Re: git: b882d21558f3 - main - arm: link all .rodata variants into one output section

John Baldwin <jhb_at_FreeBSD.org> wrote on
Date: Wed, 20 Nov 2024 14:52:06 UTC :

> On 11/19/24 08:02, Michal Meloun wrote:

> > 
> > 
> > On 19.11.2024 16:15, John Baldwin wrote:
> >> On 11/17/24 03:36, Michal Meloun wrote:
> >>> The branch main has been updated by mmel:
> >>>
> >>> URL: https://cgit.FreeBSD.org/src/commit/?
> >>> id=b882d21558f37e6a565694ac9b8f2a519e5b86fa
> >>>
> >>> commit b882d21558f37e6a565694ac9b8f2a519e5b86fa
> >>> Author:     Michal Meloun <mmel@FreeBSD.org>
> >>> AuthorDate: 2024-11-17 11:28:47 +0000
> >>> Commit:     Michal Meloun <mmel@FreeBSD.org>
> >>> CommitDate: 2024-11-17 11:35:55 +0000
> >>>
> >>>      arm: link all .rodata variants into one output section
> >>>      MFC after:      1 week
> >>> ---
> >>>   sys/conf/ldscript.arm | 2 +-
> >>>   1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/sys/conf/ldscript.arm b/sys/conf/ldscript.arm
> >>> index d9edcfac9f78..7cf904ce39ff 100644
> >>> --- a/sys/conf/ldscript.arm
> >>> +++ b/sys/conf/ldscript.arm
> >>> @@ -17,7 +17,7 @@ SECTIONS
> >>>     _etext = .;
> >>>     PROVIDE (etext = .);
> >>>     .fini      : { *(.fini)    } =0x9090
> >>> -  .rodata    : { *(.rodata) *(.gnu.linkonce.r*) }
> >>> +  .rodata    : { *(.rodata*) *(.gnu.linkonce.r*) }
> >>>     .rodata1   : { *(.rodata1) }
> >>
> >> Is this line now spurious or do linker scripts prefer more exact matches?
> >>
> >>>      .interp     : { *(.interp)     }
> >>>     .hash          : { *(.hash)        }
> >>
> > Right hit. I want write { *(.rodata) *(.rodata.*) *(.gnu.linkonce.r*) }
> > 
> > Warner already tried to tell me the same thing, but I didn't get it :(
> > Btw arm64 has the same problem.
> > 
> > This gives me another question. Who generates the .rodata1 section? This
> > section appeared in gnu ld three decades ago, with no real description.
> > Do we still need it?
> 
> I have no idea if we still need .rodata1 (or why it exists), I was just
> reading the diff of the linker script.


Looking around at examples on the web I'm seeing mostly the
likes of the following for analogous text:

  .rodata         : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
  .rodata1        : { *(.rodata1) }

(and somewhat similarly for .data.*)

I saw some examples of *(.rodata.str1.4) for examples that
lacked use of .rodata.* , giving some idea what would be
expected to match the .* part of the pattern.


===
Mark Millard
marklmi at yahoo.com