From: "H.J. Lu" <hjl.tools@gmail.com>
To: binutils@sourceware.org
Subject: [PATCH] x86: Ignore protected visibility in shared libraries on Solaris
Date: Tue, 23 Aug 2022 10:34:32 -0700 [thread overview]
Message-ID: <20220823173432.36035-1-hjl.tools@gmail.com> (raw)
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.
---
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)
--
2.37.2
next reply other threads:[~2022-08-23 17:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-23 17:34 H.J. Lu [this message]
2022-08-24 0:16 ` Alan Modra
2022-08-24 1:40 ` Alan Modra
2022-08-24 14:36 ` H.J. Lu
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