Re: [PATCH 3/3] selftests/ftrace: Use /bin/echo instead of built-in echo

[Xiao Yang]

On 2020/5/1 21:38, Masami Hiramatsu wrote:
> Since the built-in echo has different behavior in POSIX shell
> (dash) and bash, we forcibly use /bin/echo -E (not interpret
> backslash escapes) by default.
>
> This also fixes some test cases which expects built-in
> echo command.
>
> Reported-by: Liu Yiding<yidingx.liu@xxxxxxxxx>
> Signed-off-by: Masami Hiramatsu<mhiramat@xxxxxxxxxx>
> ---
>   tools/testing/selftests/ftrace/test.d/functions    |    3 +++
>   .../test.d/trigger/trigger-trace-marker-hist.tc    |    2 +-
>   .../trigger-trace-marker-synthetic-kernel.tc       |    4 ++++
>   .../trigger/trigger-trace-marker-synthetic.tc      |    4 ++--
>   4 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
> index 5d4550591ff9..ea59b6ea2c3e 100644
> --- a/tools/testing/selftests/ftrace/test.d/functions
> +++ b/tools/testing/selftests/ftrace/test.d/functions
> @@ -1,3 +1,6 @@
> +# Since the built-in echo has different behavior in POSIX shell (dash) and
> +# bash, we forcibly use /bin/echo -E (not interpret backslash escapes).
> +alias echo="/bin/echo -E"
Hi Masami, Steven

It seems that only kprobe_syntax_errors.tc is impacted by the issue 
currently.  Is it necessary for all tests to use /bin/echo and could we 
just make kprobe_syntax_errors.tc use /bin/echo?

Best Regards,
Xiao Yang

>   clear_trace() { # reset trace output
>       echo>  trace
> diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-hist.tc
> index ab6bedb25736..b3f70f53ee69 100644
> --- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-hist.tc
> +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-hist.tc
> @@ -30,7 +30,7 @@ fi
>
>   echo "Test histogram trace_marker tigger"
>
> -echo 'hist:keys=common_pid'>  events/ftrace/print/trigger
> +echo 'hist:keys=ip'>  events/ftrace/print/trigger
>   for i in `seq 1 10` ; do echo "hello">  trace_marker; done
>   grep 'hitcount: *10$' events/ftrace/print/hist>  /dev/null || \
>       fail "hist trigger did not trigger correct times on trace_marker"
> diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic-kernel.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic-kernel.tc
> index 18b4d1c2807e..c1625d945f4d 100644
> --- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic-kernel.tc
> +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic-kernel.tc
> @@ -44,6 +44,10 @@ echo 'latency u64 lat'>  synthetic_events
>   echo 'hist:keys=pid:ts0=common_timestamp.usecs'>  events/sched/sched_waking/trigger
>   echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).latency($lat)'>  events/ftrace/print/trigger
>   echo 'hist:keys=common_pid,lat:sort=lat'>  events/synthetic/latency/trigger
> +
> +# We have to use the built-in echo here because waking up pid must be same
> +# as echoing pid.
> +alias echo=echo
>   sleep 1
>   echo "hello">  trace_marker
>
> diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic.tc
> index dd262d6d0db6..23e52c8d71de 100644
> --- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic.tc
> +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-trace-marker-synthetic.tc
> @@ -36,8 +36,8 @@ fi
>   echo "Test histogram trace_marker to trace_marker latency histogram trigger"
>
>   echo 'latency u64 lat'>  synthetic_events
> -echo 'hist:keys=common_pid:ts0=common_timestamp.usecs if buf == "start"'>  events/ftrace/print/trigger
> -echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$ts0:onmatch(ftrace.print).latency($lat) if buf == "end"'>>  events/ftrace/print/trigger
> +echo 'hist:keys=ip:ts0=common_timestamp.usecs if buf == "start"'>  events/ftrace/print/trigger
> +echo 'hist:keys=ip:lat=common_timestamp.usecs-$ts0:onmatch(ftrace.print).latency($lat) if buf == "end"'>>  events/ftrace/print/trigger
>   echo 'hist:keys=common_pid,lat:sort=lat'>  events/synthetic/latency/trigger
>   echo -n "start">  trace_marker
>   echo -n "end">  trace_marker
>
>
>
> .