intel-iommu: iommu init error path bug fixes

The kcalloc() failure path in iommu_init_domains() calls
free_dmar_iommu(), which assumes that ->domains, ->domain_ids,
and ->lock have been properly initialized.

Add checks in free_[dmar]_iommu to not use ->domains,->domain_ids
if not alloced. Move the lock init to prior to the kcalloc()'s,
so it is valid in free_context_table() when free_dmar_iommu() invokes
it at the end.

Patch based on iommu-2.6,
commit 132032274a594ee9ffb6b9c9e2e9698149a09ea9

Signed-off-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index e67335ba24a3688c8116209ed15df310339ed805..beb5ccfd89bd1fab4d7ea5a2d3d9917c9feae905 100644 (file)
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1158,6 +1158,8 @@ static int iommu_init_domains(struct intel_iommu *iommu)
        pr_debug("Number of Domains supportd <%ld>\n", ndomains);
        nlongs = BITS_TO_LONGS(ndomains);
 
+       spin_lock_init(&iommu->lock);
+
        /* TBD: there might be 64K domains,
         * consider other allocation for future chip
         */
@@ -1170,12 +1172,9 @@ static int iommu_init_domains(struct intel_iommu *iommu)
                        GFP_KERNEL);
        if (!iommu->domains) {
                printk(KERN_ERR "Allocating domain array failed\n");
-               kfree(iommu->domain_ids);
                return -ENOMEM;
        }
 
-       spin_lock_init(&iommu->lock);
-
        /*
         * if Caching mode is set, then invalid translations are tagged
         * with domainid 0. Hence we need to pre-allocate it.
@@ -1195,22 +1194,24 @@ void free_dmar_iommu(struct intel_iommu *iommu)
        int i;
        unsigned long flags;
 
-       i = find_first_bit(iommu->domain_ids, cap_ndoms(iommu->cap));
-       for (; i < cap_ndoms(iommu->cap); ) {
-               domain = iommu->domains[i];
-               clear_bit(i, iommu->domain_ids);
+       if ((iommu->domains) && (iommu->domain_ids)) {
+               i = find_first_bit(iommu->domain_ids, cap_ndoms(iommu->cap));
+               for (; i < cap_ndoms(iommu->cap); ) {
+                       domain = iommu->domains[i];
+                       clear_bit(i, iommu->domain_ids);
+
+                       spin_lock_irqsave(&domain->iommu_lock, flags);
+                       if (--domain->iommu_count == 0) {
+                               if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE)
+                                       vm_domain_exit(domain);
+                               else
+                                       domain_exit(domain);
+                       }
+                       spin_unlock_irqrestore(&domain->iommu_lock, flags);
 
-               spin_lock_irqsave(&domain->iommu_lock, flags);
-               if (--domain->iommu_count == 0) {
-                       if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE)
-                               vm_domain_exit(domain);
-                       else
-                               domain_exit(domain);
+                       i = find_next_bit(iommu->domain_ids,
+                               cap_ndoms(iommu->cap), i+1);
                }
-               spin_unlock_irqrestore(&domain->iommu_lock, flags);
-
-               i = find_next_bit(iommu->domain_ids,
-                       cap_ndoms(iommu->cap), i+1);
        }
 
        if (iommu->gcmd & DMA_GCMD_TE)