[binutils-gdb] ld/ELF: leave note sections alone for relocatable linking

[Jan Beulich]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=8709351936f7308b460b3d417dd1ff2dba4858cd

commit 8709351936f7308b460b3d417dd1ff2dba4858cd
Author: Jan Beulich <jbeulich@suse.com>
Date:   Fri Dec 12 08:02:12 2025 +0100

    ld/ELF: leave note sections alone for relocatable linking
    
    Commit 023e60ced0c8 ("ld: Move note sections after .rodata section") had a
    rather undesirable effect for relocatable links (which typically wouldn't
    use a custom linker script): .note.GNU-stack, which isn't even a proper
    notes sections (it's SHT_PROGBITS instead, which likely will want
    correcting independently), would be moved immediately past .text and
    .rodata (and alike), ahead of any custom notes sections. A later final
    link, possibly simply combining all .note and .note.* sections, would then
    find .note.GNU-stack first, resulting in the output section to also become
    SHT_PROGBITS. This way consumers looking for SHT_NOTE wouldn't find the
    data they're after.
    
    The goal of mentioning some known .note.* in the linker scripts is to
    avoid orphan section diagnostics. That's not typically of interest for
    relocatable links, though (people caring about this will want to have
    custom scripts anyway, much like they may need to if they had any custom
    .note.* sections). Therefore suppress that part of the linker script for
    relocatable links.

Diff:
---
 ld/scripttempl/elf.sc | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/ld/scripttempl/elf.sc b/ld/scripttempl/elf.sc
index 6d34912e45d..7ecf536f06a 100644
--- a/ld/scripttempl/elf.sc
+++ b/ld/scripttempl/elf.sc
@@ -727,23 +727,25 @@ cat <<EOF
   .exception_ranges ${RELOCATING-0} : ONLY_IF_RO { *(.exception_ranges${RELOCATING+*}) }
 
   ${TEXT_PLT+${PLT_NEXT_DATA+${PLT} ${OTHER_PLT_SECTIONS}}}
+EOF
 
+test -n "${RELOCATING}" && cat <<EOF
   /* Various note sections.  Placed here so that they are always included
      in the read-only segment and not treated as orphan sections.  The
      current orphan handling algorithm does place note sections after R/O
      data, but this is not guaranteed to always be the case.  */
-  .note.build-id :      { *(.note.build-id) } ${RELOCATING+${REGION}}
-  .note.GNU-stack :     { *(.note.GNU-stack) } ${RELOCATING+${REGION}}
-  .note.gnu.property :  { *(.note.gnu.property) } ${RELOCATING+${REGION}}
-  .note.ABI-tag :       { *(.note.ABI-tag) } ${RELOCATING+${REGION}}
-  .note.package :       { *(.note.package) } ${RELOCATING+${REGION}}
-  .note.dlopen :        { *(.note.dlopen) } ${RELOCATING+${REGION}}
-  .note.netbsd.ident :  { *(.note.netbsd.ident) } ${RELOCATING+${REGION}}
-  .note.openbsd.ident : { *(.note.openbsd.ident) } ${RELOCATING+${REGION}}
-
-  ${RELOCATING+${ETEXT_LAST_IN_RODATA_SEGMENT+PROVIDE (__${ETEXT_NAME} = .);}}
-  ${RELOCATING+${ETEXT_LAST_IN_RODATA_SEGMENT+PROVIDE (_${ETEXT_NAME} = .);}}
-  ${RELOCATING+${ETEXT_LAST_IN_RODATA_SEGMENT+PROVIDE (${ETEXT_NAME} = .);}}
+  .note.build-id :      { *(.note.build-id) } ${REGION}
+  .note.GNU-stack :     { *(.note.GNU-stack) } ${REGION}
+  .note.gnu.property :  { *(.note.gnu.property) } ${REGION}
+  .note.ABI-tag :       { *(.note.ABI-tag) } ${REGION}
+  .note.package :       { *(.note.package) } ${REGION}
+  .note.dlopen :        { *(.note.dlopen) } ${REGION}
+  .note.netbsd.ident :  { *(.note.netbsd.ident) } ${REGION}
+  .note.openbsd.ident : { *(.note.openbsd.ident) } ${REGION}
+
+  ${ETEXT_LAST_IN_RODATA_SEGMENT+PROVIDE (__${ETEXT_NAME} = .);}
+  ${ETEXT_LAST_IN_RODATA_SEGMENT+PROVIDE (_${ETEXT_NAME} = .);}
+  ${ETEXT_LAST_IN_RODATA_SEGMENT+PROVIDE (${ETEXT_NAME} = .);}
 EOF
 }