From: Steven Rostedt <rostedt@goodmis.org>
To: "Tobin C. Harding" <me@tobin.cc>
Cc: kernel-hardening@lists.openwall.com,
Tycho Andersen <tycho@tycho.ws>,
Linus Torvalds <torvalds@linux-foundation.org>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Alexei Starovoitov <ast@kernel.org>,
linux-kernel@vger.kernel.org,
Network Development <netdev@vger.kernel.org>
Subject: [kernel-hardening] Re: [PATCH 3/3] trace: print address if symbol not found
Date: Mon, 18 Dec 2017 18:51:43 -0500 [thread overview]
Message-ID: <20171218185143.4046a71b@gandalf.local.home> (raw)
In-Reply-To: <20171218211614.GC19604@eros>
On Tue, 19 Dec 2017 08:16:14 +1100
"Tobin C. Harding" <me@tobin.cc> wrote:
> > > #endif /* _LINUX_KERNEL_TRACE_H */
> > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> > > index 1e1558c99d56..3e28522a76f4 100644
> > > --- a/kernel/trace/trace_events_hist.c
> > > +++ b/kernel/trace/trace_events_hist.c
> > > @@ -982,7 +982,7 @@ static void hist_trigger_stacktrace_print(struct seq_file *m,
> > > return;
> > >
> > > seq_printf(m, "%*c", 1 + spaces, ' ');
> > > - sprint_symbol(str, stacktrace_entries[i]);
> > > + trace_sprint_symbol_addr(str, stacktrace_entries[i]);
> >
>
> If you have the time to give me some brief pointers on how I should go
> about testing this I'd love to test it before the next version. I know
> very little about ftrace.
For hitting the histogram stacktrace trigger (this code path), make
sure you have CONFIG_HIST_TRIGGERS enabled. And then do:
# cd /sys/kernel/debug/tracing
# echo 'hist:keys=common_pid.execname,stacktrace:vals=prev_state' > \
events/sched/sched_switch/trigger
# cat events/sched/sched_switch/hist
For the "sym" part, you can do (from the same directory):
# echo 'hist:keys=call_site.sym:vals=bytes_req' > \
events/kmem/kmalloc/trigger
# cat events/kmem/kmalloc/hist
And for sym-offset:
# echo 'hist:keys=call_site.sym-offset:vals=bytes_req' > \
events/kmem/kmalloc/trigger
# cat events/kmem/kmalloc/hist
-- Steve
next prev parent reply other threads:[~2017-12-18 23:51 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-17 23:53 [kernel-hardening] [PATCH 0/3] kallsyms: don't leak address Tobin C. Harding
2017-12-17 23:53 ` [kernel-hardening] [PATCH 1/3] kallsyms: don't leak address when symbol not found Tobin C. Harding
2017-12-18 9:55 ` [kernel-hardening] " Felix Fietkau
2017-12-18 22:41 ` Tobin C. Harding
2017-12-18 23:43 ` Steven Rostedt
2017-12-19 0:24 ` Tobin C. Harding
2017-12-17 23:53 ` [kernel-hardening] [PATCH 2/3] vsprintf: print <no-symbol> if " Tobin C. Harding
2017-12-18 0:04 ` [kernel-hardening] " Joe Perches
2017-12-18 1:04 ` Tobin C. Harding
2017-12-17 23:53 ` [kernel-hardening] [PATCH 3/3] trace: print address " Tobin C. Harding
2017-12-18 16:49 ` [kernel-hardening] " Steven Rostedt
2017-12-18 21:16 ` Tobin C. Harding
2017-12-18 23:51 ` Steven Rostedt [this message]
2017-12-19 0:22 ` Tobin C. Harding
2017-12-19 3:00 ` Tobin C. Harding
2017-12-19 3:02 ` Tobin C. Harding
2017-12-19 3:37 ` Steven Rostedt
2017-12-19 4:20 ` Tobin C. Harding
2017-12-18 22:35 ` Tobin C. Harding
2017-12-19 23:19 ` kbuild test robot
2017-12-19 23:39 ` kbuild test robot
2017-12-18 5:31 ` [kernel-hardening] [PATCH 0/3] kallsyms: don't leak address Michael Ellerman
2017-12-18 6:00 ` Tobin C. Harding
2017-12-18 9:17 ` Tobin C. Harding
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