[AArch64] PR18668, repair long branch veneer for plt stub

2015-08-11  Jiong Wang  <jiong.wang@arm.com>
bfd/
   PR ld/18668
   * elfnn-aarch64.c (aarch64_type_of_stub): Update destination for
   calls go through plt stub.
   (elfNN_aarch64_final_link_relocate): Adjust code logic for CALL26,
   JUMP26 relocation to support inserting veneer for call to plt stub.

ld/testsuite/
   * ld-aarch64/farcall-b-gsym.s: New test.
   * ld-aarch64/farcall-b-plt.s: Likewise.
   * ld-aarch64/farcall-bl-plt.s: Likewise.
   * ld-aarch64/farcall-b-gsym.d: New expect file.
   * ld-aarch64/farcall-b-plt.d: Likewise.
   * ld-aarch64/farcall-bl-plt.d: Likewise.

7 files changed, 124 insertions, 0 deletions

diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp
index c8a8aae..b87b198 100644
--- a/ld/testsuite/ld-aarch64/aarch64-elf.exp
+++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp
@@ -127,6 +127,9 @@ run_dump_test "limit-b"
 run_dump_test "limit-bl"
 run_dump_test "farcall-section"
 run_dump_test "farcall-back"
+run_dump_test "farcall-b-gsym"
+run_dump_test "farcall-b-plt"
+run_dump_test "farcall-bl-plt"
 run_dump_test "farcall-bl"
 run_dump_test "farcall-b"
 run_dump_test "farcall-b-none-function"
diff --git a/ld/testsuite/ld-aarch64/farcall-b-gsym.d b/ld/testsuite/ld-aarch64/farcall-b-gsym.d
new file mode 100644
index 0000000..eced18e
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/farcall-b-gsym.d
@@ -0,0 +1,5 @@
+#name: aarch64-farcall-b-gsym
+#source: farcall-b-gsym.s
+#as:
+#ld: -Ttext 0x1000
+#error: .*\(.text\+0x0\): relocation truncated to fit: R_AARCH64_JUMP26 against symbol `bar_gsym'.*
diff --git a/ld/testsuite/ld-aarch64/farcall-b-gsym.s b/ld/testsuite/ld-aarch64/farcall-b-gsym.s
new file mode 100644
index 0000000..b7bfe23
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/farcall-b-gsym.s
@@ -0,0 +1,17 @@
+	.global _start
+	.global bar_gsym
+
+# We will place the section .text at 0x1000.
+
+	.text
+
+_start:
+# for long jump (JUMP26) to global symbol, we shouldn't insert veneer
+# as the veneer will clobber IP0/IP1 which is caller saved, gcc only
+# reserve them for function call relocation (CALL26).
+	b bar_gsym
+	# ((1 << 25) - 1) << 2
+	.skip 134217724, 0
+bar_gsym:
+	nop
+	ret
diff --git a/ld/testsuite/ld-aarch64/farcall-b-plt.d b/ld/testsuite/ld-aarch64/farcall-b-plt.d
new file mode 100644
index 0000000..9e2c891
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/farcall-b-plt.d
@@ -0,0 +1,38 @@
+#name: aarch64-farcall-b-plt
+#source: farcall-b-plt.s
+#as:
+#ld: -shared
+#objdump: -dr
+#...
+
+Disassembly of section .plt:
+
+.* <foo@plt-0x20>:
+.*:	a9bf7bf0 	stp	x16, x30, \[sp,#-16\]!
+.*:	90040090 	adrp	x16, 8010000 <__foo_veneer\+.*>
+.*:	f941f611 	ldr	x17, \[x16,#1000\]
+.*:	910fa210 	add	x16, x16, #0x3e8
+.*:	d61f0220 	br	x17
+.*:	d503201f 	nop
+.*:	d503201f 	nop
+.*:	d503201f 	nop
+
+.* <foo@plt>:
+.*:	90040090 	adrp	x16, 8010000 <__foo_veneer\+.*>
+.*:	f941fa11 	ldr	x17, \[x16,#1008\]
+.*:	910fc210 	add	x16, x16, #0x3f0
+.*:	d61f0220 	br	x17
+
+Disassembly of section .text:
+
+.* <_start>:
+	...
+.*:	14000003 	b	80002c8 <__foo_veneer>
+.*:	d65f03c0 	ret
+.*:	14000007 	b	80002e0 <__foo_veneer\+.*>
+
+.* <__foo_veneer>:
+.*:	90fc0010 	adrp	x16, 0 <foo@plt-0x2b0>
+.*:	910ac210 	add	x16, x16, #0x2b0
+.*:	d61f0200 	br	x16
+	...
diff --git a/ld/testsuite/ld-aarch64/farcall-b-plt.s b/ld/testsuite/ld-aarch64/farcall-b-plt.s
new file mode 100644
index 0000000..227f5f1
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/farcall-b-plt.s
@@ -0,0 +1,11 @@
+	.global _start
+	.global foo
+	.type foo, @function
+	.text
+_start:
+	# ((1 << 25) - 1) << 2
+	# jump26 relocation out of range to plt stub,
+	# we need long branch veneer.
+	.skip 134217724, 0
+	b foo
+	ret
diff --git a/ld/testsuite/ld-aarch64/farcall-bl-plt.d b/ld/testsuite/ld-aarch64/farcall-bl-plt.d
new file mode 100644
index 0000000..205a810
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/farcall-bl-plt.d
@@ -0,0 +1,38 @@
+#name: aarch64-farcall-bl-plt
+#source: farcall-bl-plt.s
+#as:
+#ld: -shared
+#objdump: -dr
+#...
+
+Disassembly of section .plt:
+
+.* <foo@plt-0x20>:
+.*:	a9bf7bf0 	stp	x16, x30, \[sp,#-16\]!
+.*:	90040090 	adrp	x16, 8010000 <__foo_veneer\+.*>
+.*:	f941f611 	ldr	x17, \[x16,#1000\]
+.*:	910fa210 	add	x16, x16, #0x3e8
+.*:	d61f0220 	br	x17
+.*:	d503201f 	nop
+.*:	d503201f 	nop
+.*:	d503201f 	nop
+
+.* <foo@plt>:
+.*:	90040090 	adrp	x16, 8010000 <__foo_veneer\+.*>
+.*:	f941fa11 	ldr	x17, \[x16,#1008\]
+.*:	910fc210 	add	x16, x16, #0x3f0
+.*:	d61f0220 	br	x17
+
+Disassembly of section .text:
+
+.* <_start>:
+	...
+.*:	94000003 	bl	80002c8 <__foo_veneer>
+.*:	d65f03c0 	ret
+.*:	14000007 	b	80002e0 <__foo_veneer\+.*>
+
+.* <__foo_veneer>:
+.*:	90fc0010 	adrp	x16, 0 <foo@plt-0x2b0>
+.*:	910ac210 	add	x16, x16, #0x2b0
+.*:	d61f0200 	br	x16
+	...
diff --git a/ld/testsuite/ld-aarch64/farcall-bl-plt.s b/ld/testsuite/ld-aarch64/farcall-bl-plt.s
new file mode 100644
index 0000000..2cb0dd0
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/farcall-bl-plt.s
@@ -0,0 +1,12 @@
+	.global _start
+	.global foo
+	.type foo, @function
+	.text
+
+_start:
+	# ((1 << 25) - 1) << 2
+	# call26 relocation out of range to plt stub,
+	# we need long branch veneer.
+	.skip 134217724, 0
+	bl foo
+	ret