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authorAlexey Kardashevskiy <aik@ozlabs.ru>2018-10-02 13:22:31 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2018-12-20 22:59:03 +1100
commit517ad4ae8aa93dccdb9a88c27257ecb421c9e848 (patch)
tree0e1d6ad31313e7019b383580472832604b074f1a /drivers/vfio
parentfa1ada78897f282917594ba8eba220a54f87dabb (diff)
downloadlinux-517ad4ae8aa93dccdb9a88c27257ecb421c9e848.tar.bz2
vfio/spapr_tce: Get rid of possible infinite loop
As a part of cleanup, the SPAPR TCE IOMMU subdriver releases preregistered memory. If there is a bug in memory release, the loop in tce_iommu_release() becomes infinite; this actually happened to me. This makes the loop finite and prints a warning on every failure to make the code more bug prone. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/vfio_iommu_spapr_tce.c10
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index b30926e11d87..ad637250938d 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -371,6 +371,7 @@ static void tce_iommu_release(void *iommu_data)
{
struct tce_container *container = iommu_data;
struct tce_iommu_group *tcegrp;
+ struct tce_iommu_prereg *tcemem, *tmtmp;
long i;
while (tce_groups_attached(container)) {
@@ -393,13 +394,8 @@ static void tce_iommu_release(void *iommu_data)
tce_iommu_free_table(container, tbl);
}
- while (!list_empty(&container->prereg_list)) {
- struct tce_iommu_prereg *tcemem;
-
- tcemem = list_first_entry(&container->prereg_list,
- struct tce_iommu_prereg, next);
- WARN_ON_ONCE(tce_iommu_prereg_free(container, tcemem));
- }
+ list_for_each_entry_safe(tcemem, tmtmp, &container->prereg_list, next)
+ WARN_ON(tce_iommu_prereg_free(container, tcemem));
tce_iommu_disable(container);
if (container->mm)