cmd/link: support loading R_LARCH_GOT64_PC_{LO12, HI20} relocs on loong64

On loong64, such relocations are increasingly common when built using
an "extreme" code model. To ensure future interoperability with cgo,
the linker needs to be made aware of these relocations.

Ref: https://github.com/loongson/la-abi-specs/blob/release/laelf.adoc

Fixes #78047.

Change-Id: Ibca205ab837279c69fb243a8e8519c952e11c99e
Reviewed-on: https://go-review.googlesource.com/c/go/+/753521
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Meidan Li <limeidan@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>

4 files changed, 62 insertions, 37 deletions

diff --git a/src/cmd/internal/obj/fips140.go b/src/cmd/internal/obj/fips140.go
index b888396b1f..0e4f2a47a3 100644
--- a/src/cmd/internal/obj/fips140.go
+++ b/src/cmd/internal/obj/fips140.go
@@ -356,6 +356,8 @@ func (s *LSym) checkFIPSReloc(ctxt *Link, rel Reloc) {
 		objabi.R_GOTPCREL,
 		objabi.R_LOONG64_ADDR_LO,         // used with PC-relative load
 		objabi.R_LOONG64_ADDR_HI,         // used with PC-relative load
+		objabi.R_LOONG64_ADDR64_LO,       // used with PC-relative load
+		objabi.R_LOONG64_ADDR64_HI,       // used with PC-relative load
 		objabi.R_LOONG64_ADDR_PCREL20_S2, // used with PC-relative load
 		objabi.R_LOONG64_CALL36,
 		objabi.R_LOONG64_TLS_LE_HI,
@@ -364,6 +366,8 @@ func (s *LSym) checkFIPSReloc(ctxt *Link, rel Reloc) {
 		objabi.R_LOONG64_TLS_IE_LO,
 		objabi.R_LOONG64_GOT_HI,
 		objabi.R_LOONG64_GOT_LO,
+		objabi.R_LOONG64_GOT64_HI,
+		objabi.R_LOONG64_GOT64_LO,
 		objabi.R_JMP16LOONG64,
 		objabi.R_JMP21LOONG64,
 		objabi.R_PCREL,
diff --git a/src/cmd/internal/objabi/reloctype.go b/src/cmd/internal/objabi/reloctype.go
index 8e95b5dae2..b6764ff8ef 100644
--- a/src/cmd/internal/objabi/reloctype.go
+++ b/src/cmd/internal/objabi/reloctype.go
@@ -327,13 +327,20 @@ const (
 
 	// Loong64.
 
-	// R_LOONG64_ADDR_HI resolves to the sign-adjusted "upper" 20 bits (bit 5-24) of an
-	// external address, by encoding it into the instruction.
+	// R_LOONG64_ADDR_HI resolves [31...12]bits of 32/64-bit PC-relative offset of an
+	// external address, by encoding it into addi.w/addi.d instruction
 	// R_LOONG64_ADDR_LO resolves to the low 12 bits of an external address, by encoding
-	// it into the instruction.
+	// it into pcalau12i instruction.
 	R_LOONG64_ADDR_HI
 	R_LOONG64_ADDR_LO
 
+	// R_LOONG64_ADDR64_HI resolves [63...52]bits of 64-bit PC-relative offset of an
+	// external address, by encoding it into lu52i.d instruction
+	// R_LOONG64_ADDR64_LO resolves [51...32]bits of 64-bit PC-relative offset of an
+	// external address, by encoding it into lu32i.d instruction
+	R_LOONG64_ADDR64_HI
+	R_LOONG64_ADDR64_LO
+
 	// R_LOONG64_ADDR_PCREL20_S2 resolves to the 22-bit, 4-byte aligned offset of an
 	// external address, by encoding it into a PCADDI instruction.
 	R_LOONG64_ADDR_PCREL20_S2
@@ -358,11 +365,20 @@ const (
 	R_LOONG64_TLS_IE_HI
 	R_LOONG64_TLS_IE_LO
 
