6.12-stable review patch. If anyone has any objections, please let me know.
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From: David Hildenbrand david@redhat.com
[ Upstream commit b3fefbb30a1691533cb905006b69b2a474660744 ]
In case we have to retry the loop, we are missing to unlock+put the folio. In that case, we will keep failing make_device_exclusive_range() because we cannot grab the folio lock, and even return from the function with the folio locked and referenced, effectively never succeeding the make_device_exclusive_range().
While at it, convert the other unlock+put to use a folio as well.
This was found by code inspection.
Fixes: 8f187163eb89 ("nouveau/svm: implement atomic SVM access") Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Alistair Popple apopple@nvidia.com Tested-by: Alistair Popple apopple@nvidia.com Signed-off-by: Danilo Krummrich dakr@kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20250124181524.3584236-2-david... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/nouveau/nouveau_svm.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index b4da82ddbb6b2..8ea98f06d39af 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -590,6 +590,7 @@ static int nouveau_atomic_range_fault(struct nouveau_svmm *svmm, unsigned long timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); struct mm_struct *mm = svmm->notifier.mm; + struct folio *folio; struct page *page; unsigned long start = args->p.addr; unsigned long notifier_seq; @@ -616,12 +617,16 @@ static int nouveau_atomic_range_fault(struct nouveau_svmm *svmm, ret = -EINVAL; goto out; } + folio = page_folio(page);
mutex_lock(&svmm->mutex); if (!mmu_interval_read_retry(¬ifier->notifier, notifier_seq)) break; mutex_unlock(&svmm->mutex); + + folio_unlock(folio); + folio_put(folio); }
/* Map the page on the GPU. */ @@ -637,8 +642,8 @@ static int nouveau_atomic_range_fault(struct nouveau_svmm *svmm, ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, size, NULL); mutex_unlock(&svmm->mutex);
- unlock_page(page); - put_page(page); + folio_unlock(folio); + folio_put(folio);
out: mmu_interval_notifier_remove(¬ifier->notifier);