On Mon, May 17, 2021 at 2:29 AM Florent Revest <revest@xxxxxxxxxxxx> wrote:
>
> The per-cpu buffers contain bprintf data rather than printf arguments.
> The macro name and comment were a bit confusing, this rewords them in a
> clearer way.
>
> Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
> ---
> kernel/bpf/helpers.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index ef658a9ea5c9..3a5ab614cbb0 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -692,13 +692,14 @@ static int bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
> return -EINVAL;
> }
>
> -/* Per-cpu temp buffers which can be used by printf-like helpers for %s or %p
> +/* Per-cpu temp buffers used by printf-like helpers to store the bprintf binary
> + * arguments representation.
> */
> -#define MAX_PRINTF_BUF_LEN 512
> +#define MAX_BPRINTF_BUF_LEN 512
>
> /* Support executing three nested bprintf helper calls on a given CPU */
> struct bpf_bprintf_buffers {
> - char tmp_bufs[3][MAX_PRINTF_BUF_LEN];
> + char tmp_bufs[3][MAX_BPRINTF_BUF_LEN];
> };
> static DEFINE_PER_CPU(struct bpf_bprintf_buffers, bpf_bprintf_bufs);
> static DEFINE_PER_CPU(int, bpf_bprintf_nest_level);
> @@ -761,7 +762,7 @@ int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
> if (num_args && try_get_fmt_tmp_buf(&tmp_buf))
> return -EBUSY;
>
> - tmp_buf_end = tmp_buf + MAX_PRINTF_BUF_LEN;
> + tmp_buf_end = tmp_buf + MAX_BPRINTF_BUF_LEN;
> *bin_args = (u32 *)tmp_buf;
> }
>
> --
> 2.31.1.751.gd2f1c929bd-goog
>
