bus/pci: fix TOCTOU for sysfs access

[dpdk.git] / drivers / bus / pci / linux / pci_uio.c

diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c
index 92b7f02..f240fe4 100644 (file)
--- a/drivers/bus/pci/linux/pci_uio.c
+++ b/drivers/bus/pci/linux/pci_uio.c
@@ -1,34 +1,5 @@
-/*-
- *   BSD LICENSE
- *
- *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
- *   All rights reserved.
- *
- *   Redistribution and use in source and binary forms, with or without
- *   modification, are permitted provided that the following conditions
- *   are met:
- *
- *     * Redistributions of source code must retain the above copyright
- *       notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright
- *       notice, this list of conditions and the following disclaimer in
- *       the documentation and/or other materials provided with the
- *       distribution.
- *     * Neither the name of Intel Corporation nor the names of its
- *       contributors may be used to endorse or promote products derived
- *       from this software without specific prior written permission.
- *
- *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2014 Intel Corporation
  */
 
 #include <string.h>
@@ -45,6 +16,7 @@
 #include <sys/io.h>
 #endif
 
+#include <rte_string_fns.h>
 #include <rte_log.h>
 #include <rte_pci.h>
 #include <rte_bus_pci.h>
@@ -297,7 +269,7 @@ pci_uio_alloc_resource(struct rte_pci_device *dev,
                goto error;
        }
 
-       snprintf((*uio_res)->path, sizeof((*uio_res)->path), "%s", devname);
+       strlcpy((*uio_res)->path, devname, sizeof((*uio_res)->path));
        memcpy(&(*uio_res)->pci_addr, &dev->addr, sizeof((*uio_res)->pci_addr));
 
        return 0;
@@ -311,24 +283,21 @@ int
 pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
                struct mapped_pci_resource *uio_res, int map_idx)
 {
-       int fd;
+       int fd = -1;
        char devname[PATH_MAX];
        void *mapaddr;
        struct rte_pci_addr *loc;
        struct pci_map *maps;
+       int wc_activate = 0;
+
+       if (dev->driver != NULL)
+               wc_activate = dev->driver->drv_flags & RTE_PCI_DRV_WC_ACTIVATE;
 
        loc = &dev->addr;
        maps = uio_res->maps;
 
-       /* update devname for mmap  */
-       snprintf(devname, sizeof(devname),
-                       "%s/" PCI_PRI_FMT "/resource%d",
-                       rte_pci_get_sysfs_path(),
-                       loc->domain, loc->bus, loc->devid,
-                       loc->function, res_idx);
-
        /* allocate memory to keep path */
-       maps[map_idx].path = rte_malloc(NULL, strlen(devname) + 1, 0);
+       maps[map_idx].path = rte_malloc(NULL, sizeof(devname), 0);
        if (maps[map_idx].path == NULL) {
                RTE_LOG(ERR, EAL, "Cannot allocate memory for path: %s\n",
                                strerror(errno));
@@ -338,11 +307,36 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
        /*
         * open resource file, to mmap it
         */
-       fd = open(devname, O_RDWR);
-       if (fd < 0) {
-               RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
+       if (wc_activate) {
+               /* update devname for mmap  */
+               snprintf(devname, sizeof(devname),
+                       "%s/" PCI_PRI_FMT "/resource%d_wc",
+                       rte_pci_get_sysfs_path(),
+                       loc->domain, loc->bus, loc->devid,
+                       loc->function, res_idx);
+
+               fd = open(devname, O_RDWR);
+               if (fd < 0 && errno != ENOENT) {
+                       RTE_LOG(INFO, EAL, "%s cannot be mapped. "
+                               "Fall-back to non prefetchable mode.\n",
+                               devname);
+               }
+       }
+
+       if (!wc_activate || fd < 0) {
+               snprintf(devname, sizeof(devname),
+                       "%s/" PCI_PRI_FMT "/resource%d",
+                       rte_pci_get_sysfs_path(),
+                       loc->domain, loc->bus, loc->devid,
+                       loc->function, res_idx);
+
+               /* then try to map resource file */
+               fd = open(devname, O_RDWR);
+               if (fd < 0) {
+                       RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
                                devname, strerror(errno));
-               goto error;
+                       goto error;
+               }
        }
 
        /* try mapping somewhere close to the end of hugepages */