[PATCH 5/7] iommu/amd: Set global pointers to NULL after freeing them

From: Joerg Roedel
Date: Fri Jun 16 2017 - 10:12:14 EST


From: Joerg Roedel <jroedel@xxxxxxx>

Avoid any tries to double-free these pointers.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
drivers/iommu/amd_iommu_init.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index a31f375..d04898c 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2112,18 +2112,22 @@ static void __init free_iommu_resources(void)
kmemleak_free(irq_lookup_table);
free_pages((unsigned long)irq_lookup_table,
get_order(rlookup_table_size));
+ irq_lookup_table = NULL;

kmem_cache_destroy(amd_iommu_irq_cache);
amd_iommu_irq_cache = NULL;

free_pages((unsigned long)amd_iommu_rlookup_table,
get_order(rlookup_table_size));
+ amd_iommu_rlookup_table = NULL;

free_pages((unsigned long)amd_iommu_alias_table,
get_order(alias_table_size));
+ amd_iommu_alias_table = NULL;

free_pages((unsigned long)amd_iommu_dev_table,
get_order(dev_table_size));
+ amd_iommu_dev_table = NULL;

free_iommu_all();

@@ -2193,6 +2197,7 @@ static void __init free_dma_resources(void)
{
free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
get_order(MAX_DOMAIN_ID/8));
+ amd_iommu_pd_alloc_bitmap = NULL;

free_unity_maps();
}
--
2.7.4