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References: <20200201062459.7150-1-changbin.du@gmail.com> <20200201062459.7150-2-changbin.du@gmail.com>
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From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Sun, 16 Feb 2020 13:46:13 +0900
Message-ID: <CAK7LNATvWpic8r6J6eUnKtLYMnF3bhKA17x9DNYwSK66me9LtA@mail.gmail.com>
Subject: Re: [PATCH 1/2] sanitize: Add SANITIZE_xx.o and SANITIZE to disable
 all sanitizers for specific files
To:     Changbin Du <changbin.du@gmail.com>
Cc:     Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>, X86 ML <x86@kernel.org>,
        Andy Lutomirski <luto@kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>
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Hi Changbin,

On Sat, Feb 1, 2020 at 3:25 PM Changbin Du <changbin.du@gmail.com> wrote:
>
> This patch add two new flags to disable all sanitizers (UBSAN and KASAN):
>   o SANITIZE_xx.o - disable all sanitizers for a single file.
>   o SANITIZE - disable all sanitizers for current directory.
>
> Signed-off-by: Changbin Du <changbin.du@gmail.com>
> ---
>  Documentation/dev-tools/kasan.rst | 12 ++++++++++++
>  scripts/Makefile.lib              |  4 ++--
>  2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
> index e4d66e7c50de..f59fc5fb2cd8 100644
> --- a/Documentation/dev-tools/kasan.rst
> +++ b/Documentation/dev-tools/kasan.rst
> @@ -55,6 +55,18 @@ similar to the following to the respective kernel Makefile:
>
>      KASAN_SANITIZE := n
>
> +Similarly, to disable all sanitizers (KASAN, UBSAN) for specific files or
> +directories, add a line similar to the following to the respective kernel
> +Makefile:
> +
> +- For a single file (e.g. main.o)::
> +
> +    SANITIZE_main.o := n
> +
> +- For all files in one directory::
> +
> +    SANITIZE := n
> +
>  Error reports
>  ~~~~~~~~~~~~~
>
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 3fa32f83b2d7..9b7d784e3252 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -122,13 +122,13 @@ endif
>  #
>  ifeq ($(CONFIG_KASAN),y)
>  _c_flags += $(if $(patsubst n%,, \
> -               $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
> +               $(SANITIZE_$(basetarget).o)$(SANITIZE)$(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \


I think this would be very unlikely to happen, but
if both SANITIZE and KASAN_SANITIZE existed,
KASAN_SANITIZE should take precedence over SANITIZE, maybe?


Perhaps, like this?

$(KASAN_SANITIZE_$(basetarget).o)$(SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)$(SANITIZE)y


>                 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
>  endif
>
>  ifeq ($(CONFIG_UBSAN),y)
>  _c_flags += $(if $(patsubst n%,, \
> -               $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
> +               $(SANITIZE_$(basetarget).o)$(SANITIZE)$(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
>                 $(CFLAGS_UBSAN))
>  endif
>
> --
> 2.24.0
>


-- 
Best Regards
Masahiro Yamada