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 73A65C433F5 for ; Tue, 8 Mar 2022 15:58:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348279AbiCHP5u (ORCPT ); Tue, 8 Mar 2022 10:57:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348060AbiCHP4I (ORCPT ); Tue, 8 Mar 2022 10:56:08 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21C154F9DA for ; Tue, 8 Mar 2022 07:55:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=V8QY1pYX+d9tDtpObRzYPlZyD2xDu/v2HceiF0ugrr8=; b=R6iekmSLXyHMxVdKSW5yoryFTR JTZc47RL6KLznJhS9rxZPw/msgRRtmPE9nbOey2B5vqVnAVnp4A7iPiFjJVy0YA6uCXEBnrwl5Q/m 2DKz8rpN70XkYfHred7IxVkny96XVIuKTp1UiaNkw50lVBQO8RbH8WdqURgaeKacS8hFFNVx+o3Kh wW9tTyNmmZ7J2WyMJ78CJk2u4Ep9JqddUeG5zNjZwJioYu3ilSQKM2xtSNQdukPpCawMV9BzcV27i Jc0ZYBl1/zbt0sj3IBR88/3/hJBtDyHJd8/Wx7KN7GeRbxOXz428zPlDqo+2iIdyiyD63ClFDW898 XxZxUXIA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRcAc-00GUiN-2Y; Tue, 08 Mar 2022 15:54:42 +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 206E4301169; Tue, 8 Mar 2022 16:54:40 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id DF9A82B561908; Tue, 8 Mar 2022 16:54:38 +0100 (CET) Message-ID: <20220308154317.697253958@infradead.org> User-Agent: quilt/0.66 Date: Tue, 08 Mar 2022 16:30:20 +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 v4 09/45] x86/ibt,paravirt: Use text_gen_insn() for paravirt_patch() References: <20220308153011.021123062@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 Less duplication is more better. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/text-patching.h | 20 ++++++++++++++------ arch/x86/kernel/paravirt.c | 23 +++-------------------- 2 files changed, 17 insertions(+), 26 deletions(-) --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -96,32 +96,40 @@ union text_poke_insn { }; static __always_inline -void *text_gen_insn(u8 opcode, const void *addr, const void *dest) +void __text_gen_insn(void *buf, u8 opcode, const void *addr, const void *dest, int size) { - static union text_poke_insn insn; /* per instance */ - int size = text_opcode_size(opcode); + union text_poke_insn *insn = buf; + + BUG_ON(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(insn); OPTIMIZER_HIDE_VAR(addr); OPTIMIZER_HIDE_VAR(dest); - insn.opcode = opcode; + insn->opcode = opcode; if (size > 1) { - insn.disp = (long)dest - (long)(addr + size); + insn->disp = (long)dest - (long)(addr + size); if (size == 2) { /* * Ensure that for JMP8 the displacement * actually fits the signed byte. */ - BUG_ON((insn.disp >> 31) != (insn.disp >> 7)); + BUG_ON((insn->disp >> 31) != (insn->disp >> 7)); } } +} +static __always_inline +void *text_gen_insn(u8 opcode, const void *addr, const void *dest) +{ + static union text_poke_insn insn; /* per instance */ + __text_gen_insn(&insn, opcode, addr, dest, text_opcode_size(opcode)); return &insn.text; } --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -69,29 +69,12 @@ noinstr void paravirt_BUG(void) BUG(); } -struct branch { - unsigned char opcode; - u32 delta; -} __attribute__((packed)); - static unsigned paravirt_patch_call(void *insn_buff, const void *target, unsigned long addr, unsigned len) { - const int call_len = 5; - struct branch *b = insn_buff; - unsigned long delta = (unsigned long)target - (addr+call_len); - - if (len < call_len) { - pr_warn("paravirt: Failed to patch indirect CALL at %ps\n", (void *)addr); - /* Kernel might not be viable if patching fails, bail out: */ - BUG_ON(1); - } - - b->opcode = 0xe8; /* call */ - b->delta = delta; - BUILD_BUG_ON(sizeof(*b) != call_len); - - return call_len; + __text_gen_insn(insn_buff, CALL_INSN_OPCODE, + (void *)addr, target, CALL_INSN_SIZE); + return CALL_INSN_SIZE; } #ifdef CONFIG_PARAVIRT_XXL