include/elf

2009-04-30  Nick Clifton  <nickc@redhat.com>

        * common.h (STT_GNU_IFUNC): Define.

elfcpp
2009-04-30  Nick Clifton  <nickc@redhat.com>

        * (enum STT): Add STT_GNU_IFUNC.

gas
2009-04-30  Nick Clifton  <nickc@redhat.com>

        * config/obj-elf.c (obj_elf_type): Add support for a
        gnu_indirect_function type.
        * config/tc-i386.c (tc_i386_fix_adjustable): Do not adjust fixups
        against indirect function symbols.
        * doc/as.texinfo (.type): Document the support for the
        gnu_indirect_function symbol type.
        * NEWS: Mention the new feature.

gas/testsuite
2009-04-30  Nick Clifton  <nickc@redhat.com>

        * gas/elf/elf.exp: Extend type test to include an ifunc symbol.
        Provide an alternative test for targets which do not support ifunc
        symbols.
        (type.s): Add entry for an ifunc symbol.
        (type.e): Add ifunc entry to expected symbol dump.
        (section2.e-armelf): Add  entry for ifunc symbol.
        (type-noifunc.s): New file.
        (type-noifunc.e): New file.

bfd/
2009-04-30  Nick Clifton  <nickc@redhat.com>

        * elf-bfd.h (struct bfd_elf_section_data): Add indirect_relocs
        section pointer.
        (struct elf_obj_data): Add has_ifunc_symbols boolean.
        * elf.c (swap_out_syms): Convert BSF_GNU_INDIRECT_FUNCTION flags
        into a STT_GNU_IFUNC symbol type.
        (_bfd_elf_is_function_type): Accept STT_GNU_IFUNC as a function
        type.
        (_bfd_elf_set_osabi): Set the osasbi field to ELFOSABI_LINUX if
        the binary contains ifunc symbols.
        * elfcode.h (elf_slurp_symbol_table): Translate the STT_GNU_IFUNC
        symbol type into a BSF_GNU_INDIRECT_FUNCTION flag.
        * elf32-i386.c (is_indirect_function): New function.
        (elf_i386_check_relocs): Create an ifunc output section.
        (allocate_dynrelocs): Create dynamic relocs in the ifunc output
        section if necessary.
        (elf_i386_relocate_section): Emit a reloc against an ifunc symbol
        if necessary.
        (elf_i386_add_symbol_hook): New function. Set the
        has_ifunc_symbols field of the elf_obj_data structure if an ifunc
        symbol is encountered.
        (elf_backend_post_process_headers): Define.
        (elf_backend_add_symbol_hook): Define.
        (elf_i386_post_process_headers): Rename to
        elf_i388_fbsd_post_process_headers.
        * elf64-x86_64.c (IS_X86_64_PCREL_TYPE): New macro.
        (is_indirect_function): New function.
        (elf64_x86_64_check_relocs): Create an ifunc output section.
        (allocate_dynrelocs): Create dynamic relocs in the ifunc output
        section if necessary.
        (elf64_x86_64_relocate_section): Emit a reloc against an ifunc
        symbol if necessary.
        (elf_i386_add_symbol_hook): Set the has_ifunc_symbols field of the
        elf_obj_data structure if an ifunc symbol is encountered.
        (elf_backend_post_process_headers): Define.
        * elflink.c (_bfd_elf_adjust_dynamic_symbol): Always create a PLT
        if we have ifunc symbols to handle.
        (get_ifunc_reloc_section_name): New function.  Computes the name
        for an ifunc section.
        (_bfd_elf_make_ifunc_reloc_section): New function.  Creates a
        section to hold ifunc relocs.
        * syms.c (BSF_GNU_INDIRECT_FUNCTION): Define.
        (bfd_print_symbol_vandf): Handle ifunc symbols.
        (bfd_decode_symclass): Likewise.
        * bfd-in2.h: Regenerate.

binutils
2009-04-30  Nick Clifton  <nickc@redhat.com>

        * readelf.c (dump_relocations): Display a relocation against an
        ifunc symbol as if it were a function invocation.
        (get_symbol_type): Handle STT_GNU_IFUNC.

ld
2009-04-30  Nick Clifton  <nickc@redhat.com>

        * NEWS: Mention support for IFUNC symbols.

ld/testsuite
2009-04-30  Nick Clifton  <nickc@redhat.com>

        * ld-ifunc: New directory.
        * ld-ifunc/ifunc.exp: New file: Run the IFUNC tests.
        * ld-ifunc/prog.c: New file.
        * ld-ifunc/lib.c: New file.

