From patchwork Mon Mar 2 14:25:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 5914051 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E8EA1BF440 for ; Mon, 2 Mar 2015 14:46:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2381F201FB for ; Mon, 2 Mar 2015 14:46:55 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4E689201FA for ; Mon, 2 Mar 2015 14:46:54 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YSRYy-0002d9-EF; Mon, 02 Mar 2015 14:43:16 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YSRJL-00047B-6l for linux-arm-kernel@bombadil.infradead.org; Mon, 02 Mar 2015 14:27:07 +0000 Received: from szxga03-in.huawei.com ([119.145.14.66]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YSRJI-0003SR-65 for linux-arm-kernel@lists.infradead.org; Mon, 02 Mar 2015 14:27:06 +0000 Received: from 172.24.2.119 (EHLO lggeml422-hub.china.huawei.com) ([172.24.2.119]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id BCM87894; Mon, 02 Mar 2015 22:26:05 +0800 (CST) Received: from kernel-host.huawei (10.107.197.247) by lggeml422-hub.china.huawei.com (10.72.61.32) with Microsoft SMTP Server id 14.3.158.1; Mon, 2 Mar 2015 22:25:53 +0800 From: Wang Nan To: , , , , Subject: [RFC PATCH v4 28/34] ftrace: x86: get old instruction from early kprobes when make call. Date: Mon, 2 Mar 2015 22:25:06 +0800 Message-ID: <1425306312-3437-29-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1425306312-3437-1-git-send-email-wangnan0@huawei.com> References: <1425306312-3437-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.107.197.247] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020205.54F472FD.01E3, ss=1, re=0.001, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 13fcfe0061f671c756a5d9fa66ae4491 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150302_092705_011854_7BE93C44 X-CRM114-Status: UNSURE ( 9.55 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -4.2 (----) Cc: x86@kernel.org, lizefan@huawei.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP For previously detected early kprobes on ftrace, retrieve old instruction using kprobe_on_ftrace_get_old_insn() instead of ftrace_nop_replace(). Which will enable convertion an early kprobed ftrace entry directly to 'call' instrustion without turnning off kprobe. Signed-off-by: Wang Nan --- arch/x86/kernel/ftrace.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 7bdba65..f200cd4 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -21,6 +21,7 @@ #include #include #include +#include #include @@ -164,7 +165,17 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) unsigned const char *new, *old; unsigned long ip = rec->ip; - old = ftrace_nop_replace(); +#if defined(CONFIG_KPROBES_ON_FTRACE) && defined(CONFIG_EARLY_KPROBES) + unsigned char kprobes_old_insn[MCOUNT_INSN_SIZE]; + + if (unlikely(rec->flags & FTRACE_FL_EARLY_KPROBES)) + old = kprobe_on_ftrace_get_old_insn(rec, + ftrace_nop_replace(), + kprobes_old_insn, + MCOUNT_INSN_SIZE); + else +#endif + old = ftrace_nop_replace(); new = ftrace_call_replace(ip, addr); /* Should only be called when module is loaded */ @@ -335,8 +346,16 @@ static int add_brk_on_call(struct dyn_ftrace *rec, unsigned long addr) static int add_brk_on_nop(struct dyn_ftrace *rec) { unsigned const char *old; +#if defined(CONFIG_KPROBES_ON_FTRACE) && defined(CONFIG_EARLY_KPROBES) + unsigned char kprobes_old_insn[MCOUNT_INSN_SIZE]; - old = ftrace_nop_replace(); + if (unlikely(rec->flags & FTRACE_FL_EARLY_KPROBES)) + old = kprobe_on_ftrace_get_old_insn(rec, ftrace_nop_replace(), + kprobes_old_insn, + MCOUNT_INSN_SIZE); + else +#endif + old = ftrace_nop_replace(); return add_break(rec->ip, old); }