-	// R_LOONG64_GOT_HI and R_LOONG64_GOT_LO resolves a GOT-relative instruction sequence,
-	// usually an pcalau12i followed by another ld or addi instruction.
+	// R_LOONG64_GOT_HI resolves [31...12]bits of 32/64-bit PC-relative offset of
+	// GOT entry, by encoding it into pcalau12i instruction
+	// R_LOONG64_GOT_LO resolves [11...0]bits of 32/64-bit PC-relative offset of
+	// GOT entry, by encoding it into ld.w/ld.d instruction
 	R_LOONG64_GOT_HI
 	R_LOONG64_GOT_LO
 
+	// R_LOONG64_GOT64_HI resolves [63...52]bits of 64-bit PC-relative offset of
+	// GOT entry, by encoding it into lu52i.d instruction
+	// R_LOONG64_GOT64_LO resolves [51...32]bits of 64-bit PC-relative offset of
+	// GOT entry, by encoding it into lu32i.d instruction
+	R_LOONG64_GOT64_HI
+	R_LOONG64_GOT64_LO
+
 	// 64-bit in-place addition.
 	R_LOONG64_ADD64
 	// 64-bit in-place subtraction.
diff --git a/src/cmd/internal/objabi/reloctype_string.go b/src/cmd/internal/objabi/reloctype_string.go
index 4152afd92f..c7a5e6c07a 100644
--- a/src/cmd/internal/objabi/reloctype_string.go
+++ b/src/cmd/internal/objabi/reloctype_string.go
@@ -86,40 +86,44 @@ func _() {
 	_ = x[R_PCRELDBL-76]
 	_ = x[R_LOONG64_ADDR_HI-77]
 	_ = x[R_LOONG64_ADDR_LO-78]
-	_ = x[R_LOONG64_ADDR_PCREL20_S2-79]
-	_ = x[R_LOONG64_TLS_LE_HI-80]
-	_ = x[R_LOONG64_TLS_LE_LO-81]
-	_ = x[R_CALLLOONG64-82]
-	_ = x[R_LOONG64_CALL36-83]
-	_ = x[R_LOONG64_TLS_IE_HI-84]
-	_ = x[R_LOONG64_TLS_IE_LO-85]
-	_ = x[R_LOONG64_GOT_HI-86]
-	_ = x[R_LOONG64_GOT_LO-87]
-	_ = x[R_LOONG64_ADD64-88]
-	_ = x[R_LOONG64_SUB64-89]
-	_ = x[R_JMP16LOONG64-90]
-	_ = x[R_JMP21LOONG64-91]
-	_ = x[R_ADDRMIPSU-92]
-	_ = x[R_ADDRMIPSTLS-93]
-	_ = x[R_ADDRCUOFF-94]
-	_ = x[R_WASMIMPORT-95]
-	_ = x[R_XCOFFREF-96]
-	_ = x[R_PEIMAGEOFF-97]
-	_ = x[R_INITORDER-98]
-	_ = x[R_DWTXTADDR_U1-99]
-	_ = x[R_DWTXTADDR_U2-100]
-	_ = x[R_DWTXTADDR_U3-101]
-	_ = x[R_DWTXTADDR_U4-102]
+	_ = x[R_LOONG64_ADDR64_HI-79]
+	_ = x[R_LOONG64_ADDR64_LO-80]
+	_ = x[R_LOONG64_ADDR_PCREL20_S2-81]
+	_ = x[R_LOONG64_TLS_LE_HI-82]
+	_ = x[R_LOONG64_TLS_LE_LO-83]
+	_ = x[R_CALLLOONG64-84]
+	_ = x[R_LOONG64_CALL36-85]
+	_ = x[R_LOONG64_TLS_IE_HI-86]
+	_ = x[R_LOONG64_TLS_IE_LO-87]
+	_ = x[R_LOONG64_GOT_HI-88]
+	_ = x[R_LOONG64_GOT_LO-89]
+	_ = x[R_LOONG64_GOT64_HI-90]
+	_ = x[R_LOONG64_GOT64_LO-91]
+	_ = x[R_LOONG64_ADD64-92]
+	_ = x[R_LOONG64_SUB64-93]
+	_ = x[R_JMP16LOONG64-94]
+	_ = x[R_JMP21LOONG64-95]
+	_ = x[R_ADDRMIPSU-96]
+	_ = x[R_ADDRMIPSTLS-97]
+	_ = x[R_ADDRCUOFF-98]
+	_ = x[R_WASMIMPORT-99]
+	_ = x[R_XCOFFREF-100]
+	_ = x[R_PEIMAGEOFF-101]
+	_ = x[R_INITORDER-102]
+	_ = x[R_DWTXTADDR_U1-103]
+	_ = x[R_DWTXTADDR_U2-104]
+	_ = x[R_DWTXTADDR_U3-105]
+	_ = x[R_DWTXTADDR_U4-106]
 }
 
