io_uring: use wait_event_interruptible for cq_wait conditional wait")
and related commits.
In any case, I'm not using io_uring anywhere, yet (and probably
won't, since I'll still need threads to deal with open/unlink/rename
on slow JBOD HDDs).
next prev parent reply other threads:[~2019-06-04 18:35 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 3:21 [PATCH v2] signal: Adjust error codes according to restore_user_sigmask() Deepa Dinamani
2019-05-22 15:05 ` Oleg Nesterov
2019-05-22 15:55 ` Deepa Dinamani
2019-05-22 16:14 ` Oleg Nesterov
2019-05-22 16:33 ` Deepa Dinamani
2019-05-23 9:03 ` David Laight
2019-05-23 14:59 ` Oleg Nesterov
2019-05-23 16:18 ` David Laight
2019-05-23 16:36 ` Oleg Nesterov
2019-05-23 16:56 ` David Laight
2019-05-23 18:06 ` Deepa Dinamani
2019-05-23 20:41 ` Deepa Dinamani
2019-05-23 21:06 ` Deepa Dinamani
2019-05-24 9:58 ` David Laight
2019-05-24 14:10 ` Oleg Nesterov
2019-05-24 15:16 ` Deepa Dinamani
2019-05-24 16:33 ` Oleg Nesterov
2019-05-24 17:01 ` Deepa Dinamani
2019-05-27 15:04 ` Oleg Nesterov
2019-05-28 20:47 ` Deepa Dinamani
2019-05-29 16:57 ` Oleg Nesterov
2019-05-29 18:42 ` Deepa Dinamani
2019-05-28 9:02 ` David Laight
2019-05-28 9:12 ` David Laight
2019-05-28 11:37 ` Deepa Dinamani
2019-05-28 12:04 ` David Laight
2019-05-24 14:19 ` Oleg Nesterov
2019-05-24 14:29 ` Deepa Dinamani
2019-05-24 14:51 ` Oleg Nesterov
2019-05-24 13:29 ` Oleg Nesterov
2019-05-24 14:59 ` David Laight
2019-05-24 15:09 ` David Laight
2019-05-24 15:46 ` Oleg Nesterov
2019-05-24 15:44 ` Oleg Nesterov
2019-05-24 16:40 ` David Laight
2019-05-23 14:33 ` Oleg Nesterov
2019-05-22 22:18 ` Chris Down
2019-05-22 22:52 ` Deepa Dinamani
2019-05-29 16:11 ` pselect/etc semantics (Was: [PATCH v2] signal: Adjust error codes according to restore_user_sigmask()) Oleg Nesterov
2019-05-29 16:54 ` David Laight
2019-05-29 18:50 ` Eric Wong
2019-05-30 9:34 ` David Laight
2019-05-30 13:04 ` pselect/etc semantics Eric W. Biederman
2019-05-29 16:56 ` pselect/etc semantics (Was: [PATCH v2] signal: Adjust error codes according to restore_user_sigmask()) Deepa Dinamani
2019-05-29 18:26 ` Deepa Dinamani
2019-05-29 22:32 ` Arnd Bergmann
2019-05-30 1:54 ` pselect/etc semantics Eric W. Biederman
2019-05-30 18:28 ` Arnd Bergmann
2019-05-30 14:40 ` pselect/etc semantics (Was: [PATCH v2] signal: Adjust error codes according to restore_user_sigmask()) Oleg Nesterov
2019-05-30 18:37 ` Arnd Bergmann
2019-05-30 13:01 ` pselect/etc semantics Eric W. Biederman
2019-05-30 15:18 ` David Laight
2019-05-30 16:13 ` Oleg Nesterov
2019-05-30 15:38 ` Eric W. Biederman
2019-05-30 15:48 ` Deepa Dinamani
2019-05-30 16:59 ` Deepa Dinamani
2019-05-30 16:08 ` Oleg Nesterov
2019-05-30 17:20 ` Eric W. Biederman
2019-05-30 16:22 ` David Laight
2019-05-30 15:57 ` Oleg Nesterov
2019-05-30 21:03 ` Eric Wong
2019-06-04 13:41 ` [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask() Oleg Nesterov
2019-06-04 15:31 ` Eric W. Biederman
2019-06-04 15:57 ` David Laight
2019-06-04 16:37 ` Arnd Bergmann
2019-06-04 18:14 ` Deepa Dinamani
2019-06-04 18:35 ` Eric Wong [this message]
2019-06-04 21:26 ` Linus Torvalds
2019-06-04 22:24 ` Eric Wong
2019-06-04 23:51 ` Eric W. Biederman
2019-06-05 9:04 ` Oleg Nesterov
2019-06-05 8:56 ` Oleg Nesterov
2019-06-05 9:02 ` David Laight
2019-06-05 9:25 ` Oleg Nesterov
2019-06-05 9:58 ` David Laight
2019-06-05 15:58 ` [PATCH -mm 0/1] signal: simplify set_user_sigmask/restore_user_sigmask Oleg Nesterov
2019-06-05 15:58 ` [PATCH -mm 1/1] " Oleg Nesterov
2019-06-06 0:14 ` kbuild test robot
2019-06-06 1:06 ` kbuild test robot
2019-06-06 7:25 ` Oleg Nesterov
2019-06-06 7:30 ` Sedat Dilek
2019-06-05 17:24 ` [PATCH -mm 0/1] " Linus Torvalds
2019-06-06 9:05 ` David Laight
2019-06-06 11:05 ` Oleg Nesterov
2019-06-06 11:29 ` David Laight
2019-06-06 12:41 ` Oleg Nesterov
2019-06-06 13:23 ` David Laight
2019-06-06 10:22 ` Oleg Nesterov
2019-06-06 11:32 ` [PATCH -mm V2 1/1] " Oleg Nesterov
2019-06-06 14:08 ` [PATCH 0/2] select: simplify the usage of restore_saved_sigmask_unless() Oleg Nesterov
2019-06-06 14:08 ` [PATCH 1/2] select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR Oleg Nesterov
2019-06-07 18:05 ` Linus Torvalds
2019-06-06 14:09 ` [PATCH 2/2] select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining() Oleg Nesterov
2019-06-07 21:39 ` [RFC PATCH 0/5]: Removing saved_sigmask Eric W. Biederman
2019-06-11 18:58 ` Oleg Nesterov
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