]> Cypherpunks repositories - gostls13.git/commitdiff
cmd/link: support PIE mode with internal link on linux arm64
authorerifan01 <eric.fang@arm.com>
Wed, 26 Sep 2018 10:12:18 +0000 (10:12 +0000)
committerCherry Zhang <cherryyz@google.com>
Thu, 2 May 2019 15:38:36 +0000 (15:38 +0000)
This CL improves internal link to provide basic support for cgo and PIE:
1, add support for GOT, PLT and GOTPLT.
2, add support for following ELF relocation types which have been used by std
   packages:
     R_AARCH64_ADR_GOT_PAGE
     R_AARCH64_LD64_GOT_LO12_NC
     R_AARCH64_ADR_PREL_PG_HI21
     R_AARCH64_ADD_ABS_LO12_NC
     R_AARCH64_LDST8_ABS_LO12_NC
     R_AARCH64_LDST32_ABS_LO12_NC
     R_AARCH64_LDST64_ABS_LO12_NC
     R_AARCH64_JUMP26
     R_AARCH64_ABS64
     R_AARCH64_PREL32
     R_AARCH64_PREL64

With this change, Go toolchain can be built in internal linking mode, and
pure Go programs can be built with PIE mode in internal linking mode on arm64.

Updates #10373
The prototype of this CL is contributed by Wei Xiao <wei.xiao@arm.com>

Change-Id: I2253923c69e855fd1524d54def309a961dce6247
Reviewed-on: https://go-review.googlesource.com/c/go/+/163579
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>

src/cmd/dist/test.go
src/cmd/internal/objabi/reloctype.go
src/cmd/internal/objabi/reloctype_string.go
src/cmd/link/internal/arm64/asm.go
src/cmd/link/internal/ld/config.go
src/cmd/link/internal/ld/lib.go
src/cmd/link/internal/loadelf/ldelf.go

index 577a20bf42db51f392acab4a8a4ca2edcff6eb7f..1309a0acdf8c557f71886e3ed24070f6c3f3b418 100644 (file)
@@ -569,7 +569,7 @@ func (t *tester) registerTests() {
        }
 
        // Test internal linking of PIE binaries where it is supported.
-       if goos == "linux" && goarch == "amd64" {
+       if goos == "linux" && (goarch == "amd64" || goarch == "arm64") {
                t.tests = append(t.tests, distTest{
                        name:    "pie_internal",
                        heading: "internal linking of -buildmode=pie",
@@ -910,7 +910,7 @@ func (t *tester) internalLink() bool {
        // Internally linking cgo is incomplete on some architectures.
        // https://golang.org/issue/10373
        // https://golang.org/issue/14449
-       if goarch == "arm64" || goarch == "mips64" || goarch == "mips64le" || goarch == "mips" || goarch == "mipsle" {
+       if goarch == "mips64" || goarch == "mips64le" || goarch == "mips" || goarch == "mipsle" {
                return false
        }
        if goos == "aix" {
@@ -1030,7 +1030,7 @@ func (t *tester) cgoTest(dt *distTest) error {
                "dragonfly-amd64",
                "freebsd-386", "freebsd-amd64", "freebsd-arm",
                "linux-386", "linux-amd64", "linux-arm", "linux-ppc64le", "linux-s390x",
-               "netbsd-386", "netbsd-amd64":
+               "netbsd-386", "netbsd-amd64", "linux-arm64":
 
                cmd := t.addCmd(dt, "misc/cgo/test", t.goTest())
                cmd.Env = append(os.Environ(), "GOFLAGS=-ldflags=-linkmode=external")
index 94d5469d9cec92d92a33b291400eaa3115e213c5..a28b48ba50cde6fb843c1683eb56693ba6ffaee1 100644 (file)
@@ -132,6 +132,23 @@ const (
        // slot of the referenced symbol.
        R_ARM64_GOTPCREL
 
+       // R_ARM64_GOT resolves a GOT-relative instruction sequence, usually an adrp
+       // followed by another ld instruction.
+       R_ARM64_GOT
+
+       // R_ARM64_PCREL resolves a PC-relative addresses instruction sequence, usually an
+       // adrp followed by another add instruction.
+       R_ARM64_PCREL
+
+       // R_ARM64_LDST8 sets a LD/ST immediate value to bits [11:0] of a local address.
+       R_ARM64_LDST8
+
+       // R_ARM64_LDST32 sets a LD/ST immediate value to bits [11:2] of a local address.
+       R_ARM64_LDST32
+
+       // R_ARM64_LDST64 sets a LD/ST immediate value to bits [11:3] of a local address.
+       R_ARM64_LDST64
+
        // PPC64.
 
