From owner-freebsd-hackers@freebsd.org Thu Jul 2 17:53:12 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 9D52535C784 for ; Thu, 2 Jul 2020 17:53:12 +0000 (UTC) (envelope-from arka.sw1988@gmail.com) Received: from mail-lj1-x244.google.com (mail-lj1-x244.google.com [IPv6:2a00:1450:4864:20::244]) (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 49yQgC5jYMz47QX for ; Thu, 2 Jul 2020 17:53:11 +0000 (UTC) (envelope-from arka.sw1988@gmail.com) Received: by mail-lj1-x244.google.com with SMTP id s9so33278337ljm.11 for ; Thu, 02 Jul 2020 10:53:11 -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; bh=bGUQWQR/Wg+3utYQS8WcI/uReNWPrcsCRhXZ+2Uhcos=; b=VMPIGwvsM5ixm3L6Nu1wLW64W/OyQ4XSMMz/2d7gkMmAmP1cK/Q3ltA3I8AqfJpjG6 TCY7Nd+SjhQj6JMEvxDivJdfJknSAn389SSpS7STWxJ3lB9bPCB5uMbH0lmKoXfD5ka5 WHIRsq9M1ZIqnoD41Q/rhoH1d2/mVuOQrXws7eGkDCKa7pzwLVzsJPnczeIQ5ty7FK+e mogXWmO6Vm5HK/HGWGuTymG+FXnj/++tJLKUleNu1u695IaUk2zJ4G4qU2/Oq0BNhTqZ Bs9z0kYsU4+Iwwy9zlyuE9XhGg8Dtk9C5N3q6wYy6/lDkpm2SSKzbirEJxfFGcbxBMg/ vqxA== 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; bh=bGUQWQR/Wg+3utYQS8WcI/uReNWPrcsCRhXZ+2Uhcos=; b=R1Ff7rasiivs5nmXIIM03n2z0dMoD4ipHT9YM9r5pQ2Cdg9mWSQnQcwl6vSIPnqBz3 Enb4AFXYGsjw5SS1FMb8NnSRQDHHGQU6Dlk2KU3SB0c3ztOlqTTl5xkswXEOikq2+yAp S4Foe3hkXcS1QQuZ5O3y1scyfpjg5idM8GAPejB/2TMC413AtuwJC3gIAsSNHwHqw/Hw Xiaz1nJFeYJkLRXGcdrMvHSlnpyhw9IhKqmp7FALOAWtvtFPmHnJTpg2QU1kEp+TefCb /3jAVLzeC/3FkDL1J/jHw0pxjx2quGWiZSk9ZiOuAlAFaa25Nhhlk4iYB7Bp8kZZpoj3 gp7g== X-Gm-Message-State: AOAM533/2y9ftARIrcJAEIdromzbbb95wdw1PYw9KLnIvgzvPBrv0DfU U7X9dCodjFSaGuj91iP4WCVQbRZiO+d9C35HoBghVQ== X-Google-Smtp-Source: ABdhPJw+B08UjMIVMjs37+sX8uwfLLgqnL4TWCZORk87pBbRqKpz8Bq/5ntm970GNTG95Bq1iPqkwUr3dVxz5sS8i8M= X-Received: by 2002:a2e:984a:: with SMTP id e10mr13835952ljj.248.1593712390085; Thu, 02 Jul 2020 10:53:10 -0700 (PDT) MIME-Version: 1.0 References: <20200702163829.GA3431@x270> In-Reply-To: <20200702163829.GA3431@x270> From: Arka Sharma Date: Thu, 2 Jul 2020 23:22:57 +0530 Message-ID: Subject: Re: Hang while "Switching to gdb back-end" To: Arka Sharma , freebsd-hackers@freebsd.org X-Rspamd-Queue-Id: 49yQgC5jYMz47QX X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=VMPIGwvs; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of arkasw1988@gmail.com designates 2a00:1450:4864:20::244 as permitted sender) smtp.mailfrom=arkasw1988@gmail.com X-Spamd-Result: default: False [-3.63 / 15.00]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip6:2a00:1450:4000::/36:c]; FREEMAIL_FROM(0.00)[gmail.com]; DKIM_TRACE(0.00)[gmail.com:+]; RCPT_COUNT_TWO(0.00)[2]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-0.66)[-0.664]; FREEMAIL_TO(0.00)[gmail.com,freebsd.org]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; TAGGED_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.97)[-0.974]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_LONG(-0.99)[-0.995]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::244:from]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.33 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 17:53:12 -0000 Thanks for the reply. I have one more silly question. I have a terminal at ttyu1 and I can login through telnet and it works fine except when I issue "sysctl debug.kdb.enter=1" it hangs showing "debug.kdb.enter". I have checked the freebsd handbook. At it is mentioned in chapter 26.6, I tried to put "device sio" in my Kern Conf and it gives me build failure. Looking at the build log it seems it is missing some header file while building dev/sio.c. Basically I tried to get into db from serial console and failed. One more thing is in the console after I get into db and launched gdb I have also tried connecting kgdb from another host, but got timeout while connecting the target. Regards, Arka On Thu, 2 Jul 2020, 22:08 Navdeep Parhar, wrote: > 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 >