From patchwork Mon Mar 2 14:24:57 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 5914261 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 393C99F380 for ; Mon, 2 Mar 2015 14:58:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6FCD6201DD for ; Mon, 2 Mar 2015 14:58:29 +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 9E3FE201CD for ; Mon, 2 Mar 2015 14:58:28 +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 1YSRkf-0005pJ-E4; Mon, 02 Mar 2015 14:55:21 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YSRc0-0005rj-8f for linux-arm-kernel@bombadil.infradead.org; Mon, 02 Mar 2015 14:46:24 +0000 Received: from szxga01-in.huawei.com ([119.145.14.64]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YSRJE-0008Aj-Nx for linux-arm-kernel@lists.infradead.org; Mon, 02 Mar 2015 14:27:03 +0000 Received: from 172.24.2.119 (EHLO lggeml422-hub.china.huawei.com) ([172.24.2.119]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id CKE50599; Mon, 02 Mar 2015 22:25:54 +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 22:25:46 +0800 From: Wang Nan To: , , , , Subject: [RFC PATCH v4 19/34] ftrace: don't update record flags if code modification fail. Date: Mon, 2 Mar 2015 22:24:57 +0800 Message-ID: <1425306312-3437-20-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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150302_142702_458680_C5B6D28F X-CRM114-Status: UNSURE ( 9.92 ) 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 X86 and common ftrace_replace_code() behave differently. In x86, rec->flags get updated only when (almost) all works are done. In common code, rec->flags is updated before code modification, and never get restored when code modification fails. This patch ensures rec->flags kept its original value if ftrace_replace_code() fail. A later patch will correct that function for x86. Signed-off-by: Wang Nan --- kernel/trace/ftrace.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 45e5cb1..6c6cbb1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2254,23 +2254,30 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable) /* This needs to be done before we call ftrace_update_record */ ftrace_old_addr = ftrace_get_addr_curr(rec); - ret = ftrace_update_record(rec, enable); + ret = ftrace_test_record(rec, enable); switch (ret) { case FTRACE_UPDATE_IGNORE: return 0; case FTRACE_UPDATE_MAKE_CALL: - return ftrace_make_call(rec, ftrace_addr); + ret = ftrace_make_call(rec, ftrace_addr); + break; case FTRACE_UPDATE_MAKE_NOP: - return ftrace_make_nop(NULL, rec, ftrace_old_addr); + ret = ftrace_make_nop(NULL, rec, ftrace_old_addr); + break; case FTRACE_UPDATE_MODIFY_CALL: - return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); + ret = ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); + break; } - return -1; /* unknow ftrace bug */ + if (ret) + return -1; /* unknow ftrace bug */ + + ftrace_update_record(rec, enable); + return 0; } void __weak ftrace_replace_code(int enable)