From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH v4 03/27] x86/entry: Flip _TIF_SIGPENDING and _TIF_NOTIFY_RESUME handling Date: Fri, 21 Feb 2020 14:34:19 +0100 Message-ID: <20200221134215.206604505@infradead.org> References: <20200221133416.777099322@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from bombadil.infradead.org ([198.137.202.133]:56358 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728777AbgBUNud (ORCPT ); Fri, 21 Feb 2020 08:50:33 -0500 Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org Cc: peterz@infradead.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org Make sure we run task_work before we hit any kind of userspace -- very much including signals. Suggested-by: Andy Lutomirski Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/entry/common.c | 8 usr/src/linux-2.6/arch/x86/entry/common.c | 440 ------------------------------ 2 files changed, 4 insertions(+), 444 deletions(-) --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -155,16 +155,16 @@ static void exit_to_usermode_loop(struct if (cached_flags & _TIF_PATCH_PENDING) klp_update_patch_state(current); - /* deal with pending signal delivery */ - if (cached_flags & _TIF_SIGPENDING) - do_signal(regs); - if (cached_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); rseq_handle_notify_resume(NULL, regs); } + /* deal with pending signal delivery */ + if (cached_flags & _TIF_SIGPENDING) + do_signal(regs); + if (cached_flags & _TIF_USER_RETURN_NOTIFY) fire_user_return_notifiers();