void
elfdynhash(void)
{
Sym *s, *sy, *dynstr;
int i, j, nbucket, b, nfile;
uint32 hc, *chain, *buckets;
int nsym;
char *name;
Elfaux **need;
Elflib *needlib;
Elflib *l;
Elfaux *x;
if(!iself)
return;
nsym = nelfsym;
s = lookup(".hash", 0);
s->type = SELFROSECT;
s->reachable = 1;
i = nsym;
nbucket = 1;
while(i > 0) {
++nbucket;
i >>= 1;
}
needlib = nil;
need = malloc(nsym * sizeof need[0]);
chain = malloc(nsym * sizeof chain[0]);
buckets = malloc(nbucket * sizeof buckets[0]);
if(need == nil || chain == nil || buckets == nil) {
cursym = nil;
diag("out of memory");
errorexit();
}
memset(need, 0, nsym * sizeof need[0]);
memset(chain, 0, nsym * sizeof chain[0]);
memset(buckets, 0, nbucket * sizeof buckets[0]);
for(sy=allsym; sy!=S; sy=sy->allsym) {
if (sy->dynid <= 0)
continue;
if(sy->dynimpvers)
need[sy->dynid] = addelflib(&needlib, sy->dynimplib, sy->dynimpvers);
name = sy->extname;
hc = elfhash((uchar*)name);
b = hc % nbucket;
chain[sy->dynid] = buckets[b];
buckets[b] = sy->dynid;
}
adduint32(s, nbucket);
adduint32(s, nsym);
for(i = 0; i<nbucket; i++)
adduint32(s, buckets[i]);
for(i = 0; i<nsym; i++)
adduint32(s, chain[i]);
free(chain);
free(buckets);
// version symbols
dynstr = lookup(".dynstr", 0);
s = lookup(".gnu.version_r", 0);
i = 2;
nfile = 0;
for(l=needlib; l; l=l->next) {
nfile++;
// header
adduint16(s, 1); // table version
j = 0;
for(x=l->aux; x; x=x->next)
j++;
adduint16(s, j); // aux count
adduint32(s, addstring(dynstr, l->file)); // file string offset
adduint32(s, 16); // offset from header to first aux
if(l->next)
adduint32(s, 16+j*16); // offset from this header to next
else
adduint32(s, 0);
for(x=l->aux; x; x=x->next) {
x->num = i++;
// aux struct
adduint32(s, elfhash((uchar*)x->vers)); // hash
adduint16(s, 0); // flags
adduint16(s, x->num); // other - index we refer to this by
adduint32(s, addstring(dynstr, x->vers)); // version string offset
if(x->next)
adduint32(s, 16); // offset from this aux to next
else
adduint32(s, 0);
}
}
// version references
s = lookup(".gnu.version", 0);
for(i=0; i<nsym; i++) {
if(i == 0)
adduint16(s, 0); // first entry - no symbol
else if(need[i] == nil)
adduint16(s, 1); // global
else
adduint16(s, need[i]->num);
}
free(need);
s = lookup(".dynamic", 0);
elfverneed = nfile;
if(elfverneed) {
elfwritedynentsym(s, DT_VERNEED, lookup(".gnu.version_r", 0));
elfwritedynent(s, DT_VERNEEDNUM, nfile);
elfwritedynentsym(s, DT_VERSYM, lookup(".gnu.version", 0));
}
elfwritedynent(s, DT_NULL, 0);
}
void
doelf(void)
{
Sym *s, *shstrtab, *dynstr;
if(!iself)
return;
/* predefine strings we need for section headers */
shstrtab = lookup(".shstrtab", 0);
shstrtab->type = SELFDATA;
shstrtab->reachable = 1;
elfstr[ElfStrEmpty] = addstring(shstrtab, "");
