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 828501869 for ; Fri, 29 Apr 2022 20:37:19 +0000 (UTC) Received: by mail-yb1-f201.google.com with SMTP id b6-20020a253406000000b006484c081280so8398153yba.5 for ; Fri, 29 Apr 2022 13:37:19 -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=tv2NfEjyfprEjH/WagRqqCH1hQfxPpGMj5Z2HbEgkRA=; b=pB+2omq61Q3217AvI0rEZSjmyFqJ9NJ7YuTSaZYQdZKihILOoXitcHp4Aqk4DfNuJC Ii1imHx96bqsVsHF4LbRU0itbEjHrNgVdkQ3irES1Ih8mxUshYfbtfCT+TfHZ/oz1dtP NY0q6seVOURhumX36uwOxNHojZ45LOr10er9aVaKi/UiJRMGUW9RPY1W/crXdM6e/nzW jbvzkhILVLoFfcKOggaouemXiLcCzeXKkf/R9rS3XSJYuy1mUw5kXCtFqCb5OkWHmIae AVmKCEcuaeO8akCJpncoE0TcUuvyXfT1iSaAa7lBOHuy3YgYc6i8BTmI6s6WYnCNi+AU t24g== 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=tv2NfEjyfprEjH/WagRqqCH1hQfxPpGMj5Z2HbEgkRA=; b=qA6HQ/LZfo3+6K6bj7JfHEVFv9WWlSsfB7XHq+bv4fIL/uZhljdBJdn51oUEnhN2iw EXV9IMJ896E9s7/q/6qm104a8fZeLArRULYI/A+U8ZRLrRg4nGWx3c5QkggWrjNkoM/D zEvN0utIXykFZ4cwBd+CqMPJXYcJmX95RlInnWiIOq9bMILQgN5YyPFWxMQunix5f1M6 496KxyA181qj8XlsUePAwByDBe9Wdq1y1TdEVMgiXQQtqdk0keISroQWvGpqmTQnHTWz 6Xoe56NEnAE4z9s28S0MJ1xcN+x6TCeX/rn2dRhzeYTcQAYq1/WhIP+l5UFkgINsjD2T Ej8w== X-Gm-Message-State: AOAM532Azrr5quTo+kMAeRpZ8Kf0DvdxpedgSmTKkKCWGodDmGv8N5z7 qnTIunVzucDXcvGYrIC3bPZ0jCtc/i86lbXbd3U= X-Google-Smtp-Source: ABdhPJzf8F6MhhQvERk6o6aC905EfQk7qKag0BcoEBBD0uWfioudMPTHJnGQUhT5pwFx9Z28Q9LGUrtznvm+L73jrDw= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:351:bea9:f158:1021]) (user=samitolvanen job=sendgmr) by 2002:a81:234b:0:b0:2f8:4082:bbd3 with SMTP id j72-20020a81234b000000b002f84082bbd3mr1122079ywj.47.1651264638553; Fri, 29 Apr 2022 13:37:18 -0700 (PDT) Date: Fri, 29 Apr 2022 13:36:36 -0700 In-Reply-To: <20220429203644.2868448-1-samitolvanen@google.com> Message-Id: <20220429203644.2868448-14-samitolvanen@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20220429203644.2868448-1-samitolvanen@google.com> X-Developer-Key: i=samitolvanen@google.com; a=openpgp; fpr=35CCFB63B283D6D3AEB783944CB5F6848BBC56EE X-Developer-Signature: v=1; a=openpgp-sha256; l=1454; h=from:subject; bh=tehRW82jP0RyTtdlRN0VdoftCcUQiAtEwsyBl3tnXQM=; b=owEB7QES/pANAwAKAUy19oSLvFbuAcsmYgBibExXrPGtzBdwEr3WsUJMcTa5SnMpMUdhtG1ELjyr Yo4vk3yJAbMEAAEKAB0WIQQ1zPtjsoPW0663g5RMtfaEi7xW7gUCYmxMVwAKCRBMtfaEi7xW7gG8C/ 4rBi6pp+EX2VhofKNrL5OB4Nbj0tmkbvch9On+rothI5RrjLElKTQ7rJKCbeCMf/fd9MhXmmy30ZDc 0i6d/nQFbMUJNbP3YvHszFfVozL5oetNY0LKa1tEWLrl1PmBWiMM1Y0hzUx695EFNuB9Z/IgzAWJHc VyKoFSgqL/HZvX7mFYcG2EAsOE+icuxIZICSAVt8NfVenhy3oKckN6+QZSZVHFbTE8sAiAE8x4UgZ4 nSjkqIrcznKGhg5HogEmdwZzCaAcGZxDqdA0V1aaU4kyfLHFp9XZzKmiiUwTYYSWwvCY9Tvo+xL+Vu 0CTamYHWDP1HUePZ8CB/mw9CsUeTuhu6zkvuMYcG354jmx7ooV+gAhNyCiEi4fKTuxQ5a1mRQuNNRE 8SsQdB8squmkfEfpsoDlQCt5QaUw4WeUghUIX9vTwT7ISqGIun7rYMiGMRNi2bz7Bl6AT0hPw82Lgr VbBurkClkSn9jw/pGy7ura6cWEncKA6ChV3483s2teTmc= X-Mailer: git-send-email 2.36.0.464.gb9c8b46e94-goog Subject: [RFC PATCH 13/21] cfi: Add the cfi_unchecked macro From: Sami Tolvanen To: linux-kernel@vger.kernel.org Cc: Kees Cook , Josh Poimboeuf , Peter Zijlstra , x86@kernel.org, Catalin Marinas , Will Deacon , Mark Rutland , Nathan Chancellor , Nick Desaulniers , Joao Moreira , Sedat Dilek , Steven Rostedt , linux-hardening@vger.kernel.org, linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev, Sami Tolvanen Content-Type: text/plain; charset="UTF-8" The cfi_unchecked macro allows CFI checking to be disabled for a specific indirect call expression, by passing the expression as an argument to the macro. For example: static void call(void (*f)(void)) { cfi_unchecked(f()); } Signed-off-by: Sami Tolvanen --- include/linux/compiler-clang.h | 2 ++ include/linux/compiler_types.h | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index c4ff42859077..0d6a0e7e36dc 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -94,4 +94,6 @@ #if CONFIG_CFI_CLANG /* Disable CFI checking inside a function. */ #define __nocfi __attribute__((__no_sanitize__("kcfi"))) +/* Disable CFI checking for the indirect call expression. */ +#define cfi_unchecked(expr) __builtin_kcfi_call_unchecked(expr) #endif diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index bdd2526af46a..41f547fe9724 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -263,6 +263,10 @@ struct ftrace_likely_data { # define __nocfi #endif +#ifndef cfi_unchecked +# define cfi_unchecked(expr) expr +#endif + /* * Any place that could be marked with the "alloc_size" attribute is also * a place to be marked with the "malloc" attribute. Do this as part of the -- 2.36.0.464.gb9c8b46e94-goog