Re: [PATCH v10 8/8] selftests/ftrace: Add funcgraph-retval test case

[Donglin Peng <pengdonglin@sangfor.com.cn>]

On 2023/4/2 6:04, Masami Hiramatsu (Google) wrote:
> On Fri, 31 Mar 2023 05:47:44 -0700
> Donglin Peng <pengdonglin@sangfor.com.cn> wrote:
> 
>> Add a test case for the funcgraph-retval and funcgraph-retval-hex
>> trace options.
>>
>> Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn>
>> ---
>> v10:
>>   - Fix issues in selftest
>>
>> v8:
>>   - Fix issues in selftest
>> ---
>>   .../ftrace/test.d/ftrace/fgraph-retval.tc     | 43 +++++++++++++++++++
>>   1 file changed, 43 insertions(+)
>>   create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc
>>
>> diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc
>> new file mode 100644
>> index 000000000000..5819aa2dd6ad
>> --- /dev/null
>> +++ b/tools/testing/selftests/ftrace/test.d/ftrace/fgraph-retval.tc
>> @@ -0,0 +1,43 @@
>> +#!/bin/sh
>> +# SPDX-License-Identifier: GPL-2.0
>> +# description: ftrace - function graph print function return value
>> +# requires: options/funcgraph-retval options/funcgraph-retval-hex function_graph:tracer
>> +
>> +# Make sure that funcgraph-retval works
>> +
>> +fail() { # msg
>> +    echo $1
>> +    exit_fail
>> +}
>> +
>> +disable_tracing
>> +clear_trace
>> +
>> +read PID _ < /proc/self/stat
> 
> You can use "$$" for self pid.

Yeah, I will fix it.

> 
>> +[ -f set_ftrace_pid ] && echo ${PID} > set_ftrace_pid
>> +[ -f set_ftrace_filter ] && echo proc_reg_write > set_ftrace_filter
>> +[ -f set_graph_function ] && echo proc_reg_write > set_graph_function
> 
> You should set the required files for this test, so that the test result
> is always same. BTW, you need to set either 'set_ftrace_filter' or
> 'set_graph_function'.

Yes, but I discovered that set_ftrace_filter and set_graph_function rely 
on the CONFIG_DYNAMIC_FTRACE configuration, which means that these two 
files are not present when CONFIG_DYNAMIC_FTRACE is disabled, even if 
CONFIG_FUNCTION_GRAPH_RETVAL is enabled. Therefore, I think that these 
two trace files are not necessary for this test.

I will modify the above like this:

[ -f set_ftrace_pid ] && echo $$ > set_ftrace_pid
[ -f set_ftrace_filter ] && echo proc_reg_write > set_ftrace_filter

> 
>> +echo function_graph > current_tracer
>> +echo funcgraph-retval > trace_options
>> +
>> +set +e
>> +enable_tracing
>> +echo > /proc/interrupts
>> +disable_tracing
>> +set -e
>> +
>> +: "Test printing the error code in signed decimal format"
>> +echo nofuncgraph-retval-hex > trace_options
> 
> echo 0 > options/funcgraph-retval-hex
> 
> If you require 'options/funcgraph-retval-hex' file, you can use the
> file to set it or clear it.

Yeah.

> 
>> +count=`cat trace | grep 'proc_reg_write' | grep '= -5' | wc -l`
>> +if [ $count -eq 0 ]; then
>> +    fail "Return value can not be printed in signed decimal format"
>> +fi
>> +
>> +: "Test printing the error code in hexadecimal format"
>> +echo funcgraph-retval-hex > trace_options
> 
> Ditto.

Thanks.

> 
> Thanks,
> 
>> +count=`cat trace | grep 'proc_reg_write' | grep 'fffffffb' | wc -l`
>> +if [ $count -eq 0 ]; then
>> +    fail "Return value can not be printed in hexadecimal format"
>> +fi
>> +
>> +exit 0
>> -- 
>> 2.25.1
>>
> 
>