From 4ae2182b1e3407de369f8c5d799543b7db74221b Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 25 Jan 2016 10:08:00 -0600 Subject: PCI/AER: Flush workqueue on device remove to avoid use-after-free A Root Port's AER structure (rpc) contains a queue of events. aer_irq() enqueues AER status information and schedules aer_isr() to dequeue and process it. When we remove a device, aer_remove() waits for the queue to be empty, then frees the rpc struct. But aer_isr() references the rpc struct after dequeueing and possibly emptying the queue, which can cause a use-after-free error as in the following scenario with two threads, aer_isr() on the left and a concurrent aer_remove() on the right: Thread A Thread B -------- -------- aer_irq(): rpc->prod_idx++ aer_remove(): wait_event(rpc->prod_idx == rpc->cons_idx) # now blocked until queue becomes empty aer_isr(): # ... rpc->cons_idx++ # unblocked because queue is now empty ... kfree(rpc) mutex_unlock(&rpc->rpc_mutex) To prevent this problem, use flush_work() to wait until the last scheduled instance of aer_isr() has completed before freeing the rpc struct in aer_remove(). I reproduced this use-after-free by flashing a device FPGA and re-enumerating the bus to find the new device. With SLUB debug, this crashes with 0x6b bytes (POISON_FREE, the use-after-free magic number) in GPR25: pcieport 0000:00:00.0: AER: Multiple Corrected error received: id=0000 Unable to handle kernel paging request for data at address 0x27ef9e3e Workqueue: events aer_isr GPR24: dd6aa000 6b6b6b6b 605f8378 605f8360 d99b12c0 604fc674 606b1704 d99b12c0 NIP [602f5328] pci_walk_bus+0xd4/0x104 [bhelgaas: changelog, stable tag] Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org --- drivers/pci/pcie/aer/aerdrv.c | 4 +--- drivers/pci/pcie/aer/aerdrv.h | 1 - drivers/pci/pcie/aer/aerdrv_core.c | 2 -- 3 files changed, 1 insertion(+), 6 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c index 0bf82a20a0fb..48d21e0edd56 100644 --- a/drivers/pci/pcie/aer/aerdrv.c +++ b/drivers/pci/pcie/aer/aerdrv.c @@ -262,7 +262,6 @@ static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev) rpc->rpd = dev; INIT_WORK(&rpc->dpc_handler, aer_isr); mutex_init(&rpc->rpc_mutex); - init_waitqueue_head(&rpc->wait_release); /* Use PCIe bus function to store rpc into PCIe device */ set_service_data(dev, rpc); @@ -285,8 +284,7 @@ static void aer_remove(struct pcie_device *dev) if (rpc->isr) free_irq(dev->irq, dev); - wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx); - + flush_work(&rpc->dpc_handler); aer_disable_rootport(rpc); kfree(rpc); set_service_data(dev, NULL); diff --git a/drivers/pci/pcie/aer/aerdrv.h b/drivers/pci/pcie/aer/aerdrv.h index 84420b7c9456..945c939a86c5 100644 --- a/drivers/pci/pcie/aer/aerdrv.h +++ b/drivers/pci/pcie/aer/aerdrv.h @@ -72,7 +72,6 @@ struct aer_rpc { * recovery on the same * root port hierarchy */ - wait_queue_head_t wait_release; }; struct aer_broadcast_data { diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c index 712392504ed9..521e39c1b66d 100644 --- a/drivers/pci/pcie/aer/aerdrv_core.c +++ b/drivers/pci/pcie/aer/aerdrv_core.c @@ -811,8 +811,6 @@ void aer_isr(struct work_struct *work) while (get_e_source(rpc, &e_src)) aer_isr_one_error(p_device, &e_src); mutex_unlock(&rpc->rpc_mutex); - - wake_up(&rpc->wait_release); } /** -- cgit