[PATCH] Fix stringop-overflow warning in test-strncat.

[PATCH] Fix stringop-overflow warning in test-strncat.

[Stefan Liebler]

Starting with commit
b2c474f8de4c92bfe7435853a96805ec32d68dfa
"x86: Fix strncat-avx2.S reading past length [BZ #30065]"

Building on s390 the test fails due warnings like:

In function ‘do_one_test’,
    inlined from ‘do_overflow_tests’ at test-strncat.c:175:7:
test-strncat.c:31:18: error: ‘strnlen’ specified bound [4294966546, 4294967295] exceeds maximum object size 2147483647 [-Werror=stringop-overflow=]
   31 | # define STRNLEN strnlen
      |                  ^
test-strncat.c:83:16: note: in expansion of macro ‘STRNLEN’
   83 |   size_t len = STRNLEN (src, n);
|                ^~~~~~~

In all werror cases, the call to strnlen (.., SIZE_MAX) is inlined.
Therefore this patch just marks the do_one_test function as noinline.
---
 string/test-strncat.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/string/test-strncat.c b/string/test-strncat.c
index c0cde206ee..e71724df5b 100644
--- a/string/test-strncat.c
+++ b/string/test-strncat.c
@@ -69,6 +69,7 @@ SIMPLE_STRNCAT (CHAR *dst, const CHAR *src, size_t n)
 }
 
 static void
+__attribute__((noinline))
 do_one_test (impl_t *impl, CHAR *dst, const CHAR *src, size_t n)
 {
   size_t k = STRLEN (dst);
-- 
2.39.1

Re: [PATCH] Fix stringop-overflow warning in test-strncat.

[Stefan Liebler]

On 02.03.23 11:23, Wilco Dijkstra wrote:
> Hi Stefan,
> 
>> In all werror cases, the call to strnlen (.., SIZE_MAX) is inlined.
>> Therefore this patch just marks the do_one_test function as noinline.
> 
> LGTM
> 
> Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>
> 
> Cheers,
> Wilco
> 
>  static void
> +__attribute__((noinline))
>  do_one_test (impl_t *impl, CHAR *dst, const CHAR *src, size_t n)
>  {
>    size_t k = STRLEN (dst);
> 
> OK

I've just committed the patch.

Thanks,
Stefan

Re: [PATCH] Fix stringop-overflow warning in test-strncat.

[Wilco Dijkstra]

Hi Stefan,

> In all werror cases, the call to strnlen (.., SIZE_MAX) is inlined.
> Therefore this patch just marks the do_one_test function as noinline.

LGTM

Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>

Cheers,
Wilco

 static void
+__attribute__((noinline))
 do_one_test (impl_t *impl, CHAR *dst, const CHAR *src, size_t n)
 {
   size_t k = STRLEN (dst);

OK