From f5d5e8165aee90761d3991a40a516cd2deed8146 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Fri, 24 Jan 2025 19:15:23 +0100
Subject: [PATCH] nouveau/svm: fix missing folio unlock + put after
make_device_exclusive_range()
[ 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@redhat.com
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);
--
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