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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48ECCC433F5 for ; Thu, 24 Feb 2022 15:20:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236141AbiBXPUj (ORCPT ); Thu, 24 Feb 2022 10:20:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235998AbiBXPSl (ORCPT ); Thu, 24 Feb 2022 10:18:41 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A65691617D2 for ; Thu, 24 Feb 2022 07:17:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=0vNiWWliHftrrrDMpbQA2ahn+ZapY3hO8BL9QfndM2A=; b=RCg+wXOEzBgB0NhuHzKBvcEe7N QA59pWsz7ze0+wAwnYCcju9lWAPHXc3+qYvad6JEtTRt1V/PjlmfEYXb0HWB9IH9kbCPwhD6JaPBr AKG59EVbaoX5WaFctYEww/1d85aVrArlSuEuj8itH6C+p5D5XQ2KfNFVYdr+PQc0Pkci1PlAKqIPM l1nZ/IQami2WyZAxJd8e/I7WznUhNrei6iiSWfRsfzn84Blq/uwSL9lsgcg4fPvcWMloiWefTXQjg cuWvVGnb2g01s0q4fNaP/YxFIDNMvXBu6ihQZRbNQbBn+CtOAJh1Br4VB9Mcai7BoOq83lvXipWXr 2bgSasQA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nNFs3-004s2C-Rn; Thu, 24 Feb 2022 15:17:31 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 4578630288B; Thu, 24 Feb 2022 16:17:29 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 7DF6E2B354797; Thu, 24 Feb 2022 16:17:28 +0100 (CET) Message-ID: <20220224151323.421937384@infradead.org> User-Agent: quilt/0.66 Date: Thu, 24 Feb 2022 15:52:02 +0100 From: Peter Zijlstra To: x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com, jpoimboe@redhat.com, andrew.cooper3@citrix.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, ndesaulniers@google.com, keescook@chromium.org, samitolvanen@google.com, mark.rutland@arm.com, alyssa.milburn@intel.com, mbenes@suse.cz, rostedt@goodmis.org, mhiramat@kernel.org, alexei.starovoitov@gmail.com Subject: [PATCH v2 24/39] x86/text-patching: Make text_gen_insn() IBT aware References: <20220224145138.952963315@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make sure we don't generate direct JMP/CALL instructions to an ENDBR instruction (which might be poison). Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/text-patching.h | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -5,6 +5,7 @@ #include #include #include +#include struct paravirt_patch_site; #ifdef CONFIG_PARAVIRT @@ -101,13 +102,26 @@ void *text_gen_insn(u8 opcode, const voi static union text_poke_insn insn; /* per instance */ int size = text_opcode_size(opcode); + /* + * Hide the addresses to avoid the compiler folding in constants when + * referencing code, these can mess up annotations like + * ANNOTATE_NOENDBR. + */ + OPTIMIZER_HIDE_VAR(addr); + OPTIMIZER_HIDE_VAR(dest); + +#ifdef CONFIG_X86_KERNEL_IBT + if (is_endbr(*(u32 *)dest)) + dest += 4; +#endif + insn.opcode = opcode; if (size > 1) { insn.disp = (long)dest - (long)(addr + size); if (size == 2) { /* - * Ensure that for JMP9 the displacement + * Ensure that for JMP8 the displacement * actually fits the signed byte. */ BUG_ON((insn.disp >> 31) != (insn.disp >> 7));