elfstr[ElfStrText] = addstring(shstrtab, ".text");
elfstr[ElfStrData] = addstring(shstrtab, ".data");
addstring(shstrtab, ".rodata");
elfstr[ElfStrBss] = addstring(shstrtab, ".bss");
if(!debug['s']) {
elfstr[ElfStrGosymcounts] = addstring(shstrtab, ".gosymcounts");
elfstr[ElfStrGosymtab] = addstring(shstrtab, ".gosymtab");
elfstr[ElfStrGopclntab] = addstring(shstrtab, ".gopclntab");
}
elfstr[ElfStrShstrtab] = addstring(shstrtab, ".shstrtab");
if(!debug['d']) { /* -d suppresses dynamic loader format */
elfstr[ElfStrInterp] = addstring(shstrtab, ".interp");
elfstr[ElfStrHash] = addstring(shstrtab, ".hash");
elfstr[ElfStrGot] = addstring(shstrtab, ".got");
elfstr[ElfStrGotPlt] = addstring(shstrtab, ".got.plt");
elfstr[ElfStrDynamic] = addstring(shstrtab, ".dynamic");
elfstr[ElfStrDynsym] = addstring(shstrtab, ".dynsym");
elfstr[ElfStrDynstr] = addstring(shstrtab, ".dynstr");
elfstr[ElfStrRel] = addstring(shstrtab, ".rel");
elfstr[ElfStrRelPlt] = addstring(shstrtab, ".rel.plt");
elfstr[ElfStrPlt] = addstring(shstrtab, ".plt");
/* interpreter string */
s = lookup(".interp", 0);
s->reachable = 1;
s->type = SELFDATA; // TODO: rodata
/* dynamic symbol table - first entry all zeros */
s = lookup(".dynsym", 0);
s->type = SELFDATA;
s->reachable = 1;
s->value += ELF32SYMSIZE;
/* dynamic string table */
s = lookup(".dynstr", 0);
s->type = SELFDATA;
s->reachable = 1;
if(s->size == 0)
addstring(s, "");
dynstr = s;
/* relocation table */
s = lookup(".rel", 0);
s->reachable = 1;
s->type = SELFDATA;
/* global offset table */
s = lookup(".got", 0);
s->reachable = 1;
s->type = SELFDATA;
/* hash */
s = lookup(".hash", 0);
s->reachable = 1;
s->type = SELFDATA;
/* got.plt */
s = lookup(".got.plt", 0);
s->reachable = 1;
s->type = SDATA; // writable, so not SELFDATA
s = lookup(".plt", 0);
s->reachable = 1;
s->type = SELFDATA;
s = lookup(".rel.plt", 0);
s->reachable = 1;
s->type = SELFDATA;
elfsetupplt();
/* define dynamic elf table */
s = lookup(".dynamic", 0);
s->reachable = 1;
s->type = SELFDATA;
/*
* .dynamic table
*/
elfwritedynentsym(s, DT_HASH, lookup(".hash", 0));
elfwritedynentsym(s, DT_SYMTAB, lookup(".dynsym", 0));
elfwritedynent(s, DT_SYMENT, ELF32SYMSIZE);
elfwritedynentsym(s, DT_STRTAB, lookup(".dynstr", 0));
elfwritedynentsymsize(s, DT_STRSZ, lookup(".dynstr", 0));
elfwritedynentsym(s, DT_REL, lookup(".rel", 0));
elfwritedynentsymsize(s, DT_RELSZ, lookup(".rel", 0));
elfwritedynent(s, DT_RELENT, ELF32RELSIZE);
if(rpath)
elfwritedynent(s, DT_RUNPATH, addstring(dynstr, rpath));
elfwritedynentsym(s, DT_PLTGOT, lookup(".got.plt", 0));
elfwritedynent(s, DT_PLTREL, DT_REL);
elfwritedynentsymsize(s, DT_PLTRELSZ, lookup(".rel.plt", 0));
elfwritedynentsym(s, DT_JMPREL, lookup(".rel.plt", 0));
elfwritedynent(s, DT_NULL, 0);
}
}
