RISC-V: Clarify link behaviors of R_RISCV_32/64 relocations with ABS symbol.

There are two improvements, which are all referenced to aarch64,

* R_RISCV_32 with non ABS symbol cannot be used under RV64 when making
  shard objects.

* Don't need dynamic relocation for R_RISCV_32/64 under RV32/RV64 when
  making shared objects, if the referenced symbol is local ABS symbol.

However, considering this link,
https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/341

Seems like we should makes all R_RISCV_32/64 relocs with ABS symbol
that don't need any dynamic relocations when making the shared objects.
But anyway, I just sync the current behavior as aarch64 ld, in case
there are any unexpected behaviors happen.

Passed the gcc/binutils regressions in riscv-gnu-toolchain.

bfd/
    * elfnn-riscv.c (riscv_elf_check_relocs): Only allow R_RISCV_32 with ABS
    symbol under RV64.
    (riscv_elf_relocate_section): R_RISCV_32/64 with local ABS symbol under
    RV32/RV64 doesn't need any dynamic relocation when making shared objects.
    I just make the implementations similar to other targets, so that will be
    more easy to mainatain.
ld/
    * testsuite/ld-riscv-elf/data-reloc*: New testcases.
    * testsuite/ld-riscv-elf/ld-riscv-elf.exp: Added new data-reloc* testcases,
    and need to make ifunc-seperate* testcases work for rv32.
    * testsuite/ld-riscv-elf/ifunc-seperate-caller-nonplt.s: Likewise.
    * testsuite/ld-riscv-elf/ifunc-seperate-caller-plt.s: Likewise.