        // R_POWER_TLS_LE is used to implement the "local exec" model for tls
index 2cd3a9404546a117637e008a48e16f6f26af2da4..bd6d28561722698fb9979cf2819a37b5b6a7df42 100644 (file)
@@ -1,12 +1,12 @@
-// Code generated by "stringer -type=RelocType"; DO NOT EDIT.
+// Code generated by "stringer -type RelocType"; DO NOT EDIT.
 
 package objabi
 
 import "strconv"
 
-const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_WEAKADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_METHODOFFR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_DWARFFILEREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_PCRELDBLR_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORT"
+const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_WEAKADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_METHODOFFR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_DWARFFILEREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_ARM64_GOTR_ARM64_PCRELR_ARM64_LDST8R_ARM64_LDST32R_ARM64_LDST64R_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_PCRELDBLR_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORTR_XCOFFREF"
 
-var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 60, 66, 72, 81, 92, 101, 112, 122, 129, 136, 144, 152, 160, 166, 172, 178, 188, 197, 208, 219, 229, 238, 251, 265, 279, 293, 309, 323, 337, 348, 362, 377, 394, 412, 433, 443, 454, 467, 478, 490}
+var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 60, 66, 72, 81, 92, 101, 112, 122, 129, 136, 144, 152, 160, 166, 172, 178, 188, 197, 208, 219, 229, 238, 251, 265, 279, 293, 309, 320, 333, 346, 360, 374, 388, 402, 413, 427, 442, 459, 477, 498, 508, 519, 532, 543, 555, 565}
 
 func (i RelocType) String() string {
        i -= 1
index 778946cbfdc6d32d850ffae3687a961013944220..c0e69ea02357eaa8d379db1eec3784ffd5f43d6d 100644 (file)
@@ -92,11 +92,110 @@ func gentext(ctxt *ld.Link) {
        initarray_entry.AddAddr(ctxt.Arch, initfunc)
 }
 
-// adddynrel implements just enough to support external linking to
-// the system libc functions used by the runtime.
 func adddynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool {
        targ := r.Sym
 
