From: Russ Cox Date: Sun, 10 Mar 2013 18:17:04 +0000 (-0400) Subject: cmd/ld: make mach-o sections match internal sections X-Git-Tag: go1.1rc2~615 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=b83d4af330858e819787efbbf6c5267f44d5b654;p=gostls13.git cmd/ld: make mach-o sections match internal sections This brings Mach-O generation more in line with ELF generation. Having separate sections for the symtab and pclntab mean that we can find them that way, instead of using the deprecated debug segments. (And the host linker will keep separate sections for us, but probably not the debug segments.) R=ken2 CC=golang-dev https://golang.org/cl/7688043 --- diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c index 22cb4f3e60..10dba90305 100644 --- a/src/cmd/ld/data.c +++ b/src/cmd/ld/data.c @@ -879,6 +879,9 @@ symalign(Sym *s) { int32 align; + if(s->align != 0) + return s->align; + align = MaxAlign; while(align > s->size && align > 1) align >>= 1; @@ -1136,9 +1139,10 @@ dodata(void) lookup("end", 0)->sect = sect; /* we finished segdata, begin segtext */ + s = datap; + datsize = 0; /* read-only data */ - s = datap; sect = addsection(&segtext, ".rodata", 04); sect->align = maxalign(s, STYPELINK-1); sect->vaddr = 0; @@ -1202,7 +1206,7 @@ dodata(void) } sect->len = datsize - sect->vaddr; - /* read-only ELF sections */ + /* read-only ELF, Mach-O sections */ for(; s != nil && s->type < SELFSECT; s = s->next) { sect = addsection(&segtext, s->name, 04); sect->align = symalign(s); @@ -1266,6 +1270,7 @@ address(void) Section *typelink; Sym *sym, *sub; uvlong va; + vlong vlen; va = INITTEXT; segtext.rwx = 05; @@ -1295,11 +1300,11 @@ address(void) noptrbss = nil; datarelro = nil; for(s=segdata.sect; s != nil; s=s->next) { + vlen = s->len; if(s->next) - s->len = s->next->vaddr - s->vaddr; + vlen = s->next->vaddr - s->vaddr; s->vaddr = va; - va += s->len; - segdata.filelen += s->len; + va += vlen; segdata.len = va - segdata.vaddr; if(strcmp(s->name, ".data") == 0) data = s; diff --git a/src/cmd/ld/dwarf.c b/src/cmd/ld/dwarf.c index 949752994b..99569be851 100644 --- a/src/cmd/ld/dwarf.c +++ b/src/cmd/ld/dwarf.c @@ -2298,42 +2298,42 @@ dwarfaddmachoheaders(void) ms->fileoffset = fakestart; ms->filesize = abbrevo-fakestart; - msect = newMachoSect(ms, "__debug_abbrev"); + msect = newMachoSect(ms, "__debug_abbrev", "__DWARF"); msect->off = abbrevo; msect->size = abbrevsize; ms->filesize += msect->size; - msect = newMachoSect(ms, "__debug_line"); + msect = newMachoSect(ms, "__debug_line", "__DWARF"); msect->off = lineo; msect->size = linesize; ms->filesize += msect->size; - msect = newMachoSect(ms, "__debug_frame"); + msect = newMachoSect(ms, "__debug_frame", "__DWARF"); msect->off = frameo; msect->size = framesize; ms->filesize += msect->size; - msect = newMachoSect(ms, "__debug_info"); + msect = newMachoSect(ms, "__debug_info", "__DWARF"); msect->off = infoo; msect->size = infosize; ms->filesize += msect->size; if (pubnamessize > 0) { - msect = newMachoSect(ms, "__debug_pubnames"); + msect = newMachoSect(ms, "__debug_pubnames", "__DWARF"); msect->off = pubnameso; msect->size = pubnamessize; ms->filesize += msect->size; } if (pubtypessize > 0) { - msect = newMachoSect(ms, "__debug_pubtypes"); + msect = newMachoSect(ms, "__debug_pubtypes", "__DWARF"); msect->off = pubtypeso; msect->size = pubtypessize; ms->filesize += msect->size; } if (arangessize > 0) { - msect = newMachoSect(ms, "__debug_aranges"); + msect = newMachoSect(ms, "__debug_aranges", "__DWARF"); msect->off = arangeso; msect->size = arangessize; ms->filesize += msect->size; @@ -2341,7 +2341,7 @@ dwarfaddmachoheaders(void) // TODO(lvd) fix gdb/python to load