7 files changed, 350 insertions, 10 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 793d154..26c446f 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,7 @@
+2009-04-30  Nick Clifton  <nickc@redhat.com>
+
+	* NEWS: Mention support for IFUNC symbols.
+
 2009-04-29  Anthony Green  <green@moxielogic.com>
 
 	* emulparams/elf32moxie.sh (STACK_ADDR): Move default stack
diff --git a/ld/NEWS b/ld/NEWS
index 99d5d85..a0d7fb2 100644
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -15,6 +15,10 @@
   automatically in the presence of un-stripped debug information, as GDB
   needs to be able to find the debug info sections by their full names.
 
+* For GNU/Linux systems the linker will now avoid processing any relocations
+  made against symbols of the STT_GNU_IFUNC type and instead emit them into
+  the resulting binary for processing by the loader.
+
 * --as-needed now links in a dynamic library if it satisfies undefined
   symbols in regular objects, or in other dynamic libraries.  In the
   latter case the library is not linked if it is found in a DT_NEEDED
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 4542a24..91bb3ed 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2009-04-30  Nick Clifton  <nickc@redhat.com>
+
+	* ld-ifunc: New directory.
+	* ld-ifunc/ifunc.exp: New file: Run the IFUNC tests.
+	* ld-ifunc/prog.c: New file.
+	* ld-ifunc/lib.c: New file.
+
 2009-04-30  Joseph Myers  <joseph@codesourcery.com>
 
 	* ld-arm/movw-shared-1.d, ld-arm/movw-shared-1.s,
diff --git a/ld/testsuite/ld-checks/checks.exp b/ld/testsuite/ld-checks/checks.exp
index 39e9ac7..1e4af28 100644
--- a/ld/testsuite/ld-checks/checks.exp
+++ b/ld/testsuite/ld-checks/checks.exp
@@ -1,5 +1,5 @@
 # Expect script for LD section checks tests
-#   Copyright 1999, 2001, 2003, 2007 Free Software Foundation, Inc.
+#   Copyright 1999, 2001, 2003, 2007, 2009 Free Software Foundation, Inc.
 #
 # This file is part of the GNU Binutils.
 #
@@ -26,16 +26,17 @@ proc section_check {} {
     global ld
     global srcdir
     global subdir
-    
+
     # The usage of .lcomm in asm.s is incompatible with ia64 and ppc coff.
     if { [istarget ia64-*-*]
-	 || [istarget powerpc*-*-aix*] || [istarget powerpc-*-beos*]
+	 || [istarget powerpc*-*-aix*]
+	 || [istarget powerpc-*-beos*]
 	 || [istarget rs6000-*-*] } {
 	return
     }
     set test "check sections 1"
-    
-    set ldflags "--check-sections"
+
+    set ldflags "--check-sections -e foo"
 
     if { ![ld_assemble $as $srcdir/$subdir/asm.s tmpdir/asm.o]} {
 	unresolved $test
@@ -55,15 +56,15 @@ proc section_check {} {
     set ldflags "--check-sections -T $srcdir/$subdir/script -e foo"
 
     # Perform the equivalent of invoking ld_simple_link
-    # except that we need to massage the output futher.
-    
+    # except that we need to massage the output further.
+
     set exec_output [run_host_cmd "$ld" "-o tmpdir/asm.x $ldflags tmpdir/asm.o"]
     set exec_output [prune_warnings $exec_output]
 
     # Make sure that we got some output from the linker
     if [string match "" $exec_output] then {
 	fail $test
-    } 
+    }
 
