x86: honor signedness of PC-relative relocations

PR gas/27763

While the comment in output_jump() was basically correct prior to the
introduction of 64-bit mode, both that and the not-JMP-like behavior of
XBEGIN require adjustments: Branches with 32-bit displacement do not
wrap at 4G in 64-bit mode, and XBEGIN with 16-bit operand size doesn't
wrap at 64k. Similarly %rip-relative addressing doesn't wrap at 4G.

The new testcase points out that for PE/COFF object_64bit didn't get
set so far, preventing in particular the check at the end of
md_convert_frag() to take effect.

For Mach-O the new testcase fails (bogusly), in that only the first two
of the expected errors get raised. Since for Mach-O many testcases
already fail, and since an x86_64-darwin target can't even be configured
for, I didn't think I need to bother.

Note that there are further issues in this area, in particular for
branches with operand size overrides. Such branches, which truncate
%rip / %eip, can't be correctly expressed with ordinary PC-relative
relocations. It's not really clear what to do with them - perhaps the
best we can do is to carry through all associated relocations, leaving
it to the linker (or even loader) to decide (once the final address
layout is known). Same perhaps goes for relocations associated with
32-bit addressing in 64-bit mode.

9 files changed, 146 insertions, 0 deletions

diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 0086645..1846c98 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -760,8 +760,12 @@ if [gas_64_check] then {
     } else {
       run_dump_test "x86-64-w64-pcrel"
     }
+    run_list_test "pcrel64" "-al"
     run_dump_test "x86-64-rip"
     run_dump_test "x86-64-rip-intel"
+    run_dump_test "x86-64-rip-2"
+    run_list_test "x86-64-rip-inval-1" "-al"
+    run_list_test "x86-64-rip-inval-2" "-al"
     run_dump_test "x86-64-stack"
     run_dump_test "x86-64-stack-intel"
     run_dump_test "x86-64-stack-suffix"
diff --git a/gas/testsuite/gas/i386/pcrel64.l b/gas/testsuite/gas/i386/pcrel64.l
new file mode 100644
index 0000000..7c2fc64
--- /dev/null
+++ b/gas/testsuite/gas/i386/pcrel64.l
@@ -0,0 +1,54 @@
+.*: Assembler messages:
+.*:16: Error: .*
+.*:17: Error: .*
+.*:13: Error: .*
+.*:15: Error: .*
+.*:18: Error: .*
+.*:19: Error: .*
+.*:20: Error: .*
+GAS LISTING .*
+
+
+[ 	]*[0-9]+[ 	]+\.text
+[ 	]*[0-9]+[ 	]+\.code64
+[ 	]*[0-9]+[ 	]+pcrel:
+[ 	]*[0-9]+ \?\?\?\? E8..8000[ 	]+call	target
+[ 	]*[0-9]+[ 	]+00
+[ 	]*[0-9]+ \?\?\?\? E9..8000[ 	]+jmp	target
+[ 	]*[0-9]+[ 	]+00
+[ 	]*[0-9]+ \?\?\?\? 0F84..80[ 	]+jz	target
+[ 	]*[0-9]+[ 	]+0000
+[ 	]*[0-9]+ \?\?\?\? C7F8..80[ 	]+xbegin	target
+[ 	]*[0-9]+[ 	]+0000
+[ 	]*[0-9]+ \?\?\?\? 8B05..80[ 	]+mov	target\(%rip\), %eax
+[ 	]*[0-9]+[ 	]+0000
+[ 	]*[0-9]+ \?\?\?\? 678B05..[ 	]+mov	target\(%eip\), %eax
+[ 	]*[0-9]+[ 	]+800000
+[ 	]*[0-9]+ \?\?\?\? 48C7C0..[ 	]+mov	\$target-., %rax
+[ 	]*[0-9]+[ 	]+800000
+[ 	]*[0-9]+ \?\?\?\? B8..8000[ 	]+mov	\$target-., %eax
+[ 	]*[0-9]+[ 	]+00
+[ 	]*[0-9]+[ 	]*
+[ 	]*[0-9]+ \?\?\?\? 66C7F8..[ 	]+data16 xbegin target
+[ 	]*[0-9]+[ 	]+80
+[ 	]*[0-9]+[ 	]*
+[ 	]*[0-9]+ \?\?\?\? E8...000[ 	]+call	target\+0x7ffff000
+[ 	]*[0-9]+[ 	]+80
+[ 	]*[0-9]+ \?\?\?\? E9000000[ 	]+jmp	target\+0x7ffff000
+[ 	]*[0-9]+[ 	]+00
+[ 	]*[0-9]+ \?\?\?\? 0F840000[ 	]+jz	target\+0x7ffff000
+[ 	]*[0-9]+[ 	]+0000
+[ 	]*[0-9]+ \?\?\?\? C7F8...0[ 	]+xbegin	target\+0x7ffff000
+[ 	]*[0-9]+[ 	]+0080
+[ 	]*[0-9]+ \?\?\?\? 8B05...0[ 	]+mov	target\+0x7ffff000\(%rip\), %eax
+[ 	]*[0-9]+[ 	]+0080
+[ 	]*[0-9]+ \?\?\?\? 48C7C0..[ 	]+mov	\$target\+0x7ffff000-., %rax
+[ 	]*[0-9]+[ 	]+.00080
+[ 	]*[0-9]+[ 	]*
+[ 	]*[0-9]+ \?\?\?\? 678B05..[ 	]+mov	target\+0x7ffff000\(%eip\), %eax
