From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by sourceware.org (Postfix) with ESMTPS id 2531D3858D35 for ; Tue, 7 Jul 2020 06:18:06 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 2531D3858D35 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=scylladb.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=bdenes@scylladb.com Received: by mail-ej1-x644.google.com with SMTP id w16so45396852ejj.5 for ; Mon, 06 Jul 2020 23:18:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=scylladb-com.20150623.gappssmtp.com; s=20150623; h=message-id:subject:from:to:cc:date:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=9FXX2zXor8l4Z5eou9gOrQwCWTc5Y/fD/9WREcbc7Xo=; b=gVJu7r8164ubE7ZvdffYKu3lXfsZSMkAq5VRMGqrRJ6Rs9FhHjP6IDz7eAYIvyLi0g jTBJE/OjD01N7ndNGM+za8/MFS9qhr5e7HprDfpkVJ9EmhPZyeLkuYBpTaVxecvCatFs vy33hNqJD1udUG63P7KujM0VtVueK71X6kdcqTCPHfimKArNbZP9f7uG69oljwQr+ZqS 1SurnLapECVG+fxeTH2lGGd6u9H3rpD7SnvmF9f25E8jKTXo9z8VnRLLBqZ9X82t+Njo bz15YucYToS66SyX6B5ebIdIT3mLV1uoWfsUoZ2Bfv5BDplLUnHkR6NowlhNm0N8/oVl tQTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=9FXX2zXor8l4Z5eou9gOrQwCWTc5Y/fD/9WREcbc7Xo=; b=L6RtrE365gBMCJ14PjmoWkWbUOOyLSYW/gJN89BGtRFtcCVkHqmt+HpL4BOURmT5eu lBh9ED4OUHEmu0yFUO58muq5TEUUCtpRiYaVBbESeKe3umKakSAQpRI6+t48RZ+mjTj2 DjKtnEeUWMrKqhYoNVYsNLLl7RuZnGweWB/Z28siuiZsOF4V9fnPwXKDZyIxXJH7NV7k oGLZOxS5dwF9DIcjLYgZZ7Vvo0rg500IiAh8jKBKN5cFbK1xw+AphkkN5glJl6x5iiKt 19pXokjYwGZAo6GEJ6Rf7iPpkoabN1WLg8hFQgb+mcVhYWb72muj+jQt8COi6pz11Mia KMsg== X-Gm-Message-State: AOAM531+uPXAF/ZCtamCi2meTK7dd7aTKu9IhK3/rMCgis4eFe5pHB4F eB6q7kUn4MVXyEvWV9GU59miuOEYIPs= X-Google-Smtp-Source: ABdhPJza8XNQ3SV/1IdeVigsNyeiFaD23jqIuVPeBf0hbZdXZfuN4042ypJ2ECYTg1ltAKudf3futA== X-Received: by 2002:a17:906:b15:: with SMTP id u21mr46665738ejg.520.1594102685269; Mon, 06 Jul 2020 23:18:05 -0700 (PDT) Received: from localhost.localdomain ([2a02:2f01:8315:eb00:1d10:a7c5:63e1:277a]) by smtp.gmail.com with ESMTPSA id kt4sm17383683ejb.48.2020.07.06.23.18.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Jul 2020 23:18:04 -0700 (PDT) Message-ID: <60e880f0df120996da164e379dc0323fd2069cf2.camel@scylladb.com> Subject: Re: Stack unwinding for green threads From: Botond =?ISO-8859-1?Q?D=E9nes?= To: Christian Biesinger Cc: gdb@sourceware.org Date: Tue, 07 Jul 2020 09:18:04 +0300 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.3 (3.36.3-1.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Jul 2020 06:18:09 -0000 On Mon, 2020-07-06 at 12:48 -0500, Christian Biesinger wrote: > On Fri, Jul 3, 2020 at 4:51 AM Botond Dénes > wrote: > > Hi, > > > > I'm working on Scylla [1], an application which is built using the > > seastar framework [2]. This framework provides green threads [3] > > that > > have their own stacks. These threads are created with > > `setcontext()` > > and later we switch in/out using `setjmp()`/`longjmp()`. > > > > We have a collection of python scripts [4] to help debug Scylla, > > among > > these we have a utility command which allows switching in/out of > > these > > green threads in gdb. This command basically (tries) to emulate > > `setjmp()`/`longjmp()` in python, saving and restoring registers. > > There > > are several problems with this method. For starters it crashes gdb > > for > > some time now > > It may be worth filing a bug for that at > https://sourceware.org/bugzilla/, crashing GDB sounds like a bug. We see a lot of crashes of GDB at ScyllaDB. Yes, I should get into the habit of reporting these. > > Christian