From: ebiederm@xmission.com (Eric W. Biederman)
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, e@80x24.org,
jbaron@akamai.com, linux-fsdevel@vger.kernel.org,
linux-aio@kvack.org, omar.kilani@gmail.com, tglx@linutronix.de,
Al Viro <viro@ZenIV.linux.org.uk>,
Linus Torvalds <torvalds@linux-foundation.org>,
David Laight <David.Laight@ACULAB.COM>,
<linux-arch@vger.kernel.org>
Subject: [RFC PATCH 3/5] signal: Always keep real_blocked in sync with blocked
Date: Fri, 07 Jun 2019 16:42:38 -0500 [thread overview]
Message-ID: <8736klax81.fsf_-_@xmission.com> (raw)
In-Reply-To: <87k1dxaxcl.fsf_-_@xmission.com> (Eric W. Biederman's message of "Fri, 07 Jun 2019 16:39:54 -0500")
Except where we temporarily override blocked always keep real_blocked
in sync with blocked.
By always setting real_blocked when we set blocked this allows
some slight efficiency and simplifications, by not having
to save blocked.
This also preparse the code for the removal of saved_sigmask. That
should result in a massive simplification.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
kernel/ptrace.c | 1 +
kernel/signal.c | 14 ++++++++++----
virt/kvm/kvm_main.c | 8 --------
3 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 6f357f4fc859..6507d700d70f 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -968,6 +968,7 @@ int ptrace_request(struct task_struct *child, long request,
*/
spin_lock_irq(&child->sighand->siglock);
child->blocked = new_set;
+ child->real_blocked = new_set;
spin_unlock_irq(&child->sighand->siglock);
clear_tsk_restore_sigmask(child);
diff --git a/kernel/signal.c b/kernel/signal.c
index bfa36320a4f7..fcd84f4a93c9 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2878,6 +2878,9 @@ void set_current_blocked(sigset_t *newset)
{
sigdelsetmask(newset, sigmask(SIGKILL) | sigmask(SIGSTOP));
__set_current_blocked(newset);
+
+ /* Lockless, only current can change ->real_blocked, never from irq */
+ current->real_blocked = *newset;
}
void __set_current_blocked(const sigset_t *newset)
@@ -2928,15 +2931,20 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
}
__set_current_blocked(&newset);
+
+ /* Lockless, only current can change ->real_blocked, never from irq */
+ tsk->real_blocked = newset;
return 0;
}
EXPORT_SYMBOL(sigprocmask);
-static int set_sigmask(sigset_t *kmask)
+static int set_sigmask(sigset_t *newset)
{
set_restore_sigmask();
current->saved_sigmask = current->blocked;
- set_current_blocked(kmask);
+
+ sigdelsetmask(newset, sigmask(SIGKILL) | sigmask(SIGSTOP));
+ __set_current_blocked(newset);
return 0;
}
@@ -3440,7 +3448,6 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info,
* they arrive. Unblocking is always fine, we can avoid
* set_current_blocked().
*/
- tsk->real_blocked = tsk->blocked;
sigandsets(&tsk->blocked, &tsk->blocked, &mask);
recalc_sigpending();
spin_unlock_irq(&tsk->sighand->siglock);
@@ -3450,7 +3457,6 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info,
HRTIMER_MODE_REL);
spin_lock_irq(&tsk->sighand->siglock);
__set_task_blocked(tsk, &tsk->real_blocked);
- sigemptyset(&tsk->real_blocked);
sig = dequeue_signal(tsk, &mask, info);
}
spin_unlock_irq(&tsk->sighand->siglock);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8575a1010bfc..4bfed018574a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2234,13 +2234,6 @@ void kvm_sigset_activate(struct kvm_vcpu *vcpu)
if (!vcpu->sigset_active)
return;
- /*
- * This does a lockless modification of ->real_blocked, which is fine
- * because, only current can change ->real_blocked and all readers of
- * ->real_blocked don't care as long ->real_blocked is always a subset
- * of ->blocked.
- */
- current->real_blocked = current->blocked;
__set_current_blocked(&vcpu->sigset);
}
@@ -2250,7 +2243,6 @@ void kvm_sigset_deactivate(struct kvm_vcpu *vcpu)
return;
__set_current_blocked(¤t->real_blocked);
- sigemptyset(¤t->real_blocked);
}
static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
--
2.21.0.dirty
next prev parent reply other threads:[~2019-06-07 21:42 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
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 ` Eric W. Biederman [this message]
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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