From owner-svn-src-head@freebsd.org Wed May 8 01:13:20 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DE9D715990D2; Wed, 8 May 2019 01:13:19 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: from mail-it1-f171.google.com (mail-it1-f171.google.com [209.85.166.171]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) 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 2EDC0849D8; Wed, 8 May 2019 01:13:19 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: by mail-it1-f171.google.com with SMTP id u16so963516itc.0; Tue, 07 May 2019 18:13:19 -0700 (PDT) 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:reply-to :from:date:message-id:subject:to:cc; bh=gvCqz2WyJtoT1Wv2s5Mh8DNr0QmdiL+pQ68I5Hogjpw=; b=NU7XCgYBdygzhLQHWkc82YYY5O0RlcCFZMcanm84b8fHXT9C8lj77ORGuCy5hMXvgz fIz1c578Eo37XzcaNjnztHQV9LGAkqADe91iSYvwEDihm3v4JQnAMYAe/+Ywb3lRmSoN H6xKIyWYeyypLzqRusZ/3GxU3eDXINJWNGvz+iCkmrq5N19QsWFae7qWghNKK5wRUbag 1bQSyz5uEQloidfrOZhnLUAmde/yUNNYeX+F4Ry3RPtIF9kQ/8YaboR+LgECmNpGLFyA ygXv85Nc784pNBC7B3ibvfdm6lEu1vf9+sziyyTq1LSrkqBLSpXtkxwgtPh1hLMKIFWM Gs4g== X-Gm-Message-State: APjAAAVz1810gWAmcF5a079pyfOSjKpLI0W3CM9Kdi1Q6Dx4t/ZN0iot iPeZYDNqQ6+QUwgs+q4M3hDJ5aq3 X-Google-Smtp-Source: APXvYqz+c+vV78VOVWq0Zd0cSmsfvRqfNIhMhdFmATNmDTHCqbu6c6gzNbgfRgRMugUgO+qLwwQJKg== X-Received: by 2002:a24:5711:: with SMTP id u17mr1226769ita.31.1557277997900; Tue, 07 May 2019 18:13:17 -0700 (PDT) Received: from mail-it1-f170.google.com (mail-it1-f170.google.com. [209.85.166.170]) by smtp.gmail.com with ESMTPSA id d195sm435365itc.21.2019.05.07.18.13.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 May 2019 18:13:17 -0700 (PDT) Received: by mail-it1-f170.google.com with SMTP id q19so1338262itk.3; Tue, 07 May 2019 18:13:17 -0700 (PDT) X-Received: by 2002:a02:2949:: with SMTP id p70mr26989598jap.104.1557277997553; Tue, 07 May 2019 18:13:17 -0700 (PDT) MIME-Version: 1.0 References: <201904242030.x3OKUkgN073331@repo.freebsd.org> In-Reply-To: <201904242030.x3OKUkgN073331@repo.freebsd.org> Reply-To: cem@freebsd.org From: Conrad Meyer Date: Tue, 7 May 2019 18:13:06 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: svn commit: r346645 - in head/sys: compat/linuxkpi/common/include/linux compat/linuxkpi/common/src sys To: Tycho Nightingale Cc: src-committers , svn-src-all , svn-src-head Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 2EDC0849D8 X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of csecem@gmail.com designates 209.85.166.171 as permitted sender) smtp.mailfrom=csecem@gmail.com X-Spamd-Result: default: False [-5.49 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; HAS_REPLYTO(0.00)[cem@freebsd.org]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; REPLYTO_ADDR_EQ_FROM(0.00)[]; RCVD_COUNT_THREE(0.00)[4]; TO_DN_ALL(0.00)[]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; NEURAL_HAM_SHORT(-0.95)[-0.955,0]; FORGED_SENDER(0.30)[cem@freebsd.org,csecem@gmail.com]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[cem@freebsd.org,csecem@gmail.com]; TAGGED_FROM(0.00)[]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; MIME_TRACE(0.00)[0:+]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; DMARC_NA(0.00)[freebsd.org]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; IP_SCORE(-2.52)[ip: (-6.54), ipnet: 209.85.128.0/17(-3.75), asn: 15169(-2.26), country: US(-0.06)]; RCVD_IN_DNSWL_NONE(0.00)[171.166.85.209.list.dnswl.org : 127.0.5.0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 May 2019 01:13:20 -0000 Hi Tycho, On Wed, Apr 24, 2019 at 1:31 PM Tycho Nightingale wrote: > > Author: tychon > Date: Wed Apr 24 20:30:45 2019 > New Revision: 346645 > URL: https://svnweb.freebsd.org/changeset/base/346645 > > Log: > LinuxKPI should use bus_dma(9) to be compatible with an IOMMU > > Reviewed by: hselasky, kib > Tested by: greg@unrelenting.technology > Sponsored by: Dell EMC Isilon > Differential Revision: https://reviews.freebsd.org/D19845 >... > Modified: head/sys/compat/linuxkpi/common/src/linux_pci.c > ============================================================================== > --- head/sys/compat/linuxkpi/common/src/linux_pci.c Wed Apr 24 19:56:02 2019 (r346644) > +++ head/sys/compat/linuxkpi/common/src/linux_pci.c Wed Apr 24 20:30:45 2019 (r346645) > ... > +linux_dma_map_phys(struct device *dev, vm_paddr_t phys, size_t len) > +{ > ... > + nseg = -1; > + mtx_lock(&priv->dma_lock); > + if (_bus_dmamap_load_phys(priv->dmat, obj->dmamap, phys, len, > + BUS_DMA_NOWAIT, &seg, &nseg) != 0) { > + bus_dmamap_destroy(priv->dmat, obj->dmamap); > + mtx_unlock(&priv->dma_lock); > + uma_zfree(linux_dma_obj_zone, obj); > + return (0); > + } > + mtx_unlock(&priv->dma_lock); > + > + KASSERT(++nseg == 1, ("More than one segment (nseg=%d)", nseg)); This construct is a bit odd. Coverity produces the (perhaps spurious) warning (CID 1401319) that the KASSERT (which can be compiled out in !INVARIANTS builds) has a side effect (++nseg). While true, nseg is never used afterwards, so perhaps we can use the equivalent expression with no side effect instead? I.e., something like: KASSERT(nseg == 0, ("More than one segment (nseg=%d)", nseg + 1)); Does that make sense? It is a false positive of sorts, but performing side effects in compiled-out assert is a pretty strong antipattern so I'd just as soon "fix" the warning. Thanks, Conrad