From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2BBEB372; Wed, 5 Jun 2024 10:30:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717583445; cv=none; b=iFcDdK0KsEYOIFGvGo8sPZodRCNouSeKXhc+0lwPlHTSAUYdtbJKNQKgiTnwzs7A7B6yGJ0LAgbP8U3ecfQZxuMQCsLStedi3KhFJEoTaT6AIuF09bkKR8C3i0OLQ8ueF/bw65Cd1xgiGARYSsV8MtX2Nf72MALNkmr9ok6ktyA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717583445; c=relaxed/simple; bh=u/HyFOjYb6/88R7uBNi+KKM05Pxe2XJ8tNcf8CYRkDk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fATIQWWm6awNu5TiGf/R1MLrZPQQ3pcPVipfnOFP8sWCHnQJOya8XjP/D3b0KxTvkULZou5zDzS8BrGB56EztEjglyvqJ+GOfzjVvz0VIWgN2eRo5ImeZGBHTN5rvmfQo92p8i2jLH8WNNJfIlNxmBpPks8W4G9HObAdtTPE6xo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 60985339; Wed, 5 Jun 2024 03:31:07 -0700 (PDT) Received: from [192.168.1.100] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 50EBA3F792; Wed, 5 Jun 2024 03:30:41 -0700 (PDT) Message-ID: <1b0c8c7e-2cf2-49a9-9120-3ced46f2df08@arm.com> Date: Wed, 5 Jun 2024 11:30:39 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 5/7] coresight: tmc: Add support for reading crash data To: Linu Cherian Cc: linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, devicetree@vger.kernel.org, sgoutham@marvell.com, gcherian@marvell.com, Anil Kumar Reddy , Tanmay Jagdale , suzuki.poulose@arm.com, mike.leach@linaro.org References: <20240605081725.622953-1-lcherian@marvell.com> <20240605081725.622953-6-lcherian@marvell.com> Content-Language: en-US From: James Clark In-Reply-To: <20240605081725.622953-6-lcherian@marvell.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 05/06/2024 09:17, Linu Cherian wrote: > * Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace > captured in previous crash/watchdog reset. > > * Add special device files for reading ETR/ETF crash data. > > * User can read the crash data as below > > For example, for reading crash data from tmc_etf sink > > #dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin > Hi Linu, I think you are missing the removal of the new crash file when the device is unloaded. If you reload the module you get some errors: # rmmod coresight_tmc # modprobe coresight_tmc dyndbg=+p kobject: kobject_add_internal failed for crash_tmc_etf0 with -EEXIST, don't try to register things with the same name in the same directory. coresight tmc_etf0: Failed to setup user interface for crashdata sysfs: cannot create duplicate filename '/devices/virtual /misc/crash_tmc_etr0' I'm not sure if it's related, but there are also some kasan errors at the same time which I haven't seen before: BUG: KASAN: slab-use-after-free in strcmp+0x94/0xd0 Read of size 1 at addr ffff00080b271be0 by task modprobe/570 CPU: 2 PID: 570 Comm: modprobe Not tainted 6.9.0-rc4+ #71 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Oct 19 2019 Call trace: dump_backtrace+0x100/0x158 show_stack+0x24/0x38 dump_stack_lvl+0x3c/0x98 print_report+0x178/0x508 kasan_report+0xc0/0x120 __asan_report_load1_noabort+0x20/0x30 strcmp+0x94/0xd0 cti_add_assoc_to_csdev+0x174/0x430 [coresight_cti] coresight_register+0x414/0x500 [coresight] __tmc_probe+0xd40/0x1340 [coresight_tmc] tmc_probe+0x60/0x98 [coresight_tmc] amba_probe+0x604/0x838 really_probe+0x318/0x780 __driver_probe_device+0x168/0x318 driver_probe_device+0x78/0x2a0 __driver_attach+0x22c/0x538 bus_for_each_dev+0x1bc/0x1f0 driver_attach+0x54/0x70 bus_add_driver+0x2a8/0x4c0 driver_register+0x168/0x2b8 amba_driver_register+0x74/0x98 coresight_init_driver+0x34/0xa8 [coresight] init_module+0x34/0xfb8 [coresight_tmc] do_one_initcall+0x1a0/0x8d0 do_init_module+0x1f8/0x588 load_module+0x3c20/0x44c0 __arm64_sys_finit_module+0x3c8/0x638 invoke_syscall+0x78/0x218 el0_svc_common+0x160/0x1d8 do_el0_svc+0x50/0x68 el0_svc+0x4c/0xc0 el0t_64_sync_handler+0x84/0x100 el0t_64_sync+0x190/0x198