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old-cross-binutils/ld/testsuite/ChangeLog
H.J. Lu 0ff2b86e7c Create the second PLT for BND relocations 
Intel MPX introduces 4 bound registers, which will be used for parameter
passing in x86-64.  Bound registers are cleared by branch instructions.
Branch instructions with BND prefix will keep bound register contents.
This leads to 2 requirements to 64-bit MPX run-time:

1. Dynamic linker (ld.so) should save and restore bound registers during
symbol lookup.
2. Change the current 16-byte PLT0:

  ff 35 08 00 00 00	pushq  GOT+8(%rip)
  ff 25 00 10 00	jmpq  *GOT+16(%rip)
  0f 1f 40 00		nopl   0x0(%rax)

and 16-byte PLT1:

  ff 25 00 00 00 00    	jmpq   *name@GOTPCREL(%rip)
  68 00 00 00 00       	pushq  $index
  e9 00 00 00 00       	jmpq   PLT0

which clear bound registers, to preserve bound registers.

We use 2 new relocations:

to mark branch instructions with BND prefix.

When linker sees any R_X86_64_PC32_BND or R_X86_64_PLT32_BND relocations,
it switches to a different PLT0:

  ff 35 08 00 00 00	pushq  GOT+8(%rip)
  f2 ff 25 00 10 00	bnd jmpq *GOT+16(%rip)
  0f 1f 00		nopl   (%rax)

to preserve bound registers for symbol lookup and it also creates an
external PLT section, .pl.bnd.  Linker will create a BND PLT1 entry
in .plt:

  68 00 00 00 00       	pushq  $index
  f2 e9 00 00 00 00     bnd jmpq PLT0
  0f 1f 44 00 00        nopl 0(%rax,%rax,1)

and a 8-byte BND PLT entry in .plt.bnd:

  f2 ff 25 00 00 00 00  bnd jmpq *name@GOTPCREL(%rip)
  90			nop

Otherwise, linker will create a legacy PLT1 entry in .plt:

  68 00 00 00 00       	pushq  $index
  e9 00 00 00 00        jmpq PLT0
  66 0f 1f 44 00 00     nopw 0(%rax,%rax,1)

and a 8-byte legacy PLT in .plt.bnd:

  ff 25 00 00 00 00     jmpq  *name@GOTPCREL(%rip)
  66 90                 xchg  %ax,%ax

The initial value of the GOT entry for "name" will be set to the the
"pushq" instruction in the corresponding entry in .plt.  Linker will
resolve reference of symbol "name" to the entry in the second PLT,
.plt.bnd.

Prelink stores the offset of pushq of PLT1 (plt_base + 0x10) in GOT[1]
and GOT[1] is stored in GOT[3].  We can undo prelink in GOT by computing
the corresponding the pushq offset with

GOT[1] + (GOT offset - &GOT[3]) * 2

Since for each entry in .plt except for PLT0 we create a 8-byte entry in
.plt.bnd, there is extra 8-byte per PLT symbol.

We also investigated the 16-byte entry for .plt.bnd.  We compared the
8-byte entry vs the the 16-byte entry for .plt.bnd on Sandy Bridge.
There are no performance differences in SPEC CPU 2000/2006 as well as
micro benchmarks.

Pros:
	No change to undo prelink in dynamic linker.
	Only 8-byte memory overhead for each PLT symbol.
Cons:
	Extra .plt.bnd section is needed.
	Extra 8 byte for legacy branches to PLT.
	GDB is unware of the new layout of .plt and .plt.bnd.

bfd/

	* elf64-x86-64.c (elf_x86_64_bnd_plt0_entry): New.
	(elf_x86_64_legacy_plt_entry): Likewise.
	(elf_x86_64_bnd_plt_entry): Likewise.
	(elf_x86_64_legacy_plt2_entry): Likewise.
	(elf_x86_64_bnd_plt2_entry): Likewise.
	(elf_x86_64_bnd_arch_bed): Likewise.
	(elf_x86_64_link_hash_entry): Add has_bnd_reloc and plt_bnd.
	(elf_x86_64_link_hash_table): Add plt_bnd.
	(elf_x86_64_link_hash_newfunc): Initialize has_bnd_reloc and
	plt_bnd.
	(elf_x86_64_copy_indirect_symbol): Also copy has_bnd_reloc.
	(elf_x86_64_check_relocs): Create the second PLT for Intel MPX
	in 64-bit mode.
	(elf_x86_64_allocate_dynrelocs): Handle the second PLT for IFUNC
	symbols.  Resolve call to the second PLT if it is created.
	(elf_x86_64_size_dynamic_sections): Keep the second PLT section.
	(elf_x86_64_relocate_section): Resolve PLT references to the
	second PLT if it is created.
	(elf_x86_64_finish_dynamic_symbol): Use BND PLT0 and fill the
	second PLT entry for BND relocation.
	(elf_x86_64_finish_dynamic_sections): Use MPX backend data if
	the second PLT is created.
	(elf_x86_64_get_synthetic_symtab): New.
	(bfd_elf64_get_synthetic_symtab): Likewise.  Undefine for NaCl.