MachO (16 char section name limit) if (gdbscriptsize > 0) { - msect = newMachoSect(ms, "__debug_gdb_scripts"); + msect = newMachoSect(ms, "__debug_gdb_scripts", "__DWARF"); msect->off = gdbscripto; msect->size = gdbscriptsize; ms->filesize += msect->size; diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h index 6b4f4d7044..4e18bf2677 100644 --- a/src/cmd/ld/lib.h +++ b/src/cmd/ld/lib.h @@ -34,7 +34,6 @@ enum /* order here is order in output file */ STEXT, - SMACHOPLT, STYPE, SSTRING, SGOSTRING, @@ -43,12 +42,13 @@ enum SSYMTAB, SPCLNTAB, SELFROSECT, + SMACHOPLT, SELFSECT, + SMACHO, /* Mach-O __nl_symbol_ptr */ + SMACHOGOT, SNOPTRDATA, SDATARELRO, SDATA, - SMACHO, /* Mach-O __nl_symbol_ptr */ - SMACHOGOT, SWINDOWS, SBSS, SNOPTRBSS, diff --git a/src/cmd/ld/macho.c b/src/cmd/ld/macho.c index 75be9d9402..a282987de2 100644 --- a/src/cmd/ld/macho.c +++ b/src/cmd/ld/macho.c @@ -14,7 +14,6 @@ static int macho64; static MachoHdr hdr; static MachoLoad *load; static MachoSeg seg[16]; -static MachoDebug xdebug[16]; static int nload, mload, nseg, ndebug, nsect; // Amount of space left for adding load commands @@ -86,7 +85,7 @@ newMachoSeg(char *name, int msect) } MachoSect* -newMachoSect(MachoSeg *seg, char *name) +newMachoSect(MachoSeg *seg, char *name, char *segname) { MachoSect *s; @@ -96,21 +95,11 @@ newMachoSect(MachoSeg *seg, char *name) } s = &seg->sect[seg->nsect++]; s->name = name; + s->segname = segname; nsect++; return s; } -MachoDebug* -newMachoDebug(void) -{ - if(ndebug >= nelem(xdebug)) { - diag("too many debugs"); - errorexit(); - } - return &xdebug[ndebug++]; -} - - // Generic linking code. static char **dylib; @@ -126,7 +115,6 @@ machowrite(void) int i, j; MachoSeg *s; MachoSect *t; - MachoDebug *d; MachoLoad *l; o1 = cpos(); @@ -186,7 +174,7 @@ machowrite(void) t = &s->sect[j]; if(macho64) { strnput(t->name, 16); - strnput(s->name, 16); + strnput(t->segname, 16); VPUT(t->addr); VPUT(t->size); LPUT(t->off); @@ -199,7 +187,7 @@ machowrite(void) LPUT(0); /* reserved */ } else { strnput(t->name, 16); - strnput(s->name, 16); + strnput(t->segname, 16); LPUT(t->addr); LPUT(t->size); LPUT(t->off); @@ -221,14 +209,6 @@ machowrite(void) LPUT(l->data[j]); } - for(i=0; ifileoffset); - LPUT(d->filesize); - } - return cpos() - o1; } @@ -258,6 +238,7 @@ domacho(void) s = lookup(".got", 0); // will be __nl_symbol_ptr s->type = SMACHOGOT; s->reachable = 1; + s->align = 4; s = lookup(".linkedit.plt", 0); // indirect table for .plt s->type = SMACHOINDIRECTPLT; @@ -287,6 +268,52 @@ machoadddynlib(char *lib) dylib[ndylib++] = lib; } +static void +machoshbits(MachoSeg *mseg, Section *sect, char *segname) +{ + MachoSect *msect; + char buf[40]; + char *p; + + snprint(buf, sizeof buf, "__%s", sect->name+1); + for(p=buf; *p; p++) + if(*p == '.') + *p = '_'; + + msect = newMachoSect(mseg, estrdup(buf), segname); + + while(1<align < sect->align) + msect->align++; + msect->addr = sect->vaddr; + msect->size = sect->len; + msect->off = sect->seg->fileoff + sect->vaddr - sect->seg->vaddr; + + if(sect->vaddr < sect->seg->vaddr + sect->seg->filelen) { + // data in file + if(sect->len > sect->seg->vaddr + sect->seg->filelen - sect->vaddr) + diag("macho cannot represent section %s crossing data and bss", sect->name); + } else { + // zero fill + msect->flag |= 1; + } + + if(sect->rwx & 1) + msect->flag |= 0x400; /* has instructions */ + + if(strcmp(sect->name, ".plt") == 0) { + msect->name = "__symbol_stub1"; + msect->flag = 0x80000408; /* only instructions, code, symbol stubs */ + msect->res1 = 0; + msect->res2 = 6; + } + + if(strcmp(sect->name, ".got") == 0) { + msect->name = "__nl_symbol_ptr"; + msect->flag = 6; /* section