Address of protected data defined in the shared library may be external,
i.e., due to copy relocation. By default, linker backend checks if
relocations against protected data symbols are valid for building shared
library and issues an error if relocation isn't allowed. The new option
override linker backend default. When -z noextern-protected-data is used,
updates on protected data symbols by another module won't be visibile
to the resulting shared library. This option is specific to ELF/i386
and ELF/x86-64.
bfd/
PR ld/pr17709
* elflink.c (_bfd_elf_adjust_dynamic_copy): Check
info->extern_protected_data when warning copy relocs against
protected symbols.
(_bfd_elf_symbol_refs_local_p): Check info->extern_protected_data
when checking protected non-function symbols.
include/
PR ld/pr17709
* bfdlink.h (bfd_link_info): Add extern_protected_data.
ld/
PR ld/pr17709
* ld.texinfo: Document "-z noextern-protected-data".
* ldmain.c (main): Initialize link_info.extern_protected_data
to -1.
* lexsup.c (elf_shlib_list_options): Add
"-z [no]extern-protected-data".
* emulparams/elf32_x86_64.sh: Source extern_protected_data.sh.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_i386_be.sh: Likewise.
* emulparams/elf_i386_chaos.sh: Likewise.
* emulparams/elf_i386_ldso.sh: Likewise.
* emulparams/elf_i386_vxworks.sh: Likewise.
* emulparams/elf_k1om.sh: Likewise.
* emulparams/elf_l1om.sh: Likewise.
* emulparams/elf_x86_64.sh: Source extern_protected_data.sh.
(PARSE_AND_LIST_OPTIONS): Renamed to ...
(PARSE_AND_LIST_OPTIONS_BNDPLT): This.
(PARSE_AND_LIST_ARGS_CASE_Z): Renamed to ...
(PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT): This.
(PARSE_AND_LIST_OPTIONS): Append $PARSE_AND_LIST_OPTIONS_BNDPLT.
(PARSE_AND_LIST_ARGS_CASE_Z): Append
$PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT.
* emulparams/extern_protected_data.sh: New file.
ld/testsuite/
PR ld/pr17709
* ld-i386/i386.exp: Run protected6b.
* ld-i386/protected6b.d: New file.
* ld-x86-64/protected6b.d: Likewise.
* ld-x86-64/x86-64.exp: Run protected6b.
When checking R_386_GOTOFF/R_X86_64_GOTOFF64 for building shared library,
we should check SYMBOL_REFERENCES_LOCAL instead of SYMBOLIC_BIND to cover
more cases.
bfd/
* elf32-i386.c (elf_i386_relocate_section): Replace SYMBOLIC_BIND
with SYMBOL_REFERENCES_LOCAL when checking R_386_GOTOFF against
protected data symbol when building shared library.
* elf64-x86-64.c (elf_x86_64_relocate_section): Check
R_X86_64_GOTOFF64 against undefined symbol and replace
SYMBOLIC_BIND with SYMBOL_REFERENCES_LOCAL when checking
R_X86_64_GOTOFF64 against protected data symbol when building
shared library.
ld/testsuite/
* ld-i386/i386.exp: Run protected6a.
* ld-i386/protected6.d: Renamed to ...
* ld-i386/protected6a.d: This.
* ld-x86-64/hidden4.d: New file.
* ld-x86-64/hidden4.s: Likewise.
* ld-x86-64/hidden5.d: Likewise.
* ld-x86-64/hidden5.s: Likewise.
* ld-x86-64/protected6.d: Renamed to ...
* ld-x86-64/protected6a.d: This.
* ld-x86-64/x86-64.exp: Run hidden4, hidden5, protected6a,
protected7a and protected7b.
R_386_GOTOFF/R_X86_64_GOTOFF64 relocation shouldn't be used against
protected data symbol on x86 since with copy relocation, address of
protected data defined in the shared library may be external.
