Add "-z call-nop=PADDING" option to ld

The ld linker can transform indirect call to a locally defined function,
foo, via its GOT slot, to either "NOP call foo" or "call foo NOP" where
NOP is a 1-byte NOP padding.  This patch adds a "-z call-nop=PADDING"
option to x86 ld to control 1-byte NOP padding for x86 call instruction.
PADDING is one of prefix-addr, prefix-nop, suffix-nop, prefix-NUMBER or
suffix-NUMBER.

bfd/

	* elf32-i386.c (elf_i386_convert_load): Use call_nop_byte and
	check call_nop_as_suffix for 1-byte NOP padding to pad call.
	* elf64-x86-64.c (elf_x86_64_convert_load): Likewise.

include/

	* bfdlink.h (bfd_link_info): Add call_nop_as_suffix and
	call_nop_byte.

ld/

	* ld/ld.texinfo: Document "-z call-nop=PADDING" option.
	* emulparams/call_nop.sh: New file.
	* emulparams/elf_i386_be.sh: Source
	${srcdir}/emulparams/call_nop.sh.
	* emulparams/elf_i386_chaos.sh: Likewise.
	* emulparams/elf_i386_ldso.sh: Likewise.
	* emulparams/elf_i386_vxworks.sh: Likewise.
	* emulparams/elf_iamcu.sh: Likewise.
	* emulparams/elf_k1om.sh: Likewise.
	* emulparams/elf_l1om.sh: Likewise.
	* emulparams/elf_x86_64.sh: Likewise.
	* emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Set
	link_info.call_nop_byte if $CALL_NOP_BYTE isn't empty.

ld/testsuite/

	* ld-i386/call3.s: New file.
	* ld-i386/call3a.d: Likewise.
	* ld-i386/call3b.d: Likewise.
	* ld-i386/call3c.d: Likewise.
	* ld-i386/call3d.d: Likewise.
	* ld-i386/call3e.d: Likewise.
	* ld-i386/call3f.d: Likewise.
	* ld-i386/call3g.d: Likewise.
	* ld-i386/call3h.d: Likewise.
	* ld-i386/load1-nacl.d: Likewise.
	* ld-x86-64/call1.s: Likewise.
	* ld-x86-64/call1a.d: Likewise.
	* ld-x86-64/call1b.d: Likewise.
	* ld-x86-64/call1c.d: Likewise.
	* ld-x86-64/call1d.d: Likewise.
	* ld-x86-64/call1e.d: Likewise.
	* ld-x86-64/call1f.d: Likewise.
	* ld-x86-64/call1g.d: Likewise.
	* ld-x86-64/call1h.d: Likewise.
	* ld-x86-64/call1i.d: Likewise.
	* ld-x86-64/load1a-nacl.d: Likewise.
	* ld-x86-64/load1b-nacl.d: Likewise.
	* ld-x86-64/load1c-nacl.d: Likewise.
	* ld-x86-64/load1d-nacl.d: Likewise.

