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Date: Wed, 24 Jun 2020 07:41:16 -0700
From: Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH v2 5/5] gcc-plugins/stackleak: Add 'verbose' plugin
 parameter
Message-ID: <202006240740.5AF6369E53@keescook>
References: <20200624123330.83226-1-alex.popov@linux.com>
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To: Alexander Popov <alex.popov@linux.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>, Jann Horn <jannh@google.com>, Emese Revfy <re.emese@gmail.com>, Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>, Masahiro Yamada <masahiroy@kernel.org>, Michal Marek <michal.lkml@markovi.net>, Andrew Morton <akpm@linux-foundation.org>, Masahiro Yamada <yamada.masahiro@socionext.com>, Thiago Jung Bauermann <bauerman@linux.ibm.com>, Jessica Yu <jeyu@kernel.org>, Sven Schnelle <svens@stackframe.org>, Iurii Zaikin <yzaikin@google.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Thomas Gleixner <tglx@linutronix.de>, Peter Collingbourne <pcc@google.com>, Naohiro Aota <naohiro.aota@wdc.com>, Alexander Monakov <amonakov@ispras.ru>, Mathias Krause <minipli@googlemail.com>, PaX Team <pageexec@freemail.hu>, Brad Spengler <spender@grsecurity.net>, Laura Abbott <labbott@redhat.com>, Florian Weimer <fweimer@redhat.com>, kernel-hardening@lists.openwall.com, linux-kbuild@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, gcc@gcc.gnu.org, notify@kernel.org

On Wed, Jun 24, 2020 at 04:09:20PM +0300, Alexander Popov wrote:
> On 24.06.2020 15:53, Luis Chamberlain wrote:
> > On Wed, Jun 24, 2020 at 03:33:30PM +0300, Alexander Popov wrote:
> >> Add 'verbose' plugin parameter for stackleak gcc plugin.
> >> It can be used for printing additional info about the kernel code
> >> instrumentation.
> >>
> >> For using it add the following to scripts/Makefile.gcc-plugins:
> >>   gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) \
> >>     += -fplugin-arg-stackleak_plugin-verbose
> > 
> > Would be nice if we instead could pass an argument to make which lets
> > us enable this.
> 
> This feature is useful only for debugging stackleak gcc plugin.
> 
> The cflag that enables it is similar to -fplugin-arg-structleak_plugin-verbose,
> which is used for debugging the structleak plugin.
> 
> This debugging feature clutters the kernel build output, I don't think that many
> people will use it. So IMO creating a separate argument for make is not really
> needed.

Yup, agreed. The precedent for plugin verbosity is via CONFIGs. They're
not really general purpose enough to justify a "make" argument.

-- 
Kees Cook