+       switch r.Type {
+       default:
+               if r.Type >= objabi.ElfRelocOffset {
+                       ld.Errorf(s, "unexpected relocation type %d (%s)", r.Type, sym.RelocName(ctxt.Arch, r.Type))
+                       return false
+               }
+
+       // Handle relocations found in ELF object files.
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_PREL32):
+               if targ.Type == sym.SDYNIMPORT {
+                       ld.Errorf(s, "unexpected R_AARCH64_PREL32 relocation for dynamic symbol %s", targ.Name)
+               }
+               // TODO(mwhudson): the test of VisibilityHidden here probably doesn't make
+               // sense and should be removed when someone has thought about it properly.
+               if (targ.Type == 0 || targ.Type == sym.SXREF) && !targ.Attr.VisibilityHidden() {
+                       ld.Errorf(s, "unknown symbol %s in pcrel", targ.Name)
+               }
+               r.Type = objabi.R_PCREL
+               r.Add += 4
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_PREL64):
+               if targ.Type == sym.SDYNIMPORT {
+                       ld.Errorf(s, "unexpected R_AARCH64_PREL64 relocation for dynamic symbol %s", targ.Name)
+               }
+               if targ.Type == 0 || targ.Type == sym.SXREF {
+                       ld.Errorf(s, "unknown symbol %s in pcrel", targ.Name)
+               }
+               r.Type = objabi.R_PCREL
+               r.Add += 8
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_CALL26),
+               objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_JUMP26):
+               if targ.Type == sym.SDYNIMPORT {
+                       addpltsym(ctxt, targ)
+                       r.Sym = ctxt.Syms.Lookup(".plt", 0)
+                       r.Add += int64(targ.Plt())
+               }
+               if (targ.Type == 0 || targ.Type == sym.SXREF) && !targ.Attr.VisibilityHidden() {
+                       ld.Errorf(s, "unknown symbol %s in callarm64", targ.Name)
+               }
+               r.Type = objabi.R_CALLARM64
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADR_GOT_PAGE),
+               objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LD64_GOT_LO12_NC):
+               if targ.Type != sym.SDYNIMPORT {
+                       // have symbol
+                       // TODO: turn LDR of GOT entry into ADR of symbol itself
+               }
+
+               // fall back to using GOT
+               // TODO: just needs relocation, no need to put in .dynsym
+               addgotsym(ctxt, targ)
+
+               r.Type = objabi.R_ARM64_GOT
+               r.Sym = ctxt.Syms.Lookup(".got", 0)
+               r.Add += int64(targ.Got())
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADR_PREL_PG_HI21),
+               objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ADD_ABS_LO12_NC):
+               if targ.Type == sym.SDYNIMPORT {
+                       ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
+               }
+               if targ.Type == 0 || targ.Type == sym.SXREF {
+                       ld.Errorf(s, "unknown symbol %s", targ.Name)
+               }
+               r.Type = objabi.R_ARM64_PCREL
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_ABS64):
+               if targ.Type == sym.SDYNIMPORT {
+                       ld.Errorf(s, "unexpected R_AARCH64_ABS64 relocation for dynamic symbol %s", targ.Name)
+               }
+               r.Type = objabi.R_ADDR
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST8_ABS_LO12_NC):
+               if targ.Type == sym.SDYNIMPORT {
+                       ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
+               }
+               r.Type = objabi.R_ARM64_LDST8
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST32_ABS_LO12_NC):
+               if targ.Type == sym.SDYNIMPORT {
+                       ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
+               }
+               r.Type = objabi.R_ARM64_LDST32
+               return true
+
+       case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST64_ABS_LO12_NC):
+               if targ.Type == sym.SDYNIMPORT {
+                       ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
+               }
+               r.Type = objabi.R_ARM64_LDST64
+               return true
+       }
+
        switch r.Type {
        case objabi.R_CALL,
                objabi.R_PCREL,
@@ -109,8 +208,85 @@ func adddynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool {
                        // External linker will do this relocation.
                        return true
                }
+
+       case objabi.R_ADDR:
+               if s.Type == sym.STEXT && ctxt.IsELF {
+                       // The code is asking for the address of an external
+                       // function. We provide it with the address of the
+                       // correspondent GOT symbol.
+                       addgotsym(ctxt, targ)
+
+                       r.Sym = ctxt.Syms.Lookup(".got", 0)
+                       r.Add += int64(targ.Got())
+                       return true
+               }
+
+               // Process dynamic relocations for the data sections.
+               if ctxt.BuildMode == ld.BuildModePIE && ctxt.LinkMode == ld.LinkInternal {
+                       // When internally linking, generate dynamic relocations
+                       // for all typical R_ADDR relocations. The exception
+                       // are those R_ADDR that are created as part of generating
+                       // the dynamic relocations and must be resolved statically.
+                       //
+                       // There are three phases relevant to understanding this:
+                       //
+                       //      dodata()  // we are here
+                       //      address() // symbol address assignment
+                       //      reloc()   // resolution of static R_ADDR relocs
+                       //
+                       // At this point symbol addresses have not been
+                       // assigned yet (as the final size of the .rela section
+                       // will affect the addresses), and so we cannot write
+                       // the Elf64_Rela.r_offset now. Instead we delay it
+                       // until after the 'address' phase of the linker is
+                       // complete. We do this via Addaddrplus, which creates
+                       // a new R_ADDR relocation which will be resolved in
+                       // the 'reloc' phase.
+                       //
+                       // These synthetic static R_ADDR relocs must be skipped
+                       // now, or else we will be caught in an infinite loop
+                       // of generating synthetic relocs for our synthetic
+                       // relocs.
+                       //
+                       // Furthermore, the rela sections contain dynamic
+                       // relocations with R_ADDR relocations on
+                       // Elf64_Rela.r_offset. This field should contain the
+                       // symbol offset as determined by reloc(), not the
+                       // final dynamically linked address as a dynamic
+                       // relocation would provide.
+                       switch s.Name {
+                       case ".dynsym", ".rela", ".rela.plt", ".got.plt", ".dynamic":
+                               return false
+                       }
+               } else {
+                       // Either internally linking a static executable,
+                       // in which case we can resolve these relocations
+                       // statically in the 'reloc' phase, or externally
+                       // linking, in which case the relocation will be
+                       // prepared in the 'reloc' phase and passed to the
+                       // external linker in the 'asmb' phase.
+                       if s.Type != sym.SDATA && s.Type != sym.SRODATA {
+                               break
+                       }
+               }
+
+               if ctxt.IsELF {
+                       // TODO: We generate a R_AARCH64_ABS64 relocation for every R_ADDR, even
+                       // though it would be more efficient (for the dynamic linker) if we
+                       // generated R_AARCH64_RELATIVE instead.
+                       ld.Adddynsym(ctxt, targ)
+                       rela := ctxt.Syms.Lookup(".rela", 0)
+                       rela.AddAddrPlus(ctxt.Arch, s, int64(r.Off))
+                       if r.Siz == 8 {
+                               rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(targ.Dynid), uint32(elf.R_AARCH64_ABS64)))
+                       } else {
+                               ld.Errorf(s, "unexpected relocation for dynamic symbol %s", targ.Name)
+                       }
+                       rela.AddUint64(ctxt.Arch, uint64(r.Add))
+                       r.Type = objabi.ElfRelocOffset // ignore during relocsym
+                       return true
+               }
        }
-       log.Fatalf("adddynrel not implemented for relocation type %d (%s)", r.Type, sym.RelocName(ctxt.Arch, r.Type))
        return false
 }
 
@@ -160,11 +336,6 @@ func elfreloc1(ctxt *ld.Link, r *sym.Reloc, sectoff int64) bool {
        return true
 }
 
-func elfsetupplt(ctxt *ld.Link) {
-       // TODO(aram)
-       return
-}
-
 func machoreloc1(arch *sys.Arch, out *ld.OutBuf, s *sym.Symbol, r *sym.Reloc, sectoff int64) bool {
        var v uint32
 
