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Date:   Fri, 20 May 2022 11:30:04 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Thomas Richter <tmricht@linux.ibm.com>
Cc:     linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        svens@linux.ibm.com, gor@linux.ibm.com, sumanthk@linux.ibm.com,
        hca@linux.ibm.com, Namhyung Kim <namhyung@gmail.com>
Subject: Re: [PATCH v2] perf/s390: Compiler error on s390 for bench/numa.c
Message-ID: <Yoel7HCdQr+uSKNA@kernel.org>
References: <20220520081158.2990006-1-tmricht@linux.ibm.com>
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Em Fri, May 20, 2022 at 10:11:58AM +0200, Thomas Richter escreveu:
> The compilation on s390 results in this error:
> 
>  # make DEBUG=y bench/numa.o
>  ...
>  bench/numa.c: In function ‘__bench_numa’:
>  bench/numa.c:1749:81: error: ‘%d’ directive output may be truncated
>              writing between 1 and 11 bytes into a region of size between
>              10 and 20 [-Werror=format-truncation=]
>  1749 |        snprintf(tname, sizeof(tname), "process%d:thread%d", p, t);
>                                                                ^~
>  ...
>  bench/numa.c:1749:64: note: directive argument in the range
>                 [-2147483647, 2147483646]
>  ...
>  #
> 
> The maximum length of the %d replacement is 11 characters because
> of the negative sign.  Therefore extend the array by two more
> characters.
> 
> Output after:
>  # make  DEBUG=y bench/numa.o > /dev/null 2>&1; ll bench/numa.o
>  -rw-r--r-- 1 root root 418320 May 19 09:11 bench/numa.o
>  #
> 
> Fixes: 3aff8ba0a4c9c ("perf bench numa: Avoid possible truncation when using snprintf()")
> Suggested-by: Namhyung Kim <namhyung@gmail.com>


Thanks, applied.

- Arnaldo


> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
> ---
>  tools/perf/bench/numa.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/bench/numa.c b/tools/perf/bench/numa.c
> index d5289fa58a4f..20eed1e53f80 100644
> --- a/tools/perf/bench/numa.c
> +++ b/tools/perf/bench/numa.c
> @@ -1740,7 +1740,7 @@ static int __bench_numa(const char *name)
>  		"GB/sec,", "total-speed",	"GB/sec total speed");
>  
>  	if (g->p.show_details >= 2) {
> -		char tname[14 + 2 * 10 + 1];
> +		char tname[14 + 2 * 11 + 1];
>  		struct thread_data *td;
>  		for (p = 0; p < g->p.nr_proc; p++) {
>  			for (t = 0; t < g->p.nr_threads; t++) {
> -- 
> 2.36.1

-- 

- Arnaldo