From patchwork Thu Sep 30 18:05:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12537991 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 C7057C433EF for ; Thu, 30 Sep 2021 18:05:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AED73619F6 for ; Thu, 30 Sep 2021 18:05:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353105AbhI3SHf (ORCPT ); Thu, 30 Sep 2021 14:07:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353083AbhI3SHa (ORCPT ); Thu, 30 Sep 2021 14:07:30 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4A4DC061771 for ; Thu, 30 Sep 2021 11:05:47 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id f8-20020a2585480000b02905937897e3daso9678195ybn.2 for ; Thu, 30 Sep 2021 11:05:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=+kIR6qTjG/q5eMITJU4my49cgyuaT1AvUzOJ+gtDnlg=; b=gkCn4CDHLNSjsTR7OqrAxG6q83amYoBjzRr52f4LFVrdFSlQ8WBZn3Kp+3hZbL0upx 4QgBEhfGWRMKKAB/Rg5nkWRPHjKEkG/A1Q1qhUvrWVXvLGMuMuBA65OpsS/tfbRK1pcp eZTHr+xF/PKqk0va5Z1T6QCYSxxDDVLojGTe6x4KArjInUM6eej4hO0563SYOBLYvQxu yxWiLR/GGIF9MjLLQ4I9iznSEWKsa3Wm0AcgJ7EcWRtashf7JTUQz/Fz45R7wS4Xruin N84Os+Y9Bz4ZPFcIAj4+J/A0L0R7xfD7qZl7197i2pE3AEJLLWz5uVkY+0dbWWm5rWpY CXAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=+kIR6qTjG/q5eMITJU4my49cgyuaT1AvUzOJ+gtDnlg=; b=S5jggfYtxRtMKsU0MrszN6raS4ENext3hScQiBxiI54HESG0r7JA1/MTOXyok6AfQA 0cHH4la2AhKMU4ZfNVp465feTUf4wxvZ32JjPHkfQ0AMM9WQdyJb+/wS2JgdKfL7/Mek Rz9BwasD8osK8LbcJy5BURqCXK/6IaF7ZzEDhY2SBDQ4gvQn0AdGGfFUa9J3kCSCy38h vIJaAOjaqhoxtD+NRxHEgo4Ts3pA51NKXCWUOuwCXfB1q+8WcDn6U7rNpdMSaa2l0avX FpuXCoTS3V5AbiPDaSIH8KJ25li2aX25cVoF0imI3ier9zVPJ67fCQ/ruGjNzJPyawU7 Alcw== X-Gm-Message-State: AOAM5316VqzQGrI8lf11BqYIh3L+17Vb6a1S4lhetMgEBZTeGROHfxwJ 1zopkUBBW0L9m26rSGHOmNG0JX8Qq2Z08EpUzlo= X-Google-Smtp-Source: ABdhPJzeouRFzQrqqzPBJAENZtj4Ib+N4rD5s05tDGC56V66KMQtSgvl9JGoFrlez4rsmfK0wargeV1Nvuyh26mOOio= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:ce43:4366:95ca:d6e9]) (user=samitolvanen job=sendgmr) by 2002:a25:45c6:: with SMTP id s189mr689329yba.290.1633025146834; Thu, 30 Sep 2021 11:05:46 -0700 (PDT) Date: Thu, 30 Sep 2021 11:05:21 -0700 In-Reply-To: <20210930180531.1190642-1-samitolvanen@google.com> Message-Id: <20210930180531.1190642-6-samitolvanen@google.com> Mime-Version: 1.0 References: <20210930180531.1190642-1-samitolvanen@google.com> X-Mailer: git-send-email 2.33.0.800.g4c38ced690-goog Subject: [PATCH v4 05/15] tracepoint: Exclude tp_stub_func from CFI checking From: Sami Tolvanen To: x86@kernel.org Cc: Kees Cook , Josh Poimboeuf , Peter Zijlstra , Nathan Chancellor , Nick Desaulniers , Sedat Dilek , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org 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 @@ -99,10 +99,7 @@ struct tp_probes { }; /* Called in removal of a func but failed to allocate a new tp_funcs */ -static void tp_stub_func(void) -{ - return; -} +static DEFINE_CFI_IMMEDIATE_RETURN_STUB(tp_stub_func); static inline void *allocate_probes(int count) {