On Thu, 25 Mar 2021 08:40:37 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> A new local function is added to check if a given trace clock is
> supported by the ftrace:
> clock_is_supported()
> This function is used by the other patches from the set.
> The logic should be part of the tracefs library, when a tracefs API is
> implemeneted, this local funciton will be removed.
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> ---
> tracecmd/trace-record.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
> index 635897e1..c7197ba0 100644
> --- a/tracecmd/trace-record.c
> +++ b/tracecmd/trace-record.c
> @@ -5683,6 +5683,34 @@ check_instance_die(struct buffer_instance *instance, char *param)
> tracefs_instance_get_name(instance->tracefs), param);
> }
>
> +static bool clock_is_supported(struct tracefs_instance *instance, const char *clock)
> +{
> + char *all_clocks = NULL;
> + char *ret = NULL;
> +
> + all_clocks = tracefs_instance_file_read(instance, "trace_clock", NULL);
> + if (!all_clocks)
> + return false;
> +
> + ret = strstr(all_clocks, clock);
> + if (ret && (ret == all_clocks || ret[-1] == ' ' || ret[-1] == '[')) {
> + switch (ret[strlen(clock)]) {
> + case ' ':
> + case '\0':
> + case ']':
> + case '\n':
> + break;
> + default:
> + ret = NULL;
> + }
> + } else {
> + ret = NULL;
> + }
> + free(all_clocks);
> +
> + return ret != NULL;
> +}
> +
> static void parse_record_options(int argc,
> char **argv,
> enum trace_cmd curr_cmd,
This patch could add the check to the -C as well. I went ahead and did that
with the below patch. It doesn't affect the result of the series, it was
just that this functionality could be a stand alone.
I'll apply this entire series.
Thanks Tzvetomir!
-- Steve
From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx>
Date: Thu, 25 Mar 2021 08:40:37 +0200
Subject: [PATCH] trace-cmd: Add new local function to check if a trace clock
is supported
A new local function is added to check if a given trace clock is
supported by the ftrace:
clock_is_supported()
And test that the passed in clock is supported.
The logic should be part of the tracefs library, when a tracefs API is
implemeneted, this local funciton will be removed.
Link: https://lore.kernel.org/linux-trace-devel/20210325064055.539554-6-tz.stoyanov@xxxxxxxxx
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
[ Added test to make sure passed in clock is supported ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
tracecmd/trace-record.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index e9039cd3..c6c14818 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -5687,6 +5687,34 @@ check_instance_die(struct buffer_instance *instance, char *param)
tracefs_instance_get_name(instance->tracefs), param);
}
+static bool clock_is_supported(struct tracefs_instance *instance, const char *clock)
+{
+ char *all_clocks = NULL;
+ char *ret = NULL;
+
+ all_clocks = tracefs_instance_file_read(instance, "trace_clock", NULL);
+ if (!all_clocks)
+ return false;
+
+ ret = strstr(all_clocks, clock);
+ if (ret && (ret == all_clocks || ret[-1] == ' ' || ret[-1] == '[')) {
+ switch (ret[strlen(clock)]) {
+ case ' ':
+ case '\0':
+ case ']':
+ case '\n':
+ break;
+ default:
+ ret = NULL;
+ }
+ } else {
+ ret = NULL;
+ }
+ free(all_clocks);
+
+ return ret != NULL;
+}
+
static void parse_record_options(int argc,
char **argv,
enum trace_cmd curr_cmd,
@@ -5882,6 +5910,8 @@ static void parse_record_options(int argc,
case 'C':
check_instance_die(ctx->instance, "-C");
ctx->instance->clock = optarg;
+ if (!clock_is_supported(NULL, ctx->instance->clock))
+ die("Clock %s is not supported", ctx->instance->clock);
ctx->instance->flags |= BUFFER_FL_HAS_CLOCK;
if (is_top_instance(ctx->instance))
guest_sync_set = true;
--
2.29.2
|