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=-16.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 60066C31E45 for ; Thu, 13 Jun 2019 15:23:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 34CB12177E for ; Thu, 13 Jun 2019 15:23:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mEcFMq6v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388911AbfFMPW4 (ORCPT ); Thu, 13 Jun 2019 11:22:56 -0400 Received: from mail-qk1-f201.google.com ([209.85.222.201]:40411 "EHLO mail-qk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731961AbfFMMdq (ORCPT ); Thu, 13 Jun 2019 08:33:46 -0400 Received: by mail-qk1-f201.google.com with SMTP id n5so16445648qkf.7 for ; Thu, 13 Jun 2019 05:33:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=qVLSMyZ68L0nEVi2BC3Nmk92s+29uFb8AJSu612sAz8=; b=mEcFMq6vRtXHwc1RP8jEWhkPHuu5ffLbfkkwDtzHIdY7zu0q/3RmQYU0C2M8YItYdj KrS3JrVCHUTkTVGPeJFR3558Lkzo9m+Hrt2To2Xh6dHj3rWEZdwlvfU/XobkdBa1qM1u bVUHZhGsEe6EyqwGvBRK3DpuxCKwwz93lpLFVVpqqWoWS+f1yFbvvDsQRLHdlHjEllmi 4c2+iEnMXwijfbpWUfTWtDfGTh2c6bTbPu6mYc3Z5FvYeAnfq5fhqA1ZXRpV9QGoquIe UXI/Y+mYi5zKHzhAfqrF1QBTPytuai5yqmiNP4Ah1jeWXWL6tgCc55WQHEp4ZqPnjVex sh9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=qVLSMyZ68L0nEVi2BC3Nmk92s+29uFb8AJSu612sAz8=; b=uQFtgQeDJ2dPJdnd50mLf3KPpwa91by8LXBxqIzEjvpwtvrfan3dcqLuhtJDHjcRdO GATmfUts17BKiE7zW/NcrppDC8QY8DhtNjpVlQwdro2002iCdRJFRcPdmOq9vWahhWka cu6511rt463GpAoPe8t8BDu0g5mDL04XT9hsNmNR8FiMIPnJDRzQIIJ74VJ74qjid58v Y6W+N66F1BPUSvbdqoE1QlUtZJjrk657xOWHbPd27x8CmhWoZ5qfM4fnYc3M7XQ9Fp6Y GdeZEblXL7osOjM2/AYOXPSc3MVc25PZazDMZ/y4OacW/jtTbqQJkoO3xvDwOr3SWqdu 2r8A== X-Gm-Message-State: APjAAAUGBomN0zwQNmK+2FPVweUMAxbOVNzHr7B0Gi3unwWBvlxDKdAb p0Pnk5JrR5tU+ZSA5hiVakuLvbrCEw== X-Google-Smtp-Source: APXvYqylI3cPASu223/GCT4ATKtpCP1kOJBYXot+bE63+WxXg2nIKWWXGD9ArdLXxrnm26iomhlz5BaC7Q== X-Received: by 2002:a05:6214:1249:: with SMTP id q9mr3260843qvv.154.1560429225061; Thu, 13 Jun 2019 05:33:45 -0700 (PDT) Date: Thu, 13 Jun 2019 14:30:27 +0200 In-Reply-To: <20190613123028.179447-1-elver@google.com> Message-Id: <20190613123028.179447-3-elver@google.com> Mime-Version: 1.0 References: <20190613123028.179447-1-elver@google.com> X-Mailer: git-send-email 2.22.0.rc2.383.gf4fbbf30c2-goog Subject: [PATCH v4 2/3] x86: Use static_cpu_has in uaccess region to avoid instrumentation From: Marco Elver To: peterz@infradead.org, aryabinin@virtuozzo.com, dvyukov@google.com, glider@google.com, andreyknvl@google.com, mark.rutland@arm.com, hpa@zytor.com Cc: corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, arnd@arndb.de, jpoimboe@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, kasan-dev@googlegroups.com, Marco Elver Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch is a pre-requisite for enabling KASAN bitops instrumentation; using static_cpu_has instead of boot_cpu_has avoids instrumentation of test_bit inside the uaccess region. With instrumentation, the KASAN check would otherwise be flagged by objtool. For consistency, kernel/signal.c was changed to mirror this change, however, is never instrumented with KASAN (currently unsupported under x86 32bit). Signed-off-by: Marco Elver Suggested-by: H. Peter Anvin Acked-by: Peter Zijlstra (Intel) Reviewed-by: Andrey Ryabinin --- Changes in v3: * Use static_cpu_has instead of moving boot_cpu_has outside uaccess region. Changes in v2: * Replaces patch: 'tools/objtool: add kasan_check_* to uaccess whitelist' --- arch/x86/ia32/ia32_signal.c | 2 +- arch/x86/kernel/signal.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index 629d1ee05599..1cee10091b9f 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -358,7 +358,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig, put_user_ex(ptr_to_compat(&frame->uc), &frame->puc); /* Create the ucontext. */ - if (boot_cpu_has(X86_FEATURE_XSAVE)) + if (static_cpu_has(X86_FEATURE_XSAVE)) put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); else put_user_ex(0, &frame->uc.uc_flags); diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 364813cea647..52eb1d551aed 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -391,7 +391,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, put_user_ex(&frame->uc, &frame->puc); /* Create the ucontext. */ - if (boot_cpu_has(X86_FEATURE_XSAVE)) + if (static_cpu_has(X86_FEATURE_XSAVE)) put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); else put_user_ex(0, &frame->uc.uc_flags); -- 2.22.0.rc2.383.gf4fbbf30c2-goog