selftests/bpf: revert iter test subprog precision workaround

Now that precision propagation is supported fully in the presence of
subprogs, there is no need to work around iter test. Revert original
workaround.

This reverts be7dbd27 ("selftests/bpf: avoid mark_all_scalars_precise() trigger in one of iter tests").
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-11-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/progs/iters.c

@@ -651,29 +651,25 @@ int iter_stack_array_loop(const void *ctx)
 	return sum;
 }
 
-#define ARR_SZ 16
-
-static __noinline void fill(struct bpf_iter_num *it, int *arr, int mul)
+static __noinline void fill(struct bpf_iter_num *it, int *arr, __u32 n, int mul)
 {
-	int *t;
-	__u64 i;
+	int *t, i;
 
 	while ((t = bpf_iter_num_next(it))) {
 		i = *t;
-		if (i >= ARR_SZ)
+		if (i >= n)
 			break;
 		arr[i] =  i * mul;
 	}
 }
 
-static __noinline int sum(struct bpf_iter_num *it, int *arr)
+static __noinline int sum(struct bpf_iter_num *it, int *arr, __u32 n)
 {
-	int *t, sum = 0;;
-	__u64 i;
+	int *t, i, sum = 0;;
 
 	while ((t = bpf_iter_num_next(it))) {
 		i = *t;
-		if (i >= ARR_SZ)
+		if (i >= n)
 			break;
 		sum += arr[i];
 	}
@@ -685,7 +681,7 @@ SEC("raw_tp")
 __success
 int iter_pass_iter_ptr_to_subprog(const void *ctx)
 {
-	int arr1[ARR_SZ], arr2[ARR_SZ];
+	int arr1[16], arr2[32];
 	struct bpf_iter_num it;
 	int n, sum1, sum2;
 
@@ -694,25 +690,25 @@ int iter_pass_iter_ptr_to_subprog(const void *ctx)
 	/* fill arr1 */
 	n = ARRAY_SIZE(arr1);
 	bpf_iter_num_new(&it, 0, n);
-	fill(&it, arr1, 2);
+	fill(&it, arr1, n, 2);
 	bpf_iter_num_destroy(&it);
 
 	/* fill arr2 */
 	n = ARRAY_SIZE(arr2);
 	bpf_iter_num_new(&it, 0, n);
-	fill(&it, arr2, 10);
+	fill(&it, arr2, n, 10);
 	bpf_iter_num_destroy(&it);
 
 	/* sum arr1 */
 	n = ARRAY_SIZE(arr1);
 	bpf_iter_num_new(&it, 0, n);
-	sum1 = sum(&it, arr1);
+	sum1 = sum(&it, arr1, n);
 	bpf_iter_num_destroy(&it);
 
 	/* sum arr2 */
 	n = ARRAY_SIZE(arr2);
 	bpf_iter_num_new(&it, 0, n);
-	sum2 = sum(&it, arr2);
+	sum2 = sum(&it, arr2, n);
 	bpf_iter_num_destroy(&it);
 
 	bpf_printk("sum1=%d, sum2=%d", sum1, sum2);