PR 10893

	* i386.cc (class Output_data_plt_i386): Update declarations.
	Define Global_ifunc and Local_ifunc types.  Add global_ifuncs_ and
	local_ifuncs_ fields.
	(Target_i386::do_plt_section_for_global): New function.
	(Target_i386::do_plt_section_for_local): New function.
	(Output_data_plt_i386::Output_data_plt_i386): Add symtab
	parameter; change all callers.  Initialize global_ifuncs_ and
	local_ifuncs_.  If doing a static link define __rel_iplt_start and
	__rel_iplt_end.
	(Output_data_plt_i386::add_entry): Handle IFUNC symbols.
	(Output_data_plt_i386::add_local_ifunc_entry): New function.
	(Output_data_plt_i386::do_write): Fix GOT entries for IFUNC
	symbols.
	(Target_i386::make_plt_section): New function, broken out of
	make_plt_entry.  Set sh_info field of .rel.plt to point to .plt.
	(Target_i386::make_plt_entry): Call make_plt_section.
	(Target_i386::make_local_ifunc_plt_entry): New function.
	(Target_i386::Scan::reloc_needs_iplt_for_ifunc): New function.
	(Target_i386::Scan::local): Handle IFUNC symbols.  Add
	R_386_IRELATIVE to switch.
	(Target_i386::Scan::global): Likewise.
	(Target_i386::Relocate::relocate): Likewise.
	(Target_i386::Relocatable_size_for_reloc): Add R_386_IRELATIVE to
	switch.
	* x86_64.cc (class Output_data_plt_x86_64): Update declarations.
	(Target_x86_64::do_plt_section_for_global): New function.
	(Target_x86_64::do_plt_section_for_local): New function.
	(Output_data_plt_x86_64::Output_data_plt_x86_64): Add symtab
	parameter; change all callers.  If doing a static link define
	__rela_iplt_start and __rela_iplt_end.
	(Output_data_plt_x86_64::add_entry): Handle IFUNC symbols.
	(Output_data_plt_x86_64::add_local_ifunc_entry): New function.
	(Target_x86_64::make_plt_section): Set sh_info field of .rel.plt
	to point to .plt.
	(Target_x86_64::make_local_ifunc_plt_entry): New function.
	(Target_x86_64::Scan::check_non_pic): Add R_X86_64_IRELATIVE to
	switch.
	(Target_x86_64::Scan::reloc_needs_iplt_for_ifunc): New function.
	(Target_x86_64::Scan::local): Handle IFUNC symbols.  Add
	R_X86_64_IRELATIVE to switch.
	(Target_x86_64::Scan::global): Likewise.
	(Target_x86_64::Relocate::relocate): Likewise.
	(Target_x86_64::Relocatable_size_for_reloc): Add R_X86_64_IRELATIVE to
	switch.
	* target.h (class Target): Add plt_section_for_global and
	plt_section_for_local functions.  Add do_plt_section_for_global
	and do_plt_section_for_local virtual functions.
	* symtab.h (Symbol::needs_plt_entry): Handle IFUNC symbol.  Add
	clarifying comments.
	(Symbol::use_plt_offset): Handle IFUNC symbol.
	* object.cc (Sized_relobj::Sized_relobj): Initialize
	local_plt_offsets_.
	(Sized_relobj::local_has_plt_offset): New function.
	(Sized_relobj::local_plt_offset): New function.
	(Sized_relobj::set_local_plt_offset): New function.
	(Sized_relobj::do_count): Handle IFUNC symbol.
	* object.h (class Symbol_value): Add is_ifunc_symbol_ field.  Take
	a bit away from input_shndx_ field.  Add set_is_func_symbol and
	is_ifunc_symbol functions.
	(class Sized_relobj): Update declarations.  Remove Tls_got_entry
	and Local_tls_got_offsets.  Define Local_plt_offsets.  Add
	local_plt_offsets_ field.
	(Sized_relobj::clear_local_symbols): Clear local_plt_offsets_.
	* output.h (class Output_section_data): Add non-const
	output_section function.
	(class Output_data_got): Update declarations.
	(class Output_data_got::Got_entry): Add use_plt_offset_ field.
	Add use_plt_offset parameter to global and local constructors.
	Change all callers.  Change local_sym_index_ field to 31 bits.
	Change GSYM_CODE and CONSTANT_CODE accordingly.
	* output.cc (Output_data_reloc_base::do_adjust_output_section): If
	doing a static link don't set sh_link field.
	(Output_data_got::Got_entry::write): Use PLT offset if
	appropriate.
	(Output_data_got::add_global_plt): New function.
	(Output_data_got::add_local_plt): New function.
	* target-reloc.h (relocate_section): Handle IFUNC symbol.
	* defstd.cc (in_section): Remove entries for __rel_iplt_start,
	__rel_iplt_end, __rela_iplt_start, and __rela_iplt_end.
	* configure.ac: Set IFUNC automake conditional for glibc >= 2.11.
	* testsuite/Makefile.am: Add a bunch of IFUNC tests, all within
	IFUNC conditional.
	* testsuite/ifunc-sel.h: New file.
	* testsuite/ifuncmain1.c: New file.
	* testsuite/ifuncmain1vis.c: New file.
	* testsuite/ifuncmod1.c: New file.
	* testsuite/ifuncdep2.c: New file.
	* testsuite/ifuncmain2.c: New file.
	* testsuite/ifuncmain3.c: New file.
	* testsuite/ifuncmod3.c: New file.
	* testsuite/ifuncmain4.c: New file.
	* testsuite/ifuncmain5.c: New file.
	* testsuite/ifuncmod5.c: New file.
	* testsuite/ifuncmain6pie.c: New file.
	* testsuite/ifuncmod6.c: New file.
	* testsuite/ifuncmain7.c: New file.
	* configure, testsuite/Makefile.in: Rebuild.

