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ld: reading of Mach-O object files
R=iant CC=golang-dev https://golang.org/cl/3431045
This commit is contained in:
Russ Cox
parent
37499ebcfd
commit
cf42a45587
789
src/cmd/ld/ldmacho.c
Normal file
789
src/cmd/ld/ldmacho.c
Normal file
@ -0,0 +1,789 @@
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/*
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Derived from Plan 9 from User Space's src/libmach/elf.h, elf.c
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http://code.swtch.com/plan9port/src/tip/src/libmach/
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Copyright © 2004 Russ Cox.
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Portions Copyright © 2008-2010 Google Inc.
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Portions Copyright © 2010 The Go Authors.
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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#include "l.h"
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#include "lib.h"
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enum {
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MACHO_FAKE_GOTPCREL = 100, // from macho.h
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N_EXT = 0x01,
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};
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typedef struct MachoObj MachoObj;
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typedef struct MachoCmd MachoCmd;
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typedef struct MachoSeg MachoSeg;
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typedef struct MachoSect MachoSect;
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typedef struct MachoRel MachoRel;
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typedef struct MachoSymtab MachoSymtab;
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typedef struct MachoSym MachoSym;
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typedef struct MachoDysymtab MachoDysymtab;
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enum
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{
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MachoCpuVax = 1,
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MachoCpu68000 = 6,
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MachoCpu386 = 7,
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MachoCpuAmd64 = 0x1000007,
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MachoCpuMips = 8,
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MachoCpu98000 = 10,
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MachoCpuHppa = 11,
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MachoCpuArm = 12,
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MachoCpu88000 = 13,
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MachoCpuSparc = 14,
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MachoCpu860 = 15,
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MachoCpuAlpha = 16,
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MachoCpuPower = 18,
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MachoCmdSegment = 1,
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MachoCmdSymtab = 2,
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MachoCmdSymseg = 3,
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MachoCmdThread = 4,
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MachoCmdDysymtab = 11,
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MachoCmdSegment64 = 25,
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MachoFileObject = 1,
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MachoFileExecutable = 2,
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MachoFileFvmlib = 3,
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MachoFileCore = 4,
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MachoFilePreload = 5,
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};
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struct MachoSeg
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{
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char name[16+1];
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uint64 vmaddr;
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uint64 vmsize;
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uint32 fileoff;
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uint32 filesz;
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uint32 maxprot;
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uint32 initprot;
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uint32 nsect;
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uint32 flags;
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MachoSect *sect;
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};
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struct MachoSect
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{
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char name[16+1];
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char segname[16+1];
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uint64 addr;
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uint64 size;
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uint32 off;
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uint32 align;
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uint32 reloff;
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uint32 nreloc;
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uint32 flags;
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uint32 res1;
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uint32 res2;
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Sym *sym;
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MachoRel *rel;
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};
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struct MachoRel
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{
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uint32 addr;
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uint32 symnum;
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uint8 pcrel;
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uint8 length;
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uint8 extrn;
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uint8 type;
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uint8 scattered;
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uint32 value;
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};
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struct MachoSymtab
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{
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uint32 symoff;
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uint32 nsym;
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uint32 stroff;
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uint32 strsize;
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char *str;
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MachoSym *sym;
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};
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struct MachoSym
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{
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char *name;
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uint8 type;
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uint8 sectnum;
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uint16 desc;
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char kind;
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uint64 value;
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Sym *sym;
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};
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struct MachoDysymtab
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{
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uint32 ilocalsym;
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uint32 nlocalsym;
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uint32 iextdefsym;
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uint32 nextdefsym;
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uint32 iundefsym;
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uint32 nundefsym;
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uint32 tocoff;
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uint32 ntoc;
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uint32 modtaboff;
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uint32 nmodtab;
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uint32 extrefsymoff;
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uint32 nextrefsyms;
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uint32 indirectsymoff;
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uint32 nindirectsyms;
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uint32 extreloff;
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uint32 nextrel;
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uint32 locreloff;
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uint32 nlocrel;
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uint32 *indir;
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};
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struct MachoCmd
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{
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int type;
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uint32 off;
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uint32 size;
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MachoSeg seg;
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MachoSymtab sym;
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MachoDysymtab dsym;
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};
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struct MachoObj
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{
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Biobuf *f;
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int64 base; // off in f where Mach-O begins
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int64 len; // length of Mach-O
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int is64;
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char *name;
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Endian *e;
