From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk1-xa2a.google.com (mail-vk1-xa2a.google.com [IPv6:2607:f8b0:4864:20::a2a]) by sourceware.org (Postfix) with ESMTPS id 41CA33858D3C for ; Mon, 22 Aug 2022 18:32:51 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 41CA33858D3C Received: by mail-vk1-xa2a.google.com with SMTP id i67so5997967vkb.2 for ; Mon, 22 Aug 2022 11:32:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc; bh=C5TyC8Hmx9pz2W9aHYcNK9HoorAL9WxFNr8jHTDGyzc=; b=ui2+d892BbkuQs/XnI478oezapuiHNBgBXKx0vjUoAT8Rcdb+ST02fDCRnRvgJ/U+u wWgwtj6eHk5cBjYcjV5Jc85U3g1dXdnYpmx4JkRJgXV639X5WpU18S44ORjuR6y8FffT lUo3m8l44ec7GeHVcGX6usJw8SclrnRgFDop9FIn5xbeZjvjqHonOM5cnxaDL9kFP2ko tE9nfo/tpI0B8NH1tyfWHqpUWgpaBfmEaHR2c1QVynlbIXgYsQVVBNfI23Zzh6vlGfyd hDC/jrmdTdAwYA2DtbvaDqNiVYCJeYx1lYNubtvkAbJw54Oa2MLAKYeNRMmWxOnNB1KN AM/Q== X-Gm-Message-State: ACgBeo1L2PkMry/lOyOgOKBy7fC+QFz0xz4ku/wE/lwgcKYDdEkKqGEv HBuiB4xw3D9+83GQwTGSW8Gh0g== X-Google-Smtp-Source: AA6agR7eykr6fRWyiaV1c0GlkBLSQVrfhqtwNkBr9LgEDGbcV9ulN5yAP6wOxB/ZcMAjWB78PCALgA== X-Received: by 2002:a05:6122:10c8:b0:38b:4419:ac99 with SMTP id l8-20020a05612210c800b0038b4419ac99mr4303219vko.5.1661193170564; Mon, 22 Aug 2022 11:32:50 -0700 (PDT) Received: from ?IPV6:2804:1b3:a7c0:5805:4e9:d353:8061:acad? ([2804:1b3:a7c0:5805:4e9:d353:8061:acad]) by smtp.gmail.com with ESMTPSA id v16-20020a67f6d0000000b0038a9fbef45fsm9296426vso.11.2022.08.22.11.32.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 Aug 2022 11:32:49 -0700 (PDT) Message-ID: <7c356365-34db-cc00-bb92-0e55e7a89118@linaro.org> Date: Mon, 22 Aug 2022 15:32:47 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.1.2 Subject: Re: posix_spawn: parent can get stuck in uninterruptible sleep if child receives SIGTSTP early enough Content-Language: en-US To: Florian Weimer , Adhemerval Zanella Netto via Libc-help Cc: Rain References: <2921668c-773e-465d-9480-0abb6f979bf9@www.fastmail.com> <7727e4de-a8da-1e6b-4d7c-68a132750996@linaro.org> <64917a2f-788b-4695-b799-63bbb8a4873f@www.fastmail.com> <87tu64w33v.fsf@oldenburg.str.redhat.com> From: Adhemerval Zanella Netto Organization: Linaro In-Reply-To: <87tu64w33v.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-help@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-help mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Aug 2022 18:32:52 -0000 On 22/08/22 15:21, Florian Weimer wrote: > * Adhemerval Zanella Netto via Libc-help: > >> Right, my mistake. I understood the issue better now, although I am >> still puzzled why SIGTSTP is only being triggered on sigprocmask (sing >> default action is still to stop PROCESS). > > I think it's a maskable stop, not an unmaskable one, like SIGSTOP. Yeah, we do block the signal on parent (internal_signal_block_all). > > This looks a vfork-specific bug that can't happen with fork. I don't > see how to fix it in a generic fashion because we can't unblock SIGTSTP > and launch the new process in an atomic fashion. We might ask for a new clone3 field to define the default signal mask on process start (and thus omit the final sigprocmask before execve).