[PATCH] drm/amdkfd: Fix a race condition of vram buffer unref in svm code
Eric Huang
jinhuieric.huang at amd.com
Wed Sep 27 14:19:24 UTC 2023
On 2023-09-26 23:00, Xiaogang.Chen wrote:
> From: Xiaogang Chen <xiaogang.chen at amd.com>
>
> prange->svm_bo unref can happen in both mmu callback and a callback after
> migrate to system ram. Both are async call in different tasks. Sync svm_bo
> unref operation to avoid random "use-after-free".
>
> Signed-off-by: Xiaogang.Chen <Xiaogang.Chen at amd.com>
> ---
> drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 70aa882636ab..8e246e848018 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -637,6 +637,15 @@ void svm_range_vram_node_free(struct svm_range *prange)
> {
> svm_range_bo_unref(prange->svm_bo);
> prange->ttm_res = NULL;
Are above two lines not removed?
Regards,
Eric
> + /* serialize prange->svm_bo unref */
> + mutex_lock(&prange->lock);
> + /* prange->svm_bo has not been unref */
> + if (prange->ttm_res) {
> + prange->ttm_res = NULL;
> + mutex_unlock(&prange->lock);
> + svm_range_bo_unref(prange->svm_bo);
> + } else
> + mutex_unlock(&prange->lock);
> }
>
> struct kfd_node *
More information about the amd-gfx
mailing list