12 files changed, 187 insertions, 0 deletions

diff --git a/ld/testsuite/ld-i386/call3.s b/ld/testsuite/ld-i386/call3.s
new file mode 100644
index 0000000..ce003c8
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3.s
@@ -0,0 +1,9 @@
+	.text
+	.globl	foo
+	.type	foo, @function
+foo:
+	ret
+	.globl	_start
+	.type	_start, @function
+_start:
+	call	*foo@GOT
diff --git a/ld/testsuite/ld-i386/call3a.d b/ld/testsuite/ld-i386/call3a.d
new file mode 100644
index 0000000..a8ff27f
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3a.d
@@ -0,0 +1,13 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	67 e8 ([0-9a-f]{2} ){4} *	addr16 call +[a-f0-9]+ <foo>
+#pass
diff --git a/ld/testsuite/ld-i386/call3b.d b/ld/testsuite/ld-i386/call3b.d
new file mode 100644
index 0000000..06af6f5
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3b.d
@@ -0,0 +1,13 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386 -z call-nop=prefix-addr
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	67 e8 ([0-9a-f]{2} ){4} *	addr16 call +[a-f0-9]+ <foo>
+#pass
diff --git a/ld/testsuite/ld-i386/call3c.d b/ld/testsuite/ld-i386/call3c.d
new file mode 100644
index 0000000..64e8372
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3c.d
@@ -0,0 +1,14 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386 -z call-nop=prefix-nop
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	90                   	nop
+[ 	]*[a-f0-9]+:	e8 ([0-9a-f]{2} ){4} *	call +[a-f0-9]+ <foo>
+#pass
diff --git a/ld/testsuite/ld-i386/call3d.d b/ld/testsuite/ld-i386/call3d.d
new file mode 100644
index 0000000..a9274c8
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3d.d
@@ -0,0 +1,14 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386 -z call-nop=suffix-nop
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	e8 ([0-9a-f]{2} ){4} *	call +[a-f0-9]+ <foo>
+[ 	]*[a-f0-9]+:	90                   	nop
+#pass
diff --git a/ld/testsuite/ld-i386/call3e.d b/ld/testsuite/ld-i386/call3e.d
new file mode 100644
index 0000000..2876b49
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3e.d
@@ -0,0 +1,13 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386 -z call-nop=prefix-0x67
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	67 e8 ([0-9a-f]{2} ){4} *	addr16 call +[a-f0-9]+ <foo>
+#pass
diff --git a/ld/testsuite/ld-i386/call3f.d b/ld/testsuite/ld-i386/call3f.d
new file mode 100644
index 0000000..5ab0cf1
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3f.d
@@ -0,0 +1,14 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386 -z call-nop=prefix-0x90
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	90                   	nop
+[ 	]*[a-f0-9]+:	e8 ([0-9a-f]{2} ){4} *	call +[a-f0-9]+ <foo>
+#pass
diff --git a/ld/testsuite/ld-i386/call3g.d b/ld/testsuite/ld-i386/call3g.d
new file mode 100644
index 0000000..8287770
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3g.d
@@ -0,0 +1,14 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386 -z call-nop=suffix-0x90
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	e8 ([0-9a-f]{2} ){4} *	call +[a-f0-9]+ <foo>
+[ 	]*[a-f0-9]+:	90                   	nop
+#pass
diff --git a/ld/testsuite/ld-i386/call3h.d b/ld/testsuite/ld-i386/call3h.d
new file mode 100644
index 0000000..83f371a
--- /dev/null
+++ b/ld/testsuite/ld-i386/call3h.d
@@ -0,0 +1,14 @@
+#source: call3.s
+#as: --32
+#ld: -melf_i386 -z call-nop=suffix-144
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+#...
+[ 	]*[a-f0-9]+:	e8 ([0-9a-f]{2} ){4} *	call +[a-f0-9]+ <foo>
+[ 	]*[a-f0-9]+:	90                   	nop
+#pass
diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index 3d28dcc..9bf08da 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -296,9 +296,18 @@ run_dump_test "mov1b"
 run_dump_test "branch1"
