Re: [PATCH net-next 1/3] trace: add variant without spacing in trace_print_hex_seq

From: Arnaldo Carvalho de Melo
Date: Thu Jan 26 2017 - 14:53:55 EST


Em Wed, Jan 25, 2017 at 02:28:16AM +0100, Daniel Borkmann escreveu:
> For upcoming tracepoint support for BPF, we want to dump the program's
> tag. Format should be similar to __print_hex(), but without spacing.
> Add a __print_hex_str() variant for exactly that purpose that reuses
> trace_print_hex_seq().

Steven should be back to his side of the wall soon, will wait for his
Ack, ok?

- Arnaldo

> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> ---
> include/linux/trace_events.h | 3 ++-
> include/trace/trace_events.h | 8 +++++++-
> kernel/trace/trace_output.c | 7 ++++---
> 3 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
> index be00761..cfa475a 100644
> --- a/include/linux/trace_events.h
> +++ b/include/linux/trace_events.h
> @@ -33,7 +33,8 @@ const char *trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
> unsigned int bitmask_size);
>
> const char *trace_print_hex_seq(struct trace_seq *p,
> - const unsigned char *buf, int len);
> + const unsigned char *buf, int len,
> + bool spacing);
>
> const char *trace_print_array_seq(struct trace_seq *p,
> const void *buf, int count,
> diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
> index 467e12f..9f68462 100644
> --- a/include/trace/trace_events.h
> +++ b/include/trace/trace_events.h
> @@ -297,7 +297,12 @@
> #endif
>
> #undef __print_hex
> -#define __print_hex(buf, buf_len) trace_print_hex_seq(p, buf, buf_len)
> +#define __print_hex(buf, buf_len) \
> + trace_print_hex_seq(p, buf, buf_len, true)
> +
> +#undef __print_hex_str
> +#define __print_hex_str(buf, buf_len) \
> + trace_print_hex_seq(p, buf, buf_len, false)
>
> #undef __print_array
> #define __print_array(array, count, el_size) \
> @@ -711,6 +716,7 @@
> #undef __print_flags
> #undef __print_symbolic
> #undef __print_hex
> +#undef __print_hex_str
> #undef __get_dynamic_array
> #undef __get_dynamic_array_len
> #undef __get_str
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index 5d33a73..30a144b1 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -163,14 +163,15 @@ enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
> EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
>
> const char *
> -trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
> +trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
> + bool spacing)
> {
> int i;
> const char *ret = trace_seq_buffer_ptr(p);
>
> for (i = 0; i < buf_len; i++)
> - trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
> -
> + trace_seq_printf(p, "%s%2.2x", !spacing || i == 0 ? "" : " ",
> + buf[i]);
> trace_seq_putc(p, 0);
>
> return ret;
> --
> 1.9.3