with nonlazy symbol pointers */ + msect->res1 = lookup(".linkedit.plt", 0)->size / 4; /* offset into indirect symbol table */ + } +} + void asmbmacho(void) { @@ -294,11 +321,9 @@ asmbmacho(void) vlong va; int a, i; MachoHdr *mh; - MachoSect *msect; MachoSeg *ms; - MachoDebug *md; MachoLoad *ml; - Sym *s; + Section *sect; /* apple MACH */ va = INITTEXT - HEADR; @@ -323,62 +348,29 @@ asmbmacho(void) /* text */ v = rnd(HEADR+segtext.len, INITRND); - ms = newMachoSeg("__TEXT", 2); + ms = newMachoSeg("__TEXT", 20); ms->vaddr = va; ms->vsize = v; + ms->fileoffset = 0; ms->filesize = v; ms->prot1 = 7; ms->prot2 = 5; - - msect = newMachoSect(ms, "__text"); - msect->addr = INITTEXT; - msect->size = segtext.sect->len; - msect->off = INITTEXT - va; - msect->flag = 0x400; /* flag - some instructions */ - s = lookup(".plt", 0); - if(s->size > 0) { - msect = newMachoSect(ms, "__symbol_stub1"); - msect->addr = symaddr(s); - msect->size = s->size; - msect->off = ms->fileoffset + msect->addr - ms->vaddr; - msect->flag = 0x80000408; /* flag */ - msect->res1 = 0; /* index into indirect symbol table */ - msect->res2 = 6; /* size of stubs */ - } + for(sect=segtext.sect; sect!=nil; sect=sect->next) + machoshbits(ms, sect, "__TEXT"); /* data */ w = segdata.len; - ms = newMachoSeg("__DATA", 3); + ms = newMachoSeg("__DATA", 20); ms->vaddr = va+v; ms->vsize = w; ms->fileoffset = v; ms->filesize = segdata.filelen; - ms->prot1 = 7; + ms->prot1 = 3; ms->prot2 = 3; - - msect = newMachoSect(ms, "__data"); - msect->addr = va+v; - msect->off = v; - msect->size = segdata.filelen; - - s = lookup(".got", 0); - if(s->size > 0) { - msect->size = symaddr(s) - msect->addr; - - msect = newMachoSect(ms, "__nl_symbol_ptr"); - msect->addr = symaddr(s); - msect->size = s->size; - msect->off = datoff(msect->addr); - msect->align = 2; - msect->flag = 6; /* section with nonlazy symbol pointers */ - msect->res1 = lookup(".linkedit.plt", 0)->size / 4; /* offset into indirect symbol table */ - } - - msect = newMachoSect(ms, "__bss"); - msect->addr = va+v+segdata.filelen; - msect->size = segdata.len - segdata.filelen; - msect->flag = 1; /* flag - zero fill */ + + for(sect=segdata.sect; sect!=nil; sect=sect->next) + machoshbits(ms, sect, "__DATA"); switch(thechar) { default: @@ -456,21 +448,8 @@ asmbmacho(void) } } - if(!debug['s']) { - Sym *s; - - md = newMachoDebug(); - s = lookup("symtab", 0); - md->fileoffset = datoff(s->value); - md->filesize = s->size; - - md = newMachoDebug(); - s = lookup("pclntab", 0); - md->fileoffset = datoff(s->value); - md->filesize = s->size; - + if(!debug['s']) dwarfaddmachoheaders(); - } a = machowrite(); if(a > HEADR) diff --git a/src/cmd/ld/macho.h b/src/cmd/ld/macho.h index baea6ff03d..4499bb06fe 100644 --- a/src/cmd/ld/macho.h +++ b/src/cmd/ld/macho.h @@ -11,6 +11,7 @@ struct MachoHdr { typedef struct MachoSect MachoSect; struct MachoSect { char* name; + char* segname; uint64 addr; uint64 size; uint32 off; @@ -44,17 +45,10 @@ struct MachoLoad { uint32 *data; }; -typedef struct MachoDebug MachoDebug; -struct MachoDebug { - uint32 fileoffset; - uint32 filesize; -}; - MachoHdr* getMachoHdr(void); MachoSeg* newMachoSeg(char*, int); -MachoSect* newMachoSect(MachoSeg*, char*); +MachoSect* newMachoSect(MachoSeg*, char*, char*); MachoLoad* newMachoLoad(uint32, uint32); -MachoDebug* newMachoDebug(void); int machowrite(void); void machoinit(void); diff --git a/src/libmach/executable.c b/src/libmach/executable.c index 221e56cdef..6d0bc20888 100644 --- a/src/libmach/executable.c +++ b/src/libmach/executable.c @@ -1030,8 +1030,8 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp) uvlong textsize, datasize, bsssize; uchar *cmdbuf; uchar *cmdp; - int i, hdrsize; - uint32 textva, textoff, datava, dataoff; + int i, j, hdrsize; + uint32 textva, textoff, datava, dataoff, symoff, symsize, pclnoff, pclnsize; mp = &hp->e.machhdr; if (leswal(mp->filetype) != MACH_EXECUTABLE_TYPE) { @@ -1141,33 +1141,24 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp) if (strcmp(seg32->segname, "__TEXT") == 0) { textva = seg32->vmaddr; textoff = seg32->fileoff; + textsize = seg32->vmsize; sect32 = (MachSect32*)(cmdp + sizeof(MachSeg32)); - if (strcmp(sect32->sectname, "__text") == 0) { - textsize = swal(sect32->size); - } else { - werrstr("no text section"); - goto bad; + for(j = 0; j < seg32->nsects; j++, sect32++) { + if (strcmp(sect32->sectname, "__gosymtab") == 0) { + symoff = swal(sect32->offset); + symsize = swal(sect32->size); + } + if (strcmp(sect32->sectname, "__gopclntab") == 0) { + pclnoff = swal(sect32->offset); + pclnsize = swal(sect32->size); + } } } if (strcmp(seg32->segname, "__DATA") == 0) { datava = seg32->vmaddr; dataoff = seg32->fileoff; - sect32 = (MachSect32*)(cmdp + sizeof(MachSeg32)); - if (strcmp(sect32->sectname, "__data") == 0) { - datasize = swal(sect32->size); - } else { - werrstr("no data section"); - goto bad; - } - sect32++; - if (strcmp(sect32->sectname, "__nl_symbol_ptr") == 0) - sect32++; - if (strcmp(sect32->sectname, "__bss") == 0) { - bsssize = swal(sect32->size); - } else { - werrstr("no bss section"); - goto bad; - } + datasize = seg32->filesize; + bsssize = seg32->vmsize - seg32->filesize; } break; @@ -1188,42 +1179,39 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp) if (strcmp(seg->segname, "__TEXT") == 0) { textva = seg->vmaddr; textoff = seg->fileoff; + textsize = seg->vmsize; sect = (MachSect64*)(cmdp + sizeof(MachSeg64)); - if (strcmp(sect->sectname, "__text") == 0) { - textsize = swav(sect->size); - } else { - werrstr("no text section"); - goto bad; + for(j = 0; j < seg->nsects; j++, sect++) { +print("%s %#x %#x\n", sect->sectname, swal(sect->offset), swal(sect->size)); + if (strcmp(sect->sectname, "__gosymtab") == 0) { + symoff = swal(sect->offset); + symsize = swal(sect->size); + } + if (strcmp(sect->sectname, "__gopclntab") == 0) { + pclnoff = swal(sect->offset); + pclnsize = swal(sect->size); + } } } if (strcmp(seg->segname, "__DATA") == 0) { datava = seg->vmaddr; dataoff = seg->fileoff; - sect = (MachSect64*)(cmdp + sizeof(MachSeg64)); - if (strcmp(sect->sectname, "__data") == 0) { - datasize = swav(sect->size); - } else { - werrstr("no data section"); - goto bad; - } - sect++; - if (strcmp(sect->sectname, "__nl_symbol_ptr") == 0) - sect++; - if (strcmp(sect->sectname, "__bss") == 0) { - bsssize = swav(sect->size); - } else { - werrstr("no bss section"); - goto bad; - } + datasize = seg->filesize; + bsssize = seg->vmsize - seg->filesize; } break; case MACH_UNIXTHREAD: break; case MACH_SYMSEG: - if (symtab == 0) + if (symtab == 0) { symtab = (MachSymSeg*)c; - else if (pclntab == 0) + symoff = swal(symtab->fileoff); + symsize = swal(symtab->filesize); + } else if (pclntab == 0) { pclntab = (MachSymSeg*)c; + pclnoff = swal(pclntab->fileoff); + pclnsize = swal(pclntab->filesize); + } break; } cmdp += c->size; @@ -1236,8 +1224,8 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp) /* compute entry by taking address after header - weird - BUG? */ settext(fp, textva+sizeof(Machhdr) + mp->sizeofcmds, textva, textsize, textoff); setdata(fp, datava, datasize, dataoff, bsssize); - if(symtab != 0) - setsym(fp, symtab->fileoff, symtab->filesize, 0, 0, 0, pclntab? pclntab->filesize : 0); + if(symoff > 0) + setsym(fp, symoff, symsize, 0, 0, pclnoff, pclnsize); free(cmd); free(cmdbuf); return 1;