Re: [PATCH 1/2] trace: add support for "trace clear"

On 12/13/24 13:16, Ilias Apalodimas wrote:

Thanks,

Apologies I missed something else as well

On Fri, 13 Dec 2024 at 14:14, Jerome Forissier jerome.forissier@linaro.org wrote:

...

On 12/13/24 13:09, Ilias Apalodimas wrote:

...

Hi Jerome

On Mon, 9 Dec 2024 at 17:32, Jerome Forissier jerome.forissier@linaro.org wrote:

...

Implement a "trace clear" command to delete the currently accumulated trace data. This comes handy when someone needs to trace a particular command. For example:

=> trace clear; dhcp; trace pause => trace stats => trace calls 0x02100000 0x10000000 => tftpput $profbase $profoffset 192.168.0.16:trace.bin

Signed-off-by: Jerome Forissier jerome.forissier@linaro.org

cmd/trace.c | 13 ++++++++++++- include/trace.h | 2 ++ lib/trace.c | 47 +++++++++++++++++++++++++++++++++-------------- 3 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/cmd/trace.c b/cmd/trace.c index 937e6a682ad..e95ac7ca9da 100644 --- a/cmd/trace.c +++ b/cmd/trace.c @@ -87,8 +87,18 @@ int do_trace(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) trace_set_enabled(0); break; case 'c':

•           if (create_call_list(argc, argv))
  

•           switch (*(cmd + 1)) {
  

•           case 'a':
  

•                   if (create_call_list(argc, argv))
  

•                           return cmd_usage(cmdtp);
  

•                   break;
  

•           case 'l':
  

•                   if (trace_clear())
  

•                           return CMD_RET_FAILURE;
  

•                   break;
  

Instead of this, mind changing the command to trace wipe or something similar? Then we can have a discrete case for 'w' rather than scanning for a string

Good idea.

Thanks,

Jerome

...

Cheers /Ilias

...

•           default:
                    return cmd_usage(cmdtp);
  

•           }
            break;
    case 'r':
            trace_set_enabled(1);
  

@@ -113,6 +123,7 @@ U_BOOT_CMD( "stats - display tracing statistics\n" "trace pause - pause tracing\n" "trace resume - resume tracing\n"

•   "trace clear                        - clear traces\n"
    "trace funclist [<addr> <size>]     - dump function list into buffer\n"
    "trace calls  [<addr> <size>]       "
            "- dump function call trace into buffer"
  

diff --git a/include/trace.h b/include/trace.h index 763d6d1255a..782eaae2fc2 100644 --- a/include/trace.h +++ b/include/trace.h @@ -100,6 +100,8 @@ void trace_set_enabled(int enabled);

int trace_early_init(void);

+int trace_clear(void);

/**

• Init the trace system

diff --git a/lib/trace.c b/lib/trace.c index cabbe47b58a..def9f912c92 100644 --- a/lib/trace.c +++ b/lib/trace.c @@ -351,14 +351,8 @@ static int get_func_count(void) return gd->mon_len / FUNC_SITE_SIZE; }

-/**

• • trace_init() - initialize the tracing system and enable it
• • @buff: Pointer to trace buffer
• • @buff_size: Size of trace buffer
• • Return: 0 if ok
• */

-int notrace trace_init(void *buff, size_t buff_size) +static int notrace trace_init_(void *buff, size_t buff_size, bool copy_early,

•                          bool enable)
  

{ int func_count = get_func_count(); size_t needed; @@ -368,7 +362,7 @@ int notrace trace_init(void *buff, size_t buff_size) return func_count; trace_save_gd();

•   if (!was_disabled) {
  

•   if (copy_early) {
  

#ifdef CONFIG_TRACE_EARLY ulong used, count; char *end; @@ -394,9 +388,6 @@ int notrace trace_init(void *buff, size_t buff_size) } puts("\n"); memcpy(buff, hdr, used); -#else

•           puts("trace: already enabled\n");
  

•           return -EALREADY;
  

#endif } hdr = (struct trace_hdr *)buff; @@ -419,13 +410,41 @@ int notrace trace_init(void *buff, size_t buff_size) hdr->ftrace_size = (buff_size - needed) / sizeof(*hdr->ftrace); hdr->depth_limit = CONFIG_TRACE_CALL_DEPTH_LIMIT;

•   puts("trace: enabled\n");
  

•   trace_enabled = 1;
  

•   printf("trace: initialized, %senabled\n", enable ? "" : "not ");
  

•   trace_enabled = enable;
    trace_inited = 1;
  
    return 0;
  

}

+/**

• • trace_init() - initialize the tracing system and enable it
• • @buff: Pointer to trace buffer
• • @buff_size: Size of trace buffer
• • Return: 0 if ok
• */

+int notrace trace_init(void *buff, size_t buff_size) +{

•   /* If traces are enabled already, we may have early traces to copy */
  

•   return trace_init_(buff, buff_size, trace_enabled, true);
  

This is a global, so you can skip passing it and just check the trace_enabled in trace_init_()

Unfortunately not, because trace_clear() needs to be able to invoke trace_init_() with copy_early = false (we never want to copy the early trace buffer when coming from the 'trace clear' command).

Thanks,