Re: [PATCH v4 7/7] selftests/ftrace: add test cases for VFS type "%pd" and "%pD"

["yebin (H)" <yebin10@huawei.com>]

On 2024/1/24 9:32, Masami Hiramatsu (Google) wrote:
> On Tue, 23 Jan 2024 17:21:39 +0800
> Ye Bin <yebin10@huawei.com> wrote:
>
>> This patch adds test cases for new print format type "%pd/%pD".The test cases
>> test the following items:
>> 1. Test README if add "%pd/%pD" type;
>> 2. Test "%pd" type for dput();
>> 3. Test "%pD" type for vfs_read();
>>
>> Signed-off-by: Ye Bin <yebin10@huawei.com>
>> ---
>>   .../ftrace/test.d/kprobe/kprobe_args_vfs.tc   | 79 +++++++++++++++++++
>>   1 file changed, 79 insertions(+)
>>   create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_vfs.tc
>>
>> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_vfs.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_vfs.tc
>> new file mode 100644
>> index 000000000000..1d8edd294dd6
>> --- /dev/null
>> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_vfs.tc
>> @@ -0,0 +1,79 @@
>> +#!/bin/sh
>> +# SPDX-License-Identifier: GPL-2.0
>> +# description: Kprobe event VFS type argument
>> +# requires: kprobe_events
>> +
>> +case `uname -m` in
>> +x86_64)
>> +  ARG1=%di
>> +;;
>> +i[3456]86)
>> +  ARG1=%ax
>> +;;
>> +aarch64)
>> +  ARG1=%x0
>> +;;
>> +arm*)
>> +  ARG1=%r0
>> +;;
>> +ppc64*)
>> +  ARG1=%r3
>> +;;
>> +ppc*)
>> +  ARG1=%r3
> You can merge this ppc* and ppc64* cases :)
>
>> +;;
>> +s390*)
>> +  ARG1=%r2
>> +;;
>> +mips*)
>> +  ARG1=%r4
>> +;;
>> +loongarch*)
>> +  ARG1=%r4
>> +;;
>> +riscv*)
>> +  ARG1=%a0
> Anyway, I wonder why don't you use '$arg1' instead of these registers.
> Is there any reason?
>
> Thank you,
I looked at the parameter parsing code again, and using "$arg1" requires 
the kernel to
enable the CONFIG_HAVE_FUNCTION_ARG_ACCESS_API configuration.
>> +;;
>> +*)
>> +  echo "Please implement other architecture here"
>> +  exit_untested
>> +esac
>> +
>> +: "Test argument %pd/%pD in README"
>> +grep -q "%pd/%pD" README
>> +
>> +: "Test argument %pd with name"
>> +echo "p:testprobe dput name=${ARG1}:%pd" > kprobe_events
>> +echo 1 > events/kprobes/testprobe/enable
>> +grep -q "1" events/kprobes/testprobe/enable
>> +echo 0 > events/kprobes/testprobe/enable
>> +grep "dput" trace | grep -q "enable"
>> +echo "" > kprobe_events
>> +echo "" > trace
>> +
>> +: "Test argument %pd without name"
>> +echo "p:testprobe dput ${ARG1}:%pd" > kprobe_events
>> +echo 1 > events/kprobes/testprobe/enable
>> +grep -q "1" events/kprobes/testprobe/enable
>> +echo 0 > events/kprobes/testprobe/enable
>> +grep "dput" trace | grep -q "enable"
>> +echo "" > kprobe_events
>> +echo "" > trace
>> +
>> +: "Test argument %pD with name"
>> +echo "p:testprobe vfs_read name=${ARG1}:%pD" > kprobe_events
>> +echo 1 > events/kprobes/testprobe/enable
>> +grep -q "1" events/kprobes/testprobe/enable
>> +echo 0 > events/kprobes/testprobe/enable
>> +grep "vfs_read" trace | grep -q "enable"
>> +echo "" > kprobe_events
>> +echo "" > trace
>> +
>> +: "Test argument %pD without name"
>> +echo "p:testprobe vfs_read ${ARG1}:%pD" > kprobe_events
>> +echo 1 > events/kprobes/testprobe/enable
>> +grep -q "1"  events/kprobes/testprobe/enable
>> +echo 0 > events/kprobes/testprobe/enable
>> +grep "vfs_read" trace | grep -q "enable"
>> +echo "" > kprobe_events
>> +echo "" > trace
>> -- 
>> 2.31.1
>>
>