Re: [PATCH v9 01/16] tracing: move function tracer options to Kconfig (causing parisc build failures)

From: Kees Cook <keescook@chromium.org>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Sami Tolvanen <samitolvanen@google.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Will Deacon <will@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	clang-built-linux@googlegroups.com,
	kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, linux-parisc@vger.kernel.org,
	Helge Deller <deller@gmx.de>
Subject: Re: [PATCH v9 01/16] tracing: move function tracer options to Kconfig (causing parisc build failures)
Date: Wed, 24 Feb 2021 14:42:49 -0800	[thread overview]
Message-ID: <202102241442.C456318BC0@keescook> (raw)
In-Reply-To: <20210224222807.GA74404@roeck-us.net>

On Wed, Feb 24, 2021 at 02:28:07PM -0800, Guenter Roeck wrote:
> On Wed, Feb 24, 2021 at 12:38:54PM -0800, Kees Cook wrote:
> > On Wed, Feb 24, 2021 at 12:17:23PM -0800, Guenter Roeck wrote:
> > > On Fri, Dec 11, 2020 at 10:46:18AM -0800, Sami Tolvanen wrote:
> > > > Move function tracer options to Kconfig to make it easier to add
> > > > new methods for generating __mcount_loc, and to make the options
> > > > available also when building kernel modules.
> > > > 
> > > > Note that FTRACE_MCOUNT_USE_* options are updated on rebuild and
> > > > therefore, work even if the .config was generated in a different
> > > > environment.
> > > > 
> > > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> > > > Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> > > 
> > > With this patch in place, parisc:allmodconfig no longer builds.
> > > 
> > > Error log:
> > > Arch parisc is not supported with CONFIG_FTRACE_MCOUNT_RECORD at scripts/recordmcount.pl line 405.
> > > make[2]: *** [scripts/mod/empty.o] Error 2
> > > 
> > > Due to this problem, CONFIG_FTRACE_MCOUNT_RECORD can no longer be
> > > enabled in parisc builds. Since that is auto-selected by DYNAMIC_FTRACE,
> > > DYNAMIC_FTRACE can no longer be enabled, and with it everything that
> > > depends on it.
> > 
> > Ew. Any idea why this didn't show up while it was in linux-next?
> > 
> 
> It did, I just wasn't able to bisect it there.

Ah-ha! Okay, thanks. Sorry it's been broken for so long! I've added
parisc to my local cross builder now.

-- 
Kees Cook