From 630541863b29f88c7ab34e647758344e4cd1eafd Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Wed, 16 Jan 2013 14:25:44 +1000 Subject: [PATCH] ttm: don't destroy old mm_node on memcpy failure When we are using memcpy to move objects around, and we fail to memcpy due to lack of memory to populate or failure to finish the copy, we don't want to destroy the mm_node that has been copied into old_copy. While working on a new kms driver that uses memcpy, if I overallocated bo's up to the memory limits, and eviction failed, then machine would oops soon after due to having an active bo with an already freed drm_mm embedded in it, freeing it a second time didn't end well. Reviewed-by: Jerome Glisse Signed-off-by: Dave Airlie --- drivers/gpu/drm/ttm/ttm_bo_util.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index d73d6e3e17b2..44420fca7dfa 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -344,8 +344,12 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, if (ttm->state == tt_unpopulated) { ret = ttm->bdev->driver->ttm_tt_populate(ttm); - if (ret) + if (ret) { + /* if we fail here don't nuke the mm node + * as the bo still owns it */ + old_copy.mm_node = NULL; goto out1; + } } add = 0; @@ -371,8 +375,11 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, prot); } else ret = ttm_copy_io_page(new_iomap, old_iomap, page); - if (ret) + if (ret) { + /* failing here, means keep old copy as-is */ + old_copy.mm_node = NULL; goto out1; + } } mb(); out2: -- 2.34.1