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uint cputype;
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uint subcputype;
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uint32 filetype;
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uint32 flags;
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MachoCmd *cmd;
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uint ncmd;
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};
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static int
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unpackcmd(uchar *p, MachoObj *m, MachoCmd *c, uint type, uint sz)
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{
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uint32 (*e4)(uchar*);
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uint64 (*e8)(uchar*);
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MachoSect *s;
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int i;
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e4 = m->e->e32;
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e8 = m->e->e64;
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c->type = type;
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c->size = sz;
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switch(type){
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default:
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return -1;
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case MachoCmdSegment:
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if(sz < 56)
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return -1;
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strecpy(c->seg.name, c->seg.name+sizeof c->seg.name, (char*)p+8);
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c->seg.vmaddr = e4(p+24);
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c->seg.vmsize = e4(p+28);
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c->seg.fileoff = e4(p+32);
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c->seg.filesz = e4(p+36);
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c->seg.maxprot = e4(p+40);
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c->seg.initprot = e4(p+44);
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c->seg.nsect = e4(p+48);
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c->seg.flags = e4(p+52);
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c->seg.sect = mal(c->seg.nsect * sizeof c->seg.sect[0]);
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if(sz < 56+c->seg.nsect*68)
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return -1;
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p += 56;
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for(i=0; i<c->seg.nsect; i++) {
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s = &c->seg.sect[i];
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strecpy(s->name, s->name+sizeof s->name, (char*)p+0);
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strecpy(s->segname, s->segname+sizeof s->segname, (char*)p+16);
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s->addr = e4(p+32);
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s->size = e4(p+36);
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s->off = e4(p+40);
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s->align = e4(p+44);
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s->reloff = e4(p+48);
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s->nreloc = e4(p+52);
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s->flags = e4(p+56);
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s->res1 = e4(p+60);
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s->res2 = e4(p+64);
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p += 68;
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}
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break;
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case MachoCmdSegment64:
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if(sz < 72)
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return -1;
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strecpy(c->seg.name, c->seg.name+sizeof c->seg.name, (char*)p+8);
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c->seg.vmaddr = e8(p+24);
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c->seg.vmsize = e8(p+32);
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c->seg.fileoff = e8(p+40);
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c->seg.filesz = e8(p+48);
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c->seg.maxprot = e4(p+56);
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c->seg.initprot = e4(p+60);
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c->seg.nsect = e4(p+64);
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c->seg.flags = e4(p+68);
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c->seg.sect = mal(c->seg.nsect * sizeof c->seg.sect[0]);
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if(sz < 72+c->seg.nsect*80)
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return -1;
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p += 72;
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for(i=0; i<c->seg.nsect; i++) {
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s = &c->seg.sect[i];
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strecpy(s->name, s->name+sizeof s->name, (char*)p+0);
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strecpy(s->segname, s->segname+sizeof s->segname, (char*)p+16);
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s->addr = e8(p+32);
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s->size = e8(p+40);
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s->off = e4(p+48);
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s->align = e4(p+52);
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s->reloff = e4(p+56);
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s->nreloc = e4(p+60);
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s->flags = e4(p+64);
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s->res1 = e4(p+68);
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s->res2 = e4(p+72);
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// p+76 is reserved
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p += 80;
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}
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break;
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case MachoCmdSymtab:
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if(sz < 24)
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return -1;
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c->sym.symoff = e4(p+8);
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c->sym.nsym = e4(p+12);
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c->sym.stroff = e4(p+16);
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c->sym.strsize = e4(p+20);
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break;
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case MachoCmdDysymtab:
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if(sz < 80)
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return -1;
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c->dsym.ilocalsym = e4(p+8);
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c->dsym.nlocalsym = e4(p+12);
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c->dsym.iextdefsym = e4(p+16);
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c->dsym.nextdefsym = e4(p+20);
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c->dsym.iundefsym = e4(p+24);
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c->dsym.nundefsym = e4(p+28);
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c->dsym.tocoff = e4(p+32);
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c->dsym.ntoc = e4(p+36);
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c->dsym.modtaboff = e4(p+40);
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c->dsym.nmodtab = e4(p+44);
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c->dsym.extrefsymoff = e4(p+48);
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c->dsym.nextrefsyms = e4(p+52);
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c->dsym.indirectsymoff = e4(p+56);
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c->dsym.nindirectsyms = e4(p+60);
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c->dsym.extreloff = e4(p+64);
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c->dsym.nextrel = e4(p+68);
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c->dsym.locreloff = e4(p+72);
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c->dsym.nlocrel = e4(p+76);
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break;
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}
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return 0;
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}
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static int
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macholoadrel(MachoObj *m, MachoSect *sect)
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{
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MachoRel *rel, *r;
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uchar *buf, *p;
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int i, n;
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uint32 v;
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if(sect->rel != nil || sect->nreloc == 0)
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return 0;
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rel = mal(sect->nreloc * sizeof r[0]);
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n = sect->nreloc * 8;
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buf = mal(n);
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if(Bseek(m->f, m->base + sect->reloff, 0) < 0 || Bread(m->f, buf, n) != n)
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return -1;
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for(i=0; i<sect->nreloc; i++) {
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r = &rel[i];
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p = buf+i*8;
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r->addr = m->e->e32(p);
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// TODO(rsc): Wrong interpretation for big-endian bitfields?
