From patchwork Wed Jan 7 07:35:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 5582921 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1BB0C9F2ED for ; Wed, 7 Jan 2015 07:42:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 442882027D for ; Wed, 7 Jan 2015 07:42:58 +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 687EE2026D for ; Wed, 7 Jan 2015 07:42:57 +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 1Y8lFA-0004PJ-OQ; Wed, 07 Jan 2015 07:41:28 +0000 Received: from szxga03-in.huawei.com ([119.145.14.66]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Y8lF3-000433-0D for linux-arm-kernel@lists.infradead.org; Wed, 07 Jan 2015 07:41:22 +0000 Received: from 172.24.2.119 (EHLO lggeml426-hub.china.huawei.com) ([172.24.2.119]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id AZS02703; Wed, 07 Jan 2015 15:40:34 +0800 (CST) Received: from kernel-host.huawei (10.107.197.247) by lggeml426-hub.china.huawei.com (10.72.61.36) with Microsoft SMTP Server id 14.3.158.1; Wed, 7 Jan 2015 15:40:26 +0800 From: Wang Nan To: , , , , , , , , Subject: [RFC PATCH 01/11] ARM: kprobes: directly modify code if kprobe is not initialized. Date: Wed, 7 Jan 2015 15:35:24 +0800 Message-ID: <1420616124-42765-1-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1420616086-42692-1-git-send-email-wangnan0@huawei.com> References: <1420616086-42692-1-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=0001.0A020205.54ACE2FB.007C, 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: 12074d3bc4a8d788e5193a746129849d X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150106_234121_271721_69BA3867 X-CRM114-Status: UNSURE ( 8.63 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.3 (--) Cc: 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 If kprobe is optimized before kprobe is initialized, there should be only one core, the probed instruction is not armed with breakpoint, so simply patch text is okay. Signed-off-by: Wang Nan --- arch/arm/probes/kprobes/opt-arm.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/arm/probes/kprobes/opt-arm.c b/arch/arm/probes/kprobes/opt-arm.c index 15b37c0..a021474 100644 --- a/arch/arm/probes/kprobes/opt-arm.c +++ b/arch/arm/probes/kprobes/opt-arm.c @@ -325,8 +325,17 @@ void __kprobes arch_optimize_kprobes(struct list_head *oplist) * Similar to __arch_disarm_kprobe, operations which * removing breakpoints must be wrapped by stop_machine * to avoid racing. + * + * If this function is called before kprobes initialized, + * the kprobe should be an early kprobe, the instruction + * is not armed with breakpoint. There should be only + * one core now, so directly __patch_text is enough. */ - kprobes_remove_breakpoint(op->kp.addr, insn); + if (unlikely(!kprobes_initialized)) { + BUG_ON(!(op->kp.flags & KPROBE_FLAG_EARLY)); + __patch_text(op->kp.addr, insn); + } else + kprobes_remove_breakpoint(op->kp.addr, insn); list_del_init(&op->list); }