+[ 	]*[0-9]+[ 	]+.00080
+[ 	]*[0-9]+ \?\?\?\? B8...000[ 	]+mov	\$target\+0x7ffff000-., %eax
+[ 	]*[0-9]+[ 	]+80
+[ 	]*[0-9]+[ 	]*
+[ 	]*[0-9]+ \?\?\?\? CCCCCCCC[ 	]+\.fill 0x8000, 1, 0xcc
+#pass
diff --git a/gas/testsuite/gas/i386/pcrel64.s b/gas/testsuite/gas/i386/pcrel64.s
new file mode 100644
index 0000000..831ee40
--- /dev/null
+++ b/gas/testsuite/gas/i386/pcrel64.s
@@ -0,0 +1,27 @@
+	.text
+	.code64
+pcrel:
+	call	target
+	jmp	target
+	jz	target
+	xbegin	target
+	mov	target(%rip), %eax
+	mov	target(%eip), %eax
+	mov	$target-., %rax
+	mov	$target-., %eax
+
+	data16 xbegin target
+
+	call	target+0x7ffff000
+	jmp	target+0x7ffff000
+	jz	target+0x7ffff000
+	xbegin	target+0x7ffff000
+	mov	target+0x7ffff000(%rip), %eax
+	mov	$target+0x7ffff000-., %rax
+
+	mov	target+0x7ffff000(%eip), %eax
+	mov	$target+0x7ffff000-., %eax
+
+	.fill 0x8000, 1, 0xcc
+target:
+	ret
diff --git a/gas/testsuite/gas/i386/x86-64-rip-2.d b/gas/testsuite/gas/i386/x86-64-rip-2.d
new file mode 100644
index 0000000..bf9ca39
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-rip-2.d
@@ -0,0 +1,21 @@
+#as: -J
+#objdump: -drw --syms
+#name: x86-64 rip addressing 2
+
+.*: +file format .*
+
+SYMBOL TABLE:
+0000000000000000 l       .text	0000000000000000 _start
+0000000080000006 l       .text	0000000000000000 test1
+ffffffff8000000e l       .text	0000000000000000 test2
+00000000f000000e l       .text	0000000000000000 test3
+ffffffff1000000e l       .text	0000000000000000 test4
+
+
+
+Disassembly of section .text:
+
+0000000000000000 <_start>:
+ +0:	48 8b 05 ff ff ff 7f 	mov    0x7fffffff\(%rip\),%rax        # 80000006 <test1>
+ +7:	48 8b 05 00 00 00 80 	mov    -0x80000000\(%rip\),%rax        # ffffffff8000000e <test2>
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-rip-2.s b/gas/testsuite/gas/i386/x86-64-rip-2.s
new file mode 100644
index 0000000..5ce80e8
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-rip-2.s
@@ -0,0 +1,10 @@
+	.text
+_start:
+	movq test1(%rip), %rax
+	.set test1, . + 0x7fffffff
+
+	movq test2(%rip), %rax
+	.set test2, . - 0x80000000
+
+	.set test3, . + 0xf0000000
+	.set test4, . - 0xf0000000
diff --git a/gas/testsuite/gas/i386/x86-64-rip-inval-1.l b/gas/testsuite/gas/i386/x86-64-rip-inval-1.l
new file mode 100644
index 0000000..d40099e
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-rip-inval-1.l
@@ -0,0 +1,11 @@
+.*: Assembler messages:
+.*:3: Error:.* (0x)?ffffffff7fffffff .*
+GAS LISTING .*
+
+
+[ 	]*1[ 	]+\.text
+[ 	]*2[ 	]+_start:
+[ 	]*3[ 	]+\?\?\?\? 488B05FF 		movq test1\(%rip\), %rax
+[ 	]*3[ 	]+FFFF7F
+[ 	]*4[ 	]+\.set test1, \. - 0x80000001
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-rip-inval-1.s b/gas/testsuite/gas/i386/x86-64-rip-inval-1.s
new file mode 100644
index 0000000..a0e783e
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-rip-inval-1.s
@@ -0,0 +1,4 @@
+	.text
+_start:
+	movq test1(%rip), %rax
+	.set test1, . - 0x80000001
diff --git a/gas/testsuite/gas/i386/x86-64-rip-inval-2.l b/gas/testsuite/gas/i386/x86-64-rip-inval-2.l
new file mode 100644
index 0000000..e724393
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-rip-inval-2.l
@@ -0,0 +1,11 @@
+.*: Assembler messages:
+.*:3: Error:.* (0x)?0*80000000 .*
+GAS LISTING .*
+
+
+[ 	]*1[ 	]+\.text
+[ 	]*2[ 	]+_start:
+[ 	]*3[ 	]+\?\?\?\? 488B0500 		movq test1\(%rip\), %rax
+[ 	]*3[ 	]+000080
+[ 	]*4[ 	]+\.set test1, \. \+ 0x80000000
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-rip-inval-2.s b/gas/testsuite/gas/i386/x86-64-rip-inval-2.s
new file mode 100644
index 0000000..9bdc703
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-rip-inval-2.s
@@ -0,0 +1,4 @@
+	.text
+_start:
+	movq test1(%rip), %rax
+	.set test1, . + 0x80000000