linux-kernel - Re: [PATCH] selftests/ftrace: Select an existing function in kprobe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190323210308.d47164c66489982e374f3db0@kernel.org>
Date:   Sat, 23 Mar 2019 21:03:08 +0900
From:   Masami Hiramatsu <mhiramat@...nel.org>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Shuah Khan <shuahkhan@...il.com>,
        Ingo Molnar <mingo@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH] selftests/ftrace: Select an existing function in
 kprobe_eventname test

On Fri, 22 Mar 2019 15:09:23 -0400
Steven Rostedt <rostedt@...dmis.org> wrote:

> From: Steven Rostedt (VMware) <rostedt@...dmis.org>
> 
> 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 <mhiramat@...nel.org>

Thank you,

> 
> Signed-off-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
> ---
> 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 <mhiramat@...nel.org>