Re: [PATCH] selftests/ftrace: update kprobe syntax error test for ppc64le

[Hari Bathini <hbathini@linux.ibm.com>]

On 03/11/24 10:27 am, Masami Hiramatsu (Google) wrote:
> On Sat,  2 Nov 2024 00:49:25 +0530
> Hari Bathini <hbathini@linux.ibm.com> wrote:
> 
>> For ppc64le, depending on the kernel configuration used, offset 16
>> from function start address can also be considered function entry.
>> Update the test case to accommodate such configurations.
>>
> 
> Hi Hari, so have you met any error on this test case?

Hi Masami,

vfs_read+8 is function entry on powerpc. So, the test case bails out at:
   "check_error 'p vfs_read+8 ^$arg*'		# NOFENTRY_ARGS"

as it allows setting kprobe "vfs_read+8 $arg*"

> Can you share the error result too?


End of the log file for reference:

"
Test command: p vfs_read $arg* $arg*
[2661828.483436] trace_kprobe: error: $arg* can be used only once in the 
parameters
   Command: p vfs_read $arg* $arg*
                             ^
Test command: p vfs_read+8 $arg*
"

Thanks
Hari

> 
> Thank you,
> 
>> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
>> ---
>>   .../selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc    | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
>> index a16c6a6f6055..c03b94cc5784 100644
>> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
>> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
>> @@ -111,7 +111,11 @@ check_error 'p vfs_read $arg* ^$arg*'		# DOUBLE_ARGS
>>   if !grep -q 'kernel return probes support:' README; then
>>   check_error 'r vfs_read ^$arg*'			# NOFENTRY_ARGS
>>   fi
>> +if [ "$(uname -m)" = "ppc64le" ]; then
>> +check_error 'p vfs_read+20 ^$arg*'		# NOFENTRY_ARGS
>> +else
>>   check_error 'p vfs_read+8 ^$arg*'		# NOFENTRY_ARGS
>> +fi
>>   check_error 'p vfs_read ^hoge'			# NO_BTFARG
>>   check_error 'p kfree ^$arg10'			# NO_BTFARG (exceed the number of parameters)
>>   check_error 'r kfree ^$retval'			# NO_RETVAL
>> -- 
>> 2.47.0
>>
> 
>