package ld import ( "cmd/internal/obj" "encoding/binary" "fmt" "log" "sort" ) /* Derived from Plan 9 from User Space's src/libmach/elf.h, elf.c http://code.swtch.com/plan9port/src/tip/src/libmach/ Copyright © 2004 Russ Cox. Portions Copyright © 2008-2010 Google Inc. Portions Copyright © 2010 The Go Authors. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ const ( N_EXT = 0x01 N_TYPE = 0x1e N_STAB = 0xe0 ) type LdMachoObj struct { f *obj.Biobuf base int64 // off in f where Mach-O begins length int64 // length of Mach-O is64 bool name string e binary.ByteOrder cputype uint subcputype uint filetype uint32 flags uint32 cmd []LdMachoCmd ncmd uint } type LdMachoCmd struct { type_ int off uint32 size uint32 seg LdMachoSeg sym LdMachoSymtab dsym LdMachoDysymtab } type LdMachoSeg struct { name string vmaddr uint64 vmsize uint64 fileoff uint32 filesz uint32 maxprot uint32 initprot uint32 nsect uint32 flags uint32 sect []LdMachoSect } type LdMachoSect struct { name string segname string addr uint64 size uint64 off uint32 align uint32 reloff uint32 nreloc uint32 flags uint32 res1 uint32 res2 uint32 sym *LSym rel []LdMachoRel } type LdMachoRel struct { addr uint32 symnum uint32 pcrel uint8 length uint8 extrn uint8 type_ uint8 scattered uint8 value uint32 } type LdMachoSymtab struct { symoff uint32 nsym uint32 stroff uint32 strsize uint32 str []byte sym []LdMachoSym } type LdMachoSym struct { name string type_ uint8 sectnum uint8 desc uint16 kind int8 value uint64 sym *LSym } type LdMachoDysymtab struct { ilocalsym uint32 nlocalsym uint32 iextdefsym uint32 nextdefsym uint32 iundefsym uint32 nundefsym uint32 tocoff uint32 ntoc uint32 modtaboff uint32 nmodtab uint32 extrefsymoff uint32 nextrefsyms uint32 indirectsymoff uint32 nindirectsyms uint32 extreloff uint32 nextrel uint32 locreloff uint32 nlocrel uint32 indir []uint32 } const ( LdMachoCpuVax = 1 LdMachoCpu68000 = 6 LdMachoCpu386 = 7 LdMachoCpuAmd64 = 0x1000007 LdMachoCpuMips = 8 LdMachoCpu98000 = 10 LdMachoCpuHppa = 11 LdMachoCpuArm = 12 LdMachoCpu88000 = 13 LdMachoCpuSparc = 14 LdMachoCpu860 = 15 LdMachoCpuAlpha = 16 LdMachoCpuPower = 18 LdMachoCmdSegment = 1 LdMachoCmdSymtab = 2 LdMachoCmdSymseg = 3 LdMachoCmdThread = 4 LdMachoCmdDysymtab = 11 LdMachoCmdSegment64 = 25 LdMachoFileObject = 1 LdMachoFileExecutable = 2 LdMachoFileFvmlib = 3 LdMachoFileCore = 4 LdMachoFilePreload = 5 ) func unpackcmd(p []byte, m *LdMachoObj, c *LdMachoCmd, type_ uint, sz uint) int { e4 := m.e.Uint32 e8 := m.e.Uint64 c.type_ = int(type_) c.size = uint32(sz) switch type_ { default: return -1 case LdMachoCmdSegment: if sz < 56 { return -1 } c.seg.name = cstring(p[8:24]) c.seg.vmaddr = uint64(e4(p[24:])) c.seg.vmsize = uint64(e4(p[28:])) c.seg.fileoff = e4(p[32:]) c.seg.filesz = e4(p[36:]) c.seg.maxprot = e4(p[40:]) c.seg.initprot = e4(p[44:]) c.seg.nsect = e4(p[48:]) c.seg.flags = e4(p[52:]) c.seg.sect = make([]LdMachoSect, c.seg.nsect) if uint32(sz) < 56+c.seg.nsect*68 { return -1 } p = p[56:] var s *LdMachoSect for i := 0; uint32(i) < c.seg.nsect; i++ { s = &c.seg.sect[i] s.name = cstring(p[0:16]) s.segname = cstring(p[16:32]) s.addr = uint64(e4(p[32:])) s.size = uint64(e4(p[36:])) s.off = e4(p[40:]) s.align = e4(p[44:]) s.reloff = e4(p[48:]) s.nreloc = e4(p[52:]) s.flags = e4(p[56:]) s.res1 = e4(p[60:]) s.res2 = e4(p[64:]) p = p[68:] } case LdMachoCmdSegment64: if sz < 72 { return -1 } c.seg.name = cstring(p[8:24]) c.seg.vmaddr = e8(p[24:]) c.seg.vmsize = e8(p[32:]) c.seg.fileoff = uint32(e8(p[40:])) c.seg.filesz = uint32(e8(p[48:])) c.seg.maxprot = e4(p[56:]) c.seg.initprot = e4(p[60:]) c.seg.nsect = e4(p[64:]) c.seg.flags = e4(p[68:]) c.seg.sect = make([]LdMachoSect, c.seg.nsect) if uint32(sz) < 72+c.seg.nsect*80 { return -1 } p = p[72:] var s *LdMachoSect for i := 0; uint32(i) < c.seg.nsect; i++ { s = &c.seg.sect[i] s.name = cstring(p[0:16]) s.segname = cstring(p[16:32]) s.addr = e8(p[32:]) s.size = e8(p[40:]) s.off = e4(p[48:]) s.align = e4(p[52:]) s.reloff = e4(p[56:]) s.nreloc = e4(p[60:]) s.flags = e4(p[64:]) s.res1 = e4(p[68:]) s.res2 = e4(p[72:]) // p+76 is reserved p = p[80:] } case LdMachoCmdSymtab: if sz < 24 { return -1 } c.sym.symoff = e4(p[8:]) c.sym.nsym = e4(p[12:]) c.sym.stroff = e4(p[16:]) c.sym.strsize = e4(p[20:]) case LdMachoCmdDysymtab: if sz < 80 { return -1 } c.dsym.ilocalsym = e4(p[8:]) c.dsym.nlocalsym = e4(p[12:]) c.dsym.iextdefsym = e4(p[16:]) c.dsym.nextdefsym = e4(p[20:]) c.dsym.iundefsym = e4(p[24:]) c.dsym.nundefsym = e4(p[28:]) c.dsym.tocoff = e4(p[32:]) c.dsym.ntoc = e4(p[36:]) c.dsym.modtaboff = e4(p[40:]) c.dsym.nmodtab = e4(p[44:]) c.dsym.extrefsymoff = e4(p[48:]) c.dsym.nextrefsyms = e4(p[52:]) c.dsym.indirectsymoff = e4(p[56:]) c.dsym.nindirectsyms = e4(p[60:]) c.dsym.extreloff = e4(p[64:]) c.dsym.nextrel = e4(p[68:]) c.dsym.locreloff = e4(p[72:]) c.dsym.nlocrel = e4(p[76:]) } return 0 } func macholoadrel(m *LdMachoObj, sect *LdMachoSect) int { if sect.rel != nil || sect.nreloc == 0 { return 0 } rel := make([]LdMachoRel, sect.nreloc) n := int(sect.nreloc * 8) buf := make([]byte, n) if obj.Bseek(m.f, m.base+int64(sect.reloff), 0) < 0 || obj.Bread(m.f, buf) != n { return -1 } var p []byte var r *LdMachoRel var v uint32 for i := 0; uint32(i) < sect.nreloc; i++ { r = &rel[i] p = buf[i*8:] r.addr = m.e.Uint32(p) // TODO(rsc): Wrong interpretation for big-endian bitfields? if r.addr&0x80000000 != 0 { // scatterbrained relocation r.scattered = 1 v = r.addr >> 24 r.addr &= 0xFFFFFF r.type_ = uint8(v & 0xF) v >>= 4 r.length = 1 << (v & 3) v >>= 2 r.pcrel = uint8(v & 1) r.value = m.e.Uint32(p[4:]) } else { v = m.e.Uint32(p[4:]) r.symnum = v & 0xFFFFFF v >>= 24 r.pcrel = uint8(v & 1) v >>= 1 r.length = 1 << (v & 3) v >>= 2 r.extrn = uint8(v & 1) v >>= 1 r.type_ = uint8(v) } } sect.rel = rel return 0 } func macholoaddsym(m *LdMachoObj, d *LdMachoDysymtab) int { n := int(d.nindirectsyms) p := make([]byte, n*4) if obj.Bseek(m.f, m.base+int64(d.indirectsymoff), 0) < 0 || obj.Bread(m.f, p) != len(p) { return -1 } d.indir = make([]uint32, n) for i := 0; i < n; i++ { d.indir[i] = m.e.Uint32(p[4*i:]) } return 0 } func macholoadsym(m *LdMachoObj, symtab *LdMachoSymtab) int { if symtab.sym != nil { return 0 } strbuf := make([]byte, symtab.strsize) if obj.Bseek(m.f, m.base+int64(symtab.stroff), 0) < 0 || obj.Bread(m.f, strbuf) != len(strbuf) { return -1 } symsize := 12 if m.is64 { symsize = 16 } n := int(symtab.nsym * uint32(symsize)) symbuf := make([]byte, n) if obj.Bseek(m.f, m.base+int64(symtab.symoff), 0) < 0 || obj.Bread(m.f, symbuf) != len(symbuf) { return -1 } sym := make([]LdMachoSym, symtab.nsym) p := symbuf var s *LdMachoSym var v uint32 for i := 0; uint32(i) < symtab.nsym; i++ { s = &sym[i] v = m.e.Uint32(p) if v >= symtab.strsize { return -1 } s.name = cstring(strbuf[v:]) s.type_ = uint8(p[4]) s.sectnum = uint8(p[5]) s.desc = m.e.Uint16(p[6:]) if m.is64 { s.value = m.e.Uint64(p[8:]) } else { s.value = uint64(m.e.Uint32(p[8:])) } p = p[symsize:] } symtab.str = strbuf symtab.sym = sym return 0 } func ldmacho(f *obj.Biobuf, pkg string, length int64, pn string) { var err error var j int var is64 bool var secaddr uint64 var hdr [7 * 4]uint8 var cmdp []byte var dat []byte var ncmd uint32 var cmdsz uint32 var ty uint32 var sz uint32 var off uint32 var m *LdMachoObj var e binary.ByteOrder var sect *LdMachoSect var rel *LdMachoRel var rpi int var s *LSym var s1 *LSym var outer *LSym var c *LdMachoCmd var symtab *LdMachoSymtab var dsymtab *LdMachoDysymtab var sym *LdMachoSym var r []Reloc var rp *Reloc var name string Ctxt.Version++ base := obj.Boffset(f) if obj.Bread(f, hdr[:]) != len(hdr) { goto bad } if binary.BigEndian.Uint32(hdr[:])&^1 == 0xFEEDFACE { e = binary.BigEndian } else if binary.LittleEndian.Uint32(hdr[:])&^1 == 0xFEEDFACE { e = binary.LittleEndian } else { err = fmt.Errorf("bad magic - not mach-o file") goto bad } is64 = e.Uint32(hdr[:]) == 0xFEEDFACF ncmd = e.Uint32([]byte(hdr[4*4:])) cmdsz = e.Uint32([]byte(hdr[5*4:])) if ncmd > 0x10000 || cmdsz >= 0x01000000 { err = fmt.Errorf("implausible mach-o header ncmd=%d cmdsz=%d", ncmd, cmdsz) goto bad } if is64 { var tmp [4]uint8 obj.Bread(f, tmp[:4]) // skip reserved word in header } m = new(LdMachoObj) m.f = f m.e = e m.cputype = uint(e.Uint32([]byte(hdr[1*4:]))) m.subcputype = uint(e.Uint32([]byte(hdr[2*4:]))) m.filetype = e.Uint32([]byte(hdr[3*4:])) m.ncmd = uint(ncmd) m.flags = e.Uint32([]byte(hdr[6*4:])) m.is64 = is64 m.base = base m.length = length m.name = pn switch Thearch.Thechar { default: Diag("%s: mach-o %s unimplemented", pn, Thestring) return case '6': if e != binary.LittleEndian || m.cputype != LdMachoCpuAmd64 { Diag("%s: mach-o object but not amd64", pn) return } case '8': if e != binary.LittleEndian || m.cputype != LdMachoCpu386 { Diag("%s: mach-o object but not 386", pn) return } } m.cmd = make([]LdMachoCmd, ncmd) off = uint32(len(hdr)) cmdp = make([]byte, cmdsz) if obj.Bread(f, cmdp) != len(cmdp) { err = fmt.Errorf("reading cmds: %v", err) goto bad } // read and parse load commands c = nil symtab = nil dsymtab = nil for i := 0; uint32(i) < ncmd; i++ { ty = e.Uint32(cmdp) sz = e.Uint32(cmdp[4:]) m.cmd[i].off = off unpackcmd(cmdp, m, &m.cmd[i], uint(ty), uint(sz)) cmdp = cmdp[sz:] off += sz if ty == LdMachoCmdSymtab { if symtab != nil { err = fmt.Errorf("multiple symbol tables") goto bad } symtab = &m.cmd[i].sym macholoadsym(m, symtab) } if ty == LdMachoCmdDysymtab { dsymtab = &m.cmd[i].dsym macholoaddsym(m, dsymtab) } if (is64 && ty == LdMachoCmdSegment64) || (!is64 && ty == LdMachoCmdSegment) { if c != nil { err = fmt.Errorf("multiple load commands") goto bad } c = &m.cmd[i] } } // load text and data segments into memory. // they are not as small as the load commands, but we'll need // the memory anyway for the symbol images, so we might // as well use one large chunk. if c == nil { err = fmt.Errorf("no load command") goto bad } if symtab == nil { // our work is done here - no symbols means nothing can refer to this file return } if int64(c.seg.fileoff+c.seg.filesz) >= length { err = fmt.Errorf("load segment out of range") goto bad } dat = make([]byte, c.seg.filesz) if obj.Bseek(f, m.base+int64(c.seg.fileoff), 0) < 0 || obj.Bread(f, dat) != len(dat) { err = fmt.Errorf("cannot load object data: %v", err) goto bad } for i := 0; uint32(i) < c.seg.nsect; i++ { sect = &c.seg.sect[i] if sect.segname != "__TEXT" && sect.segname != "__DATA" { continue } if sect.name == "__eh_frame" { continue } name = fmt.Sprintf("%s(%s/%s)", pkg, sect.segname, sect.name) s = Linklookup(Ctxt, name, Ctxt.Version) if s.Type != 0 { err = fmt.Errorf("duplicate %s/%s", sect.segname, sect.name) goto bad } if sect.flags&0xff == 1 { // S_ZEROFILL s.P = make([]byte, sect.size) } else { s.P = dat[sect.addr-c.seg.vmaddr:][:sect.size] } s.Size = int64(len(s.P)) if sect.segname == "__TEXT" { if sect.name == "__text" { s.Type = obj.STEXT } else { s.Type = obj.SRODATA } } else { if sect.name == "__bss" { s.Type = obj.SNOPTRBSS s.P = s.P[:0] } else { s.Type = obj.SNOPTRDATA } } sect.sym = s } // enter sub-symbols into symbol table. // have to guess sizes from next symbol. for i := 0; uint32(i) < symtab.nsym; i++ { sym = &symtab.sym[i] if sym.type_&N_STAB != 0 { continue } // TODO: check sym->type against outer->type. name = sym.name if name[0] == '_' && name[1] != '\x00' { name = name[1:] } v := 0 if sym.type_&N_EXT == 0 { v = Ctxt.Version } s = Linklookup(Ctxt, name, v) if sym.type_&N_EXT == 0 { s.Dupok = 1 } sym.sym = s if sym.sectnum == 0 { // undefined continue } if uint32(sym.sectnum) > c.seg.nsect { err = fmt.Errorf("reference to invalid section %d", sym.sectnum) goto bad } sect = &c.seg.sect[sym.sectnum-1] outer = sect.sym if outer == nil { err = fmt.Errorf("reference to invalid section %s/%s", sect.segname, sect.name) continue } if s.Outer != nil { if s.Dupok != 0 { continue } Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sect.sym.Name) } s.Type = outer.Type | obj.SSUB s.Sub = outer.Sub outer.Sub = s s.Outer = outer s.Value = int64(sym.value - sect.addr) if s.Cgoexport&CgoExportDynamic == 0 { s.Dynimplib = "" // satisfy dynimport } if outer.Type == obj.STEXT { if s.External != 0 && s.Dupok == 0 { Diag("%s: duplicate definition of %s", pn, s.Name) } s.External = 1 } sym.sym = s } // Sort outer lists by address, adding