On Sun, Oct 9, 2022 at 3:00 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Adding load_kallsyms_refresh function to re-read symbols from
> /proc/kallsyms file.
>
> This will be needed to get proper functions addresses from
> bpf_testmod.ko module, which is loaded/unloaded several times
> during the tests run, so symbols might be already old when
> we need to use them.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/trace_helpers.c | 20 +++++++++++++-------
> tools/testing/selftests/bpf/trace_helpers.h | 2 ++
> 2 files changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
> index 9c4be2cdb21a..09a16a77bae4 100644
> --- a/tools/testing/selftests/bpf/trace_helpers.c
> +++ b/tools/testing/selftests/bpf/trace_helpers.c
> @@ -23,7 +23,7 @@ static int ksym_cmp(const void *p1, const void *p2)
> return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
> }
>
> -int load_kallsyms(void)
> +int load_kallsyms_refresh(void)
> {
> FILE *f;
> char func[256], buf[256];
> @@ -31,12 +31,7 @@ int load_kallsyms(void)
> void *addr;
> int i = 0;
>
> - /*
> - * This is called/used from multiplace places,
> - * load symbols just once.
> - */
> - if (sym_cnt)
> - return 0;
> + sym_cnt = 0;
>
> f = fopen("/proc/kallsyms", "r");
> if (!f)
> @@ -57,6 +52,17 @@ int load_kallsyms(void)
> return 0;
> }
>
> +int load_kallsyms(void)
> +{
> + /*
> + * This is called/used from multiplace places,
> + * load symbols just once.
> + */
> + if (sym_cnt)
> + return 0;
> + return load_kallsyms_refresh();
> +}
> +
> struct ksym *ksym_search(long key)
> {
> int start = 0, end = sym_cnt;
> diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h
> index 238a9c98cde2..53efde0e2998 100644
> --- a/tools/testing/selftests/bpf/trace_helpers.h
> +++ b/tools/testing/selftests/bpf/trace_helpers.h
> @@ -10,6 +10,8 @@ struct ksym {
> };
>
> int load_kallsyms(void);
> +int load_kallsyms_refresh(void);
> +
> struct ksym *ksym_search(long key);
> long ksym_get_addr(const char *name);
>
> --
> 2.37.3
>
