2021-11-17 13:21:24

by Guo Zhengkui

Subject: [PATCH] selftests/bpf: fix array_size.cocci warning:

Use ARRAY_SIZE() because it uses __must_be_array(arr) to make sure
arr is really an array.

Signed-off-by: Guo Zhengkui <[email protected]>
---
.../testing/selftests/bpf/prog_tests/cgroup_attach_override.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c
index 356547e849e2..1921c5040d8c 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0

+#include <linux/kernel.h>
#include <test_progs.h>

#include "cgroup_helpers.h"
@@ -16,10 +17,9 @@ 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);

return bpf_test_load_program(BPF_PROG_TYPE_CGROUP_SKB,
- prog, insns_cnt, "GPL", 0,
+ prog, ARRAY_SIZE(prog), "GPL", 0,
bpf_log_buf, BPF_LOG_BUF_SIZE);
}

--
2.20.1

2021-11-17 22:42:16

by Daniel Borkmann

Subject: Re: [PATCH] selftests/bpf: fix array_size.cocci warning:

On 11/17/21 2:20 PM, Guo Zhengkui wrote:
> Use ARRAY_SIZE() because it uses __must_be_array(arr) to make sure
> arr is really an array.
>
> Signed-off-by: Guo Zhengkui <[email protected]>
> ---
> .../testing/selftests/bpf/prog_tests/cgroup_attach_override.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c
> index 356547e849e2..1921c5040d8c 100644
> --- a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c
> +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_override.c
> @@ -1,5 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
>
> +#include <linux/kernel.h>
> #include <test_progs.h>

No need for the extra include. test_progs.h already includes bpf_util.h, please check
such trivialities before submission. Simple grep would have revealed use of ARRAY_SIZE()
in various places under tools/testing/selftests/bpf/prog_tests/.

> #include "cgroup_helpers.h"
> @@ -16,10 +17,9 @@ 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);
>
> return bpf_test_load_program(BPF_PROG_TYPE_CGROUP_SKB,
> - prog, insns_cnt, "GPL", 0,
> + prog, ARRAY_SIZE(prog), "GPL", 0,
> bpf_log_buf, BPF_LOG_BUF_SIZE);

There are many more similar occurrences. Please just send one cleanup patch to reduce
churn in the git log.

Thanks,
Daniel

2021-11-18 07:12:55

by Guo Zhengkui

Subject: Re: [PATCH] selftests/bpf: fix array_size.cocci warning

> No need for the extra include. test_progs.h already includes bpf_util.h, please check
> such trivialities before submission. Simple grep would have revealed use of ARRAY_SIZE()
> in various places under tools/testing/selftests/bpf/prog_tests/.

Actually, ARRAY_SIZE() in ./include/linux/kernel.h is diffrent from the one defined in bpf_util.h:

./include/linux/kernel.h
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

./tools/testing/selftests/bpf/bpf_util.h
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

__must_be_array() ensures arr is an array, which is better than the one defined in bpf_util.h

> here are many more similar occurrences. Please just send one cleanup patch to reduce churn in the git log.

Yes, I will commit another patch.