[PATCH AUTOSEL 6.18-6.12] drm/amdkfd: Properly acquire queue buffers in CRIU restore

Sasha Levin posted 1 patch 3 weeks, 5 days ago
.../gpu/drm/amd/amdkfd/kfd_process_queue_manager.c   | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
[PATCH AUTOSEL 6.18-6.12] drm/amdkfd: Properly acquire queue buffers in CRIU restore
Posted by Sasha Levin 3 weeks, 5 days ago
From: David Francis <David.Francis@amd.com>

[ Upstream commit 20a5e7ffdfecddc34c60a6b4483f42acf3d8731d ]

When kfd_queue_acquire_buffers() was split off from
set_queue_properties_from_user(), set_queue_properties_from_criu()
was missed. Thus, set_queue_properties_from_criu() is not
filling out the buffer fields of queue_properties, which
can come up when subsequent code expects them to be non-null.

Add the proper call to kfd_queue_acquire_buffers(), and also
use the right cast types in set_queue_properties_from_criu()
(which were missed at the same time)

Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 88ed96abbbe27b70193544fbc1ee06448c274714)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

The background check finished: neither `git log --grep="CRIU restore
queue buffers"` nor a search for the fix’s debug string (`"failed to
acquire user queue buffers for CRIU"`) turned up anything on HEAD. That
confirms the fix isn’t already in v6.18.44 under another commit.

The earlier analysis stands: this is a real NULL-deref regression in the
KFD CRIU restore path, and it should be backported.

**YES**

 .../gpu/drm/amd/amdkfd/kfd_process_queue_manager.c   | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
index e96488f6b02d2..912c4ebd30405 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
@@ -974,8 +974,8 @@ static void set_queue_properties_from_criu(struct queue_properties *qp,
 	qp->priority = q_data->priority;
 	qp->queue_address = q_data->q_address;
 	qp->queue_size = q_data->q_size;
-	qp->read_ptr = (uint32_t *) q_data->read_ptr_addr;
-	qp->write_ptr = (uint32_t *) q_data->write_ptr_addr;
+	qp->read_ptr = (void __user *)q_data->read_ptr_addr;
+	qp->write_ptr = (void __user *)q_data->write_ptr_addr;
 	qp->eop_ring_buffer_address = q_data->eop_ring_buffer_address;
 	qp->eop_ring_buffer_size = q_data->eop_ring_buffer_size;
 	qp->ctx_save_restore_area_address = q_data->ctx_save_restore_area_address;
@@ -1064,10 +1064,18 @@ int kfd_criu_restore_queue(struct kfd_process *p,
 	memset(&qp, 0, sizeof(qp));
 	set_queue_properties_from_criu(&qp, q_data, NUM_XCC(pdd->dev->adev->gfx.xcc_mask));
 
+	ret = kfd_queue_acquire_buffers(pdd, &qp);
+	if (ret) {
+		pr_debug("failed to acquire user queue buffers for CRIU\n");
+		goto exit;
+	}
+
 	print_queue_properties(&qp);
 
 	ret = pqm_create_queue(&p->pqm, pdd->dev, &qp, &queue_id, q_data, mqd, ctl_stack, NULL);
 	if (ret) {
+		kfd_queue_unref_bo_vas(pdd, &qp);
+		kfd_queue_release_buffers(pdd, &qp);
 		pr_err("Failed to create new queue err:%d\n", ret);
 		goto exit;
 	}
-- 
2.53.0