This patch will break building shared libraries with protected data
symbols using GCCs older than GCC 5 without the bug fix for
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248
GCC backport request should be made in the GCC bug report above.
bfd/
PR ld/pr17709
* elf32-i386.c (elf_i386_relocate_section): Also check R_386_GOTOFF
against protected data symbol when building shared library.
* elf64-x86-64.c (elf_x86_64_relocate_section): Also check
R_X86_64_GOTOFF64 against protected data symbol when building
shared library.
ld/testsuite/
PR ld/pr17709
* ld-i386/protected6.d: New file.
* ld-i386/protected6.s: Likewise.
* ld-x86-64/protected6.d: Likewise.
* ld-x86-64/protected6.s: Likewise.
* ld-x86-64/protected7.d: Likewise.
* ld-x86-64/protected7.s: Likewise.
* ld-x86-64/protected7a.d: Likewise.
* ld-x86-64/protected7b.d: Likewise.
Re-apply: commit ca3fe95e46
With copy relocation, address of protected data defined in the shared
library may be external. This patch adds extern_protected_data and
changes _bfd_elf_symbol_refs_local_p to return false for protected data
if extern_protected_data is true.
This patch will break building shared libraries with protected data
symbols using GCCs older than GCC 5 without the bug fix for
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248
GCC backport request should be made in the GCC bug report above.
To get correct run-time behavior on Linux, glibc 2.22 or above are
required, which have the bug fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=17711
Backports for glibc 2.21, 2.20, 2.19 and 2.18 are on hjl/pr17711/2.21,
hjl/pr17711/2.20, hjl/pr17711/2.19 and hjl/pr17711/2.18 branches,
respectively, at
https://sourceware.org/git/?p=glibc.git;a=summary
bfd/
PR ld/pr15228
PR ld/pr17709
* elf-bfd.h (elf_backend_data): Add extern_protected_data.
* elf32-i386.c (elf_backend_extern_protected_data): New.
Defined to 1.
* elf64-x86-64.c (elf_backend_extern_protected_data): Likewise.
* elflink.c (_bfd_elf_adjust_dynamic_copy): Don't error on
copy relocs against protected symbols if extern_protected_data
is true.
(_bfd_elf_symbol_refs_local_p): Don't return true on protected
non-function symbols if extern_protected_data is true.
* elfxx-target.h (elf_backend_extern_protected_data): New.
Default to 0.
(elfNN_bed): Initialize extern_protected_data with
elf_backend_extern_protected_data.
ld/testsuite/
PR ld/pr15228
PR ld/pr17709
* ld-i386/i386.exp (i386tests): Add a test for PR ld/17709.
* ld-i386/pr17709-nacl.rd: New file.
* ld-i386/pr17709.rd: Likewise.
* ld-i386/pr17709a.s: Likewise.
* ld-i386/pr17709b.s: Likewise.
* ld-i386/protected3.d: Updated.
* ld-i386/protected3.s: Likewise.
* ld-x86-64/pr17709-nacl.rd: New file.
* ld-x86-64/pr17709.rd: Likewise.
* ld-x86-64/pr17709a.s: Likewise.
* ld-x86-64/pr17709b.s: Likewise.
* ld-x86-64/protected3.d: Updated.
* ld-x86-64/protected3.s: Likewise.
* ld-x86-64/x86-64.exp (x86_64tests): Add a test for PR ld/17709.
With copy relocation, address of protected data defined in the shared
library may be external. This patch adds extern_protected_data and
changes _bfd_elf_symbol_refs_local_p to return false for protected data
if extern_protected_data is true.
bfd/
PR ld/pr15228
PR ld/pr17709
* elf-bfd.h (elf_backend_data): Add extern_protected_data.
* elf32-i386.c (elf_backend_extern_protected_data): New.
Defined to 1.
* elf64-x86-64.c (elf_backend_extern_protected_data): Likewise.
* elflink.c (_bfd_elf_adjust_dynamic_copy): Don't error on
copy relocs against protected symbols if extern_protected_data
is true.
(_bfd_elf_symbol_refs_local_p): Don't return true on protected
non-function symbols if extern_protected_data is true.