@@ -331,8 +502,10 @@ func archreloc(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, val int64) (int64, bo
        switch r.Type {
        case objabi.R_CONST:
                return r.Add, true
+
        case objabi.R_GOTOFF:
                return ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ctxt.Syms.Lookup(".got", 0)), true
+
        case objabi.R_ADDRARM64:
                t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
                if t >= 1<<32 || t < -1<<32 {
@@ -357,6 +530,7 @@ func archreloc(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, val int64) (int64, bo
                        return int64(o0)<<32 | int64(o1), true
                }
                return int64(o1)<<32 | int64(o0), true
+
        case objabi.R_ARM64_TLS_LE:
                r.Done = false
                if ctxt.HeadType == objabi.Hdarwin {
@@ -369,12 +543,128 @@ func archreloc(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, val int64) (int64, bo
                        ld.Errorf(s, "TLS offset out of range %d", v)
                }
                return val | (v << 5), true
+
+       case objabi.R_ARM64_TLS_IE:
+               if ctxt.BuildMode == ld.BuildModePIE && ctxt.IsELF {
+                       // We are linking the final executable, so we
+                       // can optimize any TLS IE relocation to LE.
+                       r.Done = false
+                       if ctxt.HeadType != objabi.Hlinux {
+                               ld.Errorf(s, "TLS reloc on unsupported OS %v", ctxt.HeadType)
+                       }
+
+                       // The TCB is two pointers. This is not documented anywhere, but is
+                       // de facto part of the ABI.
+                       v := ld.Symaddr(r.Sym) + int64(2*ctxt.Arch.PtrSize) + r.Add
+                       if v < 0 || v >= 32678 {
+                               ld.Errorf(s, "TLS offset out of range %d", v)
+                       }
+
+                       var o0, o1 uint32
+                       if ctxt.Arch.ByteOrder == binary.BigEndian {
+                               o0 = uint32(val >> 32)
+                               o1 = uint32(val)
+                       } else {
+                               o0 = uint32(val)
+                               o1 = uint32(val >> 32)
+                       }
+
+                       // R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21
+                       // turn ADRP to MOVZ
+                       o0 = 0xd2a00000 | uint32(o0&0x1f) | (uint32((v>>16)&0xffff) << 5)
+                       // R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC
+                       // turn LD64 to MOVK
+                       if v&3 != 0 {
+                               ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC", v)
+                       }
+                       o1 = 0xf2800000 | uint32(o1&0x1f) | (uint32(v&0xffff) << 5)
+
+                       // when laid out, the instruction order must always be o0, o1.
+                       if ctxt.Arch.ByteOrder == binary.BigEndian {
+                               return int64(o0)<<32 | int64(o1), true
+                       }
+                       return int64(o1)<<32 | int64(o0), true
+               } else {
+                       log.Fatalf("cannot handle R_ARM64_TLS_IE (sym %s) when linking internally", s.Name)
+               }
+
        case objabi.R_CALLARM64:
-               t := (ld.Symaddr(r.Sym) + r.Add) - (s.Value + int64(r.Off))
+               var t int64
+               if r.Sym.Type == sym.SDYNIMPORT {
+                       t = (ld.Symaddr(ctxt.Syms.Lookup(".plt", 0)) + r.Add) - (s.Value + int64(r.Off))
+               } else {
+                       t = (ld.Symaddr(r.Sym) + r.Add) - (s.Value + int64(r.Off))
+               }
                if t >= 1<<27 || t < -1<<27 {
                        ld.Errorf(s, "program too large, call relocation distance = %d", t)
                }
                return val | ((t >> 2) & 0x03ffffff), true
+
+       case objabi.R_ARM64_GOT:
+               if s.P[r.Off+3]&0x9f == 0x90 {
+                       // R_AARCH64_ADR_GOT_PAGE
+                       // patch instruction: adrp
+                       t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
+                       if t >= 1<<32 || t < -1<<32 {
+                               ld.Errorf(s, "program too large, address relocation distance = %d", t)
+                       }
+                       var o0 uint32
+                       o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
+                       return val | int64(o0), true
+               } else if s.P[r.Off+3] == 0xf9 {
+                       // R_AARCH64_LD64_GOT_LO12_NC
+                       // patch instruction: ldr
+                       t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
+                       if t&7 != 0 {
+                               ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LD64_GOT_LO12_NC", t)
+                       }
+                       var o1 uint32
+                       o1 |= uint32(t&0xfff) << (10 - 3)
+                       return val | int64(uint64(o1)), true
+               } else {
+                       ld.Errorf(s, "unsupported instruction for %v R_GOTARM64", s.P[r.Off:r.Off+4])
+               }
+
+       case objabi.R_ARM64_PCREL:
+               if s.P[r.Off+3]&0x9f == 0x90 {
+                       // R_AARCH64_ADR_PREL_PG_HI21
+                       // patch instruction: adrp
+                       t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
+                       if t >= 1<<32 || t < -1<<32 {
+                               ld.Errorf(s, "program too large, address relocation distance = %d", t)
+                       }
+                       o0 := (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
+                       return val | int64(o0), true
+               } else if s.P[r.Off+3]&0x91 == 0x91 {
+                       // R_AARCH64_ADD_ABS_LO12_NC
+                       // patch instruction: add
+                       t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
+                       o1 := uint32(t&0xfff) << 10
+                       return val | int64(o1), true
+               } else {
+                       ld.Errorf(s, "unsupported instruction for %v R_PCRELARM64", s.P[r.Off:r.Off+4])
+               }
+
+       case objabi.R_ARM64_LDST8:
+               t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
+               o0 := uint32(t&0xfff) << 10
+               return val | int64(o0), true
+
+       case objabi.R_ARM64_LDST32:
+               t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
+               if t&3 != 0 {
+                       ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST32_ABS_LO12_NC", t)
+               }
+               o0 := (uint32(t&0xfff) >> 2) << 10
+               return val | int64(o0), true
+
+       case objabi.R_ARM64_LDST64:
+               t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
+               if t&7 != 0 {
+                       ld.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST64_ABS_LO12_NC", t)
+               }
+               o0 := (uint32(t&0xfff) >> 3) << 10
+               return val | int64(o0), true
        }
 
        return val, false
@@ -385,6 +675,118 @@ func archrelocvariant(ctxt *ld.Link, r *sym.Reloc, s *sym.Symbol, t int64) int64
        return -1
 }
 
