From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 11 Apr 2018 21:02:56 +0200 (CEST) Received: from mail.linuxfoundation.org ([140.211.169.12]:53412 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23994731AbeDKTCsBRXPB (ORCPT ); Wed, 11 Apr 2018 21:02:48 +0200 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 3179BDAC; Wed, 11 Apr 2018 19:02:39 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marcin Nowakowski , linux-mips@linux-mips.org, Ralf Baechle , Sasha Levin Subject: [PATCH 4.9 220/310] MIPS: kprobes: flush_insn_slot should flush only if probe initialised Date: Wed, 11 Apr 2018 20:35:59 +0200 Message-Id: <20180411183632.010909466@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180411183622.305902791@linuxfoundation.org> References: <20180411183622.305902791@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 63499 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: gregkh@linuxfoundation.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marcin Nowakowski [ Upstream commit 698b851073ddf5a894910d63ca04605e0473414e ] When ftrace is used with kprobes, it is possible for a kprobe to contain an invalid location (ie. only initialised to 0 and not to a specific location in the code). Trying to perform a cache flush on such location leads to a crash r4k_flush_icache_range(). Fixes: c1bf207d6ee1 ("MIPS: kprobe: Add support.") Signed-off-by: Marcin Nowakowski Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16296/ Signed-off-by: Ralf Baechle Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/kprobes.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/mips/include/asm/kprobes.h +++ b/arch/mips/include/asm/kprobes.h @@ -40,7 +40,8 @@ typedef union mips_instruction kprobe_op #define flush_insn_slot(p) \ do { \ - flush_icache_range((unsigned long)p->addr, \ + if (p->addr) \ + flush_icache_range((unsigned long)p->addr, \ (unsigned long)p->addr + \ (MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \ } while (0)