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 BD2ECC433FE for ; Thu, 3 Nov 2022 14:49:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231749AbiKCOtC (ORCPT ); Thu, 3 Nov 2022 10:49:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231757AbiKCOs4 (ORCPT ); Thu, 3 Nov 2022 10:48:56 -0400 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E4F118B15; Thu, 3 Nov 2022 07:48:55 -0700 (PDT) Received: by mail-wr1-x430.google.com with SMTP id bs21so3145786wrb.4; Thu, 03 Nov 2022 07:48:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=OyyRFN6o9cSPSQOmcN/1EM+CmiHfqIcoRrnXjizSh5k=; b=UiD6Sw+BCc8/v2kAxBpA4XlTQDkFfgJLJVlGwLZvxlPlnD5+ynC6Eq8DbPlt3NW9h0 bAD0JrWxYpZyk+g5EL9zTxmBD11V4eHsfrpY9GQ+5UfPRnbePRyzxV5OEA/zcUhujJDC Gy/COKqcAtQUFIeQ2Eo3dlOvoUYxm4Dbu87s45v+vvUNU5352mEb7lfuIpX/V4Re5rhz n+oHq03FKxelkwBIr7lr2YsKRfX3+6J3GhjH7PAw1a790wpPGH90M0pVryi1iA2ObvPO cih1QQKeW350S+iC7phkiyqumk3RQOxihOSnl3wQH8CyC4VMH4VixE5QRKtHMfFCumYF xscQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=OyyRFN6o9cSPSQOmcN/1EM+CmiHfqIcoRrnXjizSh5k=; b=GxIz5prZ/YlGxQ5hY8NrIhraw7SyW9sCXtLMaTPizmWYhS8DvTmhPtsMl2F7UMRlhP /Ez4tjByWTRpKHiuB3bZ2ATwzLHXx2y+klywaT8jo5Wdt3pMoOCrXbdQc+HIPS+7eH1n hV6abGqE8VVVRFYYg1oVKCx+FmrClFBSn0pWFc+AVKIEn7zgYB4rfHQ6X+olvvTH6X2O HwJtdUGuFK0Oml5NZxoelGwy3JgGprU/ytb+E5Q186zm8eOhU6j4NpBmMONJdgtdD1Ma qGEMdqBbI4WZX5qVfos50sdpbtFV5JPWCJ60+UGs2ufpeS+aY9ta2iZiDF4FwWq0kSnt mohQ== X-Gm-Message-State: ACrzQf1M5FpuPrJeeQsqPeU4X6G8lkCvKFD+BAPdkzwv2p5xOLbVJgyj bT6mDOGSUswzrwXS1RcOP9E5Ff3V38Er4A== X-Google-Smtp-Source: AMsMyM4K/tdvIzFule6PjRafCbDb6HsmdP5OBU7nmsT0oVnHvqtXJEI3fBPFQ1oYPtFAPthl+pvllg== X-Received: by 2002:adf:f687:0:b0:236:481f:83a6 with SMTP id v7-20020adff687000000b00236481f83a6mr19368811wrp.342.1667486933978; Thu, 03 Nov 2022 07:48:53 -0700 (PDT) Received: from krava (2001-1ae9-1c2-4c00-726e-c10f-8833-ff22.ip6.tmcz.cz. [2001:1ae9:1c2:4c00:726e:c10f:8833:ff22]) by smtp.gmail.com with ESMTPSA id y16-20020adff6d0000000b0023647841c5bsm1038753wrp.60.2022.11.03.07.48.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Nov 2022 07:48:53 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Thu, 3 Nov 2022 15:48:51 +0100 To: Peter Zijlstra Cc: olsajiri@gmail.com, ast@kernel.org, daniel@iogearbox.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, bjorn@kernel.org, toke@redhat.com, David.Laight@aculab.com, rostedt@goodmis.org Subject: Re: [PATCH 0/2] bpf: Yet another approach to fix the BPF dispatcher thing Message-ID: References: <20221103120012.717020618@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221103120012.717020618@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 03, 2022 at 01:00:12PM +0100, Peter Zijlstra wrote: > Hi! > > Even thought the __attribute__((patchable_function_entry())) solution to the > BPF dispatcher woes works, it turns out to not be supported by the whole range > of ageing compilers we support. Specifically this attribute seems to be GCC-8 > and later. > > This is another approach -- using static_call() to rewrite the dispatcher > function. I've compile tested this on: > > x86_64 (inline static-call support) > i386 (out-of-line static-call support) > aargh64 (no static-call support) > > A previous version was tested and found working by Bjorn. > > It is split in two patches; first reverting the current approach and then > introducing the new for ease of review. > Acked-by: Jiri Olsa Tested-by: Jiri Olsa thanks, jirka