elf: Add GNU_PROPERTY_1_NEEDED check

If GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS is set on any input
relocatable files:

1. Don't generate copy relocations.
2. Turn off extern_protected_data since it implies
GNU_PROPERTY_NO_COPY_ON_PROTECTED.
3. Treate reference to protected symbols with indirect external access
as local.
4. Set GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS on output.
5. When generating executable, clear this bit when there are non-GOT or
non-PLT relocations in input relocatable files without the bit set.
6. Add -z [no]indirect-extern-access to control indirect external access.

bfd/

	* elf-bfd (elf_obj_tdata): Add has_indirect_extern_access.
	(elf_has_indirect_extern_access): New.
	* elf-properties.c (_bfd_elf_parse_gnu_properties): Set
	elf_has_indirect_extern_access and elf_has_no_copy_on_protected
	when seeing GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS.
	(elf_write_gnu_propertie): Add an argument to pass link_info.
	Set needed_1_p for GNU_PROPERTY_1_NEEDED in memory.
	(_bfd_elf_link_setup_gnu_properties): Handle
	GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS for
	-z indirect-extern-access.  Set nocopyreloc to true and
	extern_protected_data to false for indirect external access.
	(_bfd_elf_convert_gnu_properties): Updated.
	* elf32-i386.c (elf_i386_check_relocs): Set
	non_got_ref_without_indirect_extern_access on legacy non-GOT or
	non-PLT references.
	* elf64-x86-64.c (elf_x86_64_check_relocs): Likewise.
	* elflink.c (_bfd_elf_symbol_refs_local_p): Return true for
	STV_PROTECTED symbols with indirect external access.
	* elfxx-x86.c (_bfd_x86_elf_adjust_dynamic_symbol): Clear
	indirect_extern_access for legacy non-GOT/non-PLT references.
	* elfxx-x86.h (elf_x86_link_hash_entry): Add
	non_got_ref_without_indirect_extern_access.

include/

	* bfdlink.h (bfd_link_info): Add indirect_extern_access and
	needed_1_p.  Change nocopyreloc to int.

ld/

	* NEWS: Mention -z [no]indirect-extern-access
	* ld.texi: Document -z [no]indirect-extern-access
	* ldmain.c (main): Initialize link_info.indirect_extern_access
	to -1.
	* emulparams/extern_protected_data.sh: Support
	-z [no]indirect-extern-access.
	* testsuite/ld-elf/indirect-extern-access-1.rd: New file
	* testsuite/ld-elf/indirect-extern-access-1a.c: Likewise.
	* testsuite/ld-elf/indirect-extern-access-1b.c: Likewise.
	* testsuite/ld-elf/indirect-extern-access-2.rd: Likewise.
	* testsuite/ld-elf/indirect-extern-access-2a.c: Likewise.
	* testsuite/ld-elf/indirect-extern-access-2b.c: Likewise.
	* testsuite/ld-elf/indirect-extern-access-3.rd: Likewise.
	* testsuite/ld-elf/indirect-extern-access.S: Likewise.
	* testsuite/ld-elf/property-1_needed-1b.d: Likewise.
	* testsuite/ld-elf/property-1_needed-1c.d: Likewise.
	* testsuite/ld-x86-64/indirect-extern-access.rd: Likewise.
	* testsuite/ld-x86-64/protected-data-1.h: Likewise.
	* testsuite/ld-x86-64/protected-data-1a.c: Likewise.
	* testsuite/ld-x86-64/protected-data-1b.c: Likewise.
	* testsuite/ld-x86-64/protected-data-2a.S: Likewise.
	* testsuite/ld-x86-64/protected-data-2b.S: Likewise.
	* testsuite/ld-x86-64/protected-func-2a.S: Likewise.
	* testsuite/ld-x86-64/protected-func-2b.S: Likewise.
	* testsuite/ld-x86-64/protected-func-2c.c: Likewise.
	* testsuite/ld-elf/linux-x86.exp: Run test with
	GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS.
	* testsuite/ld-x86-64/x86-64.exp: Run tests for protected
	function and data with indirect external access.
This commit is contained in:
H.J. Lu
2021-06-17 14:11:28 -07:00
parent 6320fd00dc
commit 6f365fda85
33 changed files with 1078 additions and 23 deletions

View File

@@ -335,10 +335,6 @@ struct bfd_link_info
/* TRUE if BFD should pre-bind symbols in a shared object. */
unsigned int symbolic: 1;
/* TRUE if executable should not contain copy relocs.
Setting this true may result in a non-sharable text segment. */
unsigned int nocopyreloc: 1;
/* TRUE if BFD should export all symbols in the dynamic symbol table
of an executable, rather than only those used. */
unsigned int export_dynamic: 1;
@@ -652,6 +648,25 @@ struct bfd_link_info
/* How many spare .dynamic DT_NULL entries should be added? */
unsigned int spare_dynamic_tags;
/* GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS control:
> 1: Turn on by -z indirect-extern-access or by backend.
== 1: Turn on by an input.
0: Turn off.
< 0: Turn on if it is set on any inputs or let backend to
decide. */
int indirect_extern_access;
/* Non-zero if executable should not contain copy relocs.
> 1: Implied by indirect_extern_access.
== 1: Turn on by -z nocopyreloc.
0: Turn off.
Setting this to non-zero may result in a non-sharable text
segment. */
int nocopyreloc;
/* Pointer to the GNU_PROPERTY_1_NEEDED property in memory. */
bfd_byte *needed_1_p;
/* May be used to set DT_FLAGS for ELF. */
bfd_vma flags;