x86: Treat relocation against IFUNC symbol as FUNC

When resolving a relocation against IFUNC symbol in a SHT_NOTE section
without SHF_ALLOC, we treat it as relocation against FUNC symbol since
it needs the address of IFUNC symbol, not the address returned by IFUNC
function.

bfd/

	PR ld/22929
	* elf32-i386.c (elf_i386_relocate_section): Treat relocation
	against IFUNC symbol in SHT_NOTE section without SHF_ALLOC as
	relocation against FUNC symbol.
	* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.

ld/

	PR ld/22929
	* testsuite/ld-i386/i386.exp: Run PR ld/22929 test.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.
	* testsuite/ld-i386/pr22929.d: New file.
	* testsuite/ld-i386/pr22929.s: Likewise.
	* testsuite/ld-x86-64/pr22929.d: Likewise.
	* testsuite/ld-x86-64/pr22929.s: Likewise.

10 files changed, 94 insertions, 0 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index c0ad7eb..74af690 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2018-03-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/22929
+	* elf32-i386.c (elf_i386_relocate_section): Treat relocation
+	against IFUNC symbol in SHT_NOTE section without SHF_ALLOC as
+	relocation against FUNC symbol.
+	* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
+
 2018-03-07  Renlin Li  <renlin.li@arm.com>
 
 	PR ld/20402
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 61a1409..5570846 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -2221,6 +2221,10 @@ elf_i386_relocate_section (bfd *output_bfd,
 
 	  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.  */
@@ -2440,6 +2444,7 @@ do_ifunc_pointer:
 	    }
 	}
 
+skip_ifunc:
       resolved_to_zero = (eh != NULL
 			  && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh));
 
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 7016964..a964316 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -2503,6 +2503,10 @@ elf_x86_64_relocate_section (bfd *output_bfd,
 
 	  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.  */
@@ -2726,6 +2730,7 @@ do_ifunc_pointer:
 	    }
 	}
 
+skip_ifunc:
       resolved_to_zero = (eh != NULL
 			  && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh));
 
diff --git a/ld/ChangeLog b/ld/ChangeLog
index a65b824..f37bdab 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,13 @@
+2018-03-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/22929
+	* testsuite/ld-i386/i386.exp: Run PR ld/22929 test.
+	* testsuite/ld-x86-64/x86-64.exp: Likewise.
+	* testsuite/ld-i386/pr22929.d: New file.
+	* testsuite/ld-i386/pr22929.s: Likewise.
+	* testsuite/ld-x86-64/pr22929.d: Likewise.
+	* testsuite/ld-x86-64/pr22929.s: Likewise.
+
 2018-03-07  Max Filippov  <jcmvbkbc@gmail.com>
 
 	* emulparams/elf32xtensa.sh (COMMONPAGESIZE): Define.
diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index 240850a..243c0a5 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -459,6 +459,7 @@ run_dump_test "pr22115-1c"
 run_dump_test "pr22115-1d"
 run_dump_test "pr22135"
 run_dump_test "pr22782"
+run_dump_test "pr22929"
 
 if { !([istarget "i?86-*-linux*"]
        || [istarget "i?86-*-gnu*"]
diff --git a/ld/testsuite/ld-i386/pr22929.d b/ld/testsuite/ld-i386/pr22929.d
new file mode 100644
index 0000000..099880e
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr22929.d
@@ -0,0 +1,11 @@
+#as: --32
+#ld: -melf_i386 -shared
+#readelf: -r --wide -s
+
+There are no relocations in this file.
+#...
+Symbol table '.symtab' contains [0-9]+ entries:
+   Num:    Value  Size Type    Bind   Vis      Ndx Name
+#...
+[ \t]+[a-f0-9]+: [a-f0-9]+ +1 IFUNC +GLOBAL DEFAULT +[a-f0-9]+ +foo
+#...
diff --git a/ld/testsuite/ld-i386/pr22929.s b/ld/testsuite/ld-i386/pr22929.s
new file mode 100644
index 0000000..3fa3dc9
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr22929.s
@@ -0,0 +1,21 @@
+	.text
+	.globl	foo
+	.type foo, %gnu_indirect_function
+foo:
+	ret
+	.size	foo, .-foo
+	.pushsection .gnu.build.attributes, "", %note
+	.dc.l 6		# size of name
+	.dc.l 16	# descsz = sizeof (addresses)
+	.dc.l 0x101	# type = FUNC
+	.dc.b 0x47, 0x41, 0x2a, 0x2, 0, 0 	# name (numeric: -fstack-protector status)
+	.dc.b 0, 0 	# Padding
+	.dc.a foo
+	.dc.a foo_end	# description (symbol name)
+	.popsection
+
+foo_end:
+	.section	.rodata.cst4,"aM",@progbits,4
+	.align 4
+.LC0:
+	.long	1065353216
diff --git a/ld/testsuite/ld-x86-64/pr22929.d b/ld/testsuite/ld-x86-64/pr22929.d
new file mode 100644
index 0000000..537b396
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr22929.d
@@ -0,0 +1,11 @@
+#as: --64
+#ld: -melf_x86_64 -shared
+#readelf: -r --wide -s
+
+There are no relocations in this file.
+#...
+Symbol table '.symtab' contains [0-9]+ entries:
+   Num:    Value          Size Type    Bind   Vis      Ndx Name
+#...
+[ \t]+[a-f0-9]+: [a-f0-9]+ +1 IFUNC +GLOBAL DEFAULT +[a-f0-9]+ +foo
+#...
diff --git a/ld/testsuite/ld-x86-64/pr22929.s b/ld/testsuite/ld-x86-64/pr22929.s
new file mode 100644
index 0000000..3fa3dc9
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr22929.s
@@ -0,0 +1,21 @@
+	.text
+	.globl	foo
+	.type foo, %gnu_indirect_function
+foo:
+	ret
+	.size	foo, .-foo
+	.pushsection .gnu.build.attributes, "", %note
+	.dc.l 6		# size of name
+	.dc.l 16	# descsz = sizeof (addresses)
+	.dc.l 0x101	# type = FUNC
+	.dc.b 0x47, 0x41, 0x2a, 0x2, 0, 0 	# name (numeric: -fstack-protector status)
+	.dc.b 0, 0 	# Padding
+	.dc.a foo
+	.dc.a foo_end	# description (symbol name)
+	.popsection
+
+foo_end:
+	.section	.rodata.cst4,"aM",@progbits,4
+	.align 4
+.LC0:
+	.long	1065353216
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 02aa38a..5a06947 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -605,6 +605,7 @@ run_dump_test "pr20253-5a"
 run_dump_test "pr20253-5b"
 run_dump_test "tlsdesc2"
 run_dump_test "pr22048"
+run_dump_test "pr22929"
 
 proc undefined_weak {cflags ldflags} {
     set testname "Undefined weak symbol"