From owner-freebsd-hackers@freebsd.org Sun May 24 09:42:38 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 303FE3283EE for ; Sun, 24 May 2020 09:42:38 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 49VFd90wmBz4fxn for ; Sun, 24 May 2020 09:42:36 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id 04O9gMOG072351 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sun, 24 May 2020 12:42:25 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 04O9gMOG072351 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id 04O9gMUh072350; Sun, 24 May 2020 12:42:22 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 24 May 2020 12:42:22 +0300 From: Konstantin Belousov To: Paul FLOYD Cc: FreeBSD Hackers Subject: Re: SIGBUS si_code 12 Message-ID: <20200524094222.GQ64045@kib.kiev.ua> References: <490544208.11847.1589489181927.JavaMail.www@wwinf1n11> <20200514224347.GB46537@kib.kiev.ua> <9840EA0E-CF11-4332-A5A0-A3CDBA0F0464@wanadoo.fr> <20200521154621.GB85681@raichu> <068F2B99-24C2-4F38-ACC1-02273C198434@wanadoo.fr> <679A6BE4-E344-49D0-B76D-DB65A41E26FA@wanadoo.fr> <20200522192804.GL64045@kib.kiev.ua> <20200522201251.GM64045@kib.kiev.ua> <816299859.1977.1590312280071.JavaMail.www@wwinf1c21> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <816299859.1977.1590312280071.JavaMail.www@wwinf1c21> X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on tom.home X-Rspamd-Queue-Id: 49VFd90wmBz4fxn X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=gmail.com (policy=none); spf=softfail (mx1.freebsd.org: 2001:470:d5e7:1::1 is neither permitted nor denied by domain of kostikbel@gmail.com) smtp.mailfrom=kostikbel@gmail.com X-Spamd-Result: default: False [0.88 / 15.00]; RCVD_TLS_ALL(0.00)[]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; NEURAL_SPAM_SHORT(0.12)[0.120]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all]; NEURAL_SPAM_MEDIUM(0.50)[0.495]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_SPAM_LONG(0.26)[0.262]; FREEMAIL_TO(0.00)[wanadoo.fr]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; FREEMAIL_ENVFROM(0.00)[gmail.com]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none] 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: Sun, 24 May 2020 09:42:38 -0000 On Sun, May 24, 2020 at 11:24:40AM +0200, Paul FLOYD wrote: >   >   >   > > > And which files/functions do that? > > ELF image activator. > > > Look in kern/imgact_elf.c. It is basically in check_note, used from > > get_brandinfo. The real function names are mangled for co-existence > > of 32 and 64 bit elf activators. > > That's quite interesting. If I run procstat -b on a running Valgrind instance I see > >   > aulf> procstat -b 2072 > PID COMM OSREL PATH > 2072 memcheck-amd64-free 0 /usr/home/paulf/scratch/valgrind/memcheck/memcheck-amd64-freebsd > > A quick recap of Valgrind execution > > 'valgrind' itself is just a small stub executable that looks at the guest executable to determine if it is amd64 or x86. It will then do an execve of the required tool e.g., memcheck-amd64-freebsd. > The tools themselves are entirely standalone and do not link with any libraries, not even libc. > > Is there a way to get the linker to add a .note section with osrel? Look at lib/csu/common/crtbrand.c > > If not, is there a way to set osrel after a process has started? sysctl kern.proc.KERN_PROC_OSREL.