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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1E19C54FC9 for ; Tue, 21 Apr 2020 20:13:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D351E206B8 for ; Tue, 21 Apr 2020 20:13:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="EPH1rPQ6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726358AbgDUUNp (ORCPT ); Tue, 21 Apr 2020 16:13:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726287AbgDUUNp (ORCPT ); Tue, 21 Apr 2020 16:13:45 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4E3EC0610D5 for ; Tue, 21 Apr 2020 13:13:44 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id h11so5670422plr.11 for ; Tue, 21 Apr 2020 13:13:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=zU+Qe13RM8w9jiKui1cp9m/91Pj+sZI1Kh2v8CmodJU=; b=EPH1rPQ6rCi6kTPTHAzZ3NTtXgmEgpZIXTaZcdakKQMCZt3v62s1FcKJkiV7cemrsw MqaOSQOiMEsKU9FuKRNqcsPFnSxO3RJ90PztyxI+rZaTItXDeP77iHsLjR1nz1C2zhYg 2Iw8iWXN5z3VLZwF7c6REihQ7wMffPCcjcZW4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=zU+Qe13RM8w9jiKui1cp9m/91Pj+sZI1Kh2v8CmodJU=; b=i6mahuJ/VZFfWdH3pNSs2rfJf8THhPJpYFofG27E7FTfWY5rfCne+jeFxAZvzHGB2R ZeoANEl0yIOS/tRT7qdtguCD+aUTRoYl0YLnowlfVDzW2bd4+TIz/sRqhYCi3eC2YXvM 51tS80EB7kiT9W/L4UkeYSNo2r57BF+JZzGzSJ7MCFxQoQPidN7Hg/Wmf5STugdV2pny vybSIVYrInG/4S/0TnVR2itiDWY/3CGAOeysQuAYtcCpCgPXHcm9q8dELLL7UgrRlJqB 83H9REKeJ8KnKLubWkcQs3+GZAY4WDlzQu4J8GfR17LdlKVtp2D3++4DDK6Hj1M7lnOy xlFA== X-Gm-Message-State: AGi0Pub/k9q39M+MdWcD1wTDlIgdf4Vy56G9209PwGtdgyaZ2WXzShaF lRm3eVps80ZTLVeWSeMF4aRYuuGvlQM= X-Google-Smtp-Source: APiQypL7cUB9UH2M34v8Tu2Ef4Wz7oX/K/T2h7kVallC0yil+djyZF8+t+dIOZi6w/mScJV+o0aq1A== X-Received: by 2002:a17:902:ba89:: with SMTP id k9mr22880374pls.199.1587500024421; Tue, 21 Apr 2020 13:13:44 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id l185sm3125944pfl.104.2020.04.21.13.13.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Apr 2020 13:13:43 -0700 (PDT) Date: Tue, 21 Apr 2020 13:13:42 -0700 From: Kees Cook To: Peter Zijlstra Cc: Sami Tolvanen , Josh Poimboeuf , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] objtool: optimize insn_hash for split sections Message-ID: <202004211313.8B7F529CE@keescook> References: <20200421180724.245410-1-samitolvanen@google.com> <20200421180724.245410-3-samitolvanen@google.com> <20200421194749.GX20730@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200421194749.GX20730@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 21, 2020 at 09:47:49PM +0200, Peter Zijlstra wrote: > On Tue, Apr 21, 2020 at 11:07:23AM -0700, Sami Tolvanen wrote: > > When running objtool on vmlinux.o compiled with -ffunction-sections, > > we end up with a ton of collisions in the insn_hash table as each > > function is in its own section. This results in a runtime of minutes > > instead of seconds. Use both section index and offset as the key to > > avoid this, similarly to rela_hash. > > > > Signed-off-by: Sami Tolvanen > > I already have this queued: > > https://lkml.kernel.org/r/20200416115119.227240432@infradead.org > > which looks very similar. Ah! Yeah, just no insn-arg helper to do the hash call; cool. Please consider both: Reviewed-by: Kees Cook -Kees -- Kees Cook