+func elfsetupplt(ctxt *ld.Link) {
+       plt := ctxt.Syms.Lookup(".plt", 0)
+       gotplt := ctxt.Syms.Lookup(".got.plt", 0)
+       if plt.Size == 0 {
+               // stp     x16, x30, [sp, #-16]!
+               // identifying information
+               plt.AddUint32(ctxt.Arch, 0xa9bf7bf0)
+
+               // the following two instructions (adrp + ldr) load *got[2] into x17
+               // adrp    x16, &got[0]
+               plt.AddAddrPlus4(gotplt, 16)
+               plt.SetUint32(ctxt.Arch, plt.Size-4, 0x90000010)
+               plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
+
+               // <imm> is the offset value of &got[2] to &got[0], the same below
+               // ldr     x17, [x16, <imm>]
+               plt.AddAddrPlus4(gotplt, 16)
+               plt.SetUint32(ctxt.Arch, plt.Size-4, 0xf9400211)
+               plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
+
+               // add     x16, x16, <imm>
+               plt.AddAddrPlus4(gotplt, 16)
+               plt.SetUint32(ctxt.Arch, plt.Size-4, 0x91000210)
+               plt.R[len(plt.R)-1].Type = objabi.R_ARM64_PCREL
+
+               // br      x17
+               plt.AddUint32(ctxt.Arch, 0xd61f0220)
+
+               // 3 nop for place holder
+               plt.AddUint32(ctxt.Arch, 0xd503201f)
+               plt.AddUint32(ctxt.Arch, 0xd503201f)
+               plt.AddUint32(ctxt.Arch, 0xd503201f)
+
+               // check gotplt.size == 0
+               if gotplt.Size != 0 {
+                       ld.Errorf(gotplt, "got.plt is not empty at the very beginning")
+               }
+               gotplt.AddAddrPlus(ctxt.Arch, ctxt.Syms.Lookup(".dynamic", 0), 0)
+
+               gotplt.AddUint64(ctxt.Arch, 0)
+               gotplt.AddUint64(ctxt.Arch, 0)
+       }
+}
+
+func addpltsym(ctxt *ld.Link, s *sym.Symbol) {
+       if s.Plt() >= 0 {
+               return
+       }
+
+       ld.Adddynsym(ctxt, s)
+
+       if ctxt.IsELF {
+               plt := ctxt.Syms.Lookup(".plt", 0)
+               gotplt := ctxt.Syms.Lookup(".got.plt", 0)
+               rela := ctxt.Syms.Lookup(".rela.plt", 0)
+               if plt.Size == 0 {
+                       elfsetupplt(ctxt)
+               }
+
+               // adrp    x16, &got.plt[0]
+               plt.AddAddrPlus4(gotplt, gotplt.Size)
+               plt.SetUint32(ctxt.Arch, plt.Size-4, 0x90000010)
+               plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
+
+               // <offset> is the offset value of &got.plt[n] to &got.plt[0]
+               // ldr     x17, [x16, <offset>]
+               plt.AddAddrPlus4(gotplt, gotplt.Size)
+               plt.SetUint32(ctxt.Arch, plt.Size-4, 0xf9400211)
+               plt.R[len(plt.R)-1].Type = objabi.R_ARM64_GOT
+
+               // add     x16, x16, <offset>
+               plt.AddAddrPlus4(gotplt, gotplt.Size)
+               plt.SetUint32(ctxt.Arch, plt.Size-4, 0x91000210)
+               plt.R[len(plt.R)-1].Type = objabi.R_ARM64_PCREL
+
+               // br      x17
+               plt.AddUint32(ctxt.Arch, 0xd61f0220)
+
+               // add to got.plt: pointer to plt[0]
+               gotplt.AddAddrPlus(ctxt.Arch, plt, 0)
+
+               // rela
+               rela.AddAddrPlus(ctxt.Arch, gotplt, gotplt.Size-8)
+               rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(s.Dynid), uint32(elf.R_AARCH64_JUMP_SLOT)))
+               rela.AddUint64(ctxt.Arch, 0)
+
+               s.SetPlt(int32(plt.Size - 16))
+       } else {
+               ld.Errorf(s, "addpltsym: unsupported binary format")
+       }
+}
+
+func addgotsym(ctxt *ld.Link, s *sym.Symbol) {
+       if s.Got() >= 0 {
+               return
+       }
+
+       ld.Adddynsym(ctxt, s)
+       got := ctxt.Syms.Lookup(".got", 0)
+       s.SetGot(int32(got.Size))
+       got.AddUint64(ctxt.Arch, 0)
+
+       if ctxt.IsELF {
+               rela := ctxt.Syms.Lookup(".rela", 0)
+               rela.AddAddrPlus(ctxt.Arch, got, int64(s.Got()))
+               rela.AddUint64(ctxt.Arch, ld.ELF64_R_INFO(uint32(s.Dynid), uint32(elf.R_AARCH64_GLOB_DAT)))
+               rela.AddUint64(ctxt.Arch, 0)
+       } else {
+               ld.Errorf(s, "addgotsym: unsupported binary format")
+       }
+}
+
 func asmb(ctxt *ld.Link) {
        if ctxt.Debugvlog != 0 {
                ctxt.Logf("%5.2f asmb\n", ld.Cputime())
index 7a83d4ef4c4c3f5ed1ec1036201329ae9cb3882a..8525a033dafa15e3380ed1b5f12eab4f09e292ea 100644 (file)
@@ -184,17 +184,16 @@ func mustLinkExternal(ctxt *Link) (res bool, reason string) {
        }
 
