iommu/dma: Don't touch invalid iova_domain members

[mirror_ubuntu-artful-kernel.git] / drivers / iommu / dmar.c

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 36e3f430d2651af655480ae323dff48d919c5ecc..cbf7763d8091035deb45d2c36a7fc7201e6b4ab0 100644 (file)
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -311,7 +311,7 @@ static int dmar_pci_bus_add_dev(struct dmar_pci_notify_info *info)
                                ((void *)drhd) + drhd->header.length,
                                dmaru->segment,
                                dmaru->devices, dmaru->devices_cnt);
-               if (ret != 0)
+               if (ret)
                        break;
        }
        if (ret >= 0)
@@ -391,7 +391,7 @@ static int dmar_parse_one_drhd(struct acpi_dmar_header *header, void *arg)
 {
        struct acpi_dmar_hardware_unit *drhd;
        struct dmar_drhd_unit *dmaru;
-       int ret = 0;
+       int ret;
 
        drhd = (struct acpi_dmar_hardware_unit *)header;
        dmaru = dmar_find_dmaru(drhd);
@@ -551,17 +551,16 @@ static int __init dmar_table_detect(void)
                status = AE_NOT_FOUND;
        }
 
-       return (ACPI_SUCCESS(status) ? 1 : 0);
+       return ACPI_SUCCESS(status) ? 0 : -ENOENT;
 }
 
 static int dmar_walk_remapping_entries(struct acpi_dmar_header *start,
                                       size_t len, struct dmar_res_callback *cb)
 {
-       int ret = 0;
        struct acpi_dmar_header *iter, *next;
        struct acpi_dmar_header *end = ((void *)start) + len;
 
-       for (iter = start; iter < end && ret == 0; iter = next) {
+       for (iter = start; iter < end; iter = next) {
                next = (void *)iter + iter->length;
                if (iter->length == 0) {
                        /* Avoid looping forever on bad ACPI tables */
@@ -570,8 +569,7 @@ static int dmar_walk_remapping_entries(struct acpi_dmar_header *start,
                } else if (next > end) {
                        /* Avoid passing table end */
                        pr_warn(FW_BUG "Record passes table end\n");
-                       ret = -EINVAL;
-                       break;
+                       return -EINVAL;
                }
 
                if (cb->print_entry)
@@ -582,15 +580,19 @@ static int dmar_walk_remapping_entries(struct acpi_dmar_header *start,
                        pr_debug("Unknown DMAR structure type %d\n",
                                 iter->type);
                } else if (cb->cb[iter->type]) {
+                       int ret;
+
                        ret = cb->cb[iter->type](iter, cb->arg[iter->type]);
+                       if (ret)
+                               return ret;
                } else if (!cb->ignore_unhandled) {
                        pr_warn("No handler for DMAR structure type %d\n",
                                iter->type);
-                       ret = -EINVAL;
+                       return -EINVAL;
                }
        }
 
-       return ret;
+       return 0;
 }
 
 static inline int dmar_walk_dmar_table(struct acpi_table_dmar *dmar,
@@ -607,8 +609,8 @@ static int __init
 parse_dmar_table(void)
 {
        struct acpi_table_dmar *dmar;
-       int ret = 0;
        int drhd_count = 0;
+       int ret;
        struct dmar_res_callback cb = {
                .print_entry = true,
                .ignore_unhandled = true,
@@ -891,17 +893,17 @@ int __init detect_intel_iommu(void)
 
        down_write(&dmar_global_lock);
        ret = dmar_table_detect();
-       if (ret)
-               ret = !dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
-                                           &validate_drhd_cb);
-       if (ret && !no_iommu && !iommu_detected && !dmar_disabled) {
+       if (!ret)
+               ret = dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
+                                          &validate_drhd_cb);
+       if (!ret && !no_iommu && !iommu_detected && !dmar_disabled) {
                iommu_detected = 1;
                /* Make sure ACS will be enabled */
                pci_request_acs();
        }
 
 #ifdef CONFIG_X86
-       if (ret)
+       if (!ret)
                x86_init.iommu.iommu_init = intel_iommu_init;
 #endif
 
@@ -911,10 +913,9 @@ int __init detect_intel_iommu(void)
        }
        up_write(&dmar_global_lock);
 
-       return ret ? 1 : -ENODEV;
+       return ret ? ret : 1;
 }
 
-
 static void unmap_iommu(struct intel_iommu *iommu)
 {
        iounmap(iommu->reg);