[binutils-gdb] gold: Ignore def/ref from a dynamic object for special symbols
H.J.Lu
hjl@sourceware.org
Thu Nov 9 00:03:00 GMT 2017
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=dc8d2d90da3f191ae0461900ab98e3b29cc2b280
commit dc8d2d90da3f191ae0461900ab98e3b29cc2b280
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Nov 8 15:56:54 2017 -0800
gold: Ignore def/ref from a dynamic object for special symbols
Since special symbol must be defined in a regular object, definition
from a dynamic object should be ignored. If special symbol has the
hidden or internal visibility, reference from a dynamic object should
also be ignored. Also __start and __stop symbols in a dynamic object
shouldn't be preempted.
PR gold/22291
* layout.cc (Layout::define_section_symbols): Use STV_PROTECTED
for __start and __stop symbols.
* symtab.cc (Symbol_table::define_special_symbol): Add an
argument, visibility. Ignore definition and reference from
a dynamic object, depending on visibility.
(Symbol_table::do_define_in_output_data): Pass visibility to
define_special_symbol.
(Symbol_table::do_define_in_output_segment): Likewise.
(Symbol_table::do_define_as_constant): Likewise.
(Symbol_table::add_undefined_symbol_from_command_line): Pass
STV_DEFAULT to define_special_symbol.
* symtab.h (Symbol_table::define_special_symbol): Add an
argument, visibility.
Diff:
---
gold/ChangeLog | 17 +++++++++++++++++
gold/layout.cc | 4 ++--
gold/symtab.cc | 48 +++++++++++++++++++++++++++++++++++++++---------
gold/symtab.h | 3 ++-
4 files changed, 60 insertions(+), 12 deletions(-)
diff --git a/gold/ChangeLog b/gold/ChangeLog
index c4c171d..bd842a6 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,20 @@
+2017-11-08 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR gold/22291
+ * layout.cc (Layout::define_section_symbols): Use STV_PROTECTED
+ for __start and __stop symbols.
+ * symtab.cc (Symbol_table::define_special_symbol): Add an
+ argument, visibility. Ignore definition and reference from
+ a dynamic object, depending on visibility.
+ (Symbol_table::do_define_in_output_data): Pass visibility to
+ define_special_symbol.
+ (Symbol_table::do_define_in_output_segment): Likewise.
+ (Symbol_table::do_define_as_constant): Likewise.
+ (Symbol_table::add_undefined_symbol_from_command_line): Pass
+ STV_DEFAULT to define_special_symbol.
+ * symtab.h (Symbol_table::define_special_symbol): Add an
+ argument, visibility.
+
2017-11-08 James Clarke <jrtc27@jrtc27.com>
PR gold/22266
diff --git a/gold/layout.cc b/gold/layout.cc
index 15c5434..351c4b4 100644
--- a/gold/layout.cc
+++ b/gold/layout.cc
@@ -2252,7 +2252,7 @@ Layout::define_section_symbols(Symbol_table* symtab)
0, // symsize
elfcpp::STT_NOTYPE,
elfcpp::STB_GLOBAL,
- elfcpp::STV_DEFAULT,
+ elfcpp::STV_PROTECTED,
0, // nonvis
false, // offset_is_from_end
true); // only_if_ref
@@ -2265,7 +2265,7 @@ Layout::define_section_symbols(Symbol_table* symtab)
0, // symsize
elfcpp::STT_NOTYPE,
elfcpp::STB_GLOBAL,
- elfcpp::STV_DEFAULT,
+ elfcpp::STV_PROTECTED,
0, // nonvis
true, // offset_is_from_end
true); // only_if_ref
diff --git a/gold/symtab.cc b/gold/symtab.cc
index 7ebcd6b..d1f71e0 100644
--- a/gold/symtab.cc
+++ b/gold/symtab.cc
@@ -1761,6 +1761,7 @@ template<int size, bool big_endian>
Sized_symbol<size>*
Symbol_table::define_special_symbol(const char** pname, const char** pversion,
bool only_if_ref,
+ elfcpp::STV visibility,
Sized_symbol<size>** poldsym,
bool* resolve_oldsym, bool is_forced_local)
{
@@ -1799,8 +1800,21 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion,
oldsym = this->lookup(*pname, *pversion);
if (oldsym == NULL && is_default_version)
oldsym = this->lookup(*pname, NULL);
- if (oldsym == NULL || !oldsym->is_undefined())
+ if (oldsym == NULL)
return NULL;
+ if (!oldsym->is_undefined())
+ {
+ // Skip if the old definition is from a regular object.
