From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.socionext.com (mx.socionext.com [202.248.49.38]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 20E572F30; Wed, 29 Jan 2025 07:54:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.248.49.38 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738137297; cv=none; b=lfIohIJIOMX/2eXnPOOpv05fshu6fLiZIaflub4kp0c06SKsnxUad1EU6xfVNJm4qIBZeYDC6dio5MCtBNdd/TrhgdqwwdtcLjFKB5wnWFjdmeijzjWsADuazdnxQFrZc27WuJcomqoIqMqBsXZ9Z7u17A3Lmp4gyAS6R3lkUiQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738137297; c=relaxed/simple; bh=3z7U0+GxeSanoE7V2Ah7ljJeeessQQSQKUHKd62z0Vw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XyD3yYYzT7GoauJLuF29qyepzvj1JB8kg4aaYNwHOdSrP+IoJp2TJzanW15vn+f8LofQi0zX+Hn+TQZGqm2Gf1HWgOY1+KLXj22mlja5HnbgmbnXjH7vD8+W2i9R2JXeiQR7dPBSS13pvtRmpE76AaGIgIglrpPwFxGJpMh+2ZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=socionext.com; spf=pass smtp.mailfrom=socionext.com; arc=none smtp.client-ip=202.248.49.38 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=socionext.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=socionext.com Received: from unknown (HELO kinkan2-ex.css.socionext.com) ([172.31.9.52]) by mx.socionext.com with ESMTP; 29 Jan 2025 16:54:47 +0900 Received: from mail.mfilter.local (mail-arc02.css.socionext.com [10.213.46.40]) by kinkan2-ex.css.socionext.com (Postfix) with ESMTP id 8639B2019755; Wed, 29 Jan 2025 16:54:47 +0900 (JST) Received: from iyokan2.css.socionext.com ([172.31.9.53]) by m-FILTER with ESMTP; Wed, 29 Jan 2025 16:54:47 +0900 Received: from [10.212.246.222] (unknown [10.212.246.222]) by iyokan2.css.socionext.com (Postfix) with ESMTP id BBB64AB186; Wed, 29 Jan 2025 16:54:46 +0900 (JST) Message-ID: <2cdb5e43-47e0-43ba-ba17-87e8d5dc602d@socionext.com> Date: Wed, 29 Jan 2025 16:54:46 +0900 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 v2 1/3] misc: pci_endpoint_test: Avoid issue of interrupts remaining after request_irq error To: Manivannan Sadhasivam Cc: =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , Kishon Vijay Abraham I , Arnd Bergmann , Greg Kroah-Hartman , Lorenzo Pieralisi , Gustavo Pimentel , Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20250122022446.2898248-1-hayashi.kunihiko@socionext.com> <20250122022446.2898248-2-hayashi.kunihiko@socionext.com> <20250128141242.pog2tuorvqmobain@thinkpad> Content-Language: en-US From: Kunihiko Hayashi In-Reply-To: <20250128141242.pog2tuorvqmobain@thinkpad> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Manivannan, On 2025/01/28 23:12, Manivannan Sadhasivam wrote: > On Wed, Jan 22, 2025 at 11:24:44AM +0900, Kunihiko Hayashi wrote: >> After devm_request_irq() fails with error, >> pci_endpoint_test_free_irq_vectors() is called to free allocated vectors >> with pci_free_irq_vectors(). >> > > You should mention the function name which you are referring to. Here it is, > pci_endpoint_test_request_irq(). I see. I'll make the commit message more clear. >> However some requested IRQs are still allocated, so there are still > > This is confusing. Are you saying that the previously requested IRQs are not > freed when an error happens during the for loop in > pci_endpoint_test_request_irq()? Yes, after jumping to "fail:" label, it just prints an error message and returns the function. The pci_endpoint_test_request_irq() is called from the following functions: - pci_endpoint_test_probe() - pci_endpoint_test_set_irq() Both call pci_endpoint_test_free_irq_vectors() after the error, though, requested IRQs are not freed anywhere. >> /proc/irq/* entries remaining and we encounters WARN() with the following >> message: >> >> remove_proc_entry: removing non-empty directory 'irq/30', leaking at >> least 'pci-endpoint-test.0' >> WARNING: CPU: 0 PID: 80 at fs/proc/generic.c:717 remove_proc_entry >> +0x190/0x19c > > When did you encounter this WARN? Usually request_irq() can successfully get an interrupt. If request_irq() returned an error, pci_endpoint_test_free_irq_vectors() was called and the following call-trace was obtained: [ 18.772522] Call trace: [ 18.773743] remove_proc_entry+0x190/0x19c [ 18.775789] unregister_irq_proc+0xd0/0x104 [ 18.777881] free_desc+0x4c/0xcc [ 18.779495] irq_free_descs+0x68/0x8c [ 18.781325] irq_domain_free_irqs+0x15c/0x1bc [ 18.783502] msi_domain_free_locked.part.0+0x184/0x1d4 [ 18.786069] msi_domain_free_irqs_all_locked+0x64/0x8c [ 18.788637] pci_msi_teardown_msi_irqs+0x48/0x54 [ 18.790947] pci_free_msi_irqs+0x18/0x38 [ 18.792907] pci_free_irq_vectors+0x64/0x8c [ 18.794997] pci_endpoint_test_ioctl+0x7e8/0xf40 [ 18.797304] __arm64_sys_ioctl+0xa4/0xe8 [ 18.799265] invoke_syscall+0x48/0x110 [ 18.801139] el0_svc_common.constprop.0+0x40/0xe8 [ 18.803489] do_el0_svc+0x20/0x2c [ 18.805145] el0_svc+0x30/0xd0 [ 18.806673] el0t_64_sync_handler+0x13c/0x158 [ 18.808850] el0t_64_sync+0x190/0x194 [ 18.810680] ---[ end trace 0000000000000000 ]--- >> To solve this issue, set the number of remaining IRQs and release the IRQs >> in advance by calling pci_endpoint_test_release_irq(). >> > > First of all, using devm_request_irq() is wrong here as > pci_endpoint_test_request_irq() might be called multiple times by the userspace. > So we cannot use managed version of request_irq(). It is infact pointless since > pci_endpoint_test_clear_irq() would free them anyway. Instead we should just use > request_irq() and call pci_endpoint_test_clear_irq() in the error path as like > this patch does. The pci_endpoint_test_clear_irq() will free all the number of IRQs. However, in this error case, since only some IRQs are allocated, need to change the number of IRQs that need to be freed. And pci_endpoint_test_free_irq_vectors() is called just before return from the function, call only pci_endpoint_test_release_irq() in the error case of pci_endpoint_test_request_irq(). For example: pci_endpoint_test_set_irq() pci_endpoint_test_request_irq() request_irq() fail: >> test->num_irqs = i // add in this patch >> pci_endpoint_test_release_irq() // add in this patch err: pci_endpoint_test_free_irq_vectors() > But this should be a separate patch. Agreed. I'll add another patch to use non-managed version. Thank you, --- Best Regards Kunihiko Hayashi