RFC: PATCHES: Properly handle reference to protected data on x86

[H.J. Lu]

On Wed, Mar 4, 2015 at 3:26 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> Protected symbol means that it can't be pre-emptied.  It
> doesn't mean its address won't be external.  This is true
> for pointer to protected function.  With copy relocation,
> address of protected data defined in the shared library may
> also be external.  We only know that for sure at run-time.
> Here are patches for glibc, binutils and GCC to handle it
> properly.
>
> Any comments?

This is the binutils patch I checked in.  It basically reverted
the change for

https://sourceware.org/bugzilla/show_bug.cgi?id=15228

on x86.  Copy relocations against protected symbols should
work.

-- 
H.J.
---
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.
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