From: Nathan Chancellor <nathan@kernel.org>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Marco Elver <elver@google.com>, Arnd Bergmann <arnd@arndb.de>,
Nicolas Schier <nicolas@fjasle.eu>,
Alexander Potapenko <glider@google.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Tom Rix <trix@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Michael Ellerman <mpe@ellerman.id.au>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
linux-kbuild@vger.kernel.org, kasan-dev@googlegroups.com,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH] kasan: remove hwasan-kernel-mem-intrinsic-prefix=1 for clang-14
Date: Fri, 14 Apr 2023 09:26:05 -0700 [thread overview]
Message-ID: <20230414162605.GA2161385@dev-arch.thelio-3990X> (raw)
In-Reply-To: <20230414082943.1341757-1-arnd@kernel.org>
On Fri, Apr 14, 2023 at 10:29:27AM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> Unknown -mllvm options don't cause an error to be returned by clang, so
> the cc-option helper adds the unknown hwasan-kernel-mem-intrinsic-prefix=1
> flag to CFLAGS with compilers that are new enough for hwasan but too
Hmmm, how did a change like commit 0e1aa5b62160 ("kcsan: Restrict
supported compilers") work if cc-option does not work with unknown
'-mllvm' flags (or did it)? That definitely seems like a problem, as I
see a few different places where '-mllvm' options are used with
cc-option. I guess I will leave that up to the sanitizer folks to
comment on that further, one small comment below.
> old for this option. This causes a rather unreadable build failure:
>
> fixdep: error opening file: scripts/mod/.empty.o.d: No such file or directory
> make[4]: *** [/home/arnd/arm-soc/scripts/Makefile.build:252: scripts/mod/empty.o] Error 2
> fixdep: error opening file: scripts/mod/.devicetable-offsets.s.d: No such file or directory
> make[4]: *** [/home/arnd/arm-soc/scripts/Makefile.build:114: scripts/mod/devicetable-offsets.s] Error 2
>
> Add a version check to only allow this option with clang-15, gcc-13
> or later versions.
>
> Fixes: 51287dcb00cc ("kasan: emit different calls for instrumentable memintrinsics")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> There is probably a better way to do this than to add version checks,
> but I could not figure it out.
> ---
> scripts/Makefile.kasan | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
> index c186110ffa20..2cea0592e343 100644
> --- a/scripts/Makefile.kasan
> +++ b/scripts/Makefile.kasan
> @@ -69,7 +69,12 @@ CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
> $(instrumentation_flags)
>
> # Instrument memcpy/memset/memmove calls by using instrumented __hwasan_mem*().
> +ifeq ($(call clang-min-version, 150000),y)
> CFLAGS_KASAN += $(call cc-param,hwasan-kernel-mem-intrinsic-prefix=1)
> +endif
> +ifeq ($(call gcc-min-version, 130000),y)
> +CFLAGS_KASAN += $(call cc-param,hwasan-kernel-mem-intrinsic-prefix=1)
> +endif
I do not think you need to duplicate this block, I think
ifeq ($(call clang-min-version, 150000)$(call gcc-min-version, 130000),y)
CFLAGS_KASAN += $(call cc-param,hwasan-kernel-mem-intrinsic-prefix=1)
endif
would work, as only one of those conditions can be true at a time.
Cheers,
Nathan
next prev parent reply other threads:[~2023-04-14 16:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-14 8:29 [PATCH] kasan: remove hwasan-kernel-mem-intrinsic-prefix=1 for clang-14 Arnd Bergmann
2023-04-14 16:26 ` Nathan Chancellor [this message]
2023-04-14 18:53 ` Arnd Bergmann
2023-04-14 19:09 ` Nathan Chancellor
2023-04-18 12:06 ` Marco Elver
2023-04-18 12:28 ` Arnd Bergmann
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