From patchwork Fri Feb 13 05:41:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 5823451 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 F22C2BF440 for ; Fri, 13 Feb 2015 05:56:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 59338202FE for ; Fri, 13 Feb 2015 05:56:45 +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 B18C12037F for ; Fri, 13 Feb 2015 05:56:40 +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 1YM9C7-0001qF-Gb; Fri, 13 Feb 2015 05:53:39 +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 1YM989-00068x-2K; Fri, 13 Feb 2015 05:49:34 +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 BBW73170; Fri, 13 Feb 2015 13:48:02 +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; Fri, 13 Feb 2015 13:47:52 +0800 From: Wang Nan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 23/26] early kprobes: x86: arch_restore_optimized_kprobe(). 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X-Spam-Score: -2.3 (--) Cc: lizefan@huawei.com, x86@kernel.org, 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 arch_restore_optimized_kprobe() can be used to temporarily restore probed instruction. It will actually disable optimized kprobe, but keep the relatived data structure. It uses stop_machine() to enforce atimicity. Signed-off-by: Wang Nan --- arch/x86/kernel/kprobes/opt.c | 26 ++++++++++++++++++++++++++ include/linux/kprobes.h | 1 + 2 files changed, 27 insertions(+) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index f3ea954..12332c2 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -486,4 +487,29 @@ void arch_fix_ftrace_early_kprobe(struct optimized_kprobe *op) memcpy(&list_p->opcode, correct_nop5, sizeof(kprobe_opcode_t)); } + +static int do_restore_kprobe(void *p) +{ + struct optimized_kprobe *op = p; + u8 insn_buf[RELATIVEJUMP_SIZE]; + + memcpy(insn_buf, &op->kp.opcode, sizeof(kprobe_opcode_t)); + memcpy(insn_buf + INT3_SIZE, + op->optinsn.copied_insn, + RELATIVE_ADDR_SIZE); + text_poke(op->kp.addr, insn_buf, RELATIVEJUMP_SIZE); + return 0; +} + +void arch_restore_optimized_kprobe(struct optimized_kprobe *op) +{ + u32 mask = KPROBE_FLAG_EARLY | + KPROBE_FLAG_OPTIMIZED | + KPROBE_FLAG_FTRACE; + + if ((op->kp.flags & mask) != mask) + return; + + stop_machine(do_restore_kprobe, op, NULL); +} #endif diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index e483f1b..e615402 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -462,6 +462,7 @@ extern int arch_prepare_kprobe_ftrace(struct kprobe *p); #ifdef CONFIG_EARLY_KPROBES extern void arch_fix_ftrace_early_kprobe(struct optimized_kprobe *p); +extern void arch_restore_optimized_kprobe(struct optimized_kprobe *p); #endif #endif