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[6/6] Main ARM STT_GNU_IFUNC patch

Nick Clifton nickc@redhat.com
Mon Mar 14 14:27:00 GMT 2011 
Hi Richard,

> include/elf/
> 	* arm.h (R_ARM_IRELATIVE): New relocation.
>
> bfd/
> 	* reloc.c (BFD_RELOC_ARM_IRELATIVE): New relocation.
> 	* bfd-in2.h: Regenerate.
> 	* elf32-arm.c (elf32_arm_howto_table_2): Rename existing definition
> 	to elf32_arm_howto_table_3 and replace with a single R_ARM_IRELATIVE
> 	entry.
> 	(elf32_arm_howto_from_type): Update accordingly.
> 	(elf32_arm_reloc_map): Map BFD_RELOC_ARM_IRELATIVE to R_ARM_IRELATIVE.
> 	(elf32_arm_reloc_name_lookup): Handle elf32_arm_howto_table_3.
> 	(arm_plt_info): New structure, split out from elf32_arm_link_hash_entry
> 	with an extra noncall_refcount field.
> 	(arm_local_iplt_info): New structure.
> 	(elf_arm_obj_tdata): Add local_iplt.
> 	(elf32_arm_local_iplt): New accessor macro.
> 	(elf32_arm_link_hash_entry): Replace plt_thumb_refcount,
> 	plt_maybe_thumb_refcount and plt_got_offset with an arm_plt_info.
> 	Change tls_type to a bitfield and add is_iplt.
> 	(elf32_arm_link_hash_newfunc): Update accordingly.
> 	(elf32_arm_allocate_local_sym_info): New function.
> 	(elf32_arm_create_local_iplt): Likewise.
> 	(elf32_arm_get_plt_info): Likewise.
> 	(elf32_arm_plt_needs_thumb_stub_p): Likewise.
> 	(elf32_arm_get_local_dynreloc_list): Likewise.
> 	(create_ifunc_sections): Likewise.
> 	(elf32_arm_copy_indirect_symbol): Update after the changes to
> 	elf32_arm_link_hash_entry.  Assert the is_iplt has not yet been set.
> 	(arm_type_of_stub): Add an st_type argument.  Use elf32_arm_get_plt_info
> 	to get PLT information.  Assert that all STT_GNU_IFUNC references
> 	are turned into PLT references.
> 	(arm_build_one_stub): Pass the symbol type to
> 	elf32_arm_final_link_relocate.
> 	(elf32_arm_size_stubs): Pass the symbol type to arm_type_of_stub.
> 	(elf32_arm_allocate_irelocs): New function.
> 	(elf32_arm_add_dynreloc): In static objects, use .rel.iplt for
> 	all R_ARM_IRELATIVE.
> 	(elf32_arm_allocate_plt_entry): New function.
> 	(elf32_arm_populate_plt_entry): Likewise.
> 	(elf32_arm_final_link_relocate): Add an st_type parameter.
> 	Set srelgot to null for static objects.  Use separate variables
> 	to record which st_value and st_type should be used when generating
> 	a dynamic relocation.  Use elf32_arm_get_plt_info to find the
> 	symbol's PLT information, setting has_iplt_entry, splt,
> 	plt_offset and gotplt_offset accordingly.  Check whether
> 	STT_GNU_IFUNC symbols should resolve to an .iplt entry, and change
> 	the relocation target accordingly.  Broaden assert to include
> 	.iplts.  Don't set sreloc for static relocations.  Assert that
> 	we only generate dynamic R_ARM_RELATIVE relocations for R_ARM_ABS32
> 	and R_ARM_ABS32_NOI.  Generate R_ARM_IRELATIVE relocations instead
> 	of R_ARM_RELATIVE relocations if the target is an STT_GNU_IFUNC
> 	symbol.  Pass the symbol type to arm_type_of_stub.  Conditionally
> 	resolve GOT references to the .igot.plt entry.
> 	(elf32_arm_relocate_section): Update the call to
> 	elf32_arm_final_link_relocate.
> 	(elf32_arm_gc_sweep_hook): Use elf32_arm_get_plt_info to get PLT
> 	information.  Treat R_ARM_REL32 and R_ARM_REL32_NOI as call
> 	relocations in shared libraries and relocatable executables.
> 	Count non-call PLT references.  Use elf32_arm_get_local_dynreloc_list
> 	to get the list of dynamic relocations for a local symbol.
> 	(elf32_arm_check_relocs): Always create ifunc sections.  Set isym
> 	at the same time as setting h.  Use elf32_arm_allocate_local_sym_info
> 	to allocate local symbol information.  Treat R_ARM_REL32 and
> 	R_ARM_REL32_NOI as call relocations in shared libraries and
> 	relocatable executables.  Record PLT information for local
> 	STT_GNU_IFUNC functions as well as global functions.   Count
