SHF_GNU_MBIND requires ELFOSABI_GNU

When SHF_GNU_MBIND was added in the SHF_LOOS to SHF_HIOS range, it
should have required ELFOSABI_GNU since these flags are already in use
by other OSes.  HPUX SHF_HP_TLS in fact has the same value.  That
means no place in binutils should test SHF_GNU_MBIND without first
checking OSABI, and SHF_GNU_MBIND should not be set without also
setting OSABI.  At least, that's the ideal, but the patch accepts
SHF_GNU_MBIND on ELFOSABI_NONE object files since gas didn't always
set OSABI.  However, to reinforce the fact that SHF_GNU_MBIND isn't
proper without a non-zero OSABI, readelf will display the flag as
LOOS+0 if OSABI isn't set.

The clash with SHF_HP_TLS means that hppa64-linux either has that flag
on .tbss sections or supports GNU_MBIND, not both.  (hppa64-linux
users, if there are any, may have noticed that GNU ld since 2017
mysteriously aligned their .tbss sections to a 4k boundary.  That was
one consequence of SHF_HP_TLS being blindly interpreted as
SHF_GNU_MBIND.)  Since it seems that binutils, gdb, gcc, glibc, and
the linux kernel don't care about SHF_HP_TLS I took that flag out of
.tbss for hppa64-linux.

bfd/
	* elf-bfd.h (enum elf_gnu_osabi): Add elf_gnu_osabi_mbind.
	* elf.c (_bfd_elf_make_section_from_shdr): Set elf_gnu_osabi_mbind.
	(get_program_header_size): Formatting.  Only test SH_GNU_MBIND
	when elf_gnu_osabi_mbind is set.
	(_bfd_elf_map_sections_to_segments): Likewise.
	(_bfd_elf_init_private_section_data): Likewise.
	(_bfd_elf_final_write_processing): Update comment.
	* elf64-hppa.c (elf64_hppa_special_sections): Move .tbss entry.
	(elf_backend_special_sections): Define without .tbss for linux.
binutils/
	* readelf.c (get_parisc_segment_type): Split off hpux entries..
	(get_ia64_segment_type): ..and these..
	(get_hpux_segment_type): ..to here.
	(get_segment_type): Condition GNU_MBIND on osabi.  Use
	get_hpux_segment_type.
	(get_symbol_binding): Do not print UNIQUE for ELFOSABI_NONE.
	(get_symbol_type): Do not print IFUNC for ELFOSABI_NONE.
gas/
	* config/obj-elf.c (obj_elf_change_section): Don't emit a fatal
	error for non-SHF_ALLOC SHF_GNU_MBIND here.
	(obj_elf_parse_section_letters): Return SHF_GNU_MBIND in new
	gnu_attr param.
	(obj_elf_section): Adjust obj_elf_parse_section_letters call.
	Formatting.  Set SHF_GNU_MBIND and elf_osabi from gnu_attr.
	Emit normal error for non-SHF_ALLOC SHF_GNU_MBIND and wrong osabi.
	(obj_elf_type): Set elf_osabi for ifunc.
	* testsuite/gas/elf/section12a.d: xfail msp430 and hpux.
	* testsuite/gas/elf/section12b.d: Likewise.
	* testsuite/gas/elf/section13.d: Likewise.
	* testsuite/gas/elf/section13.l: Adjust expected error.
ld/
	* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Condition
	SHF_GNU_MBIND on osabi.  Set output elf_gnu_osabi_mbind.

1 files changed, 4 insertions, 3 deletions

diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index 134496e..01beac6 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -1809,11 +1809,12 @@ struct output_elf_obj_tdata
   bfd_boolean flags_init;
 };
 
-/* Indicate if the bfd contains symbols that have the STT_GNU_IFUNC
-   symbol type or STB_GNU_UNIQUE binding.  Used to set the osabi
-   field in the ELF header structure.  */
+/* Indicate if the bfd contains SHF_GNU_MBIND sections or symbols that
+   have the STT_GNU_IFUNC symbol type or STB_GNU_UNIQUE binding.  Used
+   to set the osabi field in the ELF header structure.  */
 enum elf_gnu_osabi
 {
+  elf_gnu_osabi_mbind = 1 << 0,
   elf_gnu_osabi_ifunc = 1 << 1,
   elf_gnu_osabi_unique = 1 << 2,
 };