-const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_USEIFACER_USEIFACEMETHODR_USENAMEDMETHODR_METHODOFFR_KEEPR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_ARM64_GOTR_ARM64_PCRELR_ARM64_PCREL_LDST8R_ARM64_PCREL_LDST16R_ARM64_PCREL_LDST32R_ARM64_PCREL_LDST64R_ARM64_LDST8R_ARM64_LDST16R_ARM64_LDST32R_ARM64_LDST64R_ARM64_LDST128R_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_POWER_TLS_IE_PCREL34R_POWER_TLS_LE_TPREL34R_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_GOT_PCREL34R_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_ADDRPOWER_D34R_ADDRPOWER_PCREL34R_RISCV_JALR_RISCV_JAL_TRAMPR_RISCV_CALLR_RISCV_PCREL_ITYPER_RISCV_PCREL_STYPER_RISCV_TLS_IER_RISCV_TLS_LER_RISCV_GOT_HI20R_RISCV_GOT_PCREL_ITYPER_RISCV_PCREL_HI20R_RISCV_PCREL_LO12_IR_RISCV_PCREL_LO12_SR_RISCV_BRANCHR_RISCV_ADD32R_RISCV_SUB32R_RISCV_RVC_BRANCHR_RISCV_RVC_JUMPR_PCRELDBLR_LOONG64_ADDR_HIR_LOONG64_ADDR_LOR_LOONG64_ADDR_PCREL20_S2R_LOONG64_TLS_LE_HIR_LOONG64_TLS_LE_LOR_CALLLOONG64R_LOONG64_CALL36R_LOONG64_TLS_IE_HIR_LOONG64_TLS_IE_LOR_LOONG64_GOT_HIR_LOONG64_GOT_LOR_LOONG64_ADD64R_LOONG64_SUB64R_JMP16LOONG64R_JMP21LOONG64R_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORTR_XCOFFREFR_PEIMAGEOFFR_INITORDERR_DWTXTADDR_U1R_DWTXTADDR_U2R_DWTXTADDR_U3R_DWTXTADDR_U4"
+const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_USEIFACER_USEIFACEMETHODR_USENAMEDMETHODR_METHODOFFR_KEEPR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_ARM64_GOTR_ARM64_PCRELR_ARM64_PCREL_LDST8R_ARM64_PCREL_LDST16R_ARM64_PCREL_LDST32R_ARM64_PCREL_LDST64R_ARM64_LDST8R_ARM64_LDST16R_ARM64_LDST32R_ARM64_LDST64R_ARM64_LDST128R_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_POWER_TLS_IE_PCREL34R_POWER_TLS_LE_TPREL34R_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_GOT_PCREL34R_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_ADDRPOWER_D34R_ADDRPOWER_PCREL34R_RISCV_JALR_RISCV_JAL_TRAMPR_RISCV_CALLR_RISCV_PCREL_ITYPER_RISCV_PCREL_STYPER_RISCV_TLS_IER_RISCV_TLS_LER_RISCV_GOT_HI20R_RISCV_GOT_PCREL_ITYPER_RISCV_PCREL_HI20R_RISCV_PCREL_LO12_IR_RISCV_PCREL_LO12_SR_RISCV_BRANCHR_RISCV_ADD32R_RISCV_SUB32R_RISCV_RVC_BRANCHR_RISCV_RVC_JUMPR_PCRELDBLR_LOONG64_ADDR_HIR_LOONG64_ADDR_LOR_LOONG64_ADDR64_HIR_LOONG64_ADDR64_LOR_LOONG64_ADDR_PCREL20_S2R_LOONG64_TLS_LE_HIR_LOONG64_TLS_LE_LOR_CALLLOONG64R_LOONG64_CALL36R_LOONG64_TLS_IE_HIR_LOONG64_TLS_IE_LOR_LOONG64_GOT_HIR_LOONG64_GOT_LOR_LOONG64_GOT64_HIR_LOONG64_GOT64_LOR_LOONG64_ADD64R_LOONG64_SUB64R_JMP16LOONG64R_JMP21LOONG64R_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORTR_XCOFFREFR_PEIMAGEOFFR_INITORDERR_DWTXTADDR_U1R_DWTXTADDR_U2R_DWTXTADDR_U3R_DWTXTADDR_U4"
 
