[PATCH v9 01/29] iommufd: Report unmapped bytes in the error path of iopt_unmap_iova_range

[Nicolin Chen]

There are callers that read the unmapped bytes even when rc != 0. Thus, do
not forget to report it in the error path too.

Fixes: 8d40205f6093 ("iommufd: Add kAPI toward external drivers for kernel 
access")
Cc: sta...@vger.kernel.org
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
Reviewed-by: Jason Gunthorpe <j...@nvidia.com>
Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
 drivers/iommu/iommufd/io_pagetable.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/iommufd/io_pagetable.c 
b/drivers/iommu/iommufd/io_pagetable.c
index 13d010f19ed1..22fc3a12109f 100644
--- a/drivers/iommu/iommufd/io_pagetable.c
+++ b/drivers/iommu/iommufd/io_pagetable.c
@@ -743,8 +743,10 @@ static int iopt_unmap_iova_range(struct io_pagetable 
*iopt, unsigned long start,
                        iommufd_access_notify_unmap(iopt, area_first, length);
                        /* Something is not responding to unmap requests. */
                        tries++;
-                       if (WARN_ON(tries > 100))
-                               return -EDEADLOCK;
+                       if (WARN_ON(tries > 100)) {
+                               rc = -EDEADLOCK;
+                               goto out_unmapped;
+                       }
                        goto again;
                }
 
@@ -766,6 +768,7 @@ static int iopt_unmap_iova_range(struct io_pagetable *iopt, 
unsigned long start,
 out_unlock_iova:
        up_write(&iopt->iova_rwsem);
        up_read(&iopt->domains_rwsem);
+out_unmapped:
        if (unmapped)
                *unmapped = unmapped_bytes;
        return rc;
-- 
2.43.0