     # Now remove our expected error message
     regsub -all ".*: section .data .* overlaps section .text .*" $exec_output "" exec_output
@@ -78,5 +79,3 @@ proc section_check {} {
 }
 
 section_check
-
-
diff --git a/ld/testsuite/ld-ifunc/ifunc.exp b/ld/testsuite/ld-ifunc/ifunc.exp
new file mode 100644
index 0000000..2ba5da1
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/ifunc.exp
@@ -0,0 +1,254 @@
+# Expect script for linker support of IFUNC symbols and relocations.
+#
+#   Copyright 2009  Free Software Foundation, Inc.
+#   Contributed by Red Hat.
+#
+# This file is part of the GNU Binutils.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+# MA 02110-1301, USA.
+#
+# Written by Nick Clifton <nickc@redhat.com>
+
+
+# IFUNC support has only been implemented for the x86_64 and ix86 so far.
+if {! (  [istarget "x86_64-*-elf*"]
+      || [istarget "x86_64-*-linux*"]
+      || [istarget "i?86-*-elf*"]
+      || [istarget "i?86-*-linux*"]) } {
+    verbose "IFUNC tests not run - target does not support IFUNC"
+    return
+}
+
+# We need a native system.  FIXME: Strictly speaking this
+# is not true, we just need to know how to create a fully
+# linked executable, including the C and Z libraries, using
+# the linker that is under test.
+if ![isnative] {
+    verbose "IFUNC tests not run - not a native toolchain"
+    return
+}
+
+# We need a working compiler.  (Strictly speaking this is
+# not true, we could use target specific assembler files).
+if { [which $CC] == 0 } {
+    verbose "IFUNC tests not run - no compiler available"
+    return
+}
+
+# A procedure to check the OS/ABI field in the ELF header of a binary file.
+proc check_osabi { binary_file expected_osabi } {
+    global READELF
+    global READELFFLAGS
+
+    catch "exec $READELF $READELFFLAGS --file-header $binary_file > readelf.out" got
+
+    if ![string match "" $got] then {
+	verbose "proc check_osabi: Readelf produced unexpected out processing $binary_file: $got"
+	return 0
+    }
+
+    if { ![regexp "\n\[ \]*OS/ABI:\[ \]*(.+)\n\[ \]*ABI" \
+	   [file_contents readelf.out] nil osabi] } {
+	verbose "proc check_osabi: Readelf failed to extract an ELF header from $binary_file"
+	return 0
+    }
+
+    if { $osabi == $expected_osabi } {
+	return 1
+    }
+
+    verbose "Expected OSABI: $expected_osabi, Obtained osabi: $osabi"
+    
+    return 0
+}
+
+# A procedure to confirm that a file contains the IFUNC symbol.
+# Returns -1 upon error, 0 if the symbol was not found and 1 if it was found.
+proc contains_ifunc_symbol { binary_file } {
+    global READELF
+    global READELFFLAGS
+
+    catch "exec $READELF $READELFFLAGS --symbols $binary_file > readelf.out" got
+
+    if ![string match "" $got] then {
+	verbose "proc contains_ifunc_symbol: Readelf produced unexpected out processing $binary_file: $got"
+	return -1
+    }
+
+    # Look for a line like this:
+    #    58: 0000000000400600    30 IFUNC   GLOBAL DEFAULT   12 library_func2
+
+    if { ![regexp ".*\[ \]*IFUNC\[ \]+GLOBAL\[ \]+DEFAULT\[ \]+\[UND0-9\]+\[ \]+library_func2\n" [file_contents readelf.out]] } {
+	return 0
+    }
+
+    return 1
+}
+
+# A procedure to confirm that a file contains a relocation that references an IFUNC symbol.
+# Returns -1 upon error, 0 if the reloc was not found and 1 if it was found.
+proc contains_ifunc_reloc { binary_file } {
+    global READELF
+    global READELFFLAGS
+
+    catch "exec $READELF $READELFFLAGS --relocs $binary_file > readelf.out" got
+
+    if ![string match "" $got] then {
