Fix Sparc, s390 and AArch64 targets so that they can handle relocs against ifunc symbols found in note sections.

Following on from PR 22929, I have found the same problem exists with
  other ifunc supporting targets too.  Plus see this link for the bug
  being reported against the s390x binutils for Fedora rawhide:

     https://bugzilla.redhat.com/show_bug.cgi?id=1553705

  So I am going to check in the patch below which applies the same
  change that H.J. made for the x86_64 target to the other affected
  targets.  (Specifically: S390, AArch64 and Sparc).  Plus it adds a new
  test to the linker testsuite to make sure that this problem stays
  fixed.

bfd	* elf64-s390.c (elf_s390_relocate_section): Move check for
	relocations against non-allocated sections to before the code that
	handles ifunc relocations.
	* elf32-s390.c (elf_s390_relocate_section): Likewise.
	* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Treat
	relocs against IFUNC symbols in non-allocated sections as relocs
	against FUNC symbols.
	* elfxx-sparc.c (_bfd_sparc_elf_relocate_section): Likewise.

ld	* testsuite/ld-ifunc/ifuncmod5.s: New test.  Checks that targets
	that support IFUNC symbols can handle relocations against those
	symbols in NOTE sections.
	* testsuite/ld-ifunc/ifuncmod5.d: New file:  Driver for the new
	test.
	* testsuite/ld-ifunc/ifunc.exp: Run the new test.

bfd/ChangeLog

@@ -1,3 +1,14 @@
+2018-03-09  Nick Clifton  <nickc@redhat.com>
+
+	* elf64-s390.c (elf_s390_relocate_section): Move check for
+	relocations against non-allocated sections to before the code that
+	handles ifunc relocations.
+	* elf32-s390.c (elf_s390_relocate_section): Likewise.
+	* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Treat
+	relocs against IFUNC symbols in non-allocated sections as relocs
+	against FUNC symbols.
+	* elfxx-sparc.c (_bfd_sparc_elf_relocate_section): Likewise.
+
 2018-03-08  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/22929

bfd/elf32-s390.c

@@ -2605,6 +2605,9 @@ elf_s390_relocate_section (bfd *output_bfd,
 	case R_390_8:
 	case R_390_16:
 	case R_390_32:
+	  if ((input_section->flags & SEC_ALLOC) == 0)
+	    break;
+
 	  if (h != NULL
 	      && s390_is_ifunc_symbol_p (h)
 	      && h->def_regular)
@@ -2666,9 +2669,6 @@ elf_s390_relocate_section (bfd *output_bfd,
 		}
 	    }
 
-	  if ((input_section->flags & SEC_ALLOC) == 0)
-	    break;
-
 	  if ((bfd_link_pic (info)
 	       && (h == NULL
 		   || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT

bfd/elf64-s390.c

@@ -2565,6 +2565,9 @@ elf_s390_relocate_section (bfd *output_bfd,
 	case R_390_32:
 	case R_390_64:
 
+	  if ((input_section->flags & SEC_ALLOC) == 0)
+	    break;
+
 	  if (h != NULL
 	      && s390_is_ifunc_symbol_p (h)
 	      && h->def_regular)
@@ -2627,9 +2630,6 @@ elf_s390_relocate_section (bfd *output_bfd,
 		}
 	    }
 
-	  if ((input_section->flags & SEC_ALLOC) == 0)
-	    break;
-
 	  if ((bfd_link_pic (info)
 	       && (h == NULL
 		   || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT

bfd/elfnn-aarch64.c

@@ -5110,6 +5110,11 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
 
       if ((input_section->flags & SEC_ALLOC) == 0)
 	{
+	  /* If this is a SHT_NOTE section without SHF_ALLOC, treat
+	     STT_GNU_IFUNC symbol as STT_FUNC.  */
+	  if (elf_section_type (input_section) == SHT_NOTE)
+	    goto skip_ifunc;
+
 	  /* Dynamic relocs are not propagated for SEC_DEBUGGING
 	     sections because such sections are not SEC_ALLOC and
 	     thus ld.so will not process them.  */
@@ -5305,6 +5310,7 @@ bad_ifunc_reloc:
 	}
     }
 
+ skip_ifunc:
   resolved_to_zero = (h != NULL
 		      && UNDEFWEAK_NO_DYNAMIC_RELOC (info, h));
 

bfd/elfxx-sparc.c

@@ -3001,7 +3001,13 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
 
 	  if ((input_section->flags & SEC_ALLOC) == 0
 	      || h->plt.offset == (bfd_vma) -1)
-	    abort ();
+	    {
+	      /* If this is a SHT_NOTE section without SHF_ALLOC, treat
+	         STT_GNU_IFUNC symbol as STT_FUNC.  */
+	      if (elf_section_type (input_section) == SHT_NOTE)
+		goto skip_ifunc;
+	      abort ();
+	    }
 
 	  plt_sec = htab->elf.splt;
 	  if (! plt_sec)
@@ -3105,6 +3111,7 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
 	    }
 	}
 
