Fix localplt check for GNU_IFUNC

On 21-03-2014 17:33, Roland McGrath wrote:
> You need to double-check back to the oldest binutils version that we
> support for building libc (>=2.20) that had STT_GNU_IFUNC support (from
> NEWS looks like 2.20 itself did have it) to ensure that the script handles
> the output from the readelf in all the intervening binutils releases.
> If it's verified that the modified script works with all those versions of
> readelf, then it looks fine.
>
I just check against 2.20.1.20101209, 2.21.1.20110925, 2.22.0.20120801, 2.23.2.20130919,
and 2.24.0.20140325 'readelf -W -S -d -r' against a x86_64 and PowerPC64 build by generating
the jmprel files and all generate the same output for both archs.

I also check with wrong IFUNC usage code change on both archs to see if the script is now
capable to detect them:

* PowerPC64:


And both cases all readelf test correctly shows the wrong PLT cases. Ok to commit?

On 03/25/2014 02:08 PM, Adhemerval Zanella wrote:
> On 21-03-2014 17:33, Roland McGrath wrote:
>> You need to double-check back to the oldest binutils version that we
>> support for building libc (>=2.20) that had STT_GNU_IFUNC support (from
>> NEWS looks like 2.20 itself did have it) to ensure that the script handles
>> the output from the readelf in all the intervening binutils releases.
>> If it's verified that the modified script works with all those versions of
>> readelf, then it looks fine.
>>
> I just check against 2.20.1.20101209, 2.21.1.20110925, 2.22.0.20120801, 2.23.2.20130919,
> and 2.24.0.20140325 'readelf -W -S -d -r' against a x86_64 and PowerPC64 build by generating
> the jmprel files and all generate the same output for both archs.
> 
> I also check with wrong IFUNC usage code change on both archs to see if the script is now
> capable to detect them:
> 
> * PowerPC64:
> 
> diff --git a/sysdeps/powerpc/powerpc64/power7/strncat.S b/sysdeps/powerpc/powerpc64/power7/strncat.S
> index 1a1a95e..23861f6 100644
> --- a/sysdeps/powerpc/powerpc64/power7/strncat.S
> +++ b/sysdeps/powerpc/powerpc64/power7/strncat.S
> @@ -69,7 +69,7 @@ EALIGN(STRNCAT, 4, 0)
>         beq cr0,L(done)
>  
>         mr r31, r4                      /* Save "s2" in r31 from r4.  */
> -       bl STRLEN                       /* Call optimized strlen on s1; goto
> +       bl strlen                       /* Call optimized strlen on s1; goto
>                                            end of s1.  */
>         nop
>         cmpldi cr7, r29, 7              /* If s2 is <=7 process
> 
> * X86_64:
> 
> diff --git a/sysdeps/x86_64/multiarch/strcat-ssse3.S b/sysdeps/x86_64/multiarch/strcat-ssse3.S
> index fde7b90..98fd69c 100644
> --- a/sysdeps/x86_64/multiarch/strcat-ssse3.S
> +++ b/sysdeps/x86_64/multiarch/strcat-ssse3.S
> @@ -37,6 +37,8 @@ ENTRY (STRCAT)
>  /* Inline corresponding strlen file, temporary until new strcpy
>     implementation gets merged.  */
>  
> +       call    strstr
> +
>         xor     %eax, %eax
>         cmpb    $0, (%rdi)
>         jz      L(exit_tail0)
> 
> And both cases all readelf test correctly shows the wrong PLT cases. Ok to commit?

Looks good to me. Thanks for the additional manual testing.

Cheers,
Carlos.

On 25-03-2014 15:13, Carlos O'Donell wrote:
> On 03/25/2014 02:08 PM, Adhemerval Zanella wrote:
>> On 21-03-2014 17:33, Roland McGrath wrote:
>>> You need to double-check back to the oldest binutils version that we
>>> support for building libc (>=2.20) that had STT_GNU_IFUNC support (from
>>> NEWS looks like 2.20 itself did have it) to ensure that the script handles
>>> the output from the readelf in all the intervening binutils releases.
>>> If it's verified that the modified script works with all those versions of
>>> readelf, then it looks fine.
>>>
>> I just check against 2.20.1.20101209, 2.21.1.20110925, 2.22.0.20120801, 2.23.2.20130919,
>> and 2.24.0.20140325 'readelf -W -S -d -r' against a x86_64 and PowerPC64 build by generating
>> the jmprel files and all generate the same output for both archs.
>>
>> I also check with wrong IFUNC usage code change on both archs to see if the script is now
>> capable to detect them:
>>
>> * PowerPC64:
>>
>> diff --git a/sysdeps/powerpc/powerpc64/power7/strncat.S b/sysdeps/powerpc/powerpc64/power7/strncat.S
>> index 1a1a95e..23861f6 100644
>> --- a/sysdeps/powerpc/powerpc64/power7/strncat.S
>> +++ b/sysdeps/powerpc/powerpc64/power7/strncat.S
>> @@ -69,7 +69,7 @@ EALIGN(STRNCAT, 4, 0)
>>         beq cr0,L(done)
>>  
>>         mr r31, r4                      /* Save "s2" in r31 from r4.  */
>> -       bl STRLEN                       /* Call optimized strlen on s1; goto
>> +       bl strlen                       /* Call optimized strlen on s1; goto
>>                                            end of s1.  */
>>         nop
>>         cmpldi cr7, r29, 7              /* If s2 is <=7 process
>>
>> * X86_64:
>>
>> diff --git a/sysdeps/x86_64/multiarch/strcat-ssse3.S b/sysdeps/x86_64/multiarch/strcat-ssse3.S
>> index fde7b90..98fd69c 100644
>> --- a/sysdeps/x86_64/multiarch/strcat-ssse3.S
>> +++ b/sysdeps/x86_64/multiarch/strcat-ssse3.S
>> @@ -37,6 +37,8 @@ ENTRY (STRCAT)
>>  /* Inline corresponding strlen file, temporary until new strcpy
>>     implementation gets merged.  */
>>  
>> +       call    strstr
>> +
>>         xor     %eax, %eax
>>         cmpb    $0, (%rdi)
>>         jz      L(exit_tail0)
>>
>> And both cases all readelf test correctly shows the wrong PLT cases. Ok to commit?
> Looks good to me. Thanks for the additional manual testing.
>
> Cheers,
> Carlos.
>
Pushed as 7bc5a74162d044cc227b38ebf24e2d1d4594ecb8