 run_dump_test "call1"
 run_dump_test "call2"
+run_dump_test "call3a"
+run_dump_test "call3b"
+run_dump_test "call3c"
+run_dump_test "call3d"
+run_dump_test "call3e"
+run_dump_test "call3f"
+run_dump_test "call3g"
+run_dump_test "call3h"
 run_dump_test "jmp1"
 run_dump_test "jmp2"
 run_dump_test "load1"
+run_dump_test "load1-nacl"
 run_dump_test "load2"
 run_dump_test "load3"
 run_dump_test "load4a"
diff --git a/ld/testsuite/ld-i386/load1-nacl.d b/ld/testsuite/ld-i386/load1-nacl.d
new file mode 100644
index 0000000..1245639
--- /dev/null
+++ b/ld/testsuite/ld-i386/load1-nacl.d
@@ -0,0 +1,59 @@
+#source: load1.s
+#as: --32
+#ld: -melf_i386
+#objdump: -dw --sym
+#target: i?86-*-nacl* x86_64-*-nacl*
+
+.*: +file format .*
+
+SYMBOL TABLE:
+#...
+10030080 l     O .data	0+1 bar
+#...
+10030081 g     O .data	0+1 foo
+#...
+
+Disassembly of section .text:
+
+0+20000 <_start>:
+[ 	]*[a-f0-9]+:	8d 05 80 00 03 10    	lea    0x10030080,%eax
+[ 	]*[a-f0-9]+:	81 d0 80 00 03 10    	adc    \$0x10030080,%eax
+[ 	]*[a-f0-9]+:	81 c3 80 00 03 10    	add    \$0x10030080,%ebx
+[ 	]*[a-f0-9]+:	81 e1 80 00 03 10    	and    \$0x10030080,%ecx
+[ 	]*[a-f0-9]+:	81 fa 80 00 03 10    	cmp    \$0x10030080,%edx
+[ 	]*[a-f0-9]+:	81 cf 80 00 03 10    	or     \$0x10030080,%edi
+[ 	]*[a-f0-9]+:	81 de 80 00 03 10    	sbb    \$0x10030080,%esi
+[ 	]*[a-f0-9]+:	81 ed 80 00 03 10    	sub    \$0x10030080,%ebp
+[ 	]*[a-f0-9]+:	81 f4 80 00 03 10    	xor    \$0x10030080,%esp
+[ 	]*[a-f0-9]+:	f7 c1 80 00 03 10    	test   \$0x10030080,%ecx
+[ 	]*[a-f0-9]+:	8d 05 80 00 03 10    	lea    0x10030080,%eax
+[ 	]*[a-f0-9]+:	81 d0 80 00 03 10    	adc    \$0x10030080,%eax
+[ 	]*[a-f0-9]+:	81 c3 80 00 03 10    	add    \$0x10030080,%ebx
+[ 	]*[a-f0-9]+:	81 e1 80 00 03 10    	and    \$0x10030080,%ecx
+[ 	]*[a-f0-9]+:	81 fa 80 00 03 10    	cmp    \$0x10030080,%edx
+[ 	]*[a-f0-9]+:	81 cf 80 00 03 10    	or     \$0x10030080,%edi
+[ 	]*[a-f0-9]+:	81 de 80 00 03 10    	sbb    \$0x10030080,%esi
+[ 	]*[a-f0-9]+:	81 ed 80 00 03 10    	sub    \$0x10030080,%ebp
+[ 	]*[a-f0-9]+:	81 f4 80 00 03 10    	xor    \$0x10030080,%esp
+[ 	]*[a-f0-9]+:	f7 c1 80 00 03 10    	test   \$0x10030080,%ecx
+[ 	]*[a-f0-9]+:	8d 05 81 00 03 10    	lea    0x10030081,%eax
+[ 	]*[a-f0-9]+:	81 d0 81 00 03 10    	adc    \$0x10030081,%eax
+[ 	]*[a-f0-9]+:	81 c3 81 00 03 10    	add    \$0x10030081,%ebx
+[ 	]*[a-f0-9]+:	81 e1 81 00 03 10    	and    \$0x10030081,%ecx
+[ 	]*[a-f0-9]+:	81 fa 81 00 03 10    	cmp    \$0x10030081,%edx
+[ 	]*[a-f0-9]+:	81 cf 81 00 03 10    	or     \$0x10030081,%edi
+[ 	]*[a-f0-9]+:	81 de 81 00 03 10    	sbb    \$0x10030081,%esi
+[ 	]*[a-f0-9]+:	81 ed 81 00 03 10    	sub    \$0x10030081,%ebp
+[ 	]*[a-f0-9]+:	81 f4 81 00 03 10    	xor    \$0x10030081,%esp
+[ 	]*[a-f0-9]+:	f7 c1 81 00 03 10    	test   \$0x10030081,%ecx
+[ 	]*[a-f0-9]+:	8d 05 81 00 03 10    	lea    0x10030081,%eax
+[ 	]*[a-f0-9]+:	81 d0 81 00 03 10    	adc    \$0x10030081,%eax
+[ 	]*[a-f0-9]+:	81 c3 81 00 03 10    	add    \$0x10030081,%ebx
+[ 	]*[a-f0-9]+:	81 e1 81 00 03 10    	and    \$0x10030081,%ecx
+[ 	]*[a-f0-9]+:	81 fa 81 00 03 10    	cmp    \$0x10030081,%edx
+[ 	]*[a-f0-9]+:	81 cf 81 00 03 10    	or     \$0x10030081,%edi
+[ 	]*[a-f0-9]+:	81 de 81 00 03 10    	sbb    \$0x10030081,%esi
+[ 	]*[a-f0-9]+:	81 ed 81 00 03 10    	sub    \$0x10030081,%ebp
+[ 	]*[a-f0-9]+:	81 f4 81 00 03 10    	xor    \$0x10030081,%esp
+[ 	]*[a-f0-9]+:	f7 c1 81 00 03 10    	test   \$0x10030081,%ecx
+#pass
diff --git a/ld/testsuite/ld-i386/load1.d b/ld/testsuite/ld-i386/load1.d
index e93531e..062ea18 100644
--- a/ld/testsuite/ld-i386/load1.d
+++ b/ld/testsuite/ld-i386/load1.d
@@ -1,6 +1,7 @@
 #as: --32
 #ld: -melf_i386
 #objdump: -dw --sym
+#notarget: i?86-*-nacl* x86_64-*-nacl*
 
 .*: +file format .*