From: Alexander Popov <alex.popov@linux.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-hardening@lists.openwall.com,
Kees Cook <keescook@chromium.org>, Jann Horn <jannh@google.com>,
Ingo Molnar <mingo@kernel.org>, Andy Lutomirski <luto@kernel.org>,
Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@alien8.de>,
Thomas Gleixner <tglx@linutronix.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>, Jan Kara <jack@suse.cz>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Dan Williams <dan.j.williams@intel.com>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] stackleak: Disable ftrace for stackleak.c
Date: Sun, 11 Nov 2018 13:19:45 +0300 [thread overview]
Message-ID: <eeb7f5ee-1e2e-d37b-cca2-e0a29826e8eb@linux.com> (raw)
In-Reply-To: <20181110183011.2290fc20@gandalf.local.home>
On 11.11.2018 2:30, Steven Rostedt wrote:
> On Sun, 11 Nov 2018 01:05:30 +0300
> Alexander Popov <alex.popov@linux.com> wrote:
>
>> The stackleak_erase() function is called on the trampoline stack at the
>> end of syscall. This stack is not big enough for ftrace operations,
>> e.g. it can be overflowed if we enable kprobe_events for stackleak_erase().
>
> Is the issue with kprobes or with function tracing? Because this stops
> function tracing which I only want disabled if function tracing itself
> is an issue, not for other things that may use the function tracing
> infrastructure.
Hello Steven,
I believe that stackleak erasing is not compatible with function tracing itself.
That's what the kernel testing robot has hit:
https://www.openwall.com/lists/kernel-hardening/2018/11/09/1
I used kprobe_events just to reproduce the problem:
https://www.openwall.com/lists/kernel-hardening/2018/11/09/4
Best regards,
Alexander
next prev parent reply other threads:[~2018-11-11 10:19 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-10 22:05 [PATCH 1/1] stackleak: Disable ftrace for stackleak.c Alexander Popov
2018-11-10 23:30 ` Steven Rostedt
2018-11-11 10:19 ` Alexander Popov [this message]
2018-11-12 1:53 ` Steven Rostedt
2018-11-12 2:50 ` Masami Hiramatsu
2018-11-12 14:53 ` Mathieu Desnoyers
2018-11-12 16:52 ` Steven Rostedt
2018-11-12 16:51 ` Alexander Popov
2018-11-12 17:21 ` Steven Rostedt
2018-11-13 18:21 ` Masami Hiramatsu
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