From owner-freebsd-current@freebsd.org Fri Sep 13 19:04:09 2019 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 4A7D3D03B7 for ; Fri, 13 Sep 2019 19:04:09 +0000 (UTC) (envelope-from rysto32@gmail.com) Received: from mail-qk1-x732.google.com (mail-qk1-x732.google.com [IPv6:2607:f8b0:4864:20::732]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46VQ6K18Shz41DP; Fri, 13 Sep 2019 19:04:08 +0000 (UTC) (envelope-from rysto32@gmail.com) Received: by mail-qk1-x732.google.com with SMTP id u184so26334035qkd.4; Fri, 13 Sep 2019 12:04:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vzlFZh13uypuw6jx1qKWMeDx8zged9i5dMQzrKz/t/M=; b=rmm8Mzv2uwd870Y2zYQ/0178OKr/zaA+33/X2Ca/y/HXpiGGy7CNHtuGwChisxqxUv bkBHgWNTjnvS9HKgS2WqPkXY+IgUg1tSVSL4cZTdPEGGXUsgmNIu/y9zLMaDL11xuof0 o619WwaSfDkrbX2B3uDc0tNXW7DGgkJ5oNM2j7M68VYeZPXOdmvH7sbzf/pkfe+X4Zyo wGIxodboUxPYEiF1zRgvJVX84WhSKiocq10ZPwa9qsYdwODUCV+EZpGa8+7xta7MG11p b9wYsXvPIPnAXvMNlxaA6oudHfxCoFl30o68YK1ujgQh8tpGYEp36dyzWG+9Xvk+jlC5 0G7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vzlFZh13uypuw6jx1qKWMeDx8zged9i5dMQzrKz/t/M=; b=KQMOGB1i1xOjOBQEiIBb0OJ4hCzqDdf5eU8lXXlrN23gYhCBrBe+5RgkYCXJojvbGU WV2i8Dz6GjsHpyypdeKd5fi+pbLoKsC/IC1NKSO64bPHS3Ha10EqLlTpYJ0aapkB79D8 z9brk70xufe+4wvSSSoenkttrzN8ESU15MgSOLs3ADg+7n4WEHcWKlSiqs5TV85xkcg/ ISkBM9fdKaWVYzYrdKfMW2BhRU3PK4/YlKNmlcUWD5zLWa3R6ld5Nge8TKeqMr6W8/E8 AseyItSyIYIsYy1qsYOZJkI0cl2v6+Rrx2PFZ5qzJthooIU39m0+yJa+zAk0Tzpn2Sht hNMw== X-Gm-Message-State: APjAAAXDsvu4I0ph02QJwEzyqJbXSZxhKvzqnVRKZSxjfMztTVa/SHXr UIMFv3ssWojOMUjsGZcUOQyuufYW2q06GRZpMSp6m+YX X-Google-Smtp-Source: APXvYqwCMWiFMpzXYoW9uvCi3JYhfgcHlqMILGJdcYy8oBsypg0SST/PapIWOWU2uFPzTvZxZu/2CuMbvSpo2eC/8JY= X-Received: by 2002:a37:a843:: with SMTP id r64mr45063413qke.363.1568401447743; Fri, 13 Sep 2019 12:04:07 -0700 (PDT) MIME-Version: 1.0 References: <20190913183718.GC84156@raichu> In-Reply-To: <20190913183718.GC84156@raichu> From: Ryan Stone Date: Fri, 13 Sep 2019 15:03:56 -0400 Message-ID: Subject: Re: Deadlock involving truss -f, pdfork() and wait4() To: Mark Johnston Cc: Mariusz Zaborski , FreeBSD Current Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 46VQ6K18Shz41DP X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-6.00 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; REPLY(-4.00)[] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Sep 2019 19:04:09 -0000 As Conrad has pointed out, it's an explicit PID. The test completes successfully when not run under truss -f. On Fri, Sep 13, 2019 at 2:37 PM Mark Johnston wrote: > > On Fri, Sep 13, 2019 at 02:12:56PM -0400, Ryan Stone wrote: > > This gets me a little further but now the wait4 call by the parent > > never reaps the child and instead blocks forever: > > Does it perform a wildcarded wait(), or does it explicitly specify the > PID of the child? By design, the former will not return children > created by pdfork().