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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 137DBC25B74 for ; Mon, 27 May 2024 07:56:57 +0000 (UTC) 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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=iEeWEIfAz9T7qigBz+AuTiE3u9J8DTwSTlTng4HZEDs=; b=0LXylNUGe1n2qY 8MTcqnmyua9utsTA2BEBdlp0wfmvjQK4d4Dbg1M2uuIJBtrkmCSBCuosO8HcXgUnZQ1JpfXWwB7UN BjRDXo7b7xR8tGzhZtrNCAsgJyaw57lq+QnW+cHh0448R3d8YTwYs/dW50/KDW9P+9UVS8l1wBNXZ 1tYjbdpxeE1FNcRaNPBawhEeV8/oFXwCSagueVioI1ck4dBIg5YihMH1VxvXThzFYXn4yFC0ybpnW vT7Ulja/4L5DczLuSOjpvMIManqb+eINUxTE4wE/WWFjp7zerOBMLk9FO4tQV2+2upAnP28z6NFXn i/pguXoOsRpKEvajqbzw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sBVDp-0000000E9Qg-1Dxo; Mon, 27 May 2024 07:56:45 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sBVDm-0000000E9Pp-0wag for linux-arm-kernel@lists.infradead.org; Mon, 27 May 2024 07:56:43 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=gQEnB7aSCTZt0xCRrWbJeMSZboIGsJ7UMY1FMJREj0w=; b=jWk8/YaPzWQY8UC5bsSk5mNIkJ sHoxOa9NlEBwijVL4kEi+bbpQBbyuPz4bZFID87qunDIk0wU1Co1e6nSM92FjeOU0P4+MjKbqPkP7 de5F8IRD8B04GlmJhWBbhU7bsSiYXKlUGxsoooXks9r25FUfC5F8rtjsZlqJPwnpvmXOR00pV2p0G SCrJBnzFAjoQdgJl+oMdWoeTxYfXlAagGrMgGeFWKk2A7RS+zzPNyIdurcOUA3gdkegUZ9yJ3pd35 ARBiWj8K7CmvtLoVzmbI531Xdqf7rIPvmREMDGZsZU6t6cQO0RQyRZQ5DQ9v9HA87kog50vXGqwZG BSwwEJgw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:32956) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sBVDS-0003Gg-1Y; Mon, 27 May 2024 08:56:22 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1sBVDM-0002AZ-HC; Mon, 27 May 2024 08:56:16 +0100 Date: Mon, 27 May 2024 08:56:16 +0100 From: "Russell King (Oracle)" To: Thorsten Scherer Cc: ardb@kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com, linux-trace-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Justin Chen , Florian Fainelli , Doug Berger , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , kernel@pengutronix.de Subject: Re: ARM Ftrace Function Graph Fails With UNWINDER_FRAME_POINTER Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240527_005642_291973_D8FFA75A X-CRM114-Status: GOOD ( 15.29 ) 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, May 27, 2024 at 09:43:41AM +0200, Thorsten Scherer wrote: > Hello, > > in the context of a panic on an i.MX25 based v6.9 kernel [1] Uwe pointed me to > this thread. With the proposed code change applied the procedure > > # set to some known good (randomly guessed) filter function and enable function_graph > echo mtdblock_open > set_ftrace_filter > echo function_graph > current_tracer > > # walk available filter funcs > cat available_filter_functions | while read f; do echo $f | tee -a set_ftrace_filter; sleep 1; done > > produces the following output > > [ 159.832173] Insufficient stack space to handle exception! > [ 159.832241] Task stack: [0xc8e44000..0xc8e46000] > [ 159.842701] IRQ stack: [0xc8800000..0xc8802000] > [ 159.847712] Overflow stack: [0xc1934000..0xc1935000] > [ 159.852726] Internal error: Oops - BUG: 0 [#1] PREEMPT ARM > [ 159.858273] Modules linked in: capture_events_imxgpt ti_ads7950 industrialio_triggered_buffer kfifo_buf capture_events_irq capture_events iio_trig_hrtimer industrialio_sw_trigger industrialio_configfs dm_mod > [ 159.876948] CPU: 0 PID: 199 Comm: sh Not tainted 6.9.0 #3 > [ 159.882412] Hardware name: Freescale i.MX25 (Device Tree Support) > [ 159.888547] PC is at prepare_ftrace_return+0x4/0x7c > [ 159.893520] LR is at ftrace_graph_caller+0x1c/0x28 > [ 159.898376] pc : [] lr : [] psr: 60000093 > [ 159.904690] sp : c8e44018 ip : c8e44018 fp : c8e4403c > [ 159.909959] r10: c0c09e78 r9 : c35e9bc0 r8 : c010d9bc > [ 159.915227] r7 : 00000001 r6 : 00000004 r5 : c8e44064 r4 : c8e440ac > [ 159.921800] r3 : c8e44030 r2 : c8e4403c r1 : c010eb9c r0 : c8e44038 > [ 159.928376] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none > [ 159.935652] Control: 0005317f Table: 83074000 DAC: 00000051 > [ 159.941436] Register r0 information: 2-page vmalloc region starting at 0xc8e44000 allocated at kernel_clone+0xa8/0x408 > [ 159.952253] Register r1 information: non-slab/vmalloc memory > [ 159.957988] Register r2 information: 2-page vmalloc region starting at 0xc8e44000 allocated at kernel_clone+0xa8/0x408 > [ 159.968791] Register r3 information: 2-page vmalloc region starting at 0xc8e44000 allocated at kernel_clone+0xa8/0x408 > [ 159.979592] Register r4 information: 2-page vmalloc region starting at 0xc8e44000 allocated at kernel_clone+0xa8/0x408 > [ 159.990391] Register r5 information: 2-page vmalloc region starting at 0xc8e44000 allocated at kernel_clone+0xa8/0x408 > [ 160.001187] Register r6 information: non-paged memory > [ 160.006303] Register r7 information: non-paged memory > [ 160.011415] Register r8 information: non-slab/vmalloc memory > [ 160.017139] Register r9 information: slab kmalloc-32 start c35e9bc0 pointer offset 0 size 32 > [ 160.025718] Register r10 information: non-slab/vmalloc memory > [ 160.031530] Register r11 information: 2-page vmalloc region starting at 0xc8e44000 allocated at kernel_clone+0xa8/0x408 > [ 160.042422] Register r12 information: 2-page vmalloc region starting at 0xc8e44000 allocated at kernel_clone+0xa8/0x408 > [ 160.053315] Process sh (pid: 199, stack limit = 0x68fc3abb) > [ 160.058955] Stack: (0xc8e44018 to 0xc8e46000) No backtrace? No Code: line? I'm guessing there was an attempt to ftrace a function involving the ftrace tracing infrastructure, which is why 8KB of stack has been gobbled up. It could be copy_from_kernel_nofault_allowed() but it would be useful to have at least some extract of the backtrace showing the recursive cycle to confirm, otherwise there is nothing in your report to confirm. As I'm not a ftrace user myself, this isn't something I'd test for, so having a full report would be useful. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel