Re: [PATCH bpf-next 2/3] bpf: allow %pB in bpf_seq_printf()

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 6/23/20 9:08 AM, Song Liu wrote:
> This makes it easy to dump stack trace with bpf_seq_printf().
>
> Signed-off-by: Song Liu <songliubraving@xxxxxx>
> ---
>   kernel/trace/bpf_trace.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 2c13bcb5c2bce..ced3176801ae8 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -636,7 +636,8 @@ BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
>   		if (fmt[i] == 'p') {
>   			if (fmt[i + 1] == 0 ||
>   			    fmt[i + 1] == 'K' ||
> -			    fmt[i + 1] == 'x') {
> +			    fmt[i + 1] == 'x' ||
> +			    fmt[i + 1] == 'B') {
>   				/* just kernel pointers */
>   				params[fmt_cnt] = args[fmt_cnt];
>   				fmt_cnt++;

Why only bpf_seq_printf(), what about bpf_trace_printk()?