to textp. // This keeps textp in increasing address order. for i := 0; uint32(i) < c.seg.nsect; i++ { sect = &c.seg.sect[i] s = sect.sym if s == nil { continue } if s.Sub != nil { s.Sub = listsort(s.Sub, valuecmp, listsubp) // assign sizes, now that we know symbols in sorted order. for s1 = s.Sub; s1 != nil; s1 = s1.Sub { if s1.Sub != nil { s1.Size = s1.Sub.Value - s1.Value } else { s1.Size = s.Value + s.Size - s1.Value } } } if s.Type == obj.STEXT { if s.Onlist != 0 { log.Fatalf("symbol %s listed multiple times", s.Name) } s.Onlist = 1 if Ctxt.Etextp != nil { Ctxt.Etextp.Next = s } else { Ctxt.Textp = s } Ctxt.Etextp = s for s1 = s.Sub; s1 != nil; s1 = s1.Sub { if s1.Onlist != 0 { log.Fatalf("symbol %s listed multiple times", s1.Name) } s1.Onlist = 1 Ctxt.Etextp.Next = s1 Ctxt.Etextp = s1 } } } // load relocations for i := 0; uint32(i) < c.seg.nsect; i++ { sect = &c.seg.sect[i] s = sect.sym if s == nil { continue } macholoadrel(m, sect) if sect.rel == nil { continue } r = make([]Reloc, sect.nreloc) rpi = 0 Reloc: for j = 0; uint32(j) < sect.nreloc; j++ { rp = &r[rpi] rel = §.rel[j] if rel.scattered != 0 { if Thearch.Thechar != '8' { // mach-o only uses scattered relocation on 32-bit platforms Diag("unexpected scattered relocation") continue } // on 386, rewrite scattered 4/1 relocation and some // scattered 2/1 relocation into the pseudo-pc-relative // reference that it is. // assume that the second in the pair is in this section // and use that as the pc-relative base. if uint32(j+1) >= sect.nreloc { err = fmt.Errorf("unsupported scattered relocation %d", int(rel.type_)) goto bad } if sect.rel[j+1].scattered == 0 || sect.rel[j+1].type_ != 1 || (rel.type_ != 4 && rel.type_ != 2) || uint64(sect.rel[j+1].value) < sect.addr || uint64(sect.rel[j+1].value) >= sect.addr+sect.size { err = fmt.Errorf("unsupported scattered relocation %d/%d", int(rel.type_), int(sect.rel[j+1].type_)) goto bad } rp.Siz = rel.length rp.Off = int32(rel.addr) // NOTE(rsc): I haven't worked out why (really when) // we should ignore the addend on a // scattered relocation, but it seems that the // common case is we ignore it. // It's likely that this is not strictly correct // and that the math should look something // like the non-scattered case below. rp.Add = 0 // want to make it pc-relative aka relative to rp->off+4 // but the scatter asks for relative to off = sect->rel[j+1].value - sect->addr. // adjust rp->add accordingly. rp.Type = obj.R_PCREL rp.Add += int64(uint64(int64(rp.Off)+4) - (uint64(sect.rel[j+1].value) - sect.addr)) // now consider the desired symbol. // find the section where it lives. var ks *LdMachoSect for k := 0; uint32(k) < c.seg.nsect; k++ { ks = &c.seg.sect[k] if ks.addr <= uint64(rel.value) && uint64(rel.value) < ks.addr+ks.size { if ks.sym != nil { rp.Sym = ks.sym rp.Add += int64(uint64(rel.value) - ks.addr) } else if ks.segname == "__IMPORT" && ks.name == "__pointers" { // handle reference to __IMPORT/__pointers. // how much worse can this get? // why are we supporting 386 on the mac anyway? rp.Type = 512 + MACHO_FAKE_GOTPCREL // figure out which pointer this is a reference to. k = int(uint64(ks.res1) + (uint64(rel.value)-ks.addr)/4) // load indirect table for __pointers // fetch symbol number if dsymtab == nil || k < 0 || uint32(k) >= dsymtab.nindirectsyms || dsymtab.indir == nil { err = fmt.Errorf("invalid scattered relocation: indirect symbol reference out of range") goto bad } k = int(dsymtab.indir[k]) if k < 0 || uint32(k) >= symtab.nsym { err = fmt.Errorf("invalid scattered relocation: symbol reference out of range") goto bad } rp.Sym = symtab.sym[k].sym } else { err = fmt.Errorf("unsupported scattered relocation: reference to %s/%s", ks.segname, ks.name) goto bad } rpi++ // skip #1 of 2 rel; continue skips #2 of 2. j++ continue Reloc } } err = fmt.Errorf("unsupported scattered relocation: invalid address %#x", rel.addr) goto bad } rp.Siz = rel.length rp.Type = 512 + (int32(rel.type_) << 1) + int32(rel.pcrel) rp.Off = int32(rel.addr) // Handle X86_64_RELOC_SIGNED referencing a section (rel->extrn == 0). if Thearch.Thechar == '6' && rel.extrn == 0 && rel.type_ == 1 { // Calculate the addend as the offset into the section. // // The rip-relative offset stored in the object file is encoded // as follows: // // movsd 0x00000360(%rip),%xmm0 // // To get the absolute address of the value this rip-relative address is pointing // to, we must add the address of the next instruction to it. This is done by // taking the address of the relocation and adding 4 to it (since the rip-relative // offset can at most be 32 bits long). To calculate the offset into the section the // relocation is referencing, we subtract the vaddr of the start of the referenced // section found in the original object file. // // [For future reference, see Darwin's /usr/include/mach-o/x86_64/reloc.h] secaddr = c.seg.sect[rel.symnum-1].addr rp.Add = int64(uint64(int64(int32(e.Uint32(s.P[rp.Off:])))+int64(rp.Off)+4) - secaddr) } else { rp.Add = int64(int32(e.Uint32(s.P[rp.Off:]))) } // For i386 Mach-O PC-relative, the addend is written such that // it *is* the PC being subtracted. Use that to make // it match our version of PC-relative. if rel.pcrel != 0 && Thearch.Thechar == '8' { rp.Add += int64(rp.Off) + int64(rp.Siz) } if rel.extrn == 0 { if rel.symnum < 1 || rel.symnum > c.seg.nsect { err = fmt.Errorf("invalid relocation: section reference out of range %d vs %d", rel.symnum, c.seg.nsect) goto bad } rp.Sym = c.seg.sect[rel.symnum-1].sym if rp.Sym == nil { err = fmt.Errorf("invalid relocation: %s", c.seg.sect[rel.symnum-1].name) goto bad } // References to symbols in other sections // include that information in the addend. // We only care about the delta from the // section base. if Thearch.Thechar == '8' { rp.Add -= int64(c.seg.sect[rel.symnum-1].addr) } } else { if rel.symnum >= symtab.nsym { err = fmt.Errorf("invalid relocation: symbol reference out of range") goto bad } rp.Sym = symtab.sym[rel.symnum].sym } rpi++ } sort.Sort(rbyoff(r[:rpi])) s.R = r s.R = s.R[:rpi] } return bad: Diag("%s: malformed mach-o file: %v", pn, err) }