1 files changed, 98 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_arena_large.c b/tools/testing/selftests/bpf/progs/verifier_arena_large.c
index f94f30cf1bb8..9dbdf123542d 100644
--- a/tools/testing/selftests/bpf/progs/verifier_arena_large.c
+++ b/tools/testing/selftests/bpf/progs/verifier_arena_large.c
@@ -67,6 +67,104 @@ int big_alloc1(void *ctx)
 	return 0;
 }
 
+/* Try to access a reserved page. Behavior should be identical with accessing unallocated pages. */
+SEC("syscall")
+__success __retval(0)
+int access_reserved(void *ctx)
+{
+#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
+	volatile char __arena *page;
+	char __arena *base;
+	const size_t len = 4;
+	int ret, i;
+
+	/* Get a separate region of the arena. */
+	page = base = arena_base(&arena) + 16384 * PAGE_SIZE;
+
+	ret = bpf_arena_reserve_pages(&arena, base, len);
+	if (ret)
+		return 1;
+
+	/* Try to dirty reserved memory. */
+	for (i = 0; i < len && can_loop; i++)
+		*page = 0x5a;
+
+	for (i = 0; i < len && can_loop; i++) {
+		page = (volatile char __arena *)(base + i * PAGE_SIZE);
+
+		/*
+		 * Error out in case either the write went through,
+		 * or the address has random garbage.
+		 */
+		if (*page == 0x5a)
+			return 2 + 2 * i;
+
+		if (*page)
+			return 2 + 2 * i + 1;
+	}
+#endif
+	return 0;
+}
+
+/* Try to allocate a region overlapping with a reservation. */
+SEC("syscall")
+__success __retval(0)
+int request_partially_reserved(void *ctx)
+{
+#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
+	volatile char __arena *page;
+	char __arena *base;
+	int ret;
+
+	/* Add an arbitrary page offset. */
+	page = base = arena_base(&arena) + 4096 * __PAGE_SIZE;
+
+	ret = bpf_arena_reserve_pages(&arena, base + 3 * __PAGE_SIZE, 4);
+	if (ret)
+		return 1;
+
+	page = bpf_arena_alloc_pages(&arena, base, 5, NUMA_NO_NODE, 0);
+	if ((u64)page != 0ULL)
+		return 2;
+#endif
+	return 0;
+}
+
+SEC("syscall")
+__success __retval(0)
+int free_reserved(void *ctx)
+{
+#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
+	char __arena *addr;
+	char __arena *page;
+	int ret;
+
+	/* Add an arbitrary page offset. */
+	addr = arena_base(&arena) + 32768 * __PAGE_SIZE;
+
+	page = bpf_arena_alloc_pages(&arena, addr, 2, NUMA_NO_NODE, 0);
+	if (!page)
+		return 1;
+
+	ret = bpf_arena_reserve_pages(&arena, addr + 2 * __PAGE_SIZE, 2);
+	if (ret)
+		return 2;
+
+	/*
+	 * Reserved and allocated pages should be interchangeable for
+	 * bpf_arena_free_pages(). Free a reserved and an allocated
+	 * page with a single call.
+	 */
+	bpf_arena_free_pages(&arena, addr + __PAGE_SIZE , 2);
+
+	/* The free call above should have succeeded, so this allocation should too. */
+	page = bpf_arena_alloc_pages(&arena, addr + __PAGE_SIZE, 2, NUMA_NO_NODE, 0);
+	if (!page)
+		return 3;
+#endif
+	return 0;
+}
+
 #if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
 #define PAGE_CNT 100
 __u8 __arena * __arena page[PAGE_CNT]; /* occupies the first page */