From owner-freebsd-hackers@freebsd.org Wed Oct 28 23:54:14 2015 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8E45BA20ED3 for ; Wed, 28 Oct 2015 23:54:14 +0000 (UTC) (envelope-from Mark.Martinec+freebsd@ijs.si) Received: from mail.ijs.si (mail.ijs.si [IPv6:2001:1470:ff80::25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 3C5B112DC for ; Wed, 28 Oct 2015 23:54:14 +0000 (UTC) (envelope-from Mark.Martinec+freebsd@ijs.si) Received: from amavis-ori.ijs.si (localhost [IPv6:::1]) by mail.ijs.si (Postfix) with ESMTP id 3nmRZT6cKWz7J for ; Thu, 29 Oct 2015 00:54:09 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ijs.si; h= user-agent:message-id:references:in-reply-to:organization :subject:subject:from:from:date:date:content-transfer-encoding :content-type:content-type:mime-version:received:received :received:received; s=jakla4; t=1446076446; x=1448668447; bh=mXK KYJhf4UzBIv9rzaoLiOg1MsxWVXbT6Rh1Uigl9QI=; b=aMrCWnvFyfMxQJytpG0 +swKPvPwcXqaaxCZ4avztyhyV93kktuC8trw0ADjRc0RWEi9OTuDFJOrp9D2Bq3v x0YQbf+w9gLWX1NRELFUDfm8PCF4HbZP0t0gvd7MbXwDoxNERMgKc6W7VrY+q2Ok eU8ZXABenfOhWYW9aSI0d8AI= X-Virus-Scanned: amavisd-new at ijs.si Received: from mail.ijs.si ([IPv6:::1]) by amavis-ori.ijs.si (mail.ijs.si [IPv6:::1]) (amavisd-new, port 10026) with LMTP id suEQg5alUmNJ for ; Thu, 29 Oct 2015 00:54:06 +0100 (CET) Received: from mildred.ijs.si (mailbox.ijs.si [IPv6:2001:1470:ff80::143:1]) by mail.ijs.si (Postfix) with ESMTP id 3nmRZQ6b2Pz7G for ; Thu, 29 Oct 2015 00:54:06 +0100 (CET) Received: from nabiralnik.ijs.si (nabiralnik.ijs.si [IPv6:2001:1470:ff80::80:16]) by mildred.ijs.si (Postfix) with ESMTP id 3nmRZQ3JF1zyH for ; Thu, 29 Oct 2015 00:54:06 +0100 (CET) Received: from sleepy.ijs.si (2001:1470:ff80:e001::1:1) by nabiralnik.ijs.si with HTTP (HTTP/1.1 POST); Thu, 29 Oct 2015 00:54:06 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 29 Oct 2015 00:54:06 +0100 From: Mark Martinec To: freebsd-hackers@freebsd.org Subject: Re: ABI stability for loadable modules Organization: Jozef Stefan Institute In-Reply-To: References: Message-ID: <022117707d6196d7d117db0288033996@mailbox.ijs.si> X-Sender: Mark.Martinec+freebsd@ijs.si User-Agent: Roundcube Webmail/1.1.3 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Oct 2015 23:54:14 -0000 > Kernel ABI stability is guaranteed(*) within a major release branch. > -Ben > > (*) there are occasional exceptions involving portions of the network > stack, but 10.x is probably better than 9.x in this regard Two ports come to mind which crash the system when built under 10.0 and are attempted to be loaded under 10.2: emulators/virtualbox-ose-kmod x11/nvidia-driver Mark 2015-10-29 00:21, Benjamin Kaduk wrote: > On Wed, 28 Oct 2015, Koert van der Veer wrote: > >> TL;DR: Can I safely load a kernel module compiled against a slightly >> different kernel? >> >> >> I maintain a fleet of FreeBSD machines. We've encountered a problem >> with >> one of the modules (iscsi doesn't allow passwords > 16 chars). I've >> determined that patching the module solves the problem for us, and >> doesn't >> affect any other kernel component. I'd like to distribute the patched >> module and user-space components. My use-case allows me to unload the >> iscsi >> module, but doesn't allow me to reboot the machine. >> >> >> However, we're running an array of different kernels (10.0-RELEASE, >> 10.0-RELEASE-p9, 10.0-STABLE, 10.1-RELEASE, 10.1-RELEASE-p6). I'd like >> to >> minimize the number of distinct binaries being distributed, so >> preferably >> I'd compile only one or two. My preliminary tests on VMs show me that >> this >> does not cause any immediate problems. Is this actually safe, or do I >> need >> to make distinct sets of binaries for each minor version and >> patchlevel of >> kernel in production? > > Kernel ABI stability is guaranteed(*) within a major release branch. > > -Ben > > (*) there are occasional exceptions involving portions of the network > stack, but 10.x is probably better than 9.x in this regard