* elfxx-target.h (elf_backend_extern_protected_data): New.
Default to 0.
(elfNN_bed): Initialize extern_protected_data with
elf_backend_extern_protected_data.
ld/testsuite/
PR ld/pr15228
PR ld/pr17709
* ld-i386/i386.exp (i386tests): Add a test for PR ld/17709.
* ld-i386/pr17709-nacl.rd: New file.
* ld-i386/pr17709.rd: Likewise.
* ld-i386/pr17709a.s: Likewise.
* ld-i386/pr17709b.s: Likewise.
* ld-i386/protected3.d: Updated.
* ld-i386/protected3.s: Likewise.
* ld-x86-64/pr17709-nacl.rd: New file.
* ld-x86-64/pr17709.rd: Likewise.
* ld-x86-64/pr17709a.s: Likewise.
* ld-x86-64/pr17709b.s: Likewise.
* ld-x86-64/protected3.d: Updated.
* ld-x86-64/protected3.s: Likewise.
* ld-x86-64/x86-64.exp (x86_64tests): Add a test for PR ld/17709.
When building executable, undefined symbol is a fatal error. We don't
complain about -fPIC if the symbol is undefined.
bfd/
PR ld/17847
* elf64-x86-64.c (elf_x86_64_relocate_section): Don't complain
about -fPIC if the symbol is undefined when building executable.
ld/testsuite/
PR ld/17847
* ld-x86-64/pie1.d: New file.
* ld-x86-64/pie1.s: Likwise.
* ld-x86-64/x86-64.exp: Run pie1.
When building PIE, we should only discard space for pc-relative relocs
symbols which turn out to need copy relocs.
bfd/
PR ld/17827
* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): For PIE,
only discard space for pc-relative relocs symbols which turn
out to need copy relocs.
ld/testsuite/
PR ld/17827
* ld-x86-64/pr17689.out: Updated.
* ld-x86-64/pr17689b.S: Likewise.
* ld-x86-64/pr17827.rd: New file.
* ld-x86-64/x86-64.exp: Run PR ld/17827 test.
When there is a weak symbol with a real definition, the processor
independent code will have arranged for us to see the real definition
first. We need to copy the needs_copy bit from the real definition and
check it when allowing copy reloc in PIE.
bfd/
PR ld/17689
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add needs_copy.
Change has_bnd_reloc to bit field.
(elf_x86_64_link_hash_newfunc): Initialize needs_copy and
has_bnd_reloc to 0.
(elf_x86_64_check_relocs): Set has_bnd_reloc to 1 instead
of TRUE.
(elf_x86_64_adjust_dynamic_symbol): Copy needs_copy from the
real definition to a weak symbol.
(elf_x86_64_allocate_dynrelocs): Also check needs_copy of a
weak symbol for PIE when discarding space for relocs against
symbols which turn out to need copy relocs.
(elf_x86_64_relocate_section): Also check needs_copy of a
weak symbol for PIE with copy reloc.
ld/testsuite/
PR ld/17689
* ld-x86-64/pr17689.out: New file.
* ld-x86-64/pr17689.rd: Likewise.
* ld-x86-64/pr17689a.c: Likewise.
* ld-x86-64/pr17689b.S: Likewise.
* ld-x86-64/x86-64.exp: Run PR ld/17689 tests.
This patch allows copy relocs for non-GOT pc-relative relocation in PIE.
bfd/
* elf64-x86-64.c (elf_x86_64_create_dynamic_sections): Always
allow copy relocs for building executables.
(elf_x86_64_check_relocs): Allow copy relocs for non-GOT
pc-relative relocation in shared object.
(elf_x86_64_adjust_dynamic_symbol): Allocate copy relocs for
PIE.
(elf_x86_64_relocate_section): Don't copy a pc-relative
relocation into the output file if the symbol needs copy reloc.
ld/testsuite/
* ld-x86-64/copyreloc-lib.c: New file.
* ld-x86-64/copyreloc-main.c: Likewise.
* ld-x86-64/copyreloc-main.out: Likewise.
