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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 61069C34047 for ; Wed, 19 Feb 2020 15:15:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3902724672 for ; Wed, 19 Feb 2020 15:15:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="GvBJXNl/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728051AbgBSPPU (ORCPT ); Wed, 19 Feb 2020 10:15:20 -0500 Received: from merlin.infradead.org ([205.233.59.134]:52028 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727802AbgBSPOg (ORCPT ); Wed, 19 Feb 2020 10:14:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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=Cu9fMoStLdoopmELsQh0sghgcGowEYfFRTmFriwC31I=; b=GvBJXNl/nmV4ynPyvKXmgBHRyz 3gkHPPYcMQ7D/wEzHRA2TY+riSrz9HomXkLwAoORLhuUcHgttQsHlVX9BXOu05Am9Gs1kB8DNMx7Z 7GhtNJ952oMtpwlfjOQKuI8IhcuvvLte/9+S/5yPovzOFDZLpgeZhvApL5/w+EbbwNB1/7DDfCdFy kZWkkTA3BP/yYE95aICanZzvvzTQpPRIWKAAosMo0RTSLWpbdFkBIQWUfIVojJJZX4zLxy5viKaEr /FHPFhgrNI/Nyo3te1mOLXzQDU1jPFE9KJIlJ+FtccKY0MZYL/3i0nvLyRuUFzgsuzUNQcuIPf0yw doN8qB+A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4R39-0007fL-1J; Wed, 19 Feb 2020 15:14:07 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 0758D307842; Wed, 19 Feb 2020 16:12:12 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 9D36E2B4D7B86; Wed, 19 Feb 2020 16:14:03 +0100 (CET) Message-Id: <20200219150745.241364074@infradead.org> User-Agent: quilt/0.65 Date: Wed, 19 Feb 2020 15:47:39 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org Cc: peterz@infradead.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org Subject: [PATCH v3 15/22] x86/int3: Ensure that poke_int3_handler() is not traced References: <20200219144724.800607165@infradead.org> MIME-Version: 1.0 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 From: Thomas Gleixner In order to ensure poke_int3_handler() is completely self contained -- we call this while we're modifying other text, imagine the fun of hitting another INT3 -- ensure that everything it uses is not traced. The primary means here is to force inlining; bsearch() is notrace because all of lib/ is. Not-Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/ptrace.h | 2 +- arch/x86/include/asm/text-patching.h | 11 +++++++---- arch/x86/kernel/alternative.c | 11 +++++++---- 3 files changed, 15 insertions(+), 9 deletions(-) Index: linux-2.6/arch/x86/include/asm/ptrace.h =================================================================== --- linux-2.6.orig/arch/x86/include/asm/ptrace.h +++ linux-2.6/arch/x86/include/asm/ptrace.h @@ -123,7 +123,7 @@ static inline void regs_set_return_value * On x86_64, vm86 mode is mercifully nonexistent, and we don't need * the extra check. */ -static inline int user_mode(struct pt_regs *regs) +static __always_inline int user_mode(struct pt_regs *regs) { #ifdef CONFIG_X86_32 return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL; Index: linux-2.6/arch/x86/include/asm/text-patching.h =================================================================== --- linux-2.6.orig/arch/x86/include/asm/text-patching.h +++ linux-2.6/arch/x86/include/asm/text-patching.h @@ -64,7 +64,7 @@ extern void text_poke_finish(void); #define DISP32_SIZE 4 -static inline int text_opcode_size(u8 opcode) +static __always_inline int text_opcode_size(u8 opcode) { int size = 0; @@ -118,12 +118,14 @@ extern __ro_after_init struct mm_struct extern __ro_after_init unsigned long poking_addr; #ifndef CONFIG_UML_X86 -static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip) +static __always_inline +void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip) { regs->ip = ip; } -static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val) +static __always_inline +void int3_emulate_push(struct pt_regs *regs, unsigned long val) { /* * The int3 handler in entry_64.S adds a gap between the @@ -138,7 +140,8 @@ static inline void int3_emulate_push(str *(unsigned long *)regs->sp = val; } -static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func) +static __always_inline +void int3_emulate_call(struct pt_regs *regs, unsigned long func) { int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE); int3_emulate_jmp(regs, func); Index: linux-2.6/arch/x86/kernel/alternative.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/alternative.c +++ linux-2.6/arch/x86/kernel/alternative.c @@ -956,7 +956,8 @@ struct bp_patching_desc { static struct bp_patching_desc *bp_desc; -static inline struct bp_patching_desc *try_get_desc(struct bp_patching_desc **descp) +static __always_inline +struct bp_patching_desc *try_get_desc(struct bp_patching_desc **descp) { struct bp_patching_desc *desc = READ_ONCE(*descp); /* rcu_dereference */ @@ -966,13 +967,13 @@ static inline struct bp_patching_desc *t return desc; } -static inline void put_desc(struct bp_patching_desc *desc) +static __always_inline void put_desc(struct bp_patching_desc *desc) { smp_mb__before_atomic(); atomic_dec(&desc->refs); } -static inline void *text_poke_addr(struct text_poke_loc *tp) +static __always_inline void *text_poke_addr(struct text_poke_loc *tp) { return _stext + tp->rel_addr; }