2022-05-20 23:19:32

by Thomas Richter

Subject: [PATCH v2] perf/s390: Compiler error on s390 for bench/numa.c

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 <[email protected]>
Signed-off-by: Thomas Richter <[email protected]>
---
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

2022-05-23 02:07:06

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH v2] perf/s390: Compiler error on s390 for bench/numa.c

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 <[email protected]>



Thanks, applied.

- Arnaldo


> Signed-off-by: Thomas Richter <[email protected]>
> ---
> 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