2021-02-16 11:43:57

by Gerd Hoffmann

[permalink] [raw]

Subject: [PATCH 10/10] drm/qxl: add lock asserts to qxl_bo_kmap_locked + qxl_bo_kunmap_locked

---

Try avoid re-introducing locking bugs.

Signed-off-by: Gerd Hoffmann <[email protected]>
---
drivers/gpu/drm/qxl/qxl_object.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
index 22748b9566af..90d5e5b7f927 100644
--- a/drivers/gpu/drm/qxl/qxl_object.c
+++ b/drivers/gpu/drm/qxl/qxl_object.c
@@ -162,6 +162,8 @@ int qxl_bo_kmap_locked(struct qxl_bo *bo, struct dma_buf_map *map)
{
int r;

+ dma_resv_assert_held(bo->tbo.base.resv);
+
if (bo->kptr) {
bo->map_count++;
goto out;
@@ -236,6 +238,8 @@ void *qxl_bo_kmap_atomic_page(struct qxl_device *qdev,

void qxl_bo_kunmap_locked(struct qxl_bo *bo)
{
+ dma_resv_assert_held(bo->tbo.base.resv);
+
if (bo->kptr == NULL)
return;
bo->map_count--;
--
2.29.2

2021-02-16 13:32:40

by Thomas Zimmermann

[permalink] [raw]

Subject: Re: [PATCH 10/10] drm/qxl: add lock asserts to qxl_bo_kmap_locked + qxl_bo_kunmap_locked

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Hi

Am 16.02.21 um 12:37 schrieb Gerd Hoffmann:
> Try avoid re-introducing locking bugs.
>
> Signed-off-by: Gerd Hoffmann <[email protected]>

Acked-by: Thomas Zimmermann <[email protected]>

IMHO this should eventually be done in the rsp TTM functions. But so
far, I'd expect this to break some drivers.

Best regards
Thomas

> ---
> drivers/gpu/drm/qxl/qxl_object.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
> index 22748b9566af..90d5e5b7f927 100644
> --- a/drivers/gpu/drm/qxl/qxl_object.c
> +++ b/drivers/gpu/drm/qxl/qxl_object.c
> @@ -162,6 +162,8 @@ int qxl_bo_kmap_locked(struct qxl_bo *bo, struct dma_buf_map *map)
> {
> int r;
>
> + dma_resv_assert_held(bo->tbo.base.resv);
> +
> if (bo->kptr) {
> bo->map_count++;
> goto out;
> @@ -236,6 +238,8 @@ void *qxl_bo_kmap_atomic_page(struct qxl_device *qdev,
>
> void qxl_bo_kunmap_locked(struct qxl_bo *bo)
> {
> + dma_resv_assert_held(bo->tbo.base.resv);
> +
> if (bo->kptr == NULL)
> return;
> bo->map_count--;
>

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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