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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 26BBAC282C4 for ; Tue, 12 Feb 2019 16:12:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB484217D9 for ; Tue, 12 Feb 2019 16:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549987962; bh=eDQAQSChJXi5b7ULWr405cpMSDe2ysCPangIzwv5xzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KpcQ6LoxSN6pbN1AlMZzpR2LfH5ZNtA0HJCk4S7YiZneAEm5yTUKvt6BPHGLJ8tMH BneJyqou2AIdm5csS/VhlDDmm/SmkZEIRC7sQD+L3IZv4/4no6KippzbeLZzV1/+rh xO1u8DdhEtTdiMio4e562EvBmNVzMSUhHQr1BH5A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730945AbfBLQMk (ORCPT ); Tue, 12 Feb 2019 11:12:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:41516 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728585AbfBLQMk (ORCPT ); Tue, 12 Feb 2019 11:12:40 -0500 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A211E21773; Tue, 12 Feb 2019 16:12:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549987958; bh=eDQAQSChJXi5b7ULWr405cpMSDe2ysCPangIzwv5xzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pyYst/mpdN1eLcwG9kEiuM2SemxHORRF1iaaBtg6cdjR6BqSBZChKMdgfdQ/1x/EJ ooOVeOwkZsvha22rFKkTXYmuYJYNronMWUuKdlUgM6OOmXICPIYgx53sPi2AfubxS1 yjHO6GafzyPlDtUqYqoH3HqmBH/FowycNaai7MgM= From: Masami Hiramatsu To: Ingo Molnar Cc: Masami Hiramatsu , peterz@infradead.org, Mathieu Desnoyers , linux-kernel , Andrea Righi , Steven Rostedt Subject: [PATCH -tip v3 03/10] x86/kprobes: Prohibit probing on functions before kprobe_int3_handler() Date: Wed, 13 Feb 2019 01:12:15 +0900 Message-Id: <154998793571.31052.11301258949601150994.stgit@devbox> X-Mailer: git-send-email 2.13.6 In-Reply-To: <154998785011.31052.1475728497912659748.stgit@devbox> References: <154998785011.31052.1475728497912659748.stgit@devbox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Prohibit probing on the functions called before kprobe_int3_handler() in do_int3(). More specifically, ftrace_int3_handler(), poke_int3_handler(), and ist_enter(). And since rcu_nmi_enter() is called by ist_enter(), it also should be marked as NOKPROBE_SYMBOL. Since those are handled before kprobe_int3_handler(), probing those functions can cause a breakpoint recursion and crash the kernel. Signed-off-by: Masami Hiramatsu --- arch/x86/kernel/alternative.c | 3 ++- arch/x86/kernel/ftrace.c | 3 ++- arch/x86/kernel/traps.c | 1 + kernel/rcu/tree.c | 2 ++ 4 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index d458c7973c56..9a79c7808f9c 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -764,8 +765,8 @@ int poke_int3_handler(struct pt_regs *regs) regs->ip = (unsigned long) bp_int3_handler; return 1; - } +NOKPROBE_SYMBOL(poke_int3_handler); /** * text_poke_bp() -- update instructions on live kernel on SMP diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 8257a59704ae..3e3789c8f8e1 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -269,7 +269,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func) return ret; } -static int is_ftrace_caller(unsigned long ip) +static nokprobe_inline int is_ftrace_caller(unsigned long ip) { if (ip == ftrace_update_func) return 1; @@ -299,6 +299,7 @@ int ftrace_int3_handler(struct pt_regs *regs) return 1; } +NOKPROBE_SYMBOL(ftrace_int3_handler); static int ftrace_write(unsigned long ip, const char *val, int size) { diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 2684a9d11e66..d26f9e9c3d83 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -111,6 +111,7 @@ void ist_enter(struct pt_regs *regs) /* This code is a bit fragile. Test it. */ RCU_LOCKDEP_WARN(!rcu_is_watching(), "ist_enter didn't work"); } +NOKPROBE_SYMBOL(ist_enter); void ist_exit(struct pt_regs *regs) { diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 9180158756d2..74db52a0a466 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -62,6 +62,7 @@ #include #include #include +#include #include "tree.h" #include "rcu.h" @@ -872,6 +873,7 @@ void rcu_nmi_enter(void) { rcu_nmi_enter_common(false); } +NOKPROBE_SYMBOL(rcu_nmi_enter); /** * rcu_irq_enter - inform RCU that current CPU is entering irq away from idle