From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A41CC47094 for ; Mon, 7 Jun 2021 18:26:31 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 412186100B for ; Mon, 7 Jun 2021 18:26:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 412186100B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=wWpstOIJ7fuV3pEPpeqzMmhTwLOOYGWg1gK6ip71q4s=; b=CbKQNMkYcXB7yP mYO9gDcnluuWtr7mEHhTwRYpQUQ1XjwysuJMlu888hnim3h+O5/TK1KWdqvvukV5uXUNCfBw/+QV9 vgUea2fnOGiybRumXaoZW9XPueQUKQTOf3TvbEEav6tq9QpAhDX+iqTu/uMokHfYQQSQr59IOE2o2 wEz9I1Exj2LArsP47j/gt6E243Xwz68YUMQIXCYciVz4xo0A8OivR4uqiLU5l8QR+XhXdbMkqDYsM 8Vfau8DcU2aKMvG5N0NO0dLvqwSr4YN6PMdg59Z3XCeCaWqg1LZlvlSnNLdSjHdUPRSZMKqP1B4Ar YMvKYwFgCh3jvu4CC4MA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqJv6-0050ob-GL; Mon, 07 Jun 2021 18:24:16 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqJv2-0050nI-B7; Mon, 07 Jun 2021 18:24:13 +0000 X-UUID: 27f64fbeeb2b42eaad8e33083d83a47e-20210607 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=PN7JBWtgxmf7/uIMG1dcP+OTj65LMSIEioGytzk3zGo=; b=tlC/AxD0yliqE5j7XfLUERVz6CIlAW5dDtitXHNzdfFnF0R/Fui7kDAmyxAqNJOCVTdWrwuACPKdKGKnrra5Ygo3nuMYy3rxqw9akTwgysHEyI3/qIOsTmEd3lMC6eNzghibkTQhQgBWocFikeDM6KvhRFC/iYbcKmLMmXbav2c=; X-UUID: 27f64fbeeb2b42eaad8e33083d83a47e-20210607 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1252575933; Mon, 07 Jun 2021 11:24:07 -0700 Received: from mtkmbs05n1.mediatek.inc (172.21.101.15) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 7 Jun 2021 11:14:05 -0700 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs05n1.mediatek.inc (172.21.101.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 8 Jun 2021 02:14:03 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 8 Jun 2021 02:14:03 +0800 From: Mark-PK Tsai To: CC: , , , , , , , , Subject: Re: [PATCH] arm64: ftrace: don't dereference a probably invalid address Date: Tue, 8 Jun 2021 02:14:03 +0800 Message-ID: <20210607181403.4017-1-mark-pk.tsai@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20210607105217.772214e5@oasis.local.home> References: <20210607105217.772214e5@oasis.local.home> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210607_112412_411108_81E14DCA X-CRM114-Status: GOOD ( 18.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org > On Mon, 7 Jun 2021 22:15:22 +0800 > Mark-PK Tsai wrote: > > > And the crash is becuase kernel trying to read *rec->ip in print_ip_ins() if > > ftrace_bug() get error code -EINVAL. > > Right, so the actual fix should be something like this: > > [ not tested, nor even compiled ] > > -- Steve > I just test this patch, and turns out it work well. All my modification is only rename copy_from_kernel_nofault into probe_kernel_read because the older kernel version I use. Then the kernel will show the error mesage instead of panic as following. [ 0.000000] ftrace failed to modify [ 0.000000] [<0000000000000020>] 0x20 [ 0.000000] actual: [FAULT](0000000000000020) Should I resend this patch as v2? Or you will upstream this fix? > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index 2e8a3fde7104..72ef4dccbcc4 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -1967,12 +1967,18 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, > > static void print_ip_ins(const char *fmt, const unsigned char *p) > { > + char ins[MCOUNT_INSN_SIZE]; > int i; > > + if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { > + printk(KERN_CONT "%s[FAULT](%px)", fmt, p); > + return; > + } > + > printk(KERN_CONT "%s", fmt); > > for (i = 0; i < MCOUNT_INSN_SIZE; i++) > - printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); > + printk(KERN_CONT "%s%02x", i ? ":" : "", ins[i]); > } > > enum ftrace_bug_type ftrace_bug_type; _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel