Merge tag 'dma-mapping-6.10-2024-05-31' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - dma-mapping benchmark error handling fixes (Fedor Pchelkin)

 - correct a config symbol reference in the DMA API documentation (Lukas
   Bulwahn)

* tag 'dma-mapping-6.10-2024-05-31' of git://git.infradead.org/users/hch/dma-mapping:
  Documentation/core-api: correct reference to SWIOTLB_DYNAMIC
  dma-mapping: benchmark: handle NUMA_NO_NODE correctly
  dma-mapping: benchmark: fix node id validation
  dma-mapping: benchmark: avoid needless copy_to_user if benchmark fails
  dma-mapping: benchmark: fix up kthread-related error handling

Author: torvalds

Documentation/core-api/swiotlb.rst

@@ -192,7 +192,7 @@ alignment larger than PAGE_SIZE.
 
 Dynamic swiotlb
 ---------------
-When CONFIG_DYNAMIC_SWIOTLB is enabled, swiotlb can do on-demand expansion of
+When CONFIG_SWIOTLB_DYNAMIC is enabled, swiotlb can do on-demand expansion of
 the amount of memory available for allocation as bounce buffers. If a bounce
 buffer request fails due to lack of available space, an asynchronous background
 task is kicked off to allocate memory from general system memory and turn it

kernel/dma/map_benchmark.c

@@ -101,7 +101,6 @@ static int do_map_benchmark(struct map_benchmark_data *map)
 	struct task_struct **tsk;
 	int threads = map->bparam.threads;
 	int node = map->bparam.node;
-	const cpumask_t *cpu_mask = cpumask_of_node(node);
 	u64 loops;
 	int ret = 0;
 	int i;
@@ -118,11 +117,13 @@ static int do_map_benchmark(struct map_benchmark_data *map)
 		if (IS_ERR(tsk[i])) {
 			pr_err("create dma_map thread failed\n");
 			ret = PTR_ERR(tsk[i]);
+			while (--i >= 0)
+				kthread_stop(tsk[i]);
 			goto out;
 		}
 
 		if (node != NUMA_NO_NODE)
-			kthread_bind_mask(tsk[i], cpu_mask);
+			kthread_bind_mask(tsk[i], cpumask_of_node(node));
 	}
 
 	/* clear the old value in the previous benchmark */
@@ -139,13 +140,17 @@ static int do_map_benchmark(struct map_benchmark_data *map)
 
 	msleep_interruptible(map->bparam.seconds * 1000);
 
-	/* wait for the completion of benchmark threads */
+	/* wait for the completion of all started benchmark threads */
 	for (i = 0; i < threads; i++) {
-		ret = kthread_stop(tsk[i]);
-		if (ret)
-			goto out;
+		int kthread_ret = kthread_stop_put(tsk[i]);
+
+		if (kthread_ret)
+			ret = kthread_ret;
 	}
 
+	if (ret)
+		goto out;
+
 	loops = atomic64_read(&map->loops);
 	if (likely(loops > 0)) {
 		u64 map_variance, unmap_variance;
@@ -170,8 +175,6 @@ static int do_map_benchmark(struct map_benchmark_data *map)
 	}
 
 out:
-	for (i = 0; i < threads; i++)
-		put_task_struct(tsk[i]);
 	put_device(map->dev);
 	kfree(tsk);
 	return ret;
@@ -208,7 +211,8 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
 		}
 
 		if (map->bparam.node != NUMA_NO_NODE &&
-		    !node_possible(map->bparam.node)) {
+		    (map->bparam.node < 0 || map->bparam.node >= MAX_NUMNODES ||
+		     !node_possible(map->bparam.node))) {
 			pr_err("invalid numa node\n");
 			return -EINVAL;
 		}
@@ -252,6 +256,9 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
 		 * dma_mask changed by benchmark
 		 */
 		dma_set_mask(map->dev, old_dma_mask);
+
+		if (ret)
+			return ret;
 		break;
 	default:
 		return -EINVAL;