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if(r->addr & 0x80000000) {
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// scatterbrained relocation
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r->scattered = 1;
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v = r->addr >> 24;
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r->addr &= 0xFFFFFF;
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r->type = v & 0xF;
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v >>= 4;
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r->length = 1<<(v&3);
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v >>= 2;
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r->pcrel = v & 1;
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r->value = m->e->e32(p+4);
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} else {
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v = m->e->e32(p+4);
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r->symnum = v & 0xFFFFFF;
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v >>= 24;
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r->pcrel = v&1;
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v >>= 1;
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r->length = 1<<(v&3);
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v >>= 2;
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r->extrn = v&1;
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v >>= 1;
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r->type = v;
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}
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}
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sect->rel = rel;
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return 0;
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}
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static int
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macholoaddsym(MachoObj *m, MachoDysymtab *d)
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{
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uchar *p;
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int i, n;
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n = d->nindirectsyms;
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p = mal(n*4);
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if(Bseek(m->f, m->base + d->indirectsymoff, 0) < 0 || Bread(m->f, p, n*4) != n*4)
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return -1;
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d->indir = (uint32*)p;
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for(i=0; i<n; i++)
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d->indir[i] = m->e->e32(p+4*i);
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return 0;
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}
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static int
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macholoadsym(MachoObj *m, MachoSymtab *symtab)
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{
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char *strbuf;
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uchar *symbuf, *p;
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int i, n, symsize;
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MachoSym *sym, *s;
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uint32 v;
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if(symtab->sym != nil)
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return 0;
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strbuf = mal(symtab->strsize);
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if(Bseek(m->f, m->base + symtab->stroff, 0) < 0 || Bread(m->f, strbuf, symtab->strsize) != symtab->strsize)
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return -1;
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symsize = 12;
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if(m->is64)
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symsize = 16;
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n = symtab->nsym * symsize;
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symbuf = mal(n);
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if(Bseek(m->f, m->base + symtab->symoff, 0) < 0 || Bread(m->f, symbuf, n) != n)
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return -1;
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sym = mal(symtab->nsym * sizeof sym[0]);
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p = symbuf;
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for(i=0; i<symtab->nsym; i++) {
