drm/amdkfd: Fix buffer overflow in SDMA queue checkpoint/restore on GFX11

commit 352ea59 upstream.

The v11 MQD manager incorrectly assigned the CP-compute variants of
checkpoint_mqd/restore_mqd for KFD_MQD_TYPE_SDMA queues. These functions
use sizeof(struct v11_compute_mqd) (2048 bytes) instead of sizeof(struct
v11_sdma_mqd) (512 bytes), causing a 1536-byte overflow.

During CRIU checkpoint of an SDMA queue on Navi3x:
- checkpoint_mqd() reads 2048 bytes from a 512-byte SDMA MQD buffer,
  leaking 1536 bytes of adjacent GTT memory to userspace

During CRIU restore:
- restore_mqd() writes 2048 bytes into a 512-byte SDMA MQD buffer,
  corrupting 1536 bytes of adjacent GTT memory (often the ring buffer
  or neighboring MQDs)

This is a copy-paste regression unique to v11. All other ASIC backends
(cik, vi, v9, v10, v12) correctly use the SDMA-specific variants.

Add checkpoint_mqd_sdma() and restore_mqd_sdma() functions that properly
handle the smaller v11_sdma_mqd structure, matching the pattern used in
other MQD managers.

Fixes: cc009e6 ("drm/amdkfd: Add KFD support for soc21 v3")
Assisted-by: Claude:Sonnet 4-5
Signed-off-by: Andrew Martin <andrew.martin@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6fa41db)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: andmar-amd

drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v11.c

@@ -320,8 +320,7 @@ static void checkpoint_mqd(struct mqd_manager *mm, void *mqd, void *mqd_dst, voi
 
 static void restore_mqd(struct mqd_manager *mm, void **mqd,
 			struct kfd_mem_obj *mqd_mem_obj, uint64_t *gart_addr,
-			struct queue_properties *qp,
-			const void *mqd_src,
+			struct queue_properties *qp, const void *mqd_src,
 			const void *ctl_stack_src, const u32 ctl_stack_size)
 {
 	uint64_t addr;
@@ -337,14 +336,48 @@ static void restore_mqd(struct mqd_manager *mm, void **mqd,
 		*gart_addr = addr;
 
 	m->cp_hqd_pq_doorbell_control =
-		qp->doorbell_off <<
-			CP_HQD_PQ_DOORBELL_CONTROL__DOORBELL_OFFSET__SHIFT;
-	pr_debug("cp_hqd_pq_doorbell_control 0x%x\n",
-			m->cp_hqd_pq_doorbell_control);
+		qp->doorbell_off << CP_HQD_PQ_DOORBELL_CONTROL__DOORBELL_OFFSET__SHIFT;
+	pr_debug("cp_hqd_pq_doorbell_control 0x%x\n", m->cp_hqd_pq_doorbell_control);
 
 	qp->is_active = 0;
 }
 
+static void checkpoint_mqd_sdma(struct mqd_manager *mm,
+				void *mqd,
+				void *mqd_dst,
+				void *ctl_stack_dst)
+{
+	struct v11_sdma_mqd *m;
+
+	m = get_sdma_mqd(mqd);
+
+	memcpy(mqd_dst, m, sizeof(struct v11_sdma_mqd));
+}
+
+static void restore_mqd_sdma(struct mqd_manager *mm, void **mqd,
+			     struct kfd_mem_obj *mqd_mem_obj, uint64_t *gart_addr,
+			     struct queue_properties *qp,
+			     const void *mqd_src,
+			     const void *ctl_stack_src,
+			     const u32 ctl_stack_size)
+{
+	uint64_t addr;
+	struct v11_sdma_mqd *m;
+
+	m = (struct v11_sdma_mqd *) mqd_mem_obj->cpu_ptr;
+	addr = mqd_mem_obj->gpu_addr;
+
+	memcpy(m, mqd_src, sizeof(*m));
+
+	m->sdmax_rlcx_doorbell_offset =
+		qp->doorbell_off << SDMA0_QUEUE0_DOORBELL_OFFSET__OFFSET__SHIFT;
+
+	*mqd = m;
+	if (gart_addr)
+		*gart_addr = addr;
+
+	qp->is_active = 0;
+}
 
 static void init_mqd_hiq(struct mqd_manager *mm, void **mqd,
 			struct kfd_mem_obj *mqd_mem_obj, uint64_t *gart_addr,
@@ -529,8 +562,8 @@ struct mqd_manager *mqd_manager_init_v11(enum KFD_MQD_TYPE type,
 		mqd->update_mqd = update_mqd_sdma;
 		mqd->destroy_mqd = kfd_destroy_mqd_sdma;
 		mqd->is_occupied = kfd_is_occupied_sdma;
-		mqd->checkpoint_mqd = checkpoint_mqd;
-		mqd->restore_mqd = restore_mqd;
+		mqd->checkpoint_mqd = checkpoint_mqd_sdma;
+		mqd->restore_mqd = restore_mqd_sdma;
 		mqd->mqd_size = sizeof(struct v11_sdma_mqd);
 		mqd->mqd_stride = kfd_mqd_stride;
 #if defined(CONFIG_DEBUG_FS)