Re: [PATCH] arm64: vdso: remove commas between macro name and arguments

From: Ard Biesheuvel <ardb@kernel.org>
To: Jian Cai <jiancai@google.com>
Cc: "# 3.4.x" <stable@vger.kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sasha Levin <sashal@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Manoj Gupta <manojgupta@google.com>,
	Luis Lozano <llozano@google.com>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] arm64: vdso: remove commas between macro name and arguments
Date: Fri, 16 Apr 2021 21:08:03 +0200	[thread overview]
Message-ID: <CAMj1kXER9EmB4wD9SbFhJL5VHc1qJ_bDC+GhPTFdxzHAJWLT0w@mail.gmail.com> (raw)
In-Reply-To: <20210416181421.2374588-1-jiancai@google.com>

On Fri, 16 Apr 2021 at 20:16, Jian Cai <jiancai@google.com> wrote:
>
> LLVM's integrated assembler does not support using commas separating
> the name and arguments in .macro. However, only spaces are used in the
> manual page. This replaces commas between macro names and the subsequent
> arguments with space in calls to clock_gettime_return to make it
> compatible with IAS.
>
> Link:
> https://sourceware.org/binutils/docs/as/Macro.html#Macro
> Signed-off-by: Jian Cai <jiancai@google.com>
> ---
>  arch/arm64/kernel/vdso/gettimeofday.S | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S
> index 856fee6d3512..7ee685d9adfc 100644
> --- a/arch/arm64/kernel/vdso/gettimeofday.S
> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
> @@ -122,7 +122,7 @@ x_tmp               .req    x8
>  9998:
>         .endm
>
> -       .macro clock_gettime_return, shift=0
> +       .macro clock_gettime_return shift=0

Are you sure the definition needs to be changed as well? The majority
of GAS macros in arch/arm64 (if not all) use a comma after the
identifier, so I would prefer not to deviate from that arbitrarily.

Just look at

$ git grep -E \.macro\\s+\\S+,  arch/arm64/*.S

>         .if \shift == 1
>         lsr     x11, x11, x12
>         .endif
> @@ -227,7 +227,7 @@ realtime:
>         seqcnt_check fail=realtime
>         get_ts_realtime res_sec=x10, res_nsec=x11, \
>                 clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9
> -       clock_gettime_return, shift=1
> +       clock_gettime_return shift=1
>
>         ALIGN
>  monotonic:
> @@ -250,7 +250,7 @@ monotonic:
>                 clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9
>
>         add_ts sec=x10, nsec=x11, ts_sec=x3, ts_nsec=x4, nsec_to_sec=x9
> -       clock_gettime_return, shift=1
> +       clock_gettime_return shift=1
>
>         ALIGN
>  monotonic_raw:
> @@ -271,7 +271,7 @@ monotonic_raw:
>                 clock_nsec=x15, nsec_to_sec=x9
>
>         add_ts sec=x10, nsec=x11, ts_sec=x13, ts_nsec=x14, nsec_to_sec=x9
> -       clock_gettime_return, shift=1
> +       clock_gettime_return shift=1
>
>         ALIGN
>  realtime_coarse:
> --
> 2.31.1.368.gbe11c130af-goog
>
>
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