13 files changed, 183 insertions, 2 deletions

diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv32-pic.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv32-pic.d
new file mode 100644
index 0000000..13f34e0
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv32-pic.d
@@ -0,0 +1,21 @@
+#source: data-reloc.s
+#as: -march=rv32i -mabi=ilp32 -defsym __abs__=1 -defsym __addr__=1 -defsym __undef__=1
+#ld: -m[riscv_choose_ilp32_emul] -Ttext 0x8000 --defsym _start=0x0 --defsym abs=0x100 --defsym abs_local=0x200 -shared
+#objdump: -dR
+
+.*:[ 	]+file format .*
+
+
+Disassembly of section .text:
+
+0+8000 <addr_globl>:
+    8000:	00000000          	.word	0x00000000
+			8000: R_RISCV_32	addr_globl
+
+0+8004 <addr_local>:
+	...
+			8004: R_RISCV_RELATIVE	\*ABS\*\+0x8004
+			8008: R_RISCV_32	abs
+    800c:	00000200          	.word	0x00000200
+    8010:	00000000          	.word	0x00000000
+			8010: R_RISCV_32	undef
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv32-pie.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv32-pie.d
new file mode 100644
index 0000000..1e8f35a
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv32-pie.d
@@ -0,0 +1,18 @@
+#source: data-reloc.s
+#as: -march=rv32i -mabi=ilp32 -defsym __abs__=1 -defsym __addr__=1
+#ld: -m[riscv_choose_ilp32_emul] -Ttext 0x8000 --defsym _start=0x0 --defsym abs=0x100 --defsym abs_local=0x200 -pie
+#objdump: -dR
+
+.*:[ 	]+file format .*
+
+Disassembly of section .text:
+
+0+8000 <addr_globl>:
+    8000:	00000000          	.word	0x00000000
+			8000: R_RISCV_RELATIVE	\*ABS\*\+0x8000
+
+0+8004 <addr_local>:
+    8004:	00000000          	.word	0x00000000
+			8004: R_RISCV_RELATIVE	\*ABS\*\+0x8004
+    8008:	00000100          	.word	0x00000100
+    800c:	00000200          	.word	0x00000200
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv32-symbolic.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv32-symbolic.d
new file mode 100644
index 0000000..5c947e2
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv32-symbolic.d
@@ -0,0 +1,21 @@
+#source: data-reloc.s
+#as: -march=rv32i -mabi=ilp32 -defsym __abs__=1 -defsym __addr__=1 -defsym __undef__=1
+#ld: -m[riscv_choose_ilp32_emul] -Ttext 0x8000 --defsym _start=0x0 --defsym abs=0x100 --defsym abs_local=0x200 -shared -Bsymbolic
+#objdump: -dR
+
+.*:[ 	]+file format .*
+
+
+Disassembly of section .text:
+
+0+8000 <addr_globl>:
+    8000:	00000000          	.word	0x00000000
+			8000: R_RISCV_RELATIVE	\*ABS\*\+0x8000
+
+0+8004 <addr_local>:
+	...
+			8004: R_RISCV_RELATIVE	\*ABS\*\+0x8004
+			8008: R_RISCV_RELATIVE	\*ABS\*\+0x100
+    800c:	00000200          	.word	0x00000200
+    8010:	00000000          	.word	0x00000000
+			8010: R_RISCV_32	undef
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv64-abs32-pic.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-abs32-pic.d
new file mode 100644
index 0000000..1d3686d
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-abs32-pic.d
@@ -0,0 +1,13 @@
+#source: data-reloc.s
+#as: -march=rv64i -mabi=lp64 -defsym __abs__=1
+#ld: -m[riscv_choose_lp64_emul] -Ttext 0x8000 --defsym _start=0x0 --defsym abs=0x100 --defsym abs_local=0x200 -shared
+#objdump: -dR
+
+.*:[ 	]+file format .*
+
+
+Disassembly of section .text:
+
+0+8000 <.text>:
+    8000:	00000100          	.word	0x00000100
+    8004:	00000200          	.word	0x00000200
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv64-addr32-pic.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-addr32-pic.d
new file mode 100644
index 0000000..39b50e3
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-addr32-pic.d
@@ -0,0 +1,4 @@
+#source: data-reloc.s
+#as: -march=rv64i -mabi=lp64 -defsym __addr__=1
+#ld: -m[riscv_choose_lp64_emul] -Ttext 0x8000 --defsym _start=0x0  -shared
+#error: .*relocation R_RISCV_32 against non-absolute symbol `addr_globl' can not be used in RV64 when making a shared object.*
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv64-pic.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-pic.d
new file mode 100644
index 0000000..dab0ccc
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-pic.d
@@ -0,0 +1,21 @@
+#source: data-reloc.s
+#as: -march=rv64i -mabi=lp64 -defsym __64_bit__=1 -defsym __abs__=1 -defsym __addr__=1 -defsym __undef__=1
+#ld: -m[riscv_choose_lp64_emul] -Ttext 0x8000 --defsym _start=0x0 --defsym abs=0x100 --defsym abs_local=0x200 -shared
+#objdump: -dR
+
+.*:[ 	]+file format .*
+
+
+Disassembly of section .text:
+
+0+8000 <addr_globl>:
+	...
+			8000: R_RISCV_64	addr_globl
+
+0+8008 <addr_local>:
+	...
+			8008: R_RISCV_RELATIVE	\*ABS\*\+0x8008
+			8010: R_RISCV_64	abs
+    8018:	00000200          	.word	0x00000200
+	...
+			8020: R_RISCV_64	undef
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv64-pie.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-pie.d
new file mode 100644
index 0000000..fd6c470
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-pie.d
@@ -0,0 +1,21 @@
+#source: data-reloc.s
+#as: -march=rv64i -mabi=lp64 -defsym __64_bit__=1 -defsym __abs__=1 -defsym __addr__=1
+#ld: -m[riscv_choose_lp64_emul] -Ttext 0x8000 --defsym _start=0x0 --defsym abs=0x100 --defsym abs_local=0x200 -pie
+#objdump: -dR
+
+.*:[ 	]+file format .*
+
+
+Disassembly of section .text:
+
+0+8000 <addr_globl>:
+	...
+			8000: R_RISCV_RELATIVE	\*ABS\*\+0x8000
+
+0+8008 <addr_local>:
+	...
+			8008: R_RISCV_RELATIVE	\*ABS\*\+0x8008
+    8010:	00000100          	.word	0x00000100
+    8014:	00000000          	.word	0x00000000
+    8018:	00000200          	.word	0x00000200
+    801c:	00000000          	.word	0x00000000
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv64-symbolic.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-symbolic.d
new file mode 100644
index 0000000..5d41f86
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-symbolic.d
@@ -0,0 +1,21 @@
+#source: data-reloc.s
+#as: -march=rv64i -mabi=lp64 -defsym __64_bit__=1 -defsym __abs__=1 -defsym __addr__=1 -defsym __undef__=1
+#ld: -m[riscv_choose_lp64_emul] -Ttext 0x8000 --defsym _start=0x0 --defsym abs=0x100 --defsym abs_local=0x200 -shared -Bsymbolic
+#objdump: -dR
+
+.*:[ 	]+file format .*
+
+
+Disassembly of section .text:
+
+0+8000 <addr_globl>:
+	...
+			8000: R_RISCV_RELATIVE	\*ABS\*\+0x8000
+
+0+8008 <addr_local>:
+	...
+			8008: R_RISCV_RELATIVE	\*ABS\*\+0x8008
+			8010: R_RISCV_RELATIVE	\*ABS\*\+0x100
+    8018:	00000200          	.word	0x00000200
+	...
+			8020: R_RISCV_64	undef
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc-rv64-undef32-pic.d b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-undef32-pic.d
new file mode 100644
index 0000000..e5de484
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc-rv64-undef32-pic.d
@@ -0,0 +1,4 @@
+#source: data-reloc.s
+#as: -march=rv64i -mabi=lp64 -defsym __undef__=1
+#ld: -m[riscv_choose_lp64_emul] -Ttext 0x8000 --defsym _start=0x0  -shared
+#error: .*relocation R_RISCV_32 against non-absolute symbol `undef' can not be used in RV64 when making a shared object.*
diff --git a/ld/testsuite/ld-riscv-elf/data-reloc.s b/ld/testsuite/ld-riscv-elf/data-reloc.s
new file mode 100644
index 0000000..3715150
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/data-reloc.s
@@ -0,0 +1,22 @@
+	.macro	DATA symbol
+.ifdef __64_bit__
+	.quad	\symbol
+.else
+	.word	\symbol
+.endif
+	.endm
+.ifdef __addr__
+	.globl  addr_globl
+addr_globl:
+	DATA	addr_globl
+addr_local:
+	DATA	addr_local
+.endif
+.ifdef __abs__
+	.hidden abs_local
+	DATA	abs
+	DATA	abs_local
+.endif
+.ifdef __undef__
+	DATA	undef
+.endif
diff --git a/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-nonplt.s b/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-nonplt.s
index 23c7254..df0d33b 100644
--- a/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-nonplt.s
+++ b/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-nonplt.s
@@ -20,4 +20,4 @@ main:
 
