[PATCH AUTOSEL 5.6 078/129] drm/nouveau/svm: fix vma range check for migration

Sasha Levin
2020-04-15T13:05:01Z

From: Ralph Campbell <rcampbell@nvidia.com>

[ Upstream commit b92103b559c77abc5f8b7bec269230a219c880b7 ]

find_vma_intersection(mm, start, end) only guarantees that end is greater
than or equal to vma->vm_start but doesn't guarantee that start is
greater than or equal to vma->vm_start. The calculation for the
intersecting range in nouveau_svmm_bind() isn't accounting for this and
can call migrate_vma_setup() with a starting address less than
vma->vm_start. This results in migrate_vma_setup() returning -EINVAL for
the range instead of nouveau skipping that part of the range and migrating
the rest.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/nouveau/nouveau_svm.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index 3ec5da025bea7..c567526b75b83 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -184,6 +184,7 @@ nouveau_svmm_bind(struct drm_device *dev, void *data,
if (!vma)
break;

+ addr = max(addr, vma->vm_start);
next = min(vma->vm_end, end);
/* This is a best effort so we ignore errors */
nouveau_dmem_migrate_vma(cli->drm, vma, addr, next);
--
2.20.1