v1.2.3 From 46560388c476c8471fde7712c10f9fad8d0d1875 Mon Sep 17 00:00:00 2001 From: Ray Jui Date: Wed, 27 Jan 2016 16:52:24 -0600 Subject: PCI: iproc: Allow multiple devices except on PAXC Commit 943ebae781f5 ("PCI: iproc: Add PAXC interface support") only allowed device 0, which is a regression on BCMA-based platforms. All systems support only one device, a Root Port at 00:00.0, on the root bus. PAXC-based systems support only the Root Port (00:00.0) and a single device (with multiple functions) below it, e.g., 01:00.0, 01:00.1, etc. Non-PAXC systems support arbitrary devices below the Root Port. [bhelgaas: changelog, fold in removal of MAX_NUM_PAXC_PF check] Fixes: 943ebae781f5 ("PCI: iproc: Add PAXC interface support") Reported-by: Rafal Milecki Signed-off-by: Ray Jui Signed-off-by: Bjorn Helgaas --- drivers/pci/host/pcie-iproc.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c index 5816bceddb65..a576aeeb22da 100644 --- a/drivers/pci/host/pcie-iproc.c +++ b/drivers/pci/host/pcie-iproc.c @@ -64,7 +64,6 @@ #define OARR_SIZE_CFG BIT(OARR_SIZE_CFG_SHIFT) #define MAX_NUM_OB_WINDOWS 2 -#define MAX_NUM_PAXC_PF 4 #define IPROC_PCIE_REG_INVALID 0xffff @@ -170,20 +169,6 @@ static inline void iproc_pcie_ob_write(struct iproc_pcie *pcie, writel(val, pcie->base + offset + (window * 8)); } -static inline bool iproc_pcie_device_is_valid(struct iproc_pcie *pcie, - unsigned int slot, - unsigned int fn) -{ - if (slot > 0) - return false; - - /* PAXC can only support limited number of functions */ - if (pcie->type == IPROC_PCIE_PAXC && fn >= MAX_NUM_PAXC_PF) - return false; - - return true; -} - /** * Note access to the configuration registers are protected at the higher layer * by 'pci_lock' in drivers/pci/access.c @@ -199,11 +184,11 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus, u32 val; u16 offset; - if (!iproc_pcie_device_is_valid(pcie, slot, fn)) - return NULL; - /* root complex access */ if (busno == 0) { + if (slot > 0 || fn > 0) + return NULL; + iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_IND_ADDR, where & CFG_IND_ADDR_MASK); offset = iproc_pcie_reg_offset(pcie, IPROC_PCIE_CFG_IND_DATA); @@ -213,6 +198,14 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus, return (pcie->base + offset); } + /* + * PAXC is connected to an internally emulated EP within the SoC. It + * allows only one device. + */ + if (pcie->type == IPROC_PCIE_PAXC) + if (slot > 0) + return NULL; + /* EP device access */ val = (busno << CFG_ADDR_BUS_NUM_SHIFT) | (slot << CFG_ADDR_DEV_NUM_SHIFT) | -- cgit v1.2.3 From 4d8c8bd6f2062c9988817183a91fe2e623c8aa5e Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Thu, 11 Feb 2016 16:10:26 -0500 Subject: xen/pcifront: Fix mysterious crashes when NUMA locality information was extracted. Occasionaly PV guests would crash with: pciback 0000:00:00.1: Xen PCI mapped GSI0 to IRQ16 BUG: unable to handle kernel paging request at 0000000d1a8c0be0 .. snip.. ] find_next_bit+0xb/0x10 [] cpumask_next_and+0x22/0x40 [] pci_device_probe+0xb8/0x120 [] ? driver_sysfs_add+0x77/0xa0 [] driver_probe_device+0x1a4/0x2d0 [] ? pci_match_device+0xdd/0x110 [] __device_attach_driver+0xa7/0xb0 [] ? __driver_attach+0xa0/0xa0 [] bus_for_each_drv+0x62/0x90 [] __device_attach+0xbd/0x110 [] device_attach+0xb/0x10 [] pci_bus_add_device+0x3c/0x70 [] pci_bus_add_devices+0x38/0x80 [] pcifront_scan_root+0x13e/0x1a0 [] pcifront_backend_changed+0x262/0x60b [] ? xenbus_gather+0xd6/0x160 [] ? put_object+0x2f/0x50 [] xenbus_otherend_changed+0x9d/0xa0 [] backend_changed+0xe/0x10 [] xenwatch_thread+0xc8/0x190 [] ? woken_wake_function+0x10/0x10 which was the result of two things: When we call pci_scan_root_bus we would pass in 'sd' (sysdata) pointer which was an 'pcifront_sd' structure. However in the pci_device_add it expects that the 'sd' is 'struct sysdata' and sets the dev->node to what is in sd->node (offset 4): set_dev_node(&dev->dev, pcibus_to_node(bus)); __pcibus_to_node(const struct pci_bus *bus) { const struct pci_sysdata *sd = bus->sysdata; return sd->node; } However our structure was pcifront_sd which had nothing at that offset: struct pcifront_sd { int domain; /* 0 4 */ /* XXX 4 bytes hole, try to pack */ struct pcifront_device * pdev; /* 8 8 */ } That is an hole - filled with garbage as we used kmalloc instead of kzalloc (the second problem). This patch fixes the issue by: 1) Use kzalloc to initialize to a well known state. 2) Put 'struct pci_sysdata' at the start of 'pcifront_sd'. That way access to the 'node' will access the right offset. Signed-off-by: Konrad Rzeszutek Wilk Cc: Reviewed-by: Boris Ostrovsky Signed-off-by: David Vrabel --- drivers/pci/xen-pcifront.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index c777b97207d5..5f70fee59a94 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -53,7 +53,7 @@ struct pcifront_device { }; struct pcifront_sd { - int domain; + struct pci_sysdata sd; struct pcifront_device *pdev; }; @@ -67,7 +67,9 @@ static inline void pcifront_init_sd(struct pcifront_sd *sd, unsigned int domain, unsigned int bus, struct pcifront_device *pdev) { - sd->domain = domain; + /* Because we do not expose that information via XenBus. */ + sd->sd.node = first_online_node; + sd->sd.domain = domain; sd->pdev = pdev; } @@ -468,8 +470,8 @@ static int pcifront_scan_root(struct pcifront_device *pdev, dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n", domain, bus); - bus_entry = kmalloc(sizeof(*bus_entry), GFP_KERNEL); - sd = kmalloc(sizeof(*sd), GFP_KERNEL); + bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL); + sd = kzalloc(sizeof(*sd), GFP_KERNEL); if (!bus_entry || !sd) { err = -ENOMEM; goto err_out; -- cgit v1.2.3 From 61d9e854dfb91b46b99ffd3d31fc7d45d2b95f31 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Thu, 18 Feb 2016 14:32:10 +0100 Subject: PCI: mvebu: Restrict build to 32-bit ARM This driver uses PCI glue that is only available on 32-bit ARM. This used to work fine as long as ARCH_MVEBU and ARCH_DOVE were exclusively 32-bit, but there's a patch in the pipe to make ARCH_MVEBU also available on 64-bit ARM. [bhelgaas: changelog; patch is coming but not merged yet] Signed-off-by: Thierry Reding Signed-off-by: Bjorn Helgaas Acked-by: Thomas Petazzoni --- drivers/pci/host/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/pci') diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig index 75a605426538..d1cdd9c992ac 100644 --- a/drivers/pci/host/Kconfig +++ b/drivers/pci/host/Kconfig @@ -14,6 +14,7 @@ config PCI_DRA7XX config PCI_MVEBU bool "Marvell EBU PCIe controller" depends on ARCH_MVEBU || ARCH_DOVE + depends on ARM depends on OF config PCIE_DW -- cgit v1.2.3