From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20C06C433F5 for ; Thu, 3 Mar 2022 13:59:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231621AbiCCOAk (ORCPT ); Thu, 3 Mar 2022 09:00:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231544AbiCCOAi (ORCPT ); Thu, 3 Mar 2022 09:00:38 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B296D64BC9 for ; Thu, 3 Mar 2022 05:59:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646315992; 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=EPzzRx3cg/pmzHstqnOsA2Fg9HW56H+MJYqezSg++LE=; b=DY7Mnvhnjc5iSYCrRTQ9+3SkfuL7JHUgIdD5kIB25eYhYvDUWlwYHmQAHpy7dZsaW9Mc5H XhGpvvFN0OuN/STbVl06fhb3DPxZbwJawQqUF9GemzrVm7NvS3dupOYqj1SObANJoMENC5 VY1mRYF3VsOk6qPqnHK85BbyZ1YoO0g= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-324-EwjzPpnOOjWiHtzHfqONhw-1; Thu, 03 Mar 2022 08:59:51 -0500 X-MC-Unique: EwjzPpnOOjWiHtzHfqONhw-1 Received: by mail-ej1-f71.google.com with SMTP id r18-20020a17090609d200b006a6e943d09eso2760150eje.20 for ; Thu, 03 Mar 2022 05:59:51 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=EPzzRx3cg/pmzHstqnOsA2Fg9HW56H+MJYqezSg++LE=; b=FMh2iuENgz18sRkfah7C+3f8qHKtI3dFxUF6K5z4wmEevzFIhiEhmEWsfaHeWtkEyo y1GuiLN0X4oOT5MAd+FOOn93XH7g1PNlXNBbEjaq/XVTc47/LV9Wy0mTVOn8lr/w3JWy L+90iL/XEjPxbSZKXOFXGt7Ph4z3jqDJ4ZHykF20yW1gwVHtESx/4NCbzg/V6fAhZZes tKStnfFXVreoCHOxj3ASCDc5nLdX5ptJd3R1/msKxhFlHYHSXik7WdyvndtFFabxwNjT HkAPmPOTRN1pV1HG3SME+2f73sqyJ+aMjAR2OMiXuGneJBsKMoVc2QYExB57q1WGGXSP GDTw== X-Gm-Message-State: AOAM531OflVbi6DiRlB5BkxLsJAhyjBHsZQ1UUhKniu2XKYx6sl70qjn 67qmUsf7ndxhCstDgb0X20fwCRfALCFcOuiTmSO9Zwk9Mt97ay07wecgt05NHNsUjxj9h/hK3// mV5QYp0t+Tvrd X-Received: by 2002:a17:906:5d0e:b0:6da:97a8:95bd with SMTP id g14-20020a1709065d0e00b006da97a895bdmr1380848ejt.442.1646315990029; Thu, 03 Mar 2022 05:59:50 -0800 (PST) X-Google-Smtp-Source: ABdhPJxPnR2SJt5wIOYwF3ZPR//qWJvAOvhL8xvzO6S0xyW+z1dASzCi5+vPXcvA+rmAJGVgj2I9eQ== X-Received: by 2002:a17:906:5d0e:b0:6da:97a8:95bd with SMTP id g14-20020a1709065d0e00b006da97a895bdmr1380809ejt.442.1646315989561; Thu, 03 Mar 2022 05:59:49 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id t19-20020a1709060c5300b006d582121f99sm711461ejf.36.2022.03.03.05.59.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Mar 2022 05:59:48 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 78D1B13199B; Thu, 3 Mar 2022 14:59:47 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Sebastian Andrzej Siewior , netdev@vger.kernel.org, bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , "David S. Miller" , Ingo Molnar , Jakub Kicinski , Jesper Dangaard Brouer , John Fastabend , KP Singh , Martin KaFai Lau , Song Liu , Steven Rostedt , Thomas Gleixner , Yonghong Song Subject: Re: [PATCH net] xdp: xdp_mem_allocator can be NULL in trace_mem_connect(). In-Reply-To: References: X-Clacks-Overhead: GNU Terry Pratchett Date: Thu, 03 Mar 2022 14:59:47 +0100 Message-ID: <875yovdtm4.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Sebastian Andrzej Siewior writes: > Since the commit mentioned below __xdp_reg_mem_model() can return a NULL > pointer. This pointer is dereferenced in trace_mem_connect() which leads > to segfault. It can be reproduced with enabled trace events during ifup. > > Only assign the arguments in the trace-event macro if `xa' is set. > Otherwise set the parameters to 0. > > Fixes: 4a48ef70b93b8 ("xdp: Allow registering memory model without rxq reference") > Signed-off-by: Sebastian Andrzej Siewior Hmm, so before the commit you mention, the tracepoint wasn't triggered at all in the code path that now sets xdp_alloc is NULL. So I'm wondering if we should just do the same here? Is the trace event useful in all cases? Alternatively, if we keep it, I think the mem.id and mem.type should be available from rxq->mem, right? -Toke