* ld-x86-64/copyreloc-main1.rd: Likewise.
* ld-x86-64/copyreloc-main2.rd: Likewise.
* ld-x86-64/x86-64.exp: Run copyreloc tests.
When there are both PLT and GOT references to the same function symbol,
linker will create a GOTPLT slot for PLT entry and a GOT slot for GOT
reference. A run-time JUMP_SLOT relocation is created to update the
GOTPLT slot and a run-time GLOB_DAT relocation is created to update the
GOT slot. Both JUMP_SLOT and GLOB_DAT relocations will apply the same
symbol value to GOTPLT and GOT slots, respectively, at run-time.
This optimization combines GOTPLT and GOT slots into a single GOT slot
and removes the run-time JUMP_SLOT relocation. It replaces the regular
PLT entry:
indirect jump [GOTPLT slot]
push relocation index
jump PLT0
with an GOT PLT entry with an indirect jump via the GOT slot:
indirect jump [GOT slot]
nop
and resolves PLT reference to the GOT PLT entry.
We must avoid this optimization if pointer equality is needed since
we don't clear symbol value in this case and the dynamic linker won't
update the GOT slot. Otherwise, the resulting binary will get into an
infinite loop at run-time.
bfd/
* elf32-i386.c (elf_i386_got_plt_entry): New.
(elf_i386_pic_got_plt_entry): Likewise.
(elf_i386_link_hash_entry): Add plt_got.
(elf_i386_link_hash_table): Likewise.
(elf_i386_link_hash_newfunc): Initialize plt_got.offset to -1.
(elf_i386_get_local_sym_hash): Likewise.
(elf_i386_check_relocs): Create the GOT PLT if there are both
PLT and GOT references when the regular PLT is used.
(elf_i386_allocate_dynrelocs): Use the GOT PLT if there are
both PLT and GOT references unless pointer equality is needed.
(elf_i386_relocate_section): Also check the GOT PLT when
resolving R_386_PLT32.
(elf_i386_finish_dynamic_symbol): Use the GOT PLT if it is
available.
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add plt_got.
(elf_x86_64_link_hash_table): Likewise.
(elf_x86_64_link_hash_newfunc): Initialize plt_got.offset to -1.
(elf_x86_64_get_local_sym_hash): Likewise.
(elf_x86_64_check_relocs): Create the GOT PLT if there are both
PLT and GOT references when the regular PLT is used.
(elf_x86_64_allocate_dynrelocs): Use the GOT PLT if there are
both PLT and GOT references unless pointer equality is needed.
(elf_x86_64_relocate_section): Also check the GOT PLT when
resolving R_X86_64_PLT32.
(elf_x86_64_finish_dynamic_symbol): Use the GOT PLT if it is
available.
ld/
* emulparams/elf_i386.sh (TINY_READONLY_SECTION): New.
* emulparams/elf_x86_64.sh (TINY_READONLY_SECTION): Add .plt.got.
ld/testsuite/
* ld-i386/i386.exp: Add run-time relocation tests for plt-main.
* ld-i386/plt-main.rd: New file.
* ld-x86-64/plt-main-bnd.dd: Likewise.
* ld-x86-64/plt-main.rd: Likewise.
* ld-x86-64/x86-64.exp: Add run-time relocation tests for
plt-main.
bfd/
* archures.c (bfd_mach_i386_nacl): Fix definition so it doesn't
collide with bfd_mach_l1om.
* bfd-in2.h: Regenerate.
* elf32-i386.c (elf32_i386_nacl_elf_object_p): New function.
(elf_backend_object_p): Use that in elf32-i386-nacl definition.
* elf64-x86-64.c (elf64_x86_64_nacl_elf_object_p): New function.
(elf_backend_object_p): Use that in elf64-x86-64-nacl definition.
(elf32_x86_64_nacl_elf_object_p): New function.