        // Internally linking cgo is incomplete on some architectures.
-       // https://golang.org/issue/10373
        // https://golang.org/issue/14449
        // https://golang.org/issue/21961
-       if iscgo && ctxt.Arch.InFamily(sys.ARM64, sys.MIPS64, sys.MIPS, sys.PPC64) {
+       if iscgo && ctxt.Arch.InFamily(sys.MIPS64, sys.MIPS, sys.PPC64) {
                return true, objabi.GOARCH + " does not support internal cgo"
        }
 
        // When the race flag is set, the LLVM tsan relocatable file is linked
        // into the final binary, which means external linking is required because
        // internal linking does not support it.
-       if *flagRace && ctxt.Arch.InFamily(sys.PPC64, sys.ARM64) {
+       if *flagRace && ctxt.Arch.InFamily(sys.PPC64) {
                return true, "race on " + objabi.GOARCH
        }
 
@@ -206,7 +205,7 @@ func mustLinkExternal(ctxt *Link) (res bool, reason string) {
                return true, "buildmode=c-shared"
        case BuildModePIE:
                switch objabi.GOOS + "/" + objabi.GOARCH {
-               case "linux/amd64":
+               case "linux/amd64", "linux/arm64":
                default:
                        // Internal linking does not support TLS_IE.
                        return true, "buildmode=pie"
index a3f84dd008ec3054fd5b45627419408ef59a352a..cd7f21cec959480d2cc048895af74ddcdad50293 100644 (file)
@@ -2492,7 +2492,7 @@ func (ctxt *Link) callgraph() {
                        if r.Sym == nil {
                                continue
                        }
-                       if (r.Type == objabi.R_CALL || r.Type == objabi.R_CALLARM || r.Type == objabi.R_CALLPOWER || r.Type == objabi.R_CALLMIPS) && r.Sym.Type == sym.STEXT {
+                       if (r.Type == objabi.R_CALL || r.Type == objabi.R_CALLARM || r.Type == objabi.R_CALLARM64 || r.Type == objabi.R_CALLPOWER || r.Type == objabi.R_CALLMIPS) && r.Sym.Type == sym.STEXT {
                                ctxt.Logf("%s calls %s\n", s.Name, r.Sym.Name)
                        }
                }
index a38c90b1b8aeae0c47f4ad1660369bd0edf61b68..6fc343295b95ce201027dab4effa574eed705574 100644 (file)
@@ -794,6 +794,13 @@ func Load(arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length i
                                continue
                        }
 
+                       if strings.HasPrefix(elfsym.name, "$d") && elfsym.type_ == 0 && sect.name == ".debug_frame" {
+                               // "$d" is a marker, not a real symbol.
+                               // This happens with gcc on ARM64.
+                               // See https://sourceware.org/bugzilla/show_bug.cgi?id=21809
+                               continue
+                       }
+
                        if strings.HasPrefix(elfsym.name, ".LASF") { // gcc on s390x does this
                                continue
                        }
@@ -1064,8 +1071,8 @@ func readelfsym(arch *sys.Arch, syms *sym.Symbols, elfobj *ElfObj, i int, elfsym
                        }
 
                case ElfSymBindLocal:
-                       if arch.Family == sys.ARM && (strings.HasPrefix(elfsym.name, "$a") || strings.HasPrefix(elfsym.name, "$d")) {
-                               // binutils for arm generate these mapping
+                       if (arch.Family == sys.ARM || arch.Family == sys.ARM64) && (strings.HasPrefix(elfsym.name, "$a") || strings.HasPrefix(elfsym.name, "$d") || strings.HasPrefix(elfsym.name, "$x")) {
+                               // binutils for arm and arm64 generate these mapping
                                // symbols, ignore these
                                break
                        }
@@ -1127,81 +1134,94 @@ func relSize(arch *sys.Arch, pn string, elftype uint32) (uint8, error) {
        const (
                AMD64 = uint32(sys.AMD64)
                ARM   = uint32(sys.ARM)
+               ARM64 = uint32(sys.ARM64)
                I386  = uint32(sys.I386)
                PPC64 = uint32(sys.PPC64)
                S390X = uint32(sys.S390X)
        )
 
-       switch uint32(arch.Family) | elftype<<24 {
+       switch uint32(arch.Family) | elftype<<16 {
        default:
                return 0, fmt.Errorf("%s: unknown relocation type %d; compiled without -fpic?", pn, elftype)
 
