[AArch64] Also puts value in place for R_AARCH64_RELATIVE

When handling absolute relocations for global symbols bind within the
shared object, AArch64 will generate one dynamic RELATIVE relocation,
but won't apply the value for this absolution relocations at static
linking stage. This is different from AArch64 gold linker and x86-64.

This is not a bug as AArch64 is RELA, there is only guarantee that
relocation addend is placed in the relocation entry.  But some
system softwares originally writen for x86-64 might assume AArch64
bfd linker gets the same behavior as x86-64, then they could take
advantage of this buy skipping those RELATIVE dynamic relocations
if the load address is the same as the static linking address.

This patch makes AArch64 BFD linker applies absolution relocations at
static linking stage for scenario described above.  Meanwhile old AArch64
android loader has a bug (PR19163) which relies on current linker behavior
as a workaround, so the same option --no-apply-dynamic-relocs added.

5 files changed, 59 insertions, 0 deletions

diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp
index b9c4133..b27da52 100644
--- a/ld/testsuite/ld-aarch64/aarch64-elf.exp
+++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp
@@ -285,6 +285,10 @@ run_dump_test "dt_textrel"
 
 run_dump_test "plt_mapping_symbol"
 
+run_dump_test "rela-abs-relative"
+run_dump_test "rela-abs-relative-be"
+run_dump_test "rela-abs-relative-opt"
+
 set aarch64elflinktests {
   {"ld-aarch64/so with global symbol" "-shared" "" "" {copy-reloc-so.s}
     {} "copy-reloc-so.so"}
diff --git a/ld/testsuite/ld-aarch64/rela-abs-relative-be.d b/ld/testsuite/ld-aarch64/rela-abs-relative-be.d
new file mode 100644
index 0000000..88ba58d
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/rela-abs-relative-be.d
@@ -0,0 +1,13 @@
+#name: rela-abs-relative (big endian)
+#source: rela-abs-relative.s
+#ld: -shared -Ttext-segment=0x100000 -Tdata=0x200000 -Trelocs.ld
+#target: aarch64_be-*-*
+#objdump: -dR -j .data
+#...
+
+Disassembly of section .data:
+
+.* <a>:
+  200000:	00 00 00 00 ca fe ca fe 00 00 00 00 00 01 00 ca.*
+			200008: R_AARCH64_RELATIVE	\*ABS\*\+0x100ca
+  200010:	00 00 00 00 de ad de ad.*
diff --git a/ld/testsuite/ld-aarch64/rela-abs-relative-opt.d b/ld/testsuite/ld-aarch64/rela-abs-relative-opt.d
new file mode 100644
index 0000000..a1e5ca0
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/rela-abs-relative-opt.d
@@ -0,0 +1,13 @@
+#name: rela-abs-relative --no-apply-dynamic-relocs
+#source: rela-abs-relative.s
+#ld: -shared -Ttext-segment=0x100000 -Tdata=0x200000 -Trelocs.ld --no-apply-dynamic-relocs
+#notarget: aarch64_be-*-*
+#objdump: -dR -j .data
+#...
+
+Disassembly of section .data:
+
+.* <a>:
+  200000:	fe ca fe ca 00 00 00 00 00 00 00 00 00 00 00 00.*
+			200008: R_AARCH64_RELATIVE	\*ABS\*\+0x100ca
+  200010:	ad de ad de 00 00 00 00.*
diff --git a/ld/testsuite/ld-aarch64/rela-abs-relative.d b/ld/testsuite/ld-aarch64/rela-abs-relative.d
new file mode 100644
index 0000000..aba876b
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/rela-abs-relative.d
@@ -0,0 +1,13 @@
+#name: rela-abs-relative
+#source: rela-abs-relative.s
+#ld: -shared -Ttext-segment=0x100000 -Tdata=0x200000 -Trelocs.ld
+#notarget: aarch64_be-*-*
+#objdump: -dR -j .data
+#...
+
+Disassembly of section .data:
+
+.* <a>:
+  200000:	fe ca fe ca 00 00 00 00 ca 00 01 00 00 00 00 00.*
+			200008: R_AARCH64_RELATIVE	\*ABS\*\+0x100ca
+  200010:	ad de ad de 00 00 00 00.*
diff --git a/ld/testsuite/ld-aarch64/rela-abs-relative.s b/ld/testsuite/ld-aarch64/rela-abs-relative.s
new file mode 100644
index 0000000..d4c4663
--- /dev/null
+++ b/ld/testsuite/ld-aarch64/rela-abs-relative.s
@@ -0,0 +1,16 @@
+	.section	.rodata
+	.align	3
+	.type	string1, %object
+	.size	string1, 8
+local_foo:
+	.string	"local_foo"
+
+	.section	.data,"aw",%progbits
+	.align	3
+	.global	a
+	.type	a, %object
+	.size	a, 24
+a:
+	.xword	0xcafecafe
+	.xword	local_foo + 0xca
+	.xword	0xdeaddead