2019-03-22 19:10:34

by Steven Rostedt

[permalink] [raw]
Subject: [PATCH] selftests/ftrace: Select an existing function in kprobe_eventname test

From: Steven Rostedt (VMware) <[email protected]>

Running the ftrace selftests on the latest kernel caused the
kprobe_eventname test to fail. It was due to the test that searches for
a function with at "dot" in the name and adding a probe to that.
Unfortunately, for this test, it picked:

optimize_nops.isra.2.cold.4

Which happens to be marked as "__init", which means it no longer exists
in the kernel! (kallsyms keeps those function names around for tracing
purposes)

As only functions that still exist are in the
available_filter_functions file, as they are removed when the functions
are freed at boot or module exit, have the test search for a function
with ".isra." in the name as well as being in the
available_filter_functions (if the file exists).

Signed-off-by: Steven Rostedt (VMware) <[email protected]>
---
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
index 3fb70e01b1fe..3ff236719b6e 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
@@ -24,7 +24,21 @@ test -d events/kprobes2/event2 || exit_failure

:;: "Add an event on dot function without name" ;:

-FUNC=`grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
+find_dot_func() {
+ if [ ! -f available_filter_functions ]; then
+ grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "
+ return;
+ fi
+
+ grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
+ if grep -s $f available_filter_functions; then
+ echo $f
+ break
+ fi
+ done
+}
+
+FUNC=`find_dot_func | tail -n 1`
[ "x" != "x$FUNC" ] || exit_unresolved
echo "p $FUNC" > kprobe_events
EVENT=`grep $FUNC kprobe_events | cut -f 1 -d " " | cut -f 2 -d:`


2019-03-23 12:04:13

by Masami Hiramatsu

[permalink] [raw]
Subject: Re: [PATCH] selftests/ftrace: Select an existing function in kprobe_eventname test

On Fri, 22 Mar 2019 15:09:23 -0400
Steven Rostedt <[email protected]> wrote:

> From: Steven Rostedt (VMware) <[email protected]>
>
> Running the ftrace selftests on the latest kernel caused the
> kprobe_eventname test to fail. It was due to the test that searches for
> a function with at "dot" in the name and adding a probe to that.
> Unfortunately, for this test, it picked:
>
> optimize_nops.isra.2.cold.4
>
> Which happens to be marked as "__init", which means it no longer exists
> in the kernel! (kallsyms keeps those function names around for tracing
> purposes)
>
> As only functions that still exist are in the
> available_filter_functions file, as they are removed when the functions
> are freed at boot or module exit, have the test search for a function
> with ".isra." in the name as well as being in the
> available_filter_functions (if the file exists).

OK, this looks good to me.

Acked-by: Masami Hiramatsu <[email protected]>

Thank you,

>
> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
> ---
> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> index 3fb70e01b1fe..3ff236719b6e 100644
> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> @@ -24,7 +24,21 @@ test -d events/kprobes2/event2 || exit_failure
>
> :;: "Add an event on dot function without name" ;:
>
> -FUNC=`grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
> +find_dot_func() {
> + if [ ! -f available_filter_functions ]; then
> + grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "
> + return;
> + fi
> +
> + grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
> + if grep -s $f available_filter_functions; then
> + echo $f
> + break
> + fi
> + done
> +}
> +
> +FUNC=`find_dot_func | tail -n 1`
> [ "x" != "x$FUNC" ] || exit_unresolved
> echo "p $FUNC" > kprobe_events
> EVENT=`grep $FUNC kprobe_events | cut -f 1 -d " " | cut -f 2 -d:`


--
Masami Hiramatsu <[email protected]>

Subject: Re: [PATCH] selftests/ftrace: Select an existing function in kprobe_eventname test

On Fri, Mar 22, 2019 at 03:09:23PM -0400, Steven Rostedt wrote:
> From: Steven Rostedt (VMware) <[email protected]>
>
> Running the ftrace selftests on the latest kernel caused the
> kprobe_eventname test to fail. It was due to the test that searches for
> a function with at "dot" in the name and adding a probe to that.
> Unfortunately, for this test, it picked:
>
> optimize_nops.isra.2.cold.4
>
> Which happens to be marked as "__init", which means it no longer exists
> in the kernel! (kallsyms keeps those function names around for tracing
> purposes)
>
> As only functions that still exist are in the
> available_filter_functions file, as they are removed when the functions
> are freed at boot or module exit, have the test search for a function
> with ".isra." in the name as well as being in the
> available_filter_functions (if the file exists).
>

This fixes a similar problem for me.

Tested-by: Thadeu Lima de Souza Cascardo <[email protected]>

> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
> ---
> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> index 3fb70e01b1fe..3ff236719b6e 100644
> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> @@ -24,7 +24,21 @@ test -d events/kprobes2/event2 || exit_failure
>
> :;: "Add an event on dot function without name" ;:
>
> -FUNC=`grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
> +find_dot_func() {
> + if [ ! -f available_filter_functions ]; then
> + grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "
> + return;
> + fi
> +
> + grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
> + if grep -s $f available_filter_functions; then
> + echo $f
> + break
> + fi
> + done
> +}
> +
> +FUNC=`find_dot_func | tail -n 1`
> [ "x" != "x$FUNC" ] || exit_unresolved
> echo "p $FUNC" > kprobe_events
> EVENT=`grep $FUNC kprobe_events | cut -f 1 -d " " | cut -f 2 -d:`

2019-07-08 22:47:20

by Steven Rostedt

[permalink] [raw]
Subject: Re: [PATCH] selftests/ftrace: Select an existing function in kprobe_eventname test

On Mon, 8 Jul 2019 16:10:29 -0300
Thadeu Lima de Souza Cascardo <[email protected]> wrote:

