From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2056F1FD4 for ; Tue, 15 Mar 2022 13:23:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647350625; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=IEpiYhsMGlq2ReYke60gfIQZ2QzqWJpfRL9F+OcYAMY=; b=eTh/+BtUq8mkG3eLN+XzrwBClSIGZkA7ig53ycIRZfiDtSRDQzjBPWC7xbBnS7LfFbRFar o9tPJ3styOFDEd71BxS9nUnMEZobNGjjvLDosa2tbua8a10xmRmVvKSvFI5Fs5xBi4KOZu ciI++kvLZCTUSSzyxwrphkdbKJ3iFt0= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-329-7mCoEQvoM2SdxLfzJmu0qQ-1; Tue, 15 Mar 2022 09:23:43 -0400 X-MC-Unique: 7mCoEQvoM2SdxLfzJmu0qQ-1 Received: by mail-wm1-f72.google.com with SMTP id c126-20020a1c3584000000b00380dee8a62cso6625569wma.8 for ; Tue, 15 Mar 2022 06:23:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=IEpiYhsMGlq2ReYke60gfIQZ2QzqWJpfRL9F+OcYAMY=; b=u09Rv+sS1q7nNJRo4xpusWl5j3euzo5rVzJuXiPOw7Uv1k+/uAejCPVjk4TKkkn/p/ UYWYPxV8xYKJ0W3NqQcU2YG/H6YtHz9Rp+jiplG/Wn1ui+UZWqJVzgiif9+na+XqB0wi 5aHir9ClVGTTiy6CtQ4AgYzvztBzHyJ5rO2Aeo90vM2mUt1a5+DlyGZ4cLFu41XZLV6Q 1IJAbv/es27p+hGGgxuc3Otx5HyVdLwU58pUBZwSP/aLmn5QEa2TGJeNUeOVKA/jJlqT RneOt5BBxf5HBHh6zL2tFJLzUBv+tSEEAFc8dNerrtcoTBv+MpWPNbJgCFb5GpbJpmgE Q/1g== X-Gm-Message-State: AOAM531stLjz5ic+6uBRJj84sEXr5d1OMVuKcn3cg0+ryZnveSunYYC0 qeqsfxLsrtsC//KcVBb8IHHFUihIbwbXj/b9kya/gZa+MWoydYzEmBDnjqCBqi3jT7vB464Lw7z aOIknYEQ3O3lyfw== X-Received: by 2002:a5d:47ac:0:b0:1fc:f09b:c258 with SMTP id 12-20020a5d47ac000000b001fcf09bc258mr20957690wrb.618.1647350622431; Tue, 15 Mar 2022 06:23:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzhcNjWTrbaoqdRbx7Oloh29YUHJlQt1KnYFPeCC8VNb6iBtIWGW90Cdk830Tz31dWtDzSVEw== X-Received: by 2002:a5d:47ac:0:b0:1fc:f09b:c258 with SMTP id 12-20020a5d47ac000000b001fcf09bc258mr20957671wrb.618.1647350622165; Tue, 15 Mar 2022 06:23:42 -0700 (PDT) Received: from redhat.com ([2.53.2.35]) by smtp.gmail.com with ESMTPSA id b15-20020adfc74f000000b001e888b871a0sm16230818wrh.87.2022.03.15.06.23.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Mar 2022 06:23:41 -0700 (PDT) Date: Tue, 15 Mar 2022 09:23:36 -0400 From: "Michael S. Tsirkin" To: trix@redhat.com Cc: jasowang@redhat.com, nathan@kernel.org, ndesaulniers@google.com, lingshan.zhu@intel.com, sgarzare@redhat.com, xieyongji@bytedance.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH] vDPA/ifcvf: match pointer check to use Message-ID: <20220315092101-mutt-send-email-mst@kernel.org> References: <20220315124130.1710030-1-trix@redhat.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20220315124130.1710030-1-trix@redhat.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mst@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Mar 15, 2022 at 05:41:30AM -0700, trix@redhat.com wrote: > From: Tom Rix > > Clang static analysis reports this issue > ifcvf_main.c:49:4: warning: Called function > pointer is null (null dereference) > vf->vring->cb.callback(vring->cb.private); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > The check > vring = &vf->vring[i]; > if (vring->cb.callback) > > Does not match the use. Change dereference so they match. > > Fixes: 79333575b8bd ("vDPA/ifcvf: implement shared IRQ feature") > Signed-off-by: Tom Rix > --- > drivers/vdpa/ifcvf/ifcvf_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c > index 3b48e717e89f7..4366320fb68d3 100644 > --- a/drivers/vdpa/ifcvf/ifcvf_main.c > +++ b/drivers/vdpa/ifcvf/ifcvf_main.c > @@ -46,7 +46,7 @@ static irqreturn_t ifcvf_vqs_reused_intr_handler(int irq, void *arg) > for (i = 0; i < vf->nr_vring; i++) { > vring = &vf->vring[i]; > if (vring->cb.callback) > - vf->vring->cb.callback(vring->cb.private); > + vring->cb.callback(vring->cb.private); > } > > return IRQ_HANDLED; Oh, absolutely. In fact vf->vring->cb.callback is just vf->vring[0].cb.callback so it's wrong for any ring except 0. Does not make sense. So how did it work in testing then? No idea. Zhu Lingshan, care to comment? > -- > 2.26.3