6.6-stable review patch. If anyone has any objections, please let me know.
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From: Xiaogang Chen xiaogang.chen@amd.com
[ Upstream commit 709c348261618da7ed89d6c303e2ceb9e453ba74 ]
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@amd.com Reviewed-by: Philip Yang Philip.Yang@amd.com Reviewed-by: Jesse Zhang Jesse.Zhang@amd.com Tested-by: Jesse Zhang Jesse.Zhang@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 2a42fbddcb7ae..2591bdfcc2289 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -628,8 +628,15 @@ svm_range_vram_node_new(struct kfd_node *node, struct svm_range *prange,
void svm_range_vram_node_free(struct svm_range *prange) { - svm_range_bo_unref(prange->svm_bo); - prange->ttm_res = NULL; + /* 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 *