-       case S390X | uint32(elf.R_390_8)<<24:
+       case S390X | uint32(elf.R_390_8)<<16:
                return 1, nil
 
-       case PPC64 | uint32(elf.R_PPC64_TOC16)<<24,
-               PPC64 | uint32(elf.R_PPC64_TOC16_LO)<<24,
-               PPC64 | uint32(elf.R_PPC64_TOC16_HI)<<24,
-               PPC64 | uint32(elf.R_PPC64_TOC16_HA)<<24,
-               PPC64 | uint32(elf.R_PPC64_TOC16_DS)<<24,
-               PPC64 | uint32(elf.R_PPC64_TOC16_LO_DS)<<24,
-               PPC64 | uint32(elf.R_PPC64_REL16_LO)<<24,
-               PPC64 | uint32(elf.R_PPC64_REL16_HI)<<24,
-               PPC64 | uint32(elf.R_PPC64_REL16_HA)<<24,
-               S390X | uint32(elf.R_390_16)<<24,
-               S390X | uint32(elf.R_390_GOT16)<<24,
-               S390X | uint32(elf.R_390_PC16)<<24,
-               S390X | uint32(elf.R_390_PC16DBL)<<24,
-               S390X | uint32(elf.R_390_PLT16DBL)<<24:
+       case PPC64 | uint32(elf.R_PPC64_TOC16)<<16,
+               PPC64 | uint32(elf.R_PPC64_TOC16_LO)<<16,
+               PPC64 | uint32(elf.R_PPC64_TOC16_HI)<<16,
+               PPC64 | uint32(elf.R_PPC64_TOC16_HA)<<16,
+               PPC64 | uint32(elf.R_PPC64_TOC16_DS)<<16,
+               PPC64 | uint32(elf.R_PPC64_TOC16_LO_DS)<<16,
+               PPC64 | uint32(elf.R_PPC64_REL16_LO)<<16,
+               PPC64 | uint32(elf.R_PPC64_REL16_HI)<<16,
+               PPC64 | uint32(elf.R_PPC64_REL16_HA)<<16,
+               S390X | uint32(elf.R_390_16)<<16,
+               S390X | uint32(elf.R_390_GOT16)<<16,
+               S390X | uint32(elf.R_390_PC16)<<16,
+               S390X | uint32(elf.R_390_PC16DBL)<<16,
+               S390X | uint32(elf.R_390_PLT16DBL)<<16:
                return 2, nil
 