ld/

	* emulparams/elf_x86_64.sh (TINY_READONLY_SECTION): New.

ld/testsuite/

	* ld-x86-64/mpx.exp: Run bnd-ifunc-1 and bnd-plt-1.
	* ld-x86-64/bnd-ifunc-1.d: New file.
	* ld-x86-64/bnd-ifunc-1.s: Likewise.
	* ld-x86-64/bnd-plt-1.d: Likewise.
2014-02-19 11:48:23 -08:00

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2014-02-19 Igor Zamyatin <igor.zamyatin@intel.com>
H.J. Lu <hongjiu.lu@intel.com>
* ld-x86-64/mpx.exp: Run bnd-ifunc-1 and bnd-plt-1.
* ld-x86-64/bnd-ifunc-1.d: New file.
* ld-x86-64/bnd-ifunc-1.s: Likewise.
* ld-x86-64/bnd-plt-1.d: Likewise.
2014-02-18 Jack Carter <jack.carter@imgtec.com>
* ld-mips-elf/pic-and-nonpic-3a.sd: Check DYNAMIC segment flags.
2014-02-16 Thomas Schwinge <thomas@codesourcery.com>
* ld-elfweak/elfweak.exp (setup_xfail_gnu_hurd): Remove function
and all usage of it.
2014-02-10 H.J. Lu <hongjiu.lu@intel.com>
PR gold/16530
* ld-elf/dynamic-1.c: New file.
* ld-elf/dynamic-1.rd: Likewise.
* ld-elf/dynamic-1.syms: Likewise.
* ld-elf/shared.exp (build_tests): Add dynamic-1.
2014-02-02 Sebastian Huber <sebastian.huber@embedded-brains.de>
* ld-scripts/rgn-at9.d: New file.
* ld-scripts/rgn-at9.t: Likewise.
* ld-scripts/rgn-at10.d: Likewise.
* ld-scripts/rgn-at10.s: Likewise.
* ld-scripts/rgn-at10.t: Likewise.
* ld-scripts/rgn-at11.d: Likewise.
* ld-scripts/rgn-at11.t: Likewise.
2014-01-30 Sandra Loosemore <sandra@codesourcery.com>
* ld-nios2/relax_call26.s: New.
* ld-nios2/relax_call26_boundary.ld: New.
* ld-nios2/relax_call26_boundary.s: New.
* ld-nios2/relax_call26_boundary_c8.d: New.
* ld-nios2/relax_call26_boundary_cc.d: New.
* ld-nios2/relax_call26_boundary_d0.d: New.
* ld-nios2/relax_call26_boundary_d4.d: New.
* ld-nios2/relax_call26_boundary_d8.d: New.
* ld-nios2/relax_call26_boundary_dc.d: New.
* ld-nios2/relax_call26_boundary_f0.d: New.
* ld-nios2/relax_call26_boundary_f4.d: New.
* ld-nios2/relax_call26_boundary_f8.d: New.
* ld-nios2/relax_call26_boundary_fc.d: New.
* ld-nios2/relax_call26_cache.d: New.
* ld-nios2/relax_call26_cache.ld: New.
* ld-nios2/relax_call26_cache.s: New.
* ld-nios2/relax_call26_multi.d: New.
* ld-nios2/relax_call26_multi.ld: New.
* ld-nios2/relax_call26_norelax.d: New.
* ld-nios2/relax_call26_shared.d: New.
* ld-nios2/relax_call26_shared.ld: New.
2014-01-29 H.J. Lu <hongjiu.lu@intel.com>
* ld-elf/rdynamic-1.c: New file.
* ld-elf/rdynamic-1.rd: Likewise.
* ld-elf/shared.exp (build_tests): Add rdynamic-1.
2014-01-28 Nick Clifton <nickc@redhat.com>
PR binutils/16317
* ld-tic6x/shlib-1.rd: Expect I attribute with RELA sections.
* ld-tic6x/shlib-1b.rd: Likewise.
* ld-tic6x/shlib-1r.rd: Likewise.
* ld-tic6x/shlib-1rb.rd: Likewise.
* ld-tic6x/shlib-app-1rd: Likewise.
* ld-tic6x/shlib-app-1b.rd: Likewise.
* ld-tic6x/shlib-app-1r.rd: Likewise.
* ld-tic6x/shlib-app-1rb.rd: Likewise.
* ld-tic6x/shlib-noindex.rd: Likewise.
* ld-tic6x/static-app-1.rd: Likewise.
* ld-tic6x/static-app-1b.rd: Likewise.
* ld-tic6x/static-app-1r.rd: Likewise.
* ld-tic6x/static-app-1rb.rd: Likewise.
PR binutils/16318
* ld-tic6x/tic6x.exp: Expect C6000 osabi value in relocatable
objects.
2014-01-24 H.J. Lu <hongjiu.lu@intel.com>
