Re: [PATCH] string: Fix tester build with fortify enable with gcc < 12

[MAHESH BODAPATI <bmahi496@linux.ibm.com>]

On 09/08/23 7:10 pm, Rajalakshmi Srinivasaraghavan wrote:
>
> On 8/9/23 7:03 AM, bmahi496@linux.ibm.com wrote:
>> From: Mahesh Bodapati <bmahi496@linux.ibm.com>
>>
>> When building with fortify enabled, GCC < 12 issues a warning on the
>> fortify strncat wrapper might overflow the destination buffer. However,
>> GCC does not provide a specific flag to disable the warning (the
>> failure is tied to -Werror). So to avoid disable all errors, only
>> enable the check for GCC 12 or newer.
>>
>> Checked on ppc64 and x86_64.
>> ---
>>   string/tester.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/string/tester.c b/string/tester.c
>> index f7d4bac5a8..cf3f5ae495 100644
>> --- a/string/tester.c
>> +++ b/string/tester.c
>> @@ -421,6 +421,12 @@ test_strncat (void)
>>     (void) strncat (one, "ij", (size_t)-1);    /* set sign bit in 
>> count */
>>     equal (one, "abcdghij", 13);
>>   +  /* When building with fortify enabled, GCC < 12 issues a warning 
>> on the
>> +     fortify strncat wrapper might overflow the destination buffer.  
>> However,
>> +     GCC does not provide a specific flag to disable the warning (the
>> +     failure is tied to -Werror). So to avoid disable all errors, only
>> +     enable the check for GCC 12 or newer.  */
>> +#if __GNUC_PREREQ (12, 0)
>
> Is it  possible to include a check for fortify enabled option ?

__USE_FORTIFY_LEVEL is 0 if fortify not enabled.

I will include it in the condition and share the updated patch.


>
>>     int ntest = 14;
>>     char buf1[80] __attribute__ ((aligned (16)));
>>     char buf2[32] __attribute__ ((aligned (16)));
>> @@ -464,6 +470,7 @@ test_strncat (void)
>>               }
>>           }
>>         }
>> +#endif
>>   }
>>     static void