[PATCH v2 01/11] sframe: Ignore section padding when converting endianness

[Indu Bhagat]

On 5/27/25 4:07 AM, Jens Remus wrote:
> The .sframe section may have a trailing padding due to the architecture-
> specific default section alignment.  Do not treat this padding as error
> when converting between target and host endianness.
> 
> While at it reuse the determined SFrame section header size.
> 
> libsframe/
> 	* sframe.c (flip_sframe): Ignore .sframe section padding.  Reuse
> 	SFrame header size.
> 
> Reported-by: Indu Bhagat <indu.bhagat@oracle.com>
> Signed-off-by: Jens Remus <jremus@linux.ibm.com>

Reviewed-by: Indu Bhagat <indu.bhagat@oracle.com>

> ---
> 
> Notes (jremus):
>      This can be observed when building Binutils with SFrame s390 support on
>      x86-64 for s390x using configure option "--target=s390x-ibm-linux-gnu"
>      and running the GAS test suite.
> 

I would move this comment to the commit log itself, as it sheds light on 
how to reproduce the issue and that the testcase is already present.

Thanks

>   libsframe/sframe.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/libsframe/sframe.c b/libsframe/sframe.c
> index 950a6846f042..b18ea773b8b5 100644
> --- a/libsframe/sframe.c
> +++ b/libsframe/sframe.c
> @@ -498,7 +498,7 @@ flip_sframe (char *frame_buf, size_t buf_size, uint32_t to_foreign)
>   	  fre_offset = fdep->sfde_func_start_fre_off;
>   	}
>   
> -      fp = frame_buf + sframe_get_hdr_size (ihp) + ihp->sfh_freoff;
> +      fp = frame_buf + hdrsz + ihp->sfh_freoff;
>         fp += fre_offset;
>         for (; j < prev_frep_index + num_fres; j++)
>   	{
> @@ -513,8 +513,12 @@ flip_sframe (char *frame_buf, size_t buf_size, uint32_t to_foreign)
>         prev_frep_index = j;
>       }
>     /* All FDEs and FREs must have been endian flipped by now.  */
> -  if ((j != ihp->sfh_num_fres) || (bytes_flipped != (buf_size - hdrsz)))
> +  if ((j != ihp->sfh_num_fres) || (bytes_flipped > (buf_size - hdrsz)))
>       goto bad;
> +  /* Optional trailing section padding.  */
> +  for (fp = frame_buf + hdrsz + bytes_flipped; fp < frame_buf + buf_size; fp++)
> +    if (*fp != '\0')
> +      goto bad;
>   
>     /* Success.  */
>     return 0;