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s = &sym[i];
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v = m->e->e32(p);
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if(v >= symtab->strsize)
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return -1;
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s->name = strbuf + v;
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s->type = p[4];
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s->sectnum = p[5];
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s->desc = m->e->e16(p+6);
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if(m->is64)
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s->value = m->e->e64(p+8);
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else
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s->value = m->e->e32(p+8);
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p += symsize;
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}
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symtab->str = strbuf;
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symtab->sym = sym;
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return 0;
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}
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void
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ldmacho(Biobuf *f, char *pkg, int64 len, char *pn)
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{
|
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int i, j, is64;
|
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uchar hdr[7*4], *cmdp;
|
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uchar tmp[4];
|
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uchar *dat;
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ulong ncmd, cmdsz, ty, sz, off;
|
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MachoObj *m;
|
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Endian *e;
|
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int64 base;
|
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MachoSect *sect;
|
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MachoRel *rel;
|
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Sym *s, *outer;
|
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MachoCmd *c;
|
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MachoSymtab *symtab;
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MachoDysymtab *dsymtab;
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MachoSym *sym;
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Reloc *r, *rp;
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char *name;
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version++;
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base = Boffset(f);
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if(Bread(f, hdr, sizeof hdr) != sizeof hdr)
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goto bad;
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if((be.e32(hdr)&~1) == 0xFEEDFACE){
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e = &be;
|
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}else if((le.e32(hdr)&~1) == 0xFEEDFACE){
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e = ≤
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}else{
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werrstr("bad magic - not mach-o file");
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goto bad;
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}
|
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is64 = e->e32(hdr) == 0xFEEDFACF;
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ncmd = e->e32(hdr+4*4);
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cmdsz = e->e32(hdr+5*4);
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if(ncmd > 0x10000 || cmdsz >= 0x01000000){
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werrstr("implausible mach-o header ncmd=%lud cmdsz=%lud", ncmd, cmdsz);
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goto bad;
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}
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if(is64)
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Bread(f, tmp, 4); // skip reserved word in header
|
||||
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||||
m = mal(sizeof(*m)+ncmd*sizeof(MachoCmd)+cmdsz);
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m->f = f;
|
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m->e = e;
|
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m->cputype = e->e32(hdr+1*4);
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m->subcputype = e->e32(hdr+2*4);
|
||||
m->filetype = e->e32(hdr+3*4);
