/*
* Elf binaries.
*/
static int
elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
{
Ehdr *ep;
/* bitswap the header according to the DATA format */
ep = &hp->e;
if(ep->ident[CLASS] == ELFCLASS32)
return elf32dotout(fd, fp, hp);
else if(ep->ident[CLASS] == ELFCLASS64)
return elf64dotout(fd, fp, hp);
werrstr("bad ELF class - not 32 bit");
return 0;
}
static int
elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
{
uint32 (*swal)(uint32);
ushort (*swab)(ushort);
Ehdr32 *ep;
Phdr32 *ph;
int i, it, id, is, phsz, shsz;
Shdr32 *sh;
/* bitswap the header according to the DATA format */
ep = &hp->e.elfhdr32;
if(ep->ident[CLASS] != ELFCLASS32) {
return elf64dotout(fd, fp, hp);
}
if(ep->ident[DATA] == ELFDATA2LSB) {
swab = leswab;
swal = leswal;
} else if(ep->ident[DATA] == ELFDATA2MSB) {
swab = beswab;
swal = beswal;
} else {
werrstr("bad ELF encoding - not big or little endian");
return 0;
}
ep->type = swab(ep->type);
ep->machine = swab(ep->machine);
ep->version = swal(ep->version);
ep->elfentry = swal(ep->elfentry);
ep->phoff = swal(ep->phoff);
ep->shoff = swal(ep->shoff);
ep->flags = swal(ep->flags);
ep->ehsize = swab(ep->ehsize);
ep->phentsize = swab(ep->phentsize);
ep->phnum = swab(ep->phnum);
ep->shentsize = swab(ep->shentsize);
ep->shnum = swab(ep->shnum);
ep->shstrndx = swab(ep->shstrndx);
if(ep->type != EXEC || ep->version != CURRENT)
return 0;
/* we could definitely support a lot more machines here */
fp->magic = ELF_MAG;
fp->hdrsz = (ep->ehsize+ep->phnum*ep->phentsize+16)&~15;
switch(ep->machine) {
case I386:
mach = &mi386;
fp->type = FI386;
break;
case MIPS:
mach = &mmips;
fp->type = FMIPS;
break;
case SPARC64:
mach = &msparc64;
fp->type = FSPARC64;
break;
case POWER:
mach = &mpower;
fp->type = FPOWER;
break;
case ARM:
mach = &marm;
fp->type = FARM;
break;
default:
return 0;
}
if(ep->phentsize != sizeof(Phdr32)) {
werrstr("bad ELF header size");
return 0;
}
phsz = sizeof(Phdr32)*ep->phnum;
ph = malloc(phsz);
if(!ph)
return 0;
seek(fd, ep->phoff, 0);
if(read(fd, ph, phsz) < 0) {
free(ph);
return 0;
}
hswal(ph, phsz/sizeof(uint32), swal);
shsz = sizeof(Shdr32)*ep->shnum;
sh = malloc(shsz);
if(sh) {
seek(fd, ep->shoff, 0);
if(read(fd, sh, shsz) < 0) {
free(sh);
sh = 0;
} else
hswal(sh, shsz/sizeof(uint32), swal);
}
/* find text, data and symbols and install them */
it = id = is = -1;
for(i = 0; i < ep->phnum; i++) {
if(ph[i].type == LOAD
&& (ph[i].flags & (R|X)) == (R|X) && it == -1)
it = i;
else if(ph[i].type == LOAD
&& (ph[i].flags & (R|W)) == (R|W) && id == -1)
id = i;
else if(ph[i].type == NOPTYPE && is == -1)
is = i;
}
if(it == -1 || id == -1) {
/*
* The SPARC64 boot image is something of an ELF hack.
* Text+Data+BSS are represented by ph[0]. Symbols
* are represented by ph[1]:
*
* filesz, memsz, vaddr, paddr, off
* ph[0] : txtsz+datsz, txtsz+datsz+bsssz, txtaddr-KZERO, datasize, txtoff
* ph[1] : symsz, lcsz, 0, 0, symoff
*/
if(ep->machine == SPARC64 && ep->phnum == 2) {
uint32 txtaddr, txtsz, dataddr, bsssz;
txtaddr = ph[0].vaddr | 0x80000000;
txtsz = ph[0].filesz - ph[0].paddr;
dataddr = txtaddr + txtsz;
bsssz = ph[0].memsz - ph[0].filesz;
settext(fp, ep->elfentry | 0x80000000, txtaddr, txtsz, ph[0].offset);
setdata(fp, dataddr, ph[0].paddr, ph[0].offset + txtsz, bsssz);
setsym(fp, ph[1].filesz, 0, ph[1].memsz, ph[1].offset);
free(ph);
return 1;
}
werrstr("No TEXT or DATA sections");
error:
free(sh);
free(ph);
return 0;
}
settext(fp, ep->elfentry, ph[it].vaddr, ph[it].memsz, ph[it].offset);
setdata(fp, ph[id].vaddr, ph[id].filesz, ph[id].offset, ph[id].memsz - ph[id].filesz);
if(is != -1)
setsym(fp, ph[is].filesz, 0, ph[is].memsz, ph[is].offset);
else if(sh != 0){
char *buf;
uvlong symsize = 0;
uvlong symoff = 0;
uvlong pclnsz = 0;
/* load shstrtab names */
buf = malloc(sh[ep->shstrndx].size);
if (buf == 0)
goto done;
memset(buf, 0, sizeof buf);
seek(fd, sh[ep->shstrndx].offset, 0);
read(fd, buf, sh[ep->shstrndx].size);
for(i = 0; i < ep->shnum; i++) {
if (strcmp(&buf[sh[i].name], ".gosymtab") == 0) {
symsize = sh[i].size;
symoff = sh[i].offset;
}
if (strcmp(&buf[sh[i].name], ".gopclntab") == 0) {
if (sh[i].offset != symoff+symsize) {
werrstr("pc line table not contiguous with symbol table");
free(buf);
goto error;
}
pclnsz = sh[i].size;
}
}
setsym(fp, symsize, 0, pclnsz, symoff);
free(buf);
}
done:
free(sh);
free(ph);
return 1;
}
