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Date:   Thu, 4 Jun 2020 14:58:06 +0100
From:   Will Deacon <will@kernel.org>
To:     Alexander Popov <alex.popov@linux.com>
Cc:     Kees Cook <keescook@chromium.org>,
        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>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Jessica Yu <jeyu@kernel.org>,
        Sven Schnelle <svens@stackframe.org>,
        Iurii Zaikin <yzaikin@google.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Collingbourne <pcc@google.com>,
        Naohiro Aota <naohiro.aota@wdc.com>,
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        Mathias Krause <minipli@googlemail.com>,
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        Brad Spengler <spender@grsecurity.net>,
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Subject: Re: [PATCH 5/5] gcc-plugins/stackleak: Don't instrument
 vgettimeofday.c in arm64 VDSO
Message-ID: <20200604135806.GA3170@willie-the-truck>
References: <20200604134957.505389-1-alex.popov@linux.com>
 <20200604134957.505389-6-alex.popov@linux.com>
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On Thu, Jun 04, 2020 at 04:49:57PM +0300, Alexander Popov wrote:
> Don't try instrumenting functions in arch/arm64/kernel/vdso/vgettimeofday.c.
> Otherwise that can cause issues if the cleanup pass of stackleak gcc plugin
> is disabled.
> 
> Signed-off-by: Alexander Popov <alex.popov@linux.com>
> ---
>  arch/arm64/kernel/vdso/Makefile | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
> index 3862cad2410c..9b84cafbd2da 100644
> --- a/arch/arm64/kernel/vdso/Makefile
> +++ b/arch/arm64/kernel/vdso/Makefile
> @@ -32,7 +32,8 @@ UBSAN_SANITIZE			:= n
>  OBJECT_FILES_NON_STANDARD	:= y
>  KCOV_INSTRUMENT			:= n
>  
> -CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables
> +CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables \
> +		$(DISABLE_STACKLEAK_PLUGIN)

I can pick this one up via arm64, thanks. Are there any other plugins we
should be wary of? It looks like x86 filters out $(GCC_PLUGINS_CFLAGS)
when building the vDSO.

Will