* ld-elf/pr16498a.s: Replace .align with .p2align.
2014-01-24 H.J. Lu <hongjiu.lu@intel.com>
PR ld/16498
* ld-elf/pr16498b.d: New file.
* ld-elf/pr16498b.t: Likewise.
2014-01-24 H.J. Lu <hongjiu.lu@intel.com>
PR ld/16498
* ld-elf/pr16498a.d: New file.
* ld-elf/pr16498a.s: Likewise.
* ld-elf/pr16498a.t: Likewise.
2014-01-22 Alan Modra <amodra@gmail.com>
* ld-scripts/pr14962-2.d: Correct target triple.
2014-01-22 Alan Modra <amodra@gmail.com>
* ld-shared/elf-offset.ld: Align end of .bss with canonical form
of ALIGN that allows an empty .bss to be removed.
* ld-arm/arm-dyn.ld: Likewise.
* ld-arm/arm-lib.ld: Likewise.
* ld-elfvsb/elf-offset.ld: Likewise.
* ld-mips-elf/mips-dyn.ld: Likewise.
* ld-mips-elf/mips-lib.ld: Likewise.
* ld-arm/arm-no-rel-plt.ld: Remove duplicate ALIGN.
* ld-powerpc/vle-multiseg-1.ld: Remove ALIGN at start of section.
ALIGN address of section instead.
* ld-powerpc/vle-multiseg-2.ld: Likewise.
* ld-powerpc/vle-multiseg-3.ld: Likewise.
* ld-powerpc/vle-multiseg-4.ld: Likewise.
* ld-powerpc/vle-multiseg-6.ld: Likewise.
* ld-scripts/empty-aligned.d: Check section headers not program
headers. Remove xfail and notarget.
* ld-scripts/empty-aligned.t: Use canonical ALIGN for end of .text2.
2014-01-21 H.J. Lu <hongjiu.lu@intel.com>
PR ld/16467
* ld-ifunc/dummy.c: New file.
* ld-ifunc/pr16467.out: Likewise.
* ld-ifunc/pr16467a.c: Likewise.
* ld-ifunc/pr16467a.map: Likewise.
* ld-ifunc/pr16467b.c: Likewise.
* ld-ifunc/pr16467b.map: Likewise.
* ld-ifunc/pr16467c.c: Likewise.
* ld-ifunc/ifunc.exp (run_cc_link_tests): New.
(run_ld_link_exec_tests): Run pr16467.
2014-01-21 H.J. Lu <hongjiu.lu@intel.com>
PR ld/2404
* ld-elf/shared.exp: Add a PIE test for PR ld/2404.
2014-01-20 H.J. Lu <hongjiu.lu@intel.com>
PR ld/2404
* ld-elf/pr2404.out: New file.
* ld-elf/pr2404a.c: Likewise.
* ld-elf/pr2404b.c: Likewise.
* ld-elf/shared.exp (build_tests): Build libpr2404a.so and
libpr2404b.a.
(run_tests): Run pr2404.
2014-01-20 Alan Modra <amodra@gmail.com>
* ld-scripts/pr14962-2.d,
* ld-scripts/pr14962-2.t: New test.
* ld-scripts/expr.exp: Run it.
2014-01-15 Alan Modra <amodra@gmail.com>
* ld-elf/ehdr_start-shared.d: New.
* ld-elf/ehdr_start-userdef.d: xfail frv.
* ld-elf/ehdr_start-weak.d: Likewise.
* ld-elf/ehdr_start.d: Likewise.
2014-01-14 Vidya Praveen <vidyapraveen@arm.com>
* lib/ld-lib.exp (default_ld_link): Remove support for ldflags.
(default_ld_simple_link): Likewise.
2014-01-10 Alan Modra <amodra@gmail.com>
* ld-x86-64/pr14207.d: Adjust.
2014-01-09 H.J. Lu <hongjiu.lu@intel.com>
* ld-elf/binutils.exp (binutils_test): Check if GNU_RELRO segment
is generated.
2014-01-09 Vidya Praveen <vidyapraveen@arm.com>
* lib/ld-lib.exp (check_lto_shared_available): New check.
* ld-plugin/lto.exp: Use check_lto_shared_available.
2014-01-08 H.J. Lu <hongjiu.lu@intel.com>
PR ld/14207
PR ld/16322
PR binutils/16323
* ld-elf/pr16322.d: New file.
* ld-elf/pr16322.s: Likewise.
* ld-x86-64/pr14207.d: Expect PT_GNU_RELRO segment.
For older changes see ChangeLog-2013
Copyright (C) 2014 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
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