1 files changed, 25 insertions, 9 deletions

diff --git a/gold/symtab.h b/gold/symtab.h
index 8ccbca9a41..b9e34852e4 100644
--- a/gold/symtab.h
+++ b/gold/symtab.h
@@ -582,9 +582,6 @@ class Symbol
   }
 
   // Return true if this symbol is a function that needs a PLT entry.
-  // If the symbol is defined in a dynamic object or if it is subject
-  // to pre-emption, we need to make a PLT entry. If we're doing a
-  // static link or a -pie link, we don't create PLT entries.
   bool
   needs_plt_entry() const
   {
@@ -592,12 +589,27 @@ class Symbol
     if (this->is_undefined() && !parameters->options().shared())
       return false;
 
-    return (!parameters->doing_static_link()
-	    && !parameters->options().pie()
-            && this->is_func()
-            && (this->is_from_dynobj()
-                || this->is_undefined()
-                || this->is_preemptible()));
+    // An STT_GNU_IFUNC symbol always needs a PLT entry, even when
+    // doing a static link.
+    if (this->type() == elfcpp::STT_GNU_IFUNC)
+      return true;
+
+    // We only need a PLT entry for a function.
+    if (!this->is_func())
+      return false;
+
+    // If we're doing a static link or a -pie link, we don't create
+    // PLT entries.
+    if (parameters->doing_static_link()
+	|| parameters->options().pie())
+      return false;
+
+    // We need a PLT entry if the function is defined in a dynamic
+    // object, or is undefined when building a shared object, or if it
+    // is subject to pre-emption.
+    return (this->is_from_dynobj()
+	    || this->is_undefined()
+	    || this->is_preemptible());
   }
 
   // When determining whether a reference to a symbol needs a dynamic
@@ -678,6 +690,10 @@ class Symbol
     if (!this->has_plt_offset())
       return false;
 
+    // For a STT_GNU_IFUNC symbol we always have to use the PLT entry.
+    if (this->type() == elfcpp::STT_GNU_IFUNC)
+      return true;
+
     // If we are going to generate a dynamic relocation, then we will
     // wind up using that, so no need to use the PLT entry.
     if (this->needs_dynamic_reloc(FUNCTION_CALL