From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934506AbaH0NhW (ORCPT ); Wed, 27 Aug 2014 09:37:22 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:46278 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933404AbaH0NhT (ORCPT ); Wed, 27 Aug 2014 09:37:19 -0400 Message-ID: <53FDDF08.5090604@hitachi.com> Date: Wed, 27 Aug 2014 22:37:12 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Wang Nan , Ingo Molnar Cc: Thomas Gleixner , Andi Kleen , Pei Feiyue , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kprobes/x86: opt: free optinsn cache when range check fails References: <1406550019-70935-1-git-send-email-wangnan0@huawei.com> <53D6FC38.8070801@hitachi.com> <53FDCBF1.2020606@huawei.com> In-Reply-To: <53FDCBF1.2020606@huawei.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ingo, Could you pull this for a bugfix of a memory leak? (2014/08/27 21:15), Wang Nan wrote: > On 2014/7/29 9:43, Masami Hiramatsu wrote: >> (2014/07/28 21:20), Wang Nan wrote: >>> This patch frees optinsn slot when range check error to prevent memory >>> leaks. Before this patch, cache entry in kprobe_insn_cache won't be >>> freed if kprobe optimizing fails due to range check failure. >>> >>> Signed-off-by: Wang Nan >> >> Oops, thank you for finding it! >> >> Acked-by: Masami Hiramatsu >> > > Hi Masami Hiramatsu, > > I don't find this patch in newest upstream. Is there any problem? > >> BTW, would you really have hit this error? >> I'd like to know the case if this really happens. >> >>> --- >>> arch/x86/kernel/kprobes/opt.c | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c >>> index f304773..f1314d0 100644 >>> --- a/arch/x86/kernel/kprobes/opt.c >>> +++ b/arch/x86/kernel/kprobes/opt.c >>> @@ -338,8 +338,10 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op) >>> * a relative jump. >>> */ >>> rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE; >>> - if (abs(rel) > 0x7fffffff) >>> + if (abs(rel) > 0x7fffffff) { >>> + __arch_remove_optimized_kprobe(op, 0); >>> return -ERANGE; >>> + } >>> >>> buf = (u8 *)op->optinsn.insn; >>> >>> >> >> > > > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com