bfd/
* elf32-arm.c (CMSE_PREFIX): Define macro.
(elf32_arm_stub_cmse_branch_thumb_only): Define stub sequence.
(cmse_branch_thumb_only): Declare stub.
(struct elf32_arm_link_hash_table): Define cmse_stub_sec field.
(elf32_arm_get_plt_info): Add globals parameter. Use it to return
FALSE if there is no PLT.
(arm_type_of_stub): Adapt to new elf32_arm_get_plt_info signature.
(elf32_arm_final_link_relocate): Likewise.
(elf32_arm_gc_sweep_hook): Likewise.
(elf32_arm_gc_mark_extra_sections): Mark sections holding ARMv8-M
secure entry functions.
(arm_stub_is_thumb): Add case for arm_stub_cmse_branch_thumb_only.
(arm_dedicated_stub_output_section_required): Change to a switch case
and add a case for arm_stub_cmse_branch_thumb_only.
(arm_dedicated_stub_output_section_required_alignment): Likewise.
(arm_stub_dedicated_output_section_name): Likewise.
(arm_stub_dedicated_input_section_ptr): Likewise and remove
ATTRIBUTE_UNUSED for htab parameter.
(arm_stub_required_alignment): Likewise.
(arm_stub_sym_claimed): Likewise.
(arm_dedicated_stub_section_padding): Likewise.
(cmse_scan): New function.
(elf32_arm_size_stubs): Call cmse_scan for ARM M profile targets.
Set stub_changed to TRUE if such veneers were created.
(elf32_arm_swap_symbol_in): Add detection code for CMSE special
symbols.
include/
* arm.h (ARM_GET_SYM_CMSE_SPCL): Define macro.
(ARM_SET_SYM_CMSE_SPCL): Likewise.
ld/
* ld.texinfo (Placement of SG veneers): New concept entry.
* testsuite/ld-arm/arm-elf.exp
(Secure gateway veneers: no .gnu.sgstubs section): New test.
(Secure gateway veneers: wrong entry functions): Likewise.
(Secure gateway veneers (ARMv8-M Baseline)): Likewise.
(Secure gateway veneers (ARMv8-M Mainline)): Likewise.
* testsuite/ld-arm/cmse-veneers.s: New file.
* testsuite/ld-arm/cmse-veneers.d: Likewise.
* testsuite/ld-arm/cmse-veneers.rd: Likewise.
* testsuite/ld-arm/cmse-veneers.sd: Likewise.
* testsuite/ld-arm/cmse-veneers-no-gnu_sgstubs.out: Likewise.
* testsuite/ld-arm/cmse-veneers-wrong-entryfct.out: Likewise.
