linux-kernel - Re: [PATCH] tracing: remove __printf() attribute on __ftrace

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] [day] [month] [year] [list]

Message-ID: <aYIttabs_YsTiibd@smile.fi.intel.com>
Date: Tue, 3 Feb 2026 19:17:41 +0200
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Arnd Bergmann <arnd@...db.de>
Cc: kernel test robot <lkp@...el.com>, Arnd Bergmann <arnd@...nel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Simon Horman <horms@...nel.org>, Jeff Layton <jlayton@...nel.org>,
	Anna Schumaker <anna.schumaker@...cle.com>,
	Chuck Lever <chuck.lever@...cle.com>, llvm@...ts.linux.dev,
	oe-kbuild-all@...ts.linux.dev,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linux Memory Management List <linux-mm@...ck.org>,
	Randy Dunlap <rdunlap@...radead.org>,
	Yury Norov <ynorov@...dia.com>,
	Joel Fernandes <joelagnelf@...dia.com>,
	linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org
Subject: Re: [PATCH] tracing: remove __printf() attribute on
 __ftrace_vbprintk()

On Tue, Feb 03, 2026 at 04:56:03PM +0100, Arnd Bergmann wrote:
> On Tue, Feb 3, 2026, at 15:58, Andy Shevchenko wrote:
> > On Tue, Feb 03, 2026 at 08:12:57PM +0800, kernel test robot wrote:
> >
> >> kernel test robot noticed the following build warnings:
> >
> > Yeah, you need to go for the full stack of these calls and mark the 
> > bottom one with __diag() to avoid these warnings. That's my understanding
> > and what BPF people required. Chasing this one-by-one would produce
> > unneeded churn.
> 
> From what I can tell, I can just move the printf attribute
> to the __ftrace_vbprintk() definition to make this bit work.

Ah, that's cool!

...

> There are unrelated warnings for BPF that I managed to
> shut up the same way, doing

BPF rejected such an approach, see lore discussions in the past
(patches from me). Here some pointers (but not all of them):

20251208141618.2805983-1-andriy.shevchenko@...ux.intel.com
202512090407.VxRO6xAS-lkp@...el.com
20251210131234.3185985-1-andriy.shevchenko@...ux.intel.com
20251216122514.7ee70d5f@...b.auug.org.au
20251215202430.c35c2d29c4f9ff614d2ab534@...ux-foundation.org

-- 
With Best Regards,
Andy Shevchenko