(elf_backend_object_p): Use that in elf32-x86-64-nacl definition.
binutils/
* objdump.c (dump_dwarf): Grok bfd_mach_x86_64_nacl and
bfd_mach_x64_32_nacl as equivalent to bfd_mach_x86_64.
ld/testsuite/
* ld-x86-64/x86-64.exp (mixed1, mixed2): Loosen error string match
so it accepts "i386:nacl" in place of "i386".
* ld-x86-64/ilp32-2.d: Likewise.
* ld-x86-64/ilp32-3.d: Likewise.
* ld-x86-64/lp64-2.d: Likewise.
* ld-x86-64/lp64-3.d: Likewise.
* archures.c (bfd_mach_i386_nacl, bfd_mach_i386_i386_nacl): New macros.
(bfd_mach_x86_64_nacl, bfd_mach_x64_32_nacl): New macros.
* cpu-i386.c (bfd_arch_i386_onebyte_nop_fill): New function.
(bfd_i386_nacl_arch): New variable.
(bfd_x86_64_nacl_arch, bfd_x64_32_nacl_arch): New variables.
(bfd_x64_32_arch_intel_syntax): Link them into the list.
* bfd-in2.h: Regenerate.
ld/
* emulparams/elf_i386_nacl.sh (ARCH): Set to i386:nacl.
* emulparams/elf_x86_64_nacl.sh (ARCH): Set to i386:x86-64:nacl.
* emulparams/elf32_x86_64_nacl.sh (ARCH): Set to i386:x64-32:nacl.
ld/testsuite/
* ld-x86-64/x86-64.exp (Mixed x86_64 and i386 input test 1):
Loosen string match to admit i386:x86-64*.
(Mixed x86_64 and i386 input test 2): Likewise.
* ld-x86-64/ilp32-2.d: Likewise.
* ld-x86-64/ilp32-3.d: Likewise.
* ld-x86-64/lp64-2.d: Likewise.
* ld-x86-64/lp64-3.d: Likewise.
* ld-x86-64/ia32-2.d: Likewise, and i386.* too.
* ld-x86-64/ia32-3.d: Likewise.
* ld-x86-64/pr12570a.d (name): Distinguish it from pr12570b.d case.
Loosen CFI-matching regexp so it matches x86_64-*-nacl* variant too.
* ld-x86-64/pr12570b.d: Likewise.
* ld-x86-64/x86-64.exp: Revert last change.
bfd/
2012-04-13 Alan Modra <amodra@gmail.com>
PR ld/13947
* elflink.c (bfd_elf_final_link): Set reloc_count to 0 for
reloc sections.
ld/testsuite/
2012-04-13 H.J. Lu <hongjiu.lu@intel.com>
PR ld/13947
* ld-x86-64/x86-64.exp: Run pr13947.
* ld-x86-64/pr13947.d: New file.
* ld-x86-64/pr13947.s: Likewise.
bfd/
2012-03-20 H.J. Lu <hongjiu.lu@intel.com>
PR ld/13880
* elf32-i386.c (elf_i386_relocate_section): Don't issue an error
for R_386_GOTOFF relocation against protected function if
SYMBOLIC_BIND is true.
* elf64-x86-64.c (elf_x86_64_relocate_section): Don't issue an
error for R_X86_64_GOTOFF64 relocation against protected function
when building executable or SYMBOLIC_BIND is true.
ld/testsuite/
2012-03-20 H.J. Lu <hongjiu.lu@intel.com>
PR ld/13880
* ld-i386/i386.exp: Run protected4 and protected5.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/protected4.d: New.
* ld-i386/protected4.s: Likewise.
* ld-i386/protected5.d: Likewise.
* ld-i386/protected5.s: Likewise.
* ld-x86-64/protected4.d: Likewise.
* ld-x86-64/protected4.s: Likewise.
* ld-x86-64/protected5.d: Likewise.
* ld-x86-64/protected5.s: Likewise.
64-bit objects when the 32-bit object (loaded first) contains 32+
local symbols, all referenced by relocs and the 64-bit object
contains a reloc that uses a symbol in the 32-bit object.
* 32bit.s: New source file.
* 64bit.s: New source file.
* incompatible.l: New expected linker output file.