|
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m->ncmd = ncmd;
|
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m->flags = e->e32(hdr+6*4);
|
||||
m->is64 = is64;
|
||||
m->base = base;
|
||||
m->len = len;
|
||||
m->name = pn;
|
||||
|
||||
switch(thechar) {
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||||
default:
|
||||
diag("%s: mach-o %s unimplemented", thestring);
|
||||
return;
|
||||
case '6':
|
||||
if(e != &le || m->cputype != MachoCpuAmd64) {
|
||||
diag("%s: mach-o object but not amd64", pn);
|
||||
return;
|
||||
}
|
||||
break;
|
||||
case '8':
|
||||
if(e != &le || m->cputype != MachoCpu386) {
|
||||
diag("%s: mach-o object but not 386", pn);
|
||||
return;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
m->cmd = (MachoCmd*)(m+1);
|
||||
off = sizeof hdr;
|
||||
cmdp = (uchar*)(m->cmd+ncmd);
|
||||
if(Bread(f, cmdp, cmdsz) != cmdsz){
|
||||
werrstr("reading cmds: %r");
|
||||
goto bad;
|
||||
}
|
||||
|
||||
// read and parse load commands
|
||||
c = nil;
|
||||
symtab = nil;
|
||||
dsymtab = nil;
|
||||
for(i=0; i<ncmd; i++){
|
||||
ty = e->e32(cmdp);
|
||||
sz = e->e32(cmdp+4);
|
||||
m->cmd[i].off = off;
|
||||
unpackcmd(cmdp, m, &m->cmd[i], ty, sz);
|
||||
cmdp += sz;
|
||||
off += sz;
|
||||
if(ty == MachoCmdSymtab) {
|
||||
if(symtab != nil) {
|
||||
werrstr("multiple symbol tables");
|
||||
goto bad;
|
||||
}
|
||||
symtab = &m->cmd[i].sym;
|
||||
macholoadsym(m, symtab);
|
||||
}
|
||||
if(ty == MachoCmdDysymtab) {
|
||||
dsymtab = &m->cmd[i].dsym;
|
||||
macholoaddsym(m, dsymtab);
|
||||
}
|
||||
if((is64 && ty == MachoCmdSegment64) || (!is64 && ty == MachoCmdSegment)) {
|
||||
if(c != nil) {
|
||||
werrstr("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) {
|
||||
werrstr("no load command");
|
||||
goto bad;
|
||||
}
|
||||
if(symtab == nil) {
|
||||
werrstr("no symbol table");
|
||||
goto bad;
|
||||
}
|
||||
|
||||
if(c->seg.fileoff+c->seg.filesz >= len) {
|
||||
werrstr("load segment out of range");
|
||||
goto bad;
|
||||
}
|
||||
|
||||
dat = mal(c->seg.filesz);
|
||||
if(Bseek(f, m->base + c->seg.fileoff, 0) < 0 || Bread(f, dat, c->seg.filesz) != c->seg.filesz) {
|
||||
werrstr("cannot load object data: %r");
|
||||
goto bad;
|
||||
}
|
||||
|
||||
for(i=0; i<c->seg.nsect; i++) {
|
||||
sect = &c->seg.sect[i];
|
||||
if(strcmp(sect->segname, "__TEXT") != 0 && strcmp(sect->segname, "__DATA") != 0)
|
||||
continue;
|
||||
if(strcmp(sect->name, "__eh_frame") == 0)
|
||||
continue;
|
||||
name = smprint("%s(%s/%s)", pn, sect->segname, sect->name);
|
||||
s = lookup(name, version);
|
||||
if(s->type != 0) {
|
||||
werrstr("duplicate %s/%s", sect->segname, sect->name);
|
||||
goto bad;
|
||||
}
|
||||
free(name);
|
||||
s->p = dat + sect->addr - c->seg.vmaddr;
|
||||
s->np = sect->size;
|
||||
s->size = s->np;
|
||||
|
||||
if(strcmp(sect->segname, "__TEXT") == 0) {
|
||||
if(strcmp(sect->name, "__text") == 0)
|
||||
s->type = STEXT;
|
||||
else
|
||||
s->type = SRODATA;
|
||||
} else {
|
||||
s->type = SDATA;
|
||||
}
|
||||
if(s->type == STEXT) {
|
||||
if(etextp)
|
||||
etextp->next = s;
|
||||
else
|
||||
textp = s;
|
||||
etextp = s;
|
||||
}
|
||||
sect->sym = s;
|
||||
}
|
||||
|
||||
// enter sub-symbols into symbol table.
|
||||
// have to guess sizes from next symbol.
|
||||
for(i=0; i<symtab->nsym; i++) {
|
||||
int v;
|
||||
sym = &symtab->sym[i];
|
||||
// TODO: check sym->type against outer->type.
|
||||
name = sym->name;
|
||||
if(name[0] == '_' && name[1] != '\0')
|
||||
name++;
|
||||
v = 0;
|
||||
if(!(sym->type&N_EXT))
|
||||
v = version;
|
||||
s = lookup(name, v);
|
||||
sym->sym = s;
|
||||
if(sym->sectnum == 0) // undefined
|
||||
continue;
|
||||
if(sym->sectnum > c->seg.nsect) {
|
||||
werrstr("reference to invalid section %d", sym->sectnum);
|
||||
goto bad;
|
||||
}
|
||||
sect = &c->seg.sect[sym->sectnum-1];
|
||||
outer = sect->sym;
|
||||
if(outer == nil) {
|
||||
werrstr("reference to invalid section %s/%s", sect->segname, sect->name);
|
||||
continue;
|
||||
}
|
||||
s->type = outer->type | SSUB;
|
||||
s->sub = outer->sub;
|
||||
outer->sub = s;
|
||||
s->outer = outer;
|
||||
s->value = sym->value - sect->addr;
|
||||
if(i+1 < symtab->nsym)
|
||||
s->size = (sym+1)->value - sym->value;
|
||||
else
|
||||
s->size = sect->addr + sect->size - sym->value;
|
||||
s->dynimplib = nil; // satisfy dynimport
|
||||
s->dynimpname = nil; // satisfy dynimport
|
||||
if(outer->type == STEXT) {
|
||||
Prog *p;
|
||||
|
||||
if(s->text != P)
|
||||
diag("%s: duplicate definition of %s", pn, s->name);
|
||||
// build a TEXT instruction with a unique pc
|
||||
// just to make the rest of the linker happy.
|
||||
// TODO: this is too 6l-specific ?
