On Wed, Sep 30, 2020 at 08:20:58AM -0700, Song Liu wrote:
> diff --git a/tools/testing/selftests/bpf/progs/test_pe_preserve_elems.c
> b/tools/testing/selftests/bpf/progs/test_pe_preserve_elems.c
> new file mode 100644
> index 0000000000000..dc77e406de41f
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_pe_preserve_elems.c
> @@ -0,0 +1,44 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2020 Facebook
> +#include "vmlinux.h"
Does it actually need vmlinux.h ?
Just checking to make sure it compiles on older kernels.
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +
> +struct {
> + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
> + __uint(max_entries, 1);
> + __uint(key_size, sizeof(int));
> + __uint(value_size, sizeof(int));
> +} array_1 SEC(".maps");
> +
> +struct {
> + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
> + __uint(max_entries, 1);
> + __uint(key_size, sizeof(int));
> + __uint(value_size, sizeof(int));
> + __uint(map_flags, BPF_F_PRESERVE_ELEMS);
> +} array_2 SEC(".maps");
> +
> +SEC("raw_tp/sched_switch")
> +int BPF_PROG(read_array_1)
> +{
> + struct bpf_perf_event_value val;
> + long ret;
> +
> + ret = bpf_perf_event_read_value(&array_1, 0, &val, sizeof(val));
> + bpf_printk("read_array_1 returns %ld", ret);
> + return ret;
> +}
> +
> +SEC("raw_tp/task_rename")
> +int BPF_PROG(read_array_2)
> +{
> + struct bpf_perf_event_value val;
> + long ret;
> +
> + ret = bpf_perf_event_read_value(&array_2, 0, &val, sizeof(val));
> + bpf_printk("read_array_2 returns %ld", ret);
Please remove printk from the tests. It only spams the trace_pipe.
> + return ret;
The return code is already checked as far as I can see.
That's enough to pass/fail the test, right?
