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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9091C433EF for ; Fri, 1 Oct 2021 20:09:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A64BD610A3 for ; Fri, 1 Oct 2021 20:09:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229914AbhJAUKo (ORCPT ); Fri, 1 Oct 2021 16:10:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229656AbhJAUKn (ORCPT ); Fri, 1 Oct 2021 16:10:43 -0400 Received: from mail-yb1-xb34.google.com (mail-yb1-xb34.google.com [IPv6:2607:f8b0:4864:20::b34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FFD5C06177E for ; Fri, 1 Oct 2021 13:08:59 -0700 (PDT) Received: by mail-yb1-xb34.google.com with SMTP id v10so22952741ybq.7 for ; Fri, 01 Oct 2021 13:08:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=wKG27X/tAaz6ZgSm5PLct1wo5H6VtWzGqhVRfSbCJeM=; b=K/EZX9fC9ZUuzFI6jrZypY1zTFUDt/PU70tLbqJHmQR1qUSX74ZaJgv2NcYZgAKyxp IGav/zFpLLCH001ejV1vMObkwX0wGHb+UKwQ6kSvjtnd8WWRAXyBC1NiC7MxyV9iJvcy rsCUB4L+pz5p17cwq7H2NsYsiU2vmQlHJ0Tcrq5gjSQbM8w8xZKBMin7C5Qzc1rpXYdz HKHH+DsRMvAYh8BOZSJFRxikufOUyCDSOOapRM7+NoJRPhev7XGLUTfGVqW8HkZcf0k2 gZEuAouaG/VT/oHp5nPOEqDTxWb+ThYNaiR0o6i8VOaeFBhsVrUATAE4tcbhHOnazbOp 7W+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=wKG27X/tAaz6ZgSm5PLct1wo5H6VtWzGqhVRfSbCJeM=; b=7Pa++rvgnNJxfXziIztovl8/zYqEg4i+4mJSiDh472p3MtiPmH8daD4GdcgpbbLsIX COU6fnWQg8mHfJMz8t49zAinjfSEe28N7bZkTEHVgUQHIFBEg1cFTMQxnCCj7j06uEh5 I0l2UnKDlCi5clxjisTg8E3GWkUen+Y9nDYfKW2StPaYlCWeLqbOQ2/JYtpvRJEizGvt Yy8RHa11Ln539KV+w7p2zC8X3etOXWMu4wiG1Ed2nQp2ad//uu0GhtpS0ETtzj6FQ3oI HWE2SOXcTBF/dbZMJxJyuTeFA6SUdjHABihdI+ZI1CjkBEOpFPbHvQ5AT/Qi0kKS0d7U 3Jpw== X-Gm-Message-State: AOAM531OX+b2JRyIY2k9dkA2+u+HA8qEhGyd+RHVSMkaggwJhSupLzis zdbOLAM+qLgTFMkwx2M9Ra/D6LCWxgR/aCbKYhJurg== X-Google-Smtp-Source: ABdhPJwOtf4LpoL1TJ/IJSfZorBhBurQK2kH41u3Fyo5ujc2AgTfHjWisxqRuQ+5FkxK3/PBitfSFea2DlJ3i0S6fX4= X-Received: by 2002:a25:e6d0:: with SMTP id d199mr8208144ybh.527.1633118938474; Fri, 01 Oct 2021 13:08:58 -0700 (PDT) MIME-Version: 1.0 References: <20210930180531.1190642-1-samitolvanen@google.com> <20210930180531.1190642-6-samitolvanen@google.com> In-Reply-To: From: Sami Tolvanen Date: Fri, 1 Oct 2021 13:08:47 -0700 Message-ID: Subject: Re: [PATCH v4 05/15] tracepoint: Exclude tp_stub_func from CFI checking To: Nick Desaulniers Cc: X86 ML , Kees Cook , Josh Poimboeuf , Peter Zijlstra , Nathan Chancellor , Sedat Dilek , linux-hardening@vger.kernel.org, LKML , llvm@lists.linux.dev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On Thu, Sep 30, 2021 at 11:51 AM Nick Desaulniers wrote: > > On Thu, Sep 30, 2021 at 11:05 AM Sami Tolvanen wrote: > > > > If allocate_probes fails, func_remove replaces the old function > > with a pointer to tp_stub_func, which is called using a mismatching > > function pointer that will always trip indirect call checks with > > CONFIG_CFI_CLANG. Use DEFINE_CFI_IMMEDATE_RETURN_STUB to define > > tp_stub_func to allow it to pass CFI checking. > > > > Signed-off-by: Sami Tolvanen > > Reviewed-by: Nick Desaulniers > > --- > > kernel/tracepoint.c | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c > > index 64ea283f2f86..58acc7d86c3f 100644 > > --- a/kernel/tracepoint.c > > +++ b/kernel/tracepoint.c > > looking at 4+5/15 together, I wonder if this TU should explicitly > include linux/cfi.h? Good point. Currently cfi.h is included in module.h, but including it explicitly makes this less likely to break in future. I'll add an explicit include in v5. Thanks for taking a look! Sami