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

[yebin (H)]

On 2024/1/24 9:32, Masami Hiramatsu (Google) wrote:
> On Tue, 23 Jan 2024 17:21:39 +0800
> Ye Bin <yebin10@xxxxxxxxxx> 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@xxxxxxxxxx>
> > ---
> >   .../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