+ if (!oldsym->is_from_dynobj())
+ return NULL;
+
+ // If the symbol has hidden or internal visibility, ignore
+ // definition and reference from a dynamic object.
+ if ((visibility == elfcpp::STV_HIDDEN
+ || visibility == elfcpp::STV_INTERNAL)
+ && !oldsym->in_reg())
+ return NULL;
+ }
*pname = oldsym->name();
if (is_default_version)
@@ -1975,7 +1989,9 @@ Symbol_table::do_define_in_output_data(
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
- only_if_ref, &oldsym,
+ only_if_ref,
+ visibility,
+ &oldsym,
&resolve_oldsym,
is_forced_local);
#else
@@ -1986,7 +2002,9 @@ Symbol_table::do_define_in_output_data(
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
- only_if_ref, &oldsym,
+ only_if_ref,
+ visibility,
+ &oldsym,
&resolve_oldsym,
is_forced_local);
#else
@@ -2094,7 +2112,9 @@ Symbol_table::do_define_in_output_segment(
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
- only_if_ref, &oldsym,
+ only_if_ref,
+ visibility,
+ &oldsym,
&resolve_oldsym,
is_forced_local);
#else
@@ -2105,7 +2125,9 @@ Symbol_table::do_define_in_output_segment(
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
- only_if_ref, &oldsym,
+ only_if_ref,
+ visibility,
+ &oldsym,
&resolve_oldsym,
is_forced_local);
#else
@@ -2211,7 +2233,9 @@ Symbol_table::do_define_as_constant(
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
- only_if_ref, &oldsym,
+ only_if_ref,
+ visibility,
+ &oldsym,
&resolve_oldsym,
is_forced_local);
#else
@@ -2222,7 +2246,9 @@ Symbol_table::do_define_as_constant(
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
- only_if_ref, &oldsym,
+ only_if_ref,
+ visibility,
+ &oldsym,
&resolve_oldsym,
is_forced_local);
#else
@@ -2449,7 +2475,9 @@ Symbol_table::add_undefined_symbol_from_command_line(const char* name)
{
#if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
sym = this->define_special_symbol<size, true>(&name, &version,
- false, &oldsym,
+ false,
+ elfcpp::STV_DEFAULT,
+ &oldsym,
&resolve_oldsym,
false);
#else
@@ -2460,7 +2488,9 @@ Symbol_table::add_undefined_symbol_from_command_line(const char* name)
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
sym = this->define_special_symbol<size, false>(&name, &version,
- false, &oldsym,
+ false,
+ elfcpp::STV_DEFAULT,
+ &oldsym,
&resolve_oldsym,
false);
#else
diff --git a/gold/symtab.h b/gold/symtab.h
index a67d5eb..edf1c17 100644
--- a/gold/symtab.h
+++ b/gold/symtab.h
@@ -1830,7 +1830,8 @@ class Symbol_table
template<int size, bool big_endian>
Sized_symbol<size>*
define_special_symbol(const char** pname, const char** pversion,
- bool only_if_ref, Sized_symbol<size>** poldsym,
+ bool only_if_ref, elfcpp::STV visibility,
+ Sized_symbol<size>** poldsym,
bool* resolve_oldsym, bool is_forced_local);
// Define a symbol in an Output_data, sized version.
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