|
||||
p = prg();
|
||||
p->as = ATEXT;
|
||||
p->from.type = D_EXTERN;
|
||||
p->from.sym = s;
|
||||
p->from.scale = 7;
|
||||
p->to.type = D_CONST;
|
||||
p->link = nil;
|
||||
p->pc = pc++;
|
||||
s->text = p;
|
||||
|
||||
etextp->next = s;
|
||||
etextp = s;
|
||||
}
|
||||
sym->sym = s;
|
||||
}
|
||||
|
||||
|
||||
// load relocations
|
||||
for(i=0; i<c->seg.nsect; i++) {
|
||||
sect = &c->seg.sect[i];
|
||||
if((s = sect->sym) == S)
|
||||
continue;
|
||||
macholoadrel(m, sect);
|
||||
if(sect->rel == nil)
|
||||
continue;
|
||||
r = mal(sect->nreloc*sizeof r[0]);
|
||||
rp = r;
|
||||
rel = sect->rel;
|
||||
for(j=0; j<sect->nreloc; j++, rel++) {
|
||||
if(rel->scattered) {
|
||||
int k;
|
||||
MachoSect *ks;
|
||||
|
||||
if(thechar != '8')
|
||||
diag("unexpected scattered relocation");
|
||||
|
||||
// on 386, rewrite scattered 4/1 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(thechar != '8' || rel->type != 4 || j+1 >= sect->nreloc ||
|
||||
!(rel+1)->scattered || (rel+1)->type != 1 ||
|
||||
(rel+1)->value < sect->addr || (rel+1)->value >= sect->addr+sect->size) {
|
||||
werrstr("unsupported scattered relocation %d/%d", (int)rel->type, (int)(rel+1)->type);
|
||||
goto bad;
|
||||
}
|
||||
rp->siz = rel->length;
|
||||
rp->off = 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 = (rel+1)->value - sect->addr.
|
||||
// adjust rp->add accordingly.
|
||||
rp->type = D_PCREL;
|
||||
rp->add += (rp->off+4) - ((rel+1)->value - sect->addr);
|
||||
|
||||
// now consider the desired symbol.
|
||||
// find the section where it lives.
|
||||
for(k=0; k<c->seg.nsect; k++) {
|
||||
ks = &c->seg.sect[k];
|
||||
if(ks->addr <= rel->value && rel->value < ks->addr+ks->size)
|
||||
goto foundk;
|
||||
}
|
||||
werrstr("unsupported scattered relocation: invalid address %#ux", rel->addr);
|
||||
goto bad;
|
||||
foundk:
|
||||
if(ks->sym != S) {
|
||||
rp->sym = ks->sym;
|
||||
rp->add += rel->value - ks->addr;
|
||||
} else if(strcmp(ks->segname, "__IMPORT") == 0 && strcmp(ks->name, "__pointers") == 0) {
|
||||
// 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 = ks->res1 + (rel->value - ks->addr) / 4;
|
||||
// load indirect table for __pointers
|
||||
// fetch symbol number
|
||||
if(dsymtab == nil || k < 0 || k >= dsymtab->nindirectsyms || dsymtab->indir == nil) {
|
||||
werrstr("invalid scattered relocation: indirect symbol reference out of range");
|
||||
goto bad;
|
||||
}
|
||||
k = dsymtab->indir[k];
|
||||
if(k < 0 || k >= symtab->nsym) {
|
||||
werrstr("invalid scattered relocation: symbol reference out of range");
|
||||
goto bad;
|
||||
}
|
||||
rp->sym = symtab->sym[k].sym;
|
||||
} else {
|
||||
werrstr("unsupported scattered relocation: reference to %s/%s", ks->segname, ks->name);
|
||||
goto bad;
|
||||
}
|
||||
rp++;
|
||||
// skip #1 of 2 rel; continue skips #2 of 2.
|
||||
rel++;
|
||||
j++;
|
||||
continue;
|
||||
}
|
||||
|
||||
rp->siz = rel->length;
|
||||
rp->type = 512 + (rel->type<<1) + rel->pcrel;
|
||||
rp->off = rel->addr;
|
||||
|
||||
rp->add = e->e32(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 && thechar == '8')
|
||||
rp->add += rp->off+rp->siz;
|
||||
if(!rel->extrn) {
|
||||
if(rel->symnum < 1 || rel->symnum > c->seg.nsect) {
|
||||
werrstr("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) {
|
||||
werrstr("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(thechar == '8')
|
||||
rp->add -= c->seg.sect[rel->symnum-1].addr;
|
||||
} else {
|
||||
if(rel->symnum >= symtab->nsym) {
|
||||
werrstr("invalid relocation: symbol reference out of range");
|
||||
goto bad;
|
||||
}
|
||||
rp->sym = symtab->sym[rel->symnum].sym;
|
||||
}
|
||||
rp++;
|
||||
}
|
||||
qsort(r, rp - r, sizeof r[0], rbyoff);
|
||||
s->r = r;
|
||||
s->nr = rp - r;
|
||||
}
|
||||
return;
|
||||
|
||||
bad:
|
||||
diag("%s: malformed mach-o file: %r", pn);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user