Re: [Qemu-devel] [PATCH] sparc-linux-user: Fix missing symbols in .rel/.rela.plt sections

[Blue Swirl]

On Tue, Jan 10, 2012 at 17:38, Aurelien Jarno <address@hidden> wrote:
> On Sat, Jan 07, 2012 at 10:01:09PM +0100, Aurelien Jarno wrote:
>> On Sat, Jan 07, 2012 at 08:36:12PM +0000, Blue Swirl wrote:
>> > On Sat, Jan 7, 2012 at 20:16, Aurelien Jarno <address@hidden> wrote:
>> > > Fix .rel.plt sections in the output to not only include .rel.plt
>> > > sections from the input but also the .rel.iplt sections and to define
>> > > the hidden symbols __rel_iplt_start and __rel_iplt_end around
>> > > .rel.iplt as otherwise we get undefined references to these when
>> > > linking statically to a multiarch enabled libc (using STT_GNU_IFUNC).
>> > >
>> > > Blue Swirl <address@hidden>
>> > > Signed-off-by: Aurelien Jarno <address@hidden>
>> > > ---
>> > >  sparc.ld |   16 ++++++++++++++--
>> > >  1 files changed, 14 insertions(+), 2 deletions(-)
>> > >
>> > > diff --git a/sparc.ld b/sparc.ld
>> > > index 56efe34..e52c3d2 100644
>> > > --- a/sparc.ld
>> > > +++ b/sparc.ld
>> > > @@ -37,8 +37,20 @@ SECTIONS
>> > >   .rela.fini     : { *(.rela.fini)      }
>> > >   .rel.bss       : { *(.rel.bss)                }
>> > >   .rela.bss      : { *(.rela.bss)               }
>> > > -  .rel.plt       : { *(.rel.plt)                }
>> > > -  .rela.plt      : { *(.rela.plt)               }
>> > > +  .rel.plt      :
>> > > +  {
>> > > +    *(.rel.plt)
>> > > +    PROVIDE_HIDDEN (__rel_iplt_start = .);
>> > > +    *(.rel.iplt)
>> > > +    PROVIDE_HIDDEN (__rel_iplt_end = .);
>> > > +  }
>> > > +  .rela.plt       :
>> > > +  {
>> > > +    *(.rela.plt)
>> > > +    PROVIDE_HIDDEN (__rela_iplt_start = .);
>> > > +    *(.rela.iplt)
>> > > +    PROVIDE_HIDDEN (__rela_iplt_end = .);
>> > > +  }
>> >
>> > PROVIDE_HIDDEN etc. were removed by
>> > 8733f6093c2b77502e7228503fc22024e51599b8 in order to support BSDs with
>> > older binutils (2.15). Maybe the ld scripts should be generated from a
>> > source file for example with CPP, so these lines could be tweaked.
>> >
>>
>> It seems this patch was in my local tree for too long, and it seems I
>> should have updated it before sending it...
>>
>> Other architectures are now using PROVIDE instead of PROVIDE_HIDDEN for
>> __rel{a,}_iplt_{start,end}, so I guess the same can be done for sparc and
>> ppc. I am going to do a test build to check that, and I'll come with a
>> new patch if it works.
>
> The new patch below also fixes the issue, and uses PROVIDE instead of
> PROVIDE_HIDDEN.

This should work, the info page for OpenBSD ld talks about PROVIDE
(but not PROVIDE_HIDDEN).

> sparc-linux-user: Fix missing symbols in .rel/.rela.plt sections
>
> Fix .rel.plt sections in the output to not only include .rel.plt
> sections from the input but also the .rel.iplt sections and to define
> the hidden symbols __rel_iplt_start and __rel_iplt_end around
> .rel.iplt as otherwise we get undefined references to these when
> linking statically to a multiarch enabled libc (using STT_GNU_IFUNC).
>
> Cc: Blue Swirl <address@hidden>
> Signed-off-by: Aurelien Jarno <address@hidden>
> ---
>  sparc.ld |   16 ++++++++++++++--
>  1 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/sparc.ld b/sparc.ld
> index 56efe34..cec17c9 100644
> --- a/sparc.ld
> +++ b/sparc.ld
> @@ -37,8 +37,20 @@ SECTIONS
>   .rela.fini     : { *(.rela.fini)      }
>   .rel.bss       : { *(.rel.bss)                }
>   .rela.bss      : { *(.rela.bss)               }
> -  .rel.plt       : { *(.rel.plt)                }
> -  .rela.plt      : { *(.rela.plt)               }
> +  .rel.plt      :
> +  {
> +    *(.rel.plt)
> +    PROVIDE (__rel_iplt_start = .);
> +    *(.rel.iplt)
> +    PROVIDE (__rel_iplt_end = .);
> +  }
> +  .rela.plt       :
> +  {
> +    *(.rela.plt)
> +    PROVIDE (__rela_iplt_start = .);
> +    *(.rela.iplt)
> +    PROVIDE (__rela_iplt_end = .);
> +  }
>   .init          : { *(.init)   } =0x47ff041f
>   .text      :
>   {
> --
> 1.7.7.3
>
>
> --
> Aurelien Jarno                          GPG: 1024D/F1BCDB73
> address@hidden                 http://www.aurel32.net
>