From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3znCYW4VdzzF1QR for ; Thu, 22 Feb 2018 22:58:39 +1100 (AEDT) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1MBwX1j100730 for ; Thu, 22 Feb 2018 06:58:36 -0500 Received: from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com [195.75.94.109]) by mx0a-001b2d01.pphosted.com with ESMTP id 2g9rcv3p4t-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 22 Feb 2018 06:58:36 -0500 Received: from localhost by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 22 Feb 2018 11:58:33 -0000 From: Vaibhav Jain To: Russell Currey , Michael Ellerman Cc: Vaibhav Jain , Frederic Barrat , linuxppc-dev@lists.ozlabs.org, Benjamin Herrenschmidt , "Bryant G . Ly" Subject: [PATCH] PCI/AER: Add a null check before eeh_ops->notify_resume callback. Date: Thu, 22 Feb 2018 17:28:03 +0530 Message-Id: <20180222115803.21738-1-vaibhav@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This patch puts a NULL check before branching to the address pointed to by eeh_ops->notify_resume in eeh_report_resume(). The callback is used to notify the arch EEH code that a pci device is back online. For PPC64 presently, only an implementation for pseries platform is available and not for powernv. Hence without this patch EEH recovery on all non-virtualized hosts is causing a kernel panic when CONFIG_PCI_IOV is set. The panic is usually is of the form: EEH: Notify device driver to resume Unable to handle kernel paging request for instruction fetch Faulting instruction address: 0x00000000 Oops: Kernel access of bad area, sig: 11 [#1] LR eeh_report_resume+0x218/0x220 Call Trace: eeh_report_resume+0x1f0/0x220 (unreliable) eeh_pe_dev_traverse+0x98/0x170 eeh_handle_normal_event+0x3f4/0x650 eeh_handle_event+0x188/0x380 eeh_event_handler+0x208/0x210 kthread+0x168/0x1b0 ret_from_kernel_thread+0x5c/0xb4 Cc: Bryant G. Ly Fixes: 856e1eb9bdd4("PCI/AER: Add uevents in AER and EEH error/resume") Signed-off-by: Vaibhav Jain --- arch/powerpc/kernel/eeh_driver.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index beea2182d754..932858a293ea 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -384,7 +384,8 @@ static void *eeh_report_resume(void *data, void *userdata) eeh_pcid_put(dev); pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED); #ifdef CONFIG_PCI_IOV - eeh_ops->notify_resume(eeh_dev_to_pdn(edev)); + if (eeh_ops->notify_resume) + eeh_ops->notify_resume(eeh_dev_to_pdn(edev)); #endif return NULL; } -- 2.14.3