Am 22.02.24 um 08:34 schrieb Thomas Hellström:
On Wed, 2024-02-21 at 11:26 +0100, Christian König wrote:
Am 21.02.24 um 08:33 schrieb Thomas Hellström:
If caching mode change fails due to, for example, OOM we
free the allocated pages in a two-step process. First the pages
for which the caching change has already succeeded. Secondly
the pages for which a caching change did not succeed.
However the second step was incorrectly freeing the pages already
freed in the first step.
Fix.
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Fixes: 379989e7cbdc ("drm/ttm/pool: Fix ttm_pool_alloc error path")
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxxx>
Cc: Christian Koenig <christian.koenig@xxxxxxx>
Cc: Huang Rui <ray.huang@xxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # v6.4+
You don't know how much time I've spend staring at this line to find
the
bug in it and haven't seen it. Got bug reports about that for month
as well.
Yeah, sorry about that. We should probably have Kunit tests exercising
OOM in the pool code involving WC pages.
I'll push this to drm-misc-next.
drm-misc-fixes please! That needs to be backported ASAP.
Need to dig up the bug report for this again.
Thanks,
Christian.
/Thomas
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
---
drivers/gpu/drm/ttm/ttm_pool.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_pool.c
b/drivers/gpu/drm/ttm/ttm_pool.c
index b62f420a9f96..112438d965ff 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -387,7 +387,7 @@ static void ttm_pool_free_range(struct ttm_pool
*pool, struct ttm_tt *tt,
enum ttm_caching caching,
pgoff_t start_page, pgoff_t
end_page)
{
- struct page **pages = tt->pages;
+ struct page **pages = &tt->pages[start_page];
unsigned int order;
pgoff_t i, nr;
