From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CEE4672 for ; Thu, 30 Sep 2021 18:05:47 +0000 (UTC) Received: by mail-yb1-f201.google.com with SMTP id 207-20020a2503d8000000b005b6fc088578so4434336ybd.0 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=S20Ru3NGWbNI57LfGMTMVdmaUQSQvCj+MGaTKJxCcK876RSbkTQqyaDlywJY38mtSU p3kaqhV/13+MXIcd9lGLOQGOR7x3Z3nRpT25+/BQF0BSX34UemvO5NAs6N6Kh8m1rFTx t7MGAB0ml6Iso5hBnxGzJTV1OCX9DquyRmAqWXekBm6l1axvz3q7xA+mXrtjLjoTT1eL J3duqX7VYJ7bAB7g6RQ1XL8GOg3yAZY+P3B4SfOwc5HaiyoCVYrB06FNb/ALsURZxh1R d/vpjlUXGXeK9U4273QyM8Gx9uakpquQFqk2qfRiUWWFT4J0/MNYhN6m/xutUNwNgBbO 6Lkw== X-Gm-Message-State: AOAM5334saQHQlk9CS1ApkUYCSQTusynZijSYNyeBZ7zOOekoWQBSe/j 2fgvXPAh//y6OX4MOe72MjFeJDa5zq8q+68ZFcw= 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> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: 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 Content-Type: text/plain; charset="UTF-8" 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) { -- 2.33.0.800.g4c38ced690-goog