> On Fri, Mar 22, 2019 at 03:09:23PM -0400, Steven Rostedt wrote:
> > From: Steven Rostedt (VMware) <[email protected]>
> >
> > Running the ftrace selftests on the latest kernel caused the
> > kprobe_eventname test to fail. It was due to the test that searches for
> > a function with at "dot" in the name and adding a probe to that.
> > Unfortunately, for this test, it picked:
> >
> > optimize_nops.isra.2.cold.4
> >
> > Which happens to be marked as "__init", which means it no longer exists
> > in the kernel! (kallsyms keeps those function names around for tracing
> > purposes)
> >
> > As only functions that still exist are in the
> > available_filter_functions file, as they are removed when the functions
> > are freed at boot or module exit, have the test search for a function
> > with ".isra." in the name as well as being in the
> > available_filter_functions (if the file exists).
> >
>
> This fixes a similar problem for me.
>
> Tested-by: Thadeu Lima de Souza Cascardo <[email protected]>

Masami, can you ack this, and Shuah, can you take it?

Thanks!

-- Steve

>
> > Signed-off-by: Steven Rostedt (VMware) <[email protected]>
> > ---
> > diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> > index 3fb70e01b1fe..3ff236719b6e 100644
> > --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> > +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> > @@ -24,7 +24,21 @@ test -d events/kprobes2/event2 || exit_failure
> >
> > :;: "Add an event on dot function without name" ;:
> >
> > -FUNC=`grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
> > +find_dot_func() {
> > + if [ ! -f available_filter_functions ]; then
> > + grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "
> > + return;
> > + fi
> > +
> > + grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
> > + if grep -s $f available_filter_functions; then
> > + echo $f
> > + break
> > + fi
> > + done
> > +}
> > +
> > +FUNC=`find_dot_func | tail -n 1`
> > [ "x" != "x$FUNC" ] || exit_unresolved
> > echo "p $FUNC" > kprobe_events
> > EVENT=`grep $FUNC kprobe_events | cut -f 1 -d " " | cut -f 2 -d:`

2019-07-09 12:46:31

by Masami Hiramatsu

[permalink] [raw]
Subject: Re: [PATCH] selftests/ftrace: Select an existing function in kprobe_eventname test

On Mon, 8 Jul 2019 15:22:14 -0400
Steven Rostedt <[email protected]> wrote:

> On Mon, 8 Jul 2019 16:10:29 -0300
> Thadeu Lima de Souza Cascardo <[email protected]> wrote:
>
> > On Fri, Mar 22, 2019 at 03:09:23PM -0400, Steven Rostedt wrote:
> > > From: Steven Rostedt (VMware) <[email protected]>
> > >
> > > Running the ftrace selftests on the latest kernel caused the
> > > kprobe_eventname test to fail. It was due to the test that searches for
> > > a function with at "dot" in the name and adding a probe to that.
> > > Unfortunately, for this test, it picked:
> > >
> > > optimize_nops.isra.2.cold.4
> > >
> > > Which happens to be marked as "__init", which means it no longer exists
> > > in the kernel! (kallsyms keeps those function names around for tracing
> > > purposes)

Ouch!

> > >
> > > As only functions that still exist are in the
> > > available_filter_functions file, as they are removed when the functions
> > > are freed at boot or module exit, have the test search for a function
> > > with ".isra." in the name as well as being in the
> > > available_filter_functions (if the file exists).

Hmm, OK. But I think this eventually fixed in kallsyms, by something like
having [GONE] or [__init] flag for such symbols.

> > >
> >
> > This fixes a similar problem for me.
> >
> > Tested-by: Thadeu Lima de Souza Cascardo <[email protected]>
>
> Masami, can you ack this, and Shuah, can you take it?

Yeah anyway,

Acked-by: Masami Hiramatsu <[email protected]>

Thank you!

>
> Thanks!
>
> -- Steve
>
> >
> > > Signed-off-by: Steven Rostedt (VMware) <[email protected]>
> > > ---
> > > diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> > > index 3fb70e01b1fe..3ff236719b6e 100644
> > > --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> > > +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
> > > @@ -24,7 +24,21 @@ test -d events/kprobes2/event2 || exit_failure
> > >
> > > :;: "Add an event on dot function without name" ;:
> > >
> > > -FUNC=`grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "`
> > > +find_dot_func() {
> > > + if [ ! -f available_filter_functions ]; then
> > > + grep -m 10 " [tT] .*\.isra\..*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "
> > > + return;
> > > + fi
> > > +
> > > + grep " [tT] .*\.isra\..*" /proc/kallsyms | cut -f 3 -d " " | while read f; do
> > > + if grep -s $f available_filter_functions; then
> > > + echo $f
> > > + break
> > > + fi
> > > + done
> > > +}
> > > +
> > > +FUNC=`find_dot_func | tail -n 1`
> > > [ "x" != "x$FUNC" ] || exit_unresolved
> > > echo "p $FUNC" > kprobe_events
> > > EVENT=`grep $FUNC kprobe_events | cut -f 1 -d " " | cut -f 2 -d:`
>


--
Masami Hiramatsu <[email protected]>

2019-07-09 14:45:45

by Steven Rostedt

[permalink] [raw]
Subject: Re: [PATCH] selftests/ftrace: Select an existing function in kprobe_eventname test

On Tue, 9 Jul 2019 21:44:02 +0900
Masami Hiramatsu <[email protected]> wrote:

> > Masami, can you ack this, and Shuah, can you take it?
>
> Yeah anyway,
>
> Acked-by: Masami Hiramatsu <[email protected]>

Thanks Masami,

Shuah, want to take this in your tree?

-- Steve