-       case ARM | uint32(elf.R_ARM_ABS32)<<24,
-               ARM | uint32(elf.R_ARM_GOT32)<<24,
-               ARM | uint32(elf.R_ARM_PLT32)<<24,
-               ARM | uint32(elf.R_ARM_GOTOFF)<<24,
-               ARM | uint32(elf.R_ARM_GOTPC)<<24,
-               ARM | uint32(elf.R_ARM_THM_PC22)<<24,
-               ARM | uint32(elf.R_ARM_REL32)<<24,
-               ARM | uint32(elf.R_ARM_CALL)<<24,
-               ARM | uint32(elf.R_ARM_V4BX)<<24,
-               ARM | uint32(elf.R_ARM_GOT_PREL)<<24,
-               ARM | uint32(elf.R_ARM_PC24)<<24,
-               ARM | uint32(elf.R_ARM_JUMP24)<<24,
-               AMD64 | uint32(elf.R_X86_64_PC32)<<24,
-               AMD64 | uint32(elf.R_X86_64_PLT32)<<24,
-               AMD64 | uint32(elf.R_X86_64_GOTPCREL)<<24,
-               AMD64 | uint32(elf.R_X86_64_GOTPCRELX)<<24,
-               AMD64 | uint32(elf.R_X86_64_REX_GOTPCRELX)<<24,
-               I386 | uint32(elf.R_386_32)<<24,
-               I386 | uint32(elf.R_386_PC32)<<24,
-               I386 | uint32(elf.R_386_GOT32)<<24,
-               I386 | uint32(elf.R_386_PLT32)<<24,
-               I386 | uint32(elf.R_386_GOTOFF)<<24,
-               I386 | uint32(elf.R_386_GOTPC)<<24,
-               I386 | uint32(elf.R_386_GOT32X)<<24,
-               PPC64 | uint32(elf.R_PPC64_REL24)<<24,
-               PPC64 | uint32(elf.R_PPC_REL32)<<24,
-               S390X | uint32(elf.R_390_32)<<24,
-               S390X | uint32(elf.R_390_PC32)<<24,
-               S390X | uint32(elf.R_390_GOT32)<<24,
-               S390X | uint32(elf.R_390_PLT32)<<24,
-               S390X | uint32(elf.R_390_PC32DBL)<<24,
-               S390X | uint32(elf.R_390_PLT32DBL)<<24,
-               S390X | uint32(elf.R_390_GOTPCDBL)<<24,
-               S390X | uint32(elf.R_390_GOTENT)<<24:
+       case ARM | uint32(elf.R_ARM_ABS32)<<16,
+               ARM | uint32(elf.R_ARM_GOT32)<<16,
+               ARM | uint32(elf.R_ARM_PLT32)<<16,
+               ARM | uint32(elf.R_ARM_GOTOFF)<<16,
+               ARM | uint32(elf.R_ARM_GOTPC)<<16,
+               ARM | uint32(elf.R_ARM_THM_PC22)<<16,
+               ARM | uint32(elf.R_ARM_REL32)<<16,
+               ARM | uint32(elf.R_ARM_CALL)<<16,
+               ARM | uint32(elf.R_ARM_V4BX)<<16,
+               ARM | uint32(elf.R_ARM_GOT_PREL)<<16,
+               ARM | uint32(elf.R_ARM_PC24)<<16,
+               ARM | uint32(elf.R_ARM_JUMP24)<<16,
+               ARM64 | uint32(elf.R_AARCH64_CALL26)<<16,
+               ARM64 | uint32(elf.R_AARCH64_ADR_GOT_PAGE)<<16,
+               ARM64 | uint32(elf.R_AARCH64_LD64_GOT_LO12_NC)<<16,
+               ARM64 | uint32(elf.R_AARCH64_ADR_PREL_PG_HI21)<<16,
+               ARM64 | uint32(elf.R_AARCH64_ADD_ABS_LO12_NC)<<16,
+               ARM64 | uint32(elf.R_AARCH64_LDST8_ABS_LO12_NC)<<16,
+               ARM64 | uint32(elf.R_AARCH64_LDST32_ABS_LO12_NC)<<16,
+               ARM64 | uint32(elf.R_AARCH64_LDST64_ABS_LO12_NC)<<16,
+               ARM64 | uint32(elf.R_AARCH64_PREL32)<<16,
+               ARM64 | uint32(elf.R_AARCH64_JUMP26)<<16,
+               AMD64 | uint32(elf.R_X86_64_PC32)<<16,
+               AMD64 | uint32(elf.R_X86_64_PLT32)<<16,
+               AMD64 | uint32(elf.R_X86_64_GOTPCREL)<<16,
+               AMD64 | uint32(elf.R_X86_64_GOTPCRELX)<<16,
+               AMD64 | uint32(elf.R_X86_64_REX_GOTPCRELX)<<16,
+               I386 | uint32(elf.R_386_32)<<16,
+               I386 | uint32(elf.R_386_PC32)<<16,
+               I386 | uint32(elf.R_386_GOT32)<<16,
+               I386 | uint32(elf.R_386_PLT32)<<16,
+               I386 | uint32(elf.R_386_GOTOFF)<<16,
+               I386 | uint32(elf.R_386_GOTPC)<<16,
+               I386 | uint32(elf.R_386_GOT32X)<<16,
+               PPC64 | uint32(elf.R_PPC64_REL24)<<16,
+               PPC64 | uint32(elf.R_PPC_REL32)<<16,
+               S390X | uint32(elf.R_390_32)<<16,
+               S390X | uint32(elf.R_390_PC32)<<16,
+               S390X | uint32(elf.R_390_GOT32)<<16,
+               S390X | uint32(elf.R_390_PLT32)<<16,
+               S390X | uint32(elf.R_390_PC32DBL)<<16,
+               S390X | uint32(elf.R_390_PLT32DBL)<<16,
+               S390X | uint32(elf.R_390_GOTPCDBL)<<16,
+               S390X | uint32(elf.R_390_GOTENT)<<16:
                return 4, nil
 
-       case AMD64 | uint32(elf.R_X86_64_64)<<24,
-               AMD64 | uint32(elf.R_X86_64_PC64)<<24,
-               PPC64 | uint32(elf.R_PPC64_ADDR64)<<24,
-               S390X | uint32(elf.R_390_GLOB_DAT)<<24,
-               S390X | uint32(elf.R_390_RELATIVE)<<24,
-               S390X | uint32(elf.R_390_GOTOFF)<<24,
-               S390X | uint32(elf.R_390_GOTPC)<<24,
-               S390X | uint32(elf.R_390_64)<<24,
-               S390X | uint32(elf.R_390_PC64)<<24,
-               S390X | uint32(elf.R_390_GOT64)<<24,
-               S390X | uint32(elf.R_390_PLT64)<<24:
+       case AMD64 | uint32(elf.R_X86_64_64)<<16,
+               AMD64 | uint32(elf.R_X86_64_PC64)<<16,
+               ARM64 | uint32(elf.R_AARCH64_ABS64)<<16,
+               ARM64 | uint32(elf.R_AARCH64_PREL64)<<16,
+               PPC64 | uint32(elf.R_PPC64_ADDR64)<<16,
+               S390X | uint32(elf.R_390_GLOB_DAT)<<16,
+               S390X | uint32(elf.R_390_RELATIVE)<<16,
+               S390X | uint32(elf.R_390_GOTOFF)<<16,
+               S390X | uint32(elf.R_390_GOTPC)<<16,
+               S390X | uint32(elf.R_390_64)<<16,
+               S390X | uint32(elf.R_390_PC64)<<16,
+               S390X | uint32(elf.R_390_GOT64)<<16,
+               S390X | uint32(elf.R_390_PLT64)<<16:
                return 8, nil
        }
 }