+	verbose "proc contains_ifunc_reloc: Readelf produced unexpected out processing $binary_file: $got"
+	return -1
+    }
+
+    if [string match "" [file_contents readelf.out]] then {
+	verbose "No relocs found in $binary_file"
+	return 0
+    }
+
+    if { ![regexp "\\(\\)" [file_contents readelf.out]] } {
+	return 0
+    }
+
+    return 1
+}
+
+set fails 0
+
+# Create the object files, libraries and executables.
+if ![ld_compile "$CC -c -shared -fPIC" "$srcdir/$subdir/prog.c" "tmpdir/shared_prog.o"] {
+    fail "Could not create a shared object file"
+    set fails [expr $fails + 1]
+}
+if ![ld_compile "$CC -c -static" "$srcdir/$subdir/prog.c" "tmpdir/static_prog.o"] {
+    fail "Could not create a static object file"
+    set fails [expr $fails + 1]
+}
+if ![ld_compile "$CC -c -shared -fPIC -DWITH_IFUNC" "$srcdir/$subdir/lib.c" "tmpdir/shared_ifunc.o"] {
+    fail "Could not create an object file containing an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+if ![ld_compile "$CC -c -static -DWITH_IFUNC" "$srcdir/$subdir/lib.c" "tmpdir/static_ifunc.o"] {
+    fail "Could not create a static object file containing an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+if ![ld_compile "$CC -c -static -DWITHOUT_IFUNC" "$srcdir/$subdir/lib.c" "tmpdir/static_noifunc.o"] {
+    fail "Could not create an ordinary static object file"
+    set fails [expr $fails + 1]
+}
+
+if { $fails != 0 } {
+    return
+}
+
+if ![ld_simple_link $ld "tmpdir/libshared_ifunc.so" "-shared tmpdir/shared_ifunc.o"] {
+    fail "Could not create a shared library containing an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+if ![ar_simple_create $ar "" "tmpdir/libifunc.a" "tmpdir/static_ifunc.o"] {
+    fail "Could not create a static library containing an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+
+if { $fails != 0 } {
+    return
+}
+
+if ![default_ld_link $ld "tmpdir/dynamic_prog" "-Ltmpdir tmpdir/shared_prog.o -Bdynamic -lshared_ifunc -rpath ./tmpdir"] {
+    fail "Could not link a dynamic executable"
+    set fails [expr $fails + 1]
+}
+if ![default_ld_link $ld "tmpdir/static_prog" "-Ltmpdir tmpdir/static_prog.o -lifunc"] {
+    fail "Could not link a static executable"
+    set fails [expr $fails + 1]
+}
+if ![default_ld_link $ld "tmpdir/static_nonifunc_prog" "-Ltmpdir tmpdir/static_prog.o tmpdir/static_noifunc.o"] {
+    fail "Could not link a non-ifunc using static executable"
+    set fails [expr $fails + 1]
+}
+
+if { $fails == 0 } {
+  pass "Building ifunc binaries"
+  set fails 0
+} else {
+    return
+}
+
+# Check the executables.
+#
+# The linked ifunc using executables should have an OSABI field of LINUX
+# The linked non-ifunc using executable should have an OSABI field of NONE (aka System V).
+
+if {! [check_osabi tmpdir/static_prog {UNIX - Linux}]} {
+    fail "Static ifunc-using executable does not have an OS/ABI field of LINUX"
+    set fails [expr $fails + 1]
+}
+if {! [check_osabi tmpdir/dynamic_prog {UNIX - Linux}]} {
+    fail "Dynamic ifunc-using executable does not have an OS/ABI field of LINUX"
+    set fails [expr $fails + 1]
+}
+if {! [check_osabi tmpdir/static_nonifunc_prog {UNIX - System V}]} {
+    fail "Static non-ifunc-using executable does not have an OS/ABI field of System V"
+    set fails [expr $fails + 1]
+}
+
+# The linked ifunc using executables should contain an IFUNC symbol,
+# The non-ifunc using executable should not.
+
+if {[contains_ifunc_symbol tmpdir/static_prog] != 1} {