+    skip_ifunc:
       eh = (struct _bfd_sparc_elf_link_hash_entry *) h;
       resolved_to_zero = eh && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
 

ld/ChangeLog

@@ -1,3 +1,12 @@
+2018-03-09  Nick Clifton  <nickc@redhat.com>
+
+	* testsuite/ld-ifunc/ifuncmod5.s: New test.  Checks that targets
+	that support IFUNC symbols can handle relocations against those
+	symbols in NOTE sections.
+	* testsuite/ld-ifunc/ifuncmod5.d: New file:  Driver for the new
+	test.
+	* testsuite/ld-ifunc/ifunc.exp: Run the new test.
+
 2018-03-08  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/22929

ld/testsuite/ld-ifunc/ifunc.exp

@@ -47,6 +47,9 @@ if ![check_shared_lib_support] {
     return
 }
 
+# This test does not need a compiler...
+run_dump_test "ifuncmod5"
+
 # We need a working compiler.  (Strictly speaking this is
 # not true, we could use target specific assembler files).
 if { [which $CC] == 0 } {

ld/testsuite/ld-ifunc/ifuncmod5.d

@@ -0,0 +1,8 @@
+# name: Reloc against IFUNC symbol in NOTE section
+# ld: -shared
+# nm: -p
+
+# We do not actually care about the notes at the moment.
+# The purpose of this test is to make sure that the link completes successfully.
+#pass
+

ld/testsuite/ld-ifunc/ifuncmod5.s

@@ -0,0 +1,105 @@
+	.file	"ifuncmod5.c"
+
+	.text
+	.type ifuncmod5.c, STT_NOTYPE
+ifuncmod5.c:
+	.size ifuncmod5.c, 0
+
+	.pushsection .gnu.build.attributes, "", %note
+	.balign 4
+	.dc.l 8 	
+	.dc.l 16	
+	.dc.l 0x100	
+	.asciz "GA$
3p4"	
+	.dc.a ifuncmod5.c
+	.dc.a ifuncmod5.c_end	
+	.popsection
+
+.Ltext0:
+#APP
+	.protected global
+	.type foo, %gnu_indirect_function
+	.type foo_hidden, %gnu_indirect_function
+	.type foo_protected, %gnu_indirect_function
+	.hidden foo_hidden
+	.protected foo_protected
+#NO_APP
+	.align	8
+	.type	one, %function
+one:
+	.dc.l 0
+	.size	one, .-one
+	.align	8
+
+.globl foo
+	.type	foo, %function
+foo:
+	.dc.l	0
+	.size	foo, .-foo
+
+	.pushsection .gnu.build.attributes
+	.dc.l 6		
+	.dc.l 16	
+	.dc.l 0x101	
+	.dc.b 0x47, 0x41, 0x2a, 0x2, 0, 0 	
+	.dc.b 0, 0 	
+	.dc.a foo
+	.dc.a foo_end	
+	.popsection
+
+foo_end:
+	.align	8
+.globl foo_hidden
+	.type	foo_hidden, %function
+foo_hidden:
+	.dc.l	0
+	.size	foo_hidden, .-foo_hidden
+
+	.pushsection .gnu.build.attributes
+	.dc.l 6		
+	.dc.l 16	
+	.dc.l 0x101	
+	.dc.b 0x47, 0x41, 0x2a, 0x2, 0, 0 	
+	.dc.b 0, 0 	
+	.dc.a foo_hidden
+	.dc.a foo_hidden_end	
+	.popsection
+
+foo_hidden_end:
+	.align	8
+
+	.globl foo_protected
+	.type	foo_protected, %function
+foo_protected:
+	.dc.l	0
+
+	.size	foo_protected, .-foo_protected
+
+	.pushsection .gnu.build.attributes
+	.dc.l 6		
+	.dc.l 16	
+	.dc.l 0x101	
+	.dc.b 0x47, 0x41, 0x2a, 0x2, 0, 0 	
+	.dc.b 0, 0 	
+	.dc.a foo_protected
+	.dc.a foo_protected_end	
+	.popsection
+
+foo_protected_end:
+	.globl global
+
+	.data
+	.align	4
+	.type	global, %object
+	.size	global, 4
+global:
+	.long	-1
+
+	.text
+	.Letext0:
+
+ifuncmod5.c_end:
+	.type ifuncmod5.c_end, STT_NOTYPE
+	.size ifuncmod5.c_end, 0
+
+