Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   SeongJae Park <sj@kernel.org>
To:     Yuanchu Xie <yuanchu@google.com>
Cc:     Shuah Khan <shuah@kernel.org>, Markus Boehme <markubo@amazon.de>,
        SeongJae Park <sj@kernel.org>, rientjes@google.com,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] selftests/damon: suppress compiler warnings for huge_count_read_write
Date:   Wed,  4 May 2022 18:45:37 +0000
Message-Id: <20220504184537.130085-1-sj@kernel.org>
In-Reply-To: <20220504182908.1322874-1-yuanchu@google.com>
References: 
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

Hi Yuanchu,

On Wed, 4 May 2022 18:29:08 +0000 Yuanchu Xie <yuanchu@google.com> wrote:

> The test case added in commit db7a347b26fe ("mm/damon/dbgfs:
> use '__GFP_NOWARN' for user-specified size buffer allocation")
> intentionally writes and reads with a large count to cause
> allocation failure and check for kernel warnings. We suppress
> the compiler warnings for these calls as they work as intended.
> 
> Signed-off-by: Yuanchu Xie <yuanchu@google.com>
> ---

It would be a good practice to mention the changes from the previous version of
this patch here[1].

[1] https://docs.kernel.org/process/submitting-patches.html#the-canonical-patch-format

>  tools/testing/selftests/damon/huge_count_read_write.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/tools/testing/selftests/damon/huge_count_read_write.c b/tools/testing/selftests/damon/huge_count_read_write.c
> index ad7a6b4cf338..91bd80c75cd9 100644
> --- a/tools/testing/selftests/damon/huge_count_read_write.c
> +++ b/tools/testing/selftests/damon/huge_count_read_write.c
> @@ -2,6 +2,8 @@
>  /*
>   * Author: SeongJae Park <sj@kernel.org>
>   */
> +#pragma GCC diagnostic ignored "-Wstringop-overflow"
> +#pragma GCC diagnostic ignored "-Wstringop-overread"

I agree that this must be the cleaner way than v2.  But, I get below warning
after applying this:

    $ sudo make -C tools/testing/selftests/damon run_tests
    make: Entering directory '/home/sjpark/linux/tools/testing/selftests/damon'
    gcc     huge_count_read_write.c  -o /home/sjpark/linux/tools/testing/selftests/damon/huge_count_read_write
    huge_count_read_write.c:6:32: warning: unknown option after ‘#pragma GCC diagnostic’ kind [-Wpragmas]
        6 | #pragma GCC diagnostic ignored "-Wstringop-overread"
          |                                ^~~~~~~~~~~~~~~~~~~~~

My gcc version is:

    $ gcc --version
    gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0


Thanks,
SJ

>  
>  #include <fcntl.h>
>  #include <stdlib.h>
> -- 
> 2.36.0.464.gb9c8b46e94-goog
>