 	.data
 foo_addr:
-	.long	foo
+	.quad	foo
diff --git a/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-plt.s b/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-plt.s
index 8aa6403..cc1608a 100644
--- a/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-plt.s
+++ b/ld/testsuite/ld-riscv-elf/ifunc-seperate-caller-plt.s
@@ -23,4 +23,4 @@ main:
 
 	.data
 foo_addr:
-	.long	foo
+	.quad	foo
diff --git a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
index 5dd6144..1b2a5ce 100644
--- a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
+++ b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
@@ -217,6 +217,16 @@ if [istarget "riscv*-*-*"] {
     run_dump_test "shared-lib-nopic-03"
     run_dump_test "shared-lib-nopic-04"
 
+    run_dump_test "data-reloc-rv64-pic"
+    run_dump_test "data-reloc-rv64-pie"
+    run_dump_test "data-reloc-rv64-symbolic"
+    run_dump_test "data-reloc-rv32-pic"
+    run_dump_test "data-reloc-rv32-pie"
+    run_dump_test "data-reloc-rv32-symbolic"
+    run_dump_test "data-reloc-rv64-abs32-pic"
+    run_dump_test "data-reloc-rv64-addr32-pic"
+    run_dump_test "data-reloc-rv64-undef32-pic"
+
     # IFUNC testcases.
     # Check IFUNC by single type relocs.
     run_dump_test_ifunc "ifunc-reloc-call-01" rv32 exe
@@ -270,6 +280,11 @@ if [istarget "riscv*-*-*"] {
     run_dump_test_ifunc "ifunc-plt-got-overwrite" rv64 pie
     run_dump_test_ifunc "ifunc-plt-got-overwrite" rv64 pic
 
+    # TODO: Make the following tests work under RV32.
+    if [istarget "riscv32-*-*"] {
+      return
+    }
+
     # Setup shared libraries.
     run_ld_link_tests {
        { "Build shared library for IFUNC non-PLT caller"