From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 3sFHvq6CkQzDr5M for ; Thu, 18 Aug 2016 17:36:06 +1000 (AEST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u7I7Ybr2007872 for ; Thu, 18 Aug 2016 03:36:02 -0400 Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) by mx0b-001b2d01.pphosted.com with ESMTP id 24vky4bsnk-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 18 Aug 2016 03:36:02 -0400 Received: from localhost by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 18 Aug 2016 17:35:59 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id DDFC02CE8057 for ; Thu, 18 Aug 2016 17:35:56 +1000 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u7I7ZuEp30474284 for ; Thu, 18 Aug 2016 17:35:56 +1000 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u7I7Ztqd029337 for ; Thu, 18 Aug 2016 17:35:56 +1000 From: Andrew Donnellan To: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org, helgaas@kernel.org, mauricfo@linux.vnet.ibm.com, gwshan@linux.vnet.ibm.com, ruscur@russell.cc, mrochs@linux.vnet.ibm.com, ukrishn@linux.vnet.ibm.com, imunsie@au1.ibm.com, fbarrat@linux.vnet.ibm.com, clombard@linux.vnet.ibm.com, felix@linux.vnet.ibm.com Subject: [PATCH] cxl: use pcibios_free_controller_deferred() when removing vPHBs Date: Thu, 18 Aug 2016 17:35:14 +1000 Message-Id: <1471505714-30049-1-git-send-email-andrew.donnellan@au1.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , When cxl removes a vPHB, it's possible that the pci_controller may be freed before all references to the devices on the vPHB have been released. This in turn causes an invalid memory access when the devices are eventually released, as pcibios_release_device() attempts to call the phb's release_device hook. In cxl_pci_vphb_remove(), remove the existing call to pcibios_free_controller(). Instead, use pcibios_free_controller_deferred() to free the pci_controller after all devices have been released. Export pci_set_host_bridge_release() so we can do this. Cc: stable@vger.kernel.org Signed-off-by: Andrew Donnellan --- This patch requires http://patchwork.ozlabs.org/patch/658324/. It should go through the powerpc tree. --- drivers/misc/cxl/vphb.c | 10 +++++++++- drivers/pci/host-bridge.c | 1 + 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c index 7ada5f1..3519ace 100644 --- a/drivers/misc/cxl/vphb.c +++ b/drivers/misc/cxl/vphb.c @@ -230,6 +230,11 @@ int cxl_pci_vphb_add(struct cxl_afu *afu) if (phb->bus == NULL) return -ENXIO; + /* Set release hook on root bus */ + pci_set_host_bridge_release(to_pci_host_bridge(phb->bus->bridge), + pcibios_free_controller_deferred, + (void *) phb); + /* Claim resources. This might need some rework as well depending * whether we are doing probe-only or not, like assigning unassigned * resources etc... @@ -256,7 +261,10 @@ void cxl_pci_vphb_remove(struct cxl_afu *afu) afu->phb = NULL; pci_remove_root_bus(phb->bus); - pcibios_free_controller(phb); + /* + * We don't free phb here - that's handled by + * pcibios_free_controller_deferred() + */ } static bool _cxl_pci_is_vphb_device(struct pci_controller *phb) diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c index 5f4a2e0..add6623 100644 --- a/drivers/pci/host-bridge.c +++ b/drivers/pci/host-bridge.c @@ -44,6 +44,7 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge, bridge->release_fn = release_fn; bridge->release_data = release_data; } +EXPORT_SYMBOL_GPL(pci_set_host_bridge_release); void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region, struct resource *res) -- Andrew Donnellan OzLabs, ADL Canberra andrew.donnellan@au1.ibm.com IBM Australia Limited