[binutils-gdb] x86: Ignore protected visibility in shared libraries on Solaris

[binutils-gdb] x86: Ignore protected visibility in shared libraries on Solaris

[H.J. Lu]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2c43d202aefb2b6f202a44bbb8a0baf251aae845

commit 2c43d202aefb2b6f202a44bbb8a0baf251aae845
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Mon Aug 22 10:26:17 2022 -0700

    x86: Ignore protected visibility in shared libraries on Solaris
    
    On x86, the PLT entry in executable may be used as function address for
    functions in shared libraries.  If functions are protected, the function
    address used in executable can be different from the function address
    used in shared library.  This will lead to incorrect run-time behavior
    if function pointer equality is needed.  By default, x86 linker issues
    an error in this case.
    
    On Solaris, linker issued an error for
    
    struct tm *tb = (kind == CPP_time_kind::FIXED ? gmtime : localtime) (&tt);
    
    where gmtime is a protected function in libc.so.  Use gmtime's PLT entry
    in executable as function address is safe since function pointer equality
    isn't needed.  Ignore protected visibility in shared libraries on Solaris
    to disable linker error.  If function pointer equality is needed, linker
    will silently generate executable with incorrect run-time behavior on
    Solaris.
    
            PR ld/29512
            * elf32-i386.c (elf_i386_scan_relocs): Ignore protected
            visibility in shared libraries on Solaris.
            * elf64-x86-64.c (elf_x86_64_scan_relocs): Likewise.

Diff:
---
 bfd/elf32-i386.c   | 3 ++-
 bfd/elf64-x86-64.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 52b1db44546..9717e2c5ed6 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -1808,7 +1808,8 @@ elf_i386_scan_relocs (bfd *abfd,
 		      || (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
 		    h->plt.refcount = 1;
 
-		  if (h->pointer_equality_needed
+		  if (htab->elf.target_os != is_solaris
+		      && h->pointer_equality_needed
 		      && h->type == STT_FUNC
 		      && eh->def_protected
 		      && !SYMBOL_DEFINED_NON_SHARED_P (h)
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 62a9a22317a..f3b54400013 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -2251,7 +2251,8 @@ elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info,
 		      || (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
 		    h->plt.refcount = 1;
 
-		  if (h->pointer_equality_needed
+		  if (htab->elf.target_os != is_solaris
+		      && h->pointer_equality_needed
 		      && h->type == STT_FUNC
 		      && eh->def_protected
 		      && !SYMBOL_DEFINED_NON_SHARED_P (h)