-var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 53, 59, 68, 79, 88, 99, 109, 116, 123, 131, 139, 147, 153, 159, 165, 175, 184, 194, 210, 226, 237, 243, 254, 264, 273, 286, 300, 314, 330, 341, 354, 373, 393, 413, 433, 446, 460, 474, 488, 503, 517, 531, 542, 564, 586, 600, 615, 638, 655, 673, 694, 709, 728, 739, 756, 768, 787, 806, 820, 834, 850, 873, 891, 911, 931, 945, 958, 971, 989, 1005, 1015, 1032, 1049, 1074, 1093, 1112, 1125, 1141, 1160, 1179, 1195, 1211, 1226, 1241, 1255, 1269, 1280, 1293, 1304, 1316, 1326, 1338, 1349, 1363, 1377, 1391, 1405}
+var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 53, 59, 68, 79, 88, 99, 109, 116, 123, 131, 139, 147, 153, 159, 165, 175, 184, 194, 210, 226, 237, 243, 254, 264, 273, 286, 300, 314, 330, 341, 354, 373, 393, 413, 433, 446, 460, 474, 488, 503, 517, 531, 542, 564, 586, 600, 615, 638, 655, 673, 694, 709, 728, 739, 756, 768, 787, 806, 820, 834, 850, 873, 891, 911, 931, 945, 958, 971, 989, 1005, 1015, 1032, 1049, 1068, 1087, 1112, 1131, 1150, 1163, 1179, 1198, 1217, 1233, 1249, 1267, 1285, 1300, 1315, 1329, 1343, 1354, 1367, 1378, 1390, 1400, 1412, 1423, 1437, 1451, 1465, 1479}
 
 func (i RelocType) String() string {
-	i -= 1
-	if i < 0 || i >= RelocType(len(_RelocType_index)-1) {
-		return "RelocType(" + strconv.FormatInt(int64(i+1), 10) + ")"
+	idx := int(i) - 1
+	if i < 1 || idx >= len(_RelocType_index)-1 {
+		return "RelocType(" + strconv.FormatInt(int64(i), 10) + ")"
 	}
-	return _RelocType_name[_RelocType_index[i]:_RelocType_index[i+1]]
+	return _RelocType_name[_RelocType_index[idx]:_RelocType_index[idx+1]]
 }
diff --git a/src/cmd/internal/objabi/symkind_string.go b/src/cmd/internal/objabi/symkind_string.go
index fbf6a826a4..a22f9a6a1c 100644
--- a/src/cmd/internal/objabi/symkind_string.go
+++ b/src/cmd/internal/objabi/symkind_string.go
@@ -41,8 +41,9 @@ const _SymKind_name = "SxxxSTEXTSTEXTFIPSSRODATASRODATAFIPSSNOPTRDATASNOPTRDATAF
 var _SymKind_index = [...]uint16{0, 4, 9, 18, 25, 36, 46, 60, 65, 74, 78, 87, 94, 106, 117, 126, 138, 148, 157, 168, 177, 188, 198, 221, 238, 254, 268}
 
 func (i SymKind) String() string {
-	if i >= SymKind(len(_SymKind_index)-1) {
+	idx := int(i) - 0
+	if i < 0 || idx >= len(_SymKind_index)-1 {
 		return "SymKind(" + strconv.FormatInt(int64(i), 10) + ")"
 	}
-	return _SymKind_name[_SymKind_index[i]:_SymKind_index[i+1]]
+	return _SymKind_name[_SymKind_index[idx]:_SymKind_index[idx+1]]
 }