[PATCH 4/8] amd/amdkfd:fix overflowed constant in the function svm_migrate_copy_to_ram

[Jesse Zhang]

If the svm migration copy memory gart fails or the dma mapping page fails for the first time.
But the variable i is still 0, and executing i-- will overflow.

Signed-off-by: Jesse Zhang <Jesse.Zhang at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index 8ee3d07ffbdf..3620eabf13c7 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -650,9 +650,10 @@ svm_migrate_copy_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
 out_oom:
 	if (r) {
 		pr_debug("failed %d copy to ram\n", r);
-		while (i--) {
+		while (i) {
 			svm_migrate_put_sys_page(dst[i]);
 			migrate->dst[i] = 0;
+			i--;
 		}
 	}
 
-- 
2.25.1