From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE43CC43381 for ; Wed, 20 Mar 2019 13:27:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BFD0213F2 for ; Wed, 20 Mar 2019 13:27:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727619AbfCTN1f (ORCPT ); Wed, 20 Mar 2019 09:27:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33912 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725905AbfCTN1e (ORCPT ); Wed, 20 Mar 2019 09:27:34 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B8D9C306641B; Wed, 20 Mar 2019 13:27:34 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.34]) by smtp.corp.redhat.com (Postfix) with SMTP id 764144127; Wed, 20 Mar 2019 13:27:33 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 20 Mar 2019 14:27:33 +0100 (CET) Date: Wed, 20 Mar 2019 14:27:32 +0100 From: Oleg Nesterov To: Andrei Vagin Cc: Andrew Morton , linux-kernel@vger.kernel.org, "Eric W. Biederman" , Stephen Rothwell Subject: Re: [RESEND PATCH] ptrace: take into account saved_sigmask in PTRACE_{GET,SET}SIGMASK Message-ID: <20190320132731.GC21673@redhat.com> References: <20190319191957.27156-1-avagin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190319191957.27156-1-avagin@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Wed, 20 Mar 2019 13:27:34 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/19, Andrei Vagin wrote: > > There are a few system calls (pselect, ppoll, etc) which replace a task > sigmask while they are running in a kernel-space > > When a task calls one of these syscalls, the kernel saves a current > sigmask in task->saved_sigmask and sets a syscall sigmask. > > On syscall-exit-stop, ptrace traps a task before restoring the > saved_sigmask, so PTRACE_GETSIGMASK returns the syscall sigmask and > PTRACE_SETSIGMASK does nothing, because its sigmask is replaced by > saved_sigmask, when the task returns to user-space. > > This patch fixes this problem. PTRACE_GET_SIGMASK returns saved_sigmask > is it's set. PTRACE_SETSIGMASK drops the TIF_RESTORE_SIGMASK flag. Acked-by: Oleg Nesterov