linux-kernel - Re: [PATCH v2] tracing: Add sched_prepare

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: <202404110814.B219872F76@keescook>
Date: Thu, 11 Apr 2024 08:15:05 -0700
From: Kees Cook <keescook@...omium.org>
To: Marco Elver <elver@...gle.com>
Cc: Steven Rostedt <rostedt@...dmis.org>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
	Eric Biederman <ebiederm@...ssion.com>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Azeem Shaikh <azeemshaikh38@...il.com>,
	linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
	Dmitry Vyukov <dvyukov@...gle.com>
Subject: Re: [PATCH v2] tracing: Add sched_prepare_exec tracepoint

On Thu, Apr 11, 2024 at 12:20:57PM +0200, Marco Elver wrote:
> Add "sched_prepare_exec" tracepoint, which is run right after the point
> of no return but before the current task assumes its new exec identity.
> 
> Unlike the tracepoint "sched_process_exec", the "sched_prepare_exec"
> tracepoint runs before flushing the old exec, i.e. while the task still
> has the original state (such as original MM), but when the new exec
> either succeeds or crashes (but never returns to the original exec).
> 
> Being able to trace this event can be helpful in a number of use cases:
> 
>   * allowing tracing eBPF programs access to the original MM on exec,
>     before current->mm is replaced;
>   * counting exec in the original task (via perf event);
>   * profiling flush time ("sched_prepare_exec" to "sched_process_exec").
> 
> Example of tracing output:
> 
>  $ cat /sys/kernel/debug/tracing/trace_pipe
>     <...>-379  [003] .....  179.626921: sched_prepare_exec: interp=/usr/bin/sshd filename=/usr/bin/sshd pid=379 comm=sshd
>     <...>-381  [002] .....  180.048580: sched_prepare_exec: interp=/bin/bash filename=/bin/bash pid=381 comm=sshd
>     <...>-385  [001] .....  180.068277: sched_prepare_exec: interp=/usr/bin/tty filename=/usr/bin/tty pid=385 comm=bash
>     <...>-389  [006] .....  192.020147: sched_prepare_exec: interp=/usr/bin/dmesg filename=/usr/bin/dmesg pid=389 comm=bash
> 
> Signed-off-by: Marco Elver <elver@...gle.com>

This looks good to me. If tracing wants to take it:

Acked-by: Kees Cook <keescook@...omium.org>

If not, I can take it in my tree if I get a tracing Ack. :)

-Kees

-- 
Kees Cook