From owner-freebsd-hackers@freebsd.org Thu Jul 2 16:38:43 2020 Return-Path: Delivered-To: freebsd-hackers@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 8030A35AB75 for ; Thu, 2 Jul 2020 16:38:43 +0000 (UTC) (envelope-from nparhar@gmail.com) Received: from mail-io1-xd41.google.com (mail-io1-xd41.google.com [IPv6:2607:f8b0:4864:20::d41]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 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 49yP1G0Yy6z43F8 for ; Thu, 2 Jul 2020 16:38:41 +0000 (UTC) (envelope-from nparhar@gmail.com) Received: by mail-io1-xd41.google.com with SMTP id k23so29510425iom.10 for ; Thu, 02 Jul 2020 09:38:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to; bh=91BQuK1tlC45QhHqo/J79sow/gVXFkkPk5+1XR2gjG0=; b=Y1q+TWDUpD39jxKPg/L36StKmY+PzLt9y6SAoA6/3guZETwF61DxWUzsUhEiUluZQi aTcHcGAf2ftteZnoizyAATUIFmwGVDw8416RywiZbaJ9zL73iwcCwvkWPY4U9OOBhGkr CMyFCgRalTrKPAYTcQl7OS2w31126Zz8OUN1CXv68drvhCTHRkBEm8JjfHAIbnj/o9Tp HLss9Md+V8FJ4uH6Dxh+zxt0Qt68P+ccfTbeXZ4UPyDnGA5Y4lpPwhs5/T4ki2A0IgGp 2TxfIKON4yaP6xDhRHSjZLh0UrYOhdRL3a7zvvx9WDm6vOIcokiDWVs9wjU4YqeXRfro fJqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to; bh=91BQuK1tlC45QhHqo/J79sow/gVXFkkPk5+1XR2gjG0=; b=NTQJvPKmTE06lH+fQjf7u2u3vhQW5EbYFgjceoPwa5u4U2DMWwLa1v36f4FoKXRZ3F ZKHr4PSDm9VP89jARZKxU9oxfAORYI3BeyjT9Ow5vufvjT5kGbtpoNw6YHWrVQ+z+r/9 lveXfI5OWVuDegatmzyCuv4iEPqGb+wZrZtDZb/mEdeLvOfKDuvrSqku9oRWbDl2ARLb /W66OgIXK5VMsjPskOd0qNHK53Av0LrGxbNWXNSEZV4bF36qZZxsMZmfv5c8MO+X+iCh thatlrDB2hLMgDv760Hr5XiDvcZ//VGawST/Knvc+ji5+YWlwamYCSLUJATvdICUz8OM 1kLQ== X-Gm-Message-State: AOAM531b2JL+lYxvmaCKUAH/LWEUBMjjjdzeaNBaE7vPLyIsrnKZWdNl W3Oonxs+WYf7v6nNXoLYv3c= X-Google-Smtp-Source: ABdhPJxEtlBHxlJuVfX/YHvqV5n931rk0cxo14Rpld32q7XjV8HEk1iT58Z+cln1bJ0NALgn93rLEA== X-Received: by 2002:a05:6602:2c8b:: with SMTP id i11mr8234662iow.139.1593707920276; Thu, 02 Jul 2020 09:38:40 -0700 (PDT) Received: from x270 ([2601:641:c000:b500::1353]) by smtp.gmail.com with ESMTPSA id v3sm5355524ili.12.2020.07.02.09.38.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jul 2020 09:38:39 -0700 (PDT) Date: Thu, 2 Jul 2020 09:38:29 -0700 From: Navdeep Parhar To: Arka Sharma Cc: freebsd-hackers@freebsd.org Subject: Re: Hang while "Switching to gdb back-end" Message-ID: <20200702163829.GA3431@x270> Mail-Followup-To: Arka Sharma , freebsd-hackers@freebsd.org References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 49yP1G0Yy6z43F8 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=Y1q+TWDU; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of nparhar@gmail.com designates 2607:f8b0:4864:20::d41 as permitted sender) smtp.mailfrom=nparhar@gmail.com X-Spamd-Result: default: False [-2.83 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[gmail.com:+]; RCPT_COUNT_TWO(0.00)[2]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-0.37)[-0.366]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.97)[-0.975]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_LONG(-0.99)[-0.993]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::d41:from]; MID_RHS_NOT_FQDN(0.50)[]; RCVD_TLS_ALL(0.00)[] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Jul 2020 16:38:43 -0000 On Thu, Jul 02, 2020 at 05:57:58PM +0530, Arka Sharma wrote: > Dear All, > > I have installed FreeBSD 12.1. I have set the "hint.uart.0.flags="0x90" in > the /boot/device.hints file. I also have both ddb and gdb listed when I > issue "sysctl debug.kdb.available". So when I launch db using "sysctl > debug.kdb.enter=1" and issue gdb to change the mode to gdb it shows > "Switching to gdb back-end" and doesn't respond to Ctrl+c. I have to reset > the system in order to get the system up. All this is expected behavior. You have to connect to the gdb backend over the serial port using kgdb running on a different system after you see the "Switching to gdb ..." message. Then debug as usual and detach when done. Regards, Navdeep