selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/rust/helpers/dma.c b/rust/helpers/dma.c
new file mode 100644
index 000000000..9fbeb507b
--- /dev/null
+++ b/rust/helpers/dma.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/dma-mapping.h>
+
+__rust_helper void *rust_helper_dma_alloc_attrs(struct device *dev, size_t size,
+						dma_addr_t *dma_handle,
+						gfp_t flag, unsigned long attrs)
+{
+	return dma_alloc_attrs(dev, size, dma_handle, flag, attrs);
+}
+
+__rust_helper void rust_helper_dma_free_attrs(struct device *dev, size_t size,
+					      void *cpu_addr,
+					      dma_addr_t dma_handle,
+					      unsigned long attrs)
+{
+	dma_free_attrs(dev, size, cpu_addr, dma_handle, attrs);
+}
+
+__rust_helper int rust_helper_dma_set_mask_and_coherent(struct device *dev,
+							u64 mask)
+{
+	return dma_set_mask_and_coherent(dev, mask);
+}
+
+__rust_helper int rust_helper_dma_set_mask(struct device *dev, u64 mask)
+{
+	return dma_set_mask(dev, mask);
+}
+
+__rust_helper int rust_helper_dma_set_coherent_mask(struct device *dev, u64 mask)
+{
+	return dma_set_coherent_mask(dev, mask);
+}
+
+__rust_helper int rust_helper_dma_map_sgtable(struct device *dev, struct sg_table *sgt,
+					      enum dma_data_direction dir, unsigned long attrs)
+{
+	return dma_map_sgtable(dev, sgt, dir, attrs);
+}
+
+__rust_helper size_t rust_helper_dma_max_mapping_size(struct device *dev)
+{
+	return dma_max_mapping_size(dev);
+}
+
+__rust_helper void rust_helper_dma_set_max_seg_size(struct device *dev,
+						    unsigned int size)
+{
+	dma_set_max_seg_size(dev, size);
+}