> 	non-call PLT references.  Use elf32_arm_get_local_dynreloc_list
> 	to get the list of dynamic relocations for a local symbol.
> 	(elf32_arm_adjust_dynamic_symbol): Handle STT_GNU_IFUNC symbols.
> 	Don't remove STT_GNU_IFUNC PLTs unless all references have been
> 	removed.  Update after the changes to elf32_arm_link_hash_entry.
> 	(allocate_dynrelocs_for_symbol): Decide whether STT_GNU_IFUNC PLT
> 	entries should live in .plt or .iplt.  Check whether the .igot.plt
> 	and .got entries can be combined.  Use elf32_arm_allocate_plt_entry
> 	to allocate .plt and .(i)got.plt entries.  Detect which .got
> 	entries will need R_ARM_IRELATIVE relocations and use
> 	elf32_arm_allocate_irelocs to allocate them.  Likewise other
> 	non-.got dynamic relocations.
> 	(elf32_arm_size_dynamic_sections): Allocate .iplt, .igot.plt
> 	and dynamic relocations for local STT_GNU_IFUNC symbols.
> 	Check whether the .igot.plt and .got entries can be combined.
> 	Detect which .got entries will need R_ARM_IRELATIVE relocations
> 	and use elf32_arm_allocate_irelocs to allocate them.  Use stashed
> 	section pointers intead of strcmp checks.  Handle iplt and igotplt.
> 	(elf32_arm_finish_dynamic_symbol): Use elf32_arm_populate_plt_entry
> 	to fill in .plt, .got.plt and .rel(a).plt entries.  Point
> 	STT_GNU_IFUNC symbols at an .iplt entry if non-call relocations
> 	resolve to it.
> 	(elf32_arm_output_plt_map_1): New function, split out from
> 	elf32_arm_output_plt_map.  Handle .iplt entries.  Use
> 	elf32_arm_plt_needs_thumb_stub_p.
> 	(elf32_arm_output_plt_map): Call it.
> 	(elf32_arm_output_arch_local_syms): Add mapping symbols for
> 	local .iplt entries.
> 	(elf32_arm_swap_symbol_in): Handle Thumb STT_GNU_IFUNC symbols.
> 	(elf32_arm_swap_symbol_out): Likewise.
> 	(elf32_arm_add_symbol_hook): New function.
> 	(elf_backend_add_symbol_hook): Define for all targets.
>
> opcodes/
> 	* arm-dis.c (get_sym_code_type): Treat STT_GNU_IFUNCs as code.
>
> gas/
> 	* config/tc-arm.c (md_pcrel_from_section): Use S_FORCE_RELOC to
> 	determine whether a relocation is needed.
> 	(md_apply_fix, arm_apply_sym_value): Likewise.
>
> ld/testsuite/
> 	* ld-arm/ifunc-1.s, ld-arm/ifunc-1.dd, ld-arm/ifunc-1.gd,
> 	ld-arm/ifunc-1.rd, ld-arm/ifunc-2.s, ld-arm/ifunc-2.dd,
> 	ld-arm/ifunc-2.gd, ld-arm/ifunc-2.rd, ld-arm/ifunc-3.s,
> 	ld-arm/ifunc-3.dd, ld-arm/ifunc-3.gd, ld-arm/ifunc-3.rd,
> 	ld-arm/ifunc-4.s, ld-arm/ifunc-4.dd, ld-arm/ifunc-4.gd,
> 	ld-arm/ifunc-4.rd, ld-arm/ifunc-5.s, ld-arm/ifunc-5.dd,
> 	ld-arm/ifunc-5.gd, ld-arm/ifunc-5.rd, ld-arm/ifunc-6.s,
> 	ld-arm/ifunc-6.dd, ld-arm/ifunc-6.gd, ld-arm/ifunc-6.rd,
> 	ld-arm/ifunc-7.s, ld-arm/ifunc-7.dd, ld-arm/ifunc-7.gd,
> 	ld-arm/ifunc-7.rd, ld-arm/ifunc-8.s, ld-arm/ifunc-8.dd,
> 	ld-arm/ifunc-8.gd, ld-arm/ifunc-8.rd, ld-arm/ifunc-9.s,
> 	ld-arm/ifunc-9.dd, ld-arm/ifunc-9.gd, ld-arm/ifunc-9.rd,
> 	ld-arm/ifunc-10.s, ld-arm/ifunc-10.dd, ld-arm/ifunc-10.gd,
> 	ld-arm/ifunc-10.rd, ld-arm/ifunc-11.s, ld-arm/ifunc-11.dd,
> 	ld-arm/ifunc-11.gd, ld-arm/ifunc-11.rd, ld-arm/ifunc-12.s,
> 	ld-arm/ifunc-12.dd, ld-arm/ifunc-12.gd, ld-arm/ifunc-12.rd,
> 	ld-arm/ifunc-13.s, ld-arm/ifunc-13.dd, ld-arm/ifunc-13.gd,
> 	ld-arm/ifunc-13.rd, ld-arm/ifunc-14.s, ld-arm/ifunc-14.dd,
> 	ld-arm/ifunc-14.gd, ld-arm/ifunc-14.rd, ld-arm/ifunc-15.s,
> 	ld-arm/ifunc-15.dd, ld-arm/ifunc-15.gd, ld-arm/ifunc-15.rd,
> 	ld-arm/ifunc-16.s, ld-arm/ifunc-16.dd, ld-arm/ifunc-16.gd,
> 	ld-arm/ifunc-16.rd, ld-arm/ifunc-dynamic.ld,
> 	ld-arm/ifunc-static.ld: New tests.
> 	* ld-arm/farcall-group.d, ld-arm/farcall-group-size2.d,
> 	ld-arm/farcall-mixed-lib-v4t.d, ld-arm/farcall-mixed-lib.d: Update
> 	for new stub hashes.
> 	* ld-arm/arm-elf.exp: Run them.

Approved - please apply.

Cheers
   Nick
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