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From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Tue, 9 Apr 2024 17:05:15 +0200
Message-ID: <CAJZ5v0h7XEV__S4pvQJt54Ab832z6PZFTNTRspfLF507MNo9Og@mail.gmail.com>
Subject: Re: [PATCH 2/5] [v2] acpi: disable -Wstringop-truncation
To: Arnd Bergmann <arnd@kernel.org>
Cc: linux-kbuild@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>, 
	Richard Russon <ldm@flatcap.org>, Jens Axboe <axboe@kernel.dk>, Robert Moore <robert.moore@intel.com>, 
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>, Len Brown <lenb@kernel.org>, 
	Steven Rostedt <rostedt@goodmis.org>, Masami Hiramatsu <mhiramat@kernel.org>, 
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, Andrew Morton <akpm@linux-foundation.org>, 
	Masahiro Yamada <masahiroy@kernel.org>, Nathan Chancellor <nathan@kernel.org>, 
	Nicolas Schier <nicolas@fjasle.eu>, Lin Ming <ming.m.lin@intel.com>, 
	Alexey Starikovskiy <astarikovskiy@suse.de>, linux-ntfs-dev@lists.sourceforge.net, 
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, 
	linux-acpi@vger.kernel.org, acpica-devel@lists.linux.dev, 
	linux-trace-kernel@vger.kernel.org
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On Tue, Apr 9, 2024 at 4:01=E2=80=AFPM Arnd Bergmann <arnd@kernel.org> wrot=
e:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> gcc -Wstringop-truncation warns about copying a string that results in a
> missing nul termination:
>
> drivers/acpi/acpica/tbfind.c: In function 'acpi_tb_find_table':
> drivers/acpi/acpica/tbfind.c:60:9: error: 'strncpy' specified bound 6 equ=
als destination size [-Werror=3Dstringop-truncation]
>    60 |         strncpy(header.oem_id, oem_id, ACPI_OEM_ID_SIZE);
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/acpi/acpica/tbfind.c:61:9: error: 'strncpy' specified bound 8 equ=
als destination size [-Werror=3Dstringop-truncation]
>    61 |         strncpy(header.oem_table_id, oem_table_id, ACPI_OEM_TABLE=
_ID_SIZE);
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~=
~~~~~~~~~
>
> The code works as intended, and the warning could be addressed by using
> a memcpy(), but turning the warning off for this file works equally well
> and may be easir to merge.

"easier" (fixed up).

Tricky that, but OK.let's get the warning off the table.

Applied as 6.10 material, thanks!

> Fixes: 47c08729bf1c ("ACPICA: Fix for LoadTable operator, input strings")
> Link: https://lore.kernel.org/lkml/CAJZ5v0hoUfv54KW7y4223Mn9E7D4xvR7whRFN=
LTBqCZMUxT50Q@mail.gmail.com/#t
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/acpi/acpica/Makefile | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/acpica/Makefile b/drivers/acpi/acpica/Makefile
> index 30f3fc13c29d..8d18af396de9 100644
> --- a/drivers/acpi/acpica/Makefile
> +++ b/drivers/acpi/acpica/Makefile
> @@ -5,6 +5,7 @@
>
>  ccflags-y                      :=3D -D_LINUX -DBUILDING_ACPICA
>  ccflags-$(CONFIG_ACPI_DEBUG)   +=3D -DACPI_DEBUG_OUTPUT
> +CFLAGS_tbfind.o                +=3D $(call cc-disable-warning, stringop-=
truncation)
>
>  # use acpi.o to put all files here into acpi.o modparam namespace
>  obj-y  +=3D acpi.o
> --
> 2.39.2
>
>