diff mbox series

trace: add support for "trace clear"

Message ID 20241206102917.1095207-1-jerome.forissier@linaro.org
State Superseded
Headers show
Series trace: add support for "trace clear" | expand

Commit Message

Jerome Forissier Dec. 6, 2024, 10:29 a.m. UTC
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(-)

Comments

Tom Rini Dec. 6, 2024, 5:07 p.m. UTC | #1
On Fri, Dec 06, 2024 at 11:29:16AM +0100, Jerome Forissier 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(-)

We have trace tests already, can they easily be expanded to cover this?
Jerome Forissier Dec. 9, 2024, 3:34 p.m. UTC | #2
On 12/6/24 18:07, Tom Rini wrote:
> On Fri, Dec 06, 2024 at 11:29:16AM +0100, Jerome Forissier 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(-)
> 
> We have trace tests already, can they easily be expanded to cover this?
> 

Sure, please check [1].

[1] https://lists.denx.de/pipermail/u-boot/2024-December/574457.html

Thanks,
diff mbox series

Patch

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;
+		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);
+}
+
+/**
+ * trace_clear() - clear accumulated traced data
+ *
+ * May be called with tracing enabled or disabled.
+ */
+int notrace trace_clear(void)
+{
+	bool was_enabled = trace_enabled;
+
+	if (trace_enabled)
+		trace_enabled = 0;
+	return trace_init_(gd->trace_buff, CONFIG_TRACE_BUFFER_SIZE,
+			   false, was_enabled);
+}
+
 #ifdef CONFIG_TRACE_EARLY
 /**
  * trace_early_init() - initialize the tracing system for early tracing