selftests/bpf: fix array_size.cocci warning

Fix the array_size.cocci warning in tools/testing/selftests/bpf/

Use `ARRAY_SIZE(arr)` instead of forms like `sizeof(arr)/sizeof(arr[0])`.

syscall.c and test_rdonly_maps.c don't contain header files which
implement ARRAY_SIZE() macro. So I add `#include <linux/kernel.h>`,
in which ARRAY_SIZE(arr) not only calculates the size of `arr`, but also
checks that `arr` is really an array (using __must_be_array(arr)).

Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>

Author: Guo Zhengkui

tools/testing/selftests/bpf/prog_tests/cgroup_attach_autodetach.c

@@ -14,7 +14,7 @@ static int prog_load(void)
 		BPF_MOV64_IMM(BPF_REG_0, 1), /* r0 = 1 */
 		BPF_EXIT_INSN(),
 	};
-	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+	size_t insns_cnt = ARRAY_SIZE(prog);
 
 	return bpf_test_load_program(BPF_PROG_TYPE_CGROUP_SKB,
 			       prog, insns_cnt, "GPL", 0,

tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c

@@ -63,7 +63,7 @@ static int prog_load_cnt(int verdict, int val)
 		BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
 		BPF_EXIT_INSN(),
 	};
-	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+	size_t insns_cnt = ARRAY_SIZE(prog);
 	int ret;
 
 	ret = bpf_test_load_program(BPF_PROG_TYPE_CGROUP_SKB,

tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c

@@ -16,7 +16,7 @@ static int prog_load(int verdict)
 		BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
 		BPF_EXIT_INSN(),
 	};
-	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+	size_t insns_cnt = ARRAY_SIZE(prog);
 
 	return bpf_test_load_program(BPF_PROG_TYPE_CGROUP_SKB,
 			       prog, insns_cnt, "GPL", 0,

tools/testing/selftests/bpf/prog_tests/global_data.c

@@ -29,7 +29,7 @@ static void test_global_data_number(struct bpf_object *obj, __u32 duration)
 		{ "relocate .rodata reference", 10, ~0 },
 	};
 
-	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
 		err = bpf_map_lookup_elem(map_fd, &tests[i].key, &num);
 		CHECK(err || num != tests[i].num, tests[i].name,
 		      "err %d result %llx expected %llx\n",
@@ -58,7 +58,7 @@ static void test_global_data_string(struct bpf_object *obj, __u32 duration)
 		{ "relocate .bss reference",    4, "\0\0hello" },
 	};
 
-	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
 		err = bpf_map_lookup_elem(map_fd, &tests[i].key, str);
 		CHECK(err || memcmp(str, tests[i].str, sizeof(str)),
 		      tests[i].name, "err %d result \'%s\' expected \'%s\'\n",
@@ -92,7 +92,7 @@ static void test_global_data_struct(struct bpf_object *obj, __u32 duration)
 		{ "relocate .data reference",   3, { 41, 0xeeeeefef, 0x2111111111111111ULL, } },
 	};
 
-	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
 		err = bpf_map_lookup_elem(map_fd, &tests[i].key, &val);
 		CHECK(err || memcmp(&val, &tests[i].val, sizeof(val)),
 		      tests[i].name, "err %d result { %u, %u, %llu } expected { %u, %u, %llu }\n",

tools/testing/selftests/bpf/prog_tests/obj_name.c

@@ -20,7 +20,7 @@ void test_obj_name(void)
 	__u32 duration = 0;
 	int i;
 
-	for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
 		size_t name_len = strlen(tests[i].name) + 1;
 		union bpf_attr attr;
 		size_t ncopy;

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

@@ -6,6 +6,7 @@
 #include <bpf/bpf_tracing.h>
 #include <../../../tools/include/linux/filter.h>
 #include <linux/btf.h>
+#include <linux/kernel.h>
 
 char _license[] SEC("license") = "GPL";
 
@@ -82,7 +83,7 @@ int bpf_prog(struct args *ctx)
 	static __u64 value = 34;
 	static union bpf_attr prog_load_attr = {
 		.prog_type = BPF_PROG_TYPE_XDP,
-		.insn_cnt = sizeof(insns) / sizeof(insns[0]),
+		.insn_cnt = ARRAY_SIZE(insns),
 	};
 	int ret;
 

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

@@ -3,6 +3,7 @@
 
 #include <linux/ptrace.h>
 #include <linux/bpf.h>
+#include <linux/kernel.h>
 #include <bpf/bpf_helpers.h>
 
 const struct {
@@ -64,7 +65,7 @@ int full_loop(struct pt_regs *ctx)
 {
 	/* prevent compiler to optimize everything out */
 	unsigned * volatile p = (void *)&rdonly_values.a;
-	int i = sizeof(rdonly_values.a) / sizeof(rdonly_values.a[0]);
+	int i = ARRAY_SIZE(rdonly_values.a);
 	unsigned iters = 0, sum = 0;
 
 	/* validate verifier can allow full loop as well */

tools/testing/selftests/bpf/test_cgroup_storage.c

@@ -36,7 +36,7 @@ int main(int argc, char **argv)
 		BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
 		BPF_EXIT_INSN(),
 	};
-	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+	size_t insns_cnt = ARRAY_SIZE(prog);
 	int error = EXIT_FAILURE;
 	int map_fd, percpu_map_fd, prog_fd, cgroup_fd;
 	struct bpf_cgroup_storage_key key;

tools/testing/selftests/bpf/test_lru_map.c

@@ -878,11 +878,11 @@ int main(int argc, char **argv)
 	assert(nr_cpus != -1);
 	printf("nr_cpus:%d\n\n", nr_cpus);
 
-	for (f = 0; f < sizeof(map_flags) / sizeof(*map_flags); f++) {
+	for (f = 0; f < ARRAY_SIZE(map_flags); f++) {
 		unsigned int tgt_free = (map_flags[f] & BPF_F_NO_COMMON_LRU) ?
 			PERCPU_FREE_TARGET : LOCAL_FREE_TARGET;
 
-		for (t = 0; t < sizeof(map_types) / sizeof(*map_types); t++) {
+		for (t = 0; t < ARRAY_SIZE(map_types); t++) {
 			test_lru_sanity0(map_types[t], map_flags[f]);
 			test_lru_sanity1(map_types[t], map_flags[f], tgt_free);
 			test_lru_sanity2(map_types[t], map_flags[f], tgt_free);

tools/testing/selftests/bpf/test_sock_addr.c

@@ -723,7 +723,7 @@ static int xmsg_ret_only_prog_load(const struct sock_addr_test *test,
 		BPF_MOV64_IMM(BPF_REG_0, rc),
 		BPF_EXIT_INSN(),
 	};
-	return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
+	return load_insns(test, insns, ARRAY_SIZE(insns));
 }
 
 static int sendmsg_allow_prog_load(const struct sock_addr_test *test)
@@ -795,7 +795,7 @@ static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test)
 		BPF_EXIT_INSN(),
 	};
 
-	return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
+	return load_insns(test, insns, ARRAY_SIZE(insns));
 }
 
 static int recvmsg4_rw_c_prog_load(const struct sock_addr_test *test)
@@ -858,7 +858,7 @@ static int sendmsg6_rw_dst_asm_prog_load(const struct sock_addr_test *test,
 		BPF_EXIT_INSN(),
 	};
 
-	return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
+	return load_insns(test, insns, ARRAY_SIZE(insns));
 }
 
 static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test)