+    fail "Static ifunc-using executable does not contain an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+if {[contains_ifunc_symbol tmpdir/dynamic_prog] != 1} {
+    fail "Dynamic ifunc-using executable does not contain an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+if {[contains_ifunc_symbol tmpdir/static_nonifunc_prog] != 0} {
+    fail "Static non-ifunc-using executable contains an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+
+# The linked ifunc using executablea should contain a dynamic reloc referencing the IFUNC symbol.
+# (Even the static executable which should have a dynamic section created for it).
+# The non-ifunc using executable should not.
+
+if {[contains_ifunc_reloc tmpdir/static_prog] != 1} {
+    fail "Static ifunc-using executable does not contain a reloc against an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+if {[contains_ifunc_reloc tmpdir/dynamic_prog] != 1} {
+    fail "Dynamic ifunc-using executable does not contain a reloc against an IFUNC symbol"
+    set fails [expr $fails + 1]
+}
+if {[contains_ifunc_reloc tmpdir/static_nonifunc_prog] == 1} {
+    fail "Static non-ifunc-using executable contains a reloc against an IFUNC symbol!"
+    set fails [expr $fails + 1]
+}
+
+if { $fails == 0 } {
+  pass "Checking ifunc binaries"
+}
+
+# Clean up, unless we are being verbose, in which case we leave the files available.
+if { $verbose < 1 } {
+    remote_file host delete "tmpdir/shared_prog.o"
+    remote_file host delete "tmpdir/static_prog.o"
+    remote_file host delete "tmpdir/shared_ifunc.o"
+    remote_file host delete "tmpdir/static_ifunc.o"
+    remote_file host delete "tmpdir/static_noifunc.o"
+    remote_file host delete "tmpdir/libshared_ifunc.so"
+    remote_file host delete "tmpdir/libifunc.a"
+    remote_file host delete "tmpdir/dynamic_prog"
+    remote_file host delete "tmpdir/static_prog"
+    remote_file host delete "tmpdir/static_nonifunc_prog"
+}
diff --git a/ld/testsuite/ld-ifunc/lib.c b/ld/testsuite/ld-ifunc/lib.c
new file mode 100644
index 0000000..5bfd2cd
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/lib.c
@@ -0,0 +1,26 @@
+int
+library_func1 (void)
+{
+  return 2;
+}
+
+int global = 1;
+
+#ifdef WITH_IFUNC
+
+static int minus_one (void) { return -1; }
+static int zero (void) { return 0; }
+
+void * library_func2_ifunc (void) __asm__ ("library_func2");
+void * library_func2_ifunc (void) { return global ? minus_one : zero ; }
+__asm__(".type library_func2, %gnu_indirect_function");
+
+#else /* WITHOUT_IFUNC */
+
+int
+library_func2 (void)
+{
+  return 3;
+}
+
+#endif
diff --git a/ld/testsuite/ld-ifunc/prog.c b/ld/testsuite/ld-ifunc/prog.c
new file mode 100644
index 0000000..da786a5
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/prog.c
@@ -0,0 +1,46 @@
+extern int printf (const char *, ...);
+
+extern int library_func1 (void);
+extern int library_func2 (void);
+extern int global;
+
+int
+main (void)
+{
+  int res = -1;
+
+  res += library_func1 ();
+  res += library_func2 ();
+
+  switch (res)
+    {
+    case 0:
+      if (global)
+	printf ("ifunc working correctly\n");
+      else
+	{
+	  printf ("wrong value returned by library_func2\n");
+	  res = -1;
+	}
+      break;
+
+    case 1:
+      if (global)
+	printf ("wrong value returned by library_func2\n");
+      else
+	{
+	  printf ("ifunc working correctly\n");
+	  res = 0;
+	}
+      break;
+
+    case 4:
+      printf ("non-ifunc testcase\n");
+      break;
+
+    default:
+      printf ("ifunc function not evaluated at run-time, res = %x\n", res);
+      break;
+    }
+  return res;
+}