From: Deepa Dinamani <deepa.kernel@gmail.com>
To: David Laight <David.Laight@aculab.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Arnd Bergmann <arnd@arndb.de>, "dbueso@suse.de" <dbueso@suse.de>,
"axboe@kernel.dk" <axboe@kernel.dk>,
Davidlohr Bueso <dave@stgolabs.net>, Eric Wong <e@80x24.org>,
Jason Baron <jbaron@akamai.com>,
Linux FS-devel Mailing List <linux-fsdevel@vger.kernel.org>,
linux-aio <linux-aio@kvack.org>,
Omar Kilani <omar.kilani@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCH v2] signal: Adjust error codes according to restore_user_sigmask()
Date: Tue, 28 May 2019 04:37:46 -0700 [thread overview]
Message-ID: <B9F0F146-C687-4D1D-8BFF-1236564631F6@gmail.com> (raw)
In-Reply-To: <ea7a1808990a4c319faa38d5d08d8f19@AcuMS.aculab.com>
> On May 28, 2019, at 2:12 AM, David Laight <David.Laight@aculab.com> wrote:
>
> From: Deepa Dinamani
>> Sent: 24 May 2019 18:02
> ...
>> Look at the code before 854a6ed56839a:
>>
>> /*
>> * If we changed the signal mask, we need to restore the original one.
>> * In case we've got a signal while waiting, we do not restore the
>> * signal mask yet, and we allow do_signal() to deliver the signal on
>> * the way back to userspace, before the signal mask is restored.
>> */
>> if (sigmask) {
>> ####### This err has not been changed since ep_poll()
>> ####### So if there is a signal before this point, but
>> err = 0, then we goto else.
>> if (err == -EINTR) {
>> memcpy(¤t->saved_sigmask, &sigsaved,
>> sizeof(sigsaved));
>> set_restore_sigmask();
>> } else
>> ############ This is a problem if there is signal
>> pending that is sigmask should block.
>> ########### This is the whole reason we have
>> current->saved_sigmask?
>> set_current_blocked(&sigsaved);
>> }
>
> What happens if all that crap is just deleted (I presume from the
> bottom of ep_wait()) ?
Hmm, you have to update the saved_sigmask or the sigmask.
> I'm guessing that on the way back to userspace signal handlers for
> signals enabled in the process's current mask (the one specified
> to epoll_pwait) get called.
> Then the signal mask is loaded from current->saved_sigmask and
> and enabled signal handlers are called again.
Who is saving this saved_sigmask that is being restored on the way back?
> No special code there that depends on the syscall result, errno
> of the syscall number.
I didn’t say this has anything to do with errno.
-Deepa
next prev parent reply other threads:[~2019-05-28 11:37 UTC|newest]
Thread overview: 123+ 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 [this message]
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
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
2019-06-07 21:41 ` [RFC PATCH 1/5] signal: Teach sigsuspend to use set_user_sigmask Eric W. Biederman
2019-06-07 22:07 ` Linus Torvalds
2019-06-10 16:22 ` Oleg Nesterov
2019-06-10 21:20 ` Eric W. Biederman
2019-06-11 9:52 ` David Laight
2019-06-11 11:14 ` David Laight
2019-06-12 12:55 ` Eric W. Biederman
2019-06-12 13:24 ` David Laight
2019-06-12 13:35 ` Oleg Nesterov
2019-06-12 13:39 ` David Laight
2019-06-11 15:46 ` David Laight
2019-06-12 12:40 ` Eric W. Biederman
2019-06-12 13:45 ` Oleg Nesterov
2019-06-12 14:18 ` David Laight
2019-06-12 15:11 ` Eric W. Biederman
2019-06-12 15:37 ` Oleg Nesterov
2019-06-13 8:48 ` David Laight
2019-06-13 9:43 ` Oleg Nesterov
2019-06-13 10:56 ` David Laight
2019-06-13 12:43 ` Oleg Nesterov
2019-06-11 18:55 ` Oleg Nesterov
2019-06-11 19:02 ` Eric W. Biederman
2019-06-12 8:39 ` David Laight
2019-06-12 13:09 ` Eric W. Biederman
2019-06-07 21:41 ` [RFC PATCH 2/5] signal/kvm: Stop using sigprocmask in kvm_sigset_(activate|deactivate) Eric W. Biederman
2019-06-07 21:42 ` [RFC PATCH 3/5] signal: Always keep real_blocked in sync with blocked Eric W. Biederman
2019-06-07 21:43 ` [RFC PATCH 4/5] signal: Remove saved_sigmask Eric W. Biederman
2019-06-07 21:44 ` [RFC PATCH 5/5] signal: Remove the unnecessary restore_sigmask flag Eric W. Biederman
2019-06-11 18:58 ` [RFC PATCH 0/5]: Removing saved_sigmask Oleg Nesterov
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