NetBSD/sys/compat/svr4/svr4_exec.c
1994-10-24 17:37:34 +00:00

643 lines
16 KiB
C

/* $NetBSD: svr4_exec.c,v 1.5 1994/10/24 17:37:36 deraadt Exp $ */
/*
* Copyright (c) 1994 Christos Zoulas
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/resourcevar.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_pager.h>
#include <machine/cpu.h>
#include <machine/reg.h>
#include <machine/exec.h>
#include <compat/svr4/svr4_util.h>
#include <compat/svr4/svr4_exec.h>
#define SVR4_ALIGN(a, b) ((a) & ~((b) - 1))
#define SVR4_PAGESIZE 4096
#define SVR4_AUX_ARGSIZ (sizeof(AuxInfo) * 8)
/*
* I know this is horrible, but I cannot load the interpreter after
* the data segment because brk(2) breaks. I have to load it somewhere
* before. Programs start at 0x08000000 so I load the interpreter far
* before.
*/
#define SVR4_INTERP_ADDR 0x01000000
struct svr4_args {
u_long arg_entry; /* progran entry point */
u_long arg_interp; /* Interpreter load address */
u_long arg_phaddr; /* program header address */
u_long arg_phentsize; /* Size of program header */
u_long arg_phnum; /* Number of program headers */
};
static void svr4_setup_args __P((int, struct proc *, struct exec_package *,
void *));
static int svr4_check_header __P((Elf32_Ehdr *, int));
static void svr4_load_psection __P((struct exec_package *, struct vnode *,
Elf32_Phdr *, u_long *, u_long *, int *));
static int svr4_set_segment __P((struct exec_package *, u_long, u_long, int));
static int svr4_read_from __P((struct vnode *, u_long, struct proc *, caddr_t,
int));
static int svr4_load_interp __P((struct proc *, char *, struct exec_package *,
struct svr4_args *, u_long* last));
#ifdef DEBUG_EXEC_SVR4
static void
print_Ehdr(e)
Elf32_Ehdr *e;
{
printf("e_ident %s, ", e->e_ident);
printf("e_type %d, ", e->e_type);
printf("e_machine %d, ", e->e_machine);
printf("e_version %ld, ", e->e_version);
printf("e_entry %lx, ", e->e_entry);
printf("e_phoff %lx, ", e->e_phoff);
printf("e_shoff %lx, ", e->e_shoff);
printf("e_flags %lx, ", e->e_flags);
printf("e_ehsize %d, ", e->e_ehsize);
printf("e_phentsize %d, ", e->e_phentsize);
printf("e_phnum %d, ", e->e_phnum);
printf("e_shentsize %d, ", e->e_shentsize);
printf("e_shnum %d, ", e->e_shnum);
printf("e_shstrndx %d\n", e->e_shstrndx);
}
static void
print_Phdr(p)
Elf32_Phdr *p;
{
static char *types[] =
{
"null", "load", "dynamic", "interp",
"note", "shlib", "phdr", "entry7"
};
printf("p_type %ld [%s], ", p->p_type, types[p->p_type & 7]);
printf("p_offset %lx, ", p->p_offset);
printf("p_vaddr %lx, ", p->p_vaddr);
printf("p_paddr %lx, ", p->p_paddr);
printf("p_filesz %ld, ", p->p_filesz);
printf("p_memsz %ld, ", p->p_memsz);
printf("p_flags %lx, ", p->p_flags);
printf("p_align %ld\n", p->p_align);
}
#endif
/*
* svr4_setup_args():
*
* Push extra arguments on the stack needed by dynamically linked binaries
*/
static void
svr4_setup_args(cmd, pp, ep, sp)
int cmd;
struct proc *pp;
struct exec_package *ep;
void *sp;
{
AuxInfo *a = sp;
struct svr4_args* ap = (struct svr4_args *) ep->ep_setup_arg;
if (cmd == EXEC_SETUP_CLEANUP) {
if (ap != NULL)
free((char *) ap, M_TEMP);
return;
}
if (cmd != EXEC_SETUP_ADDARGS)
return;
DPRINTF(("phaddr=0x%x, phentsize=%d, phnum=%d, interp=0x%x, entry=0x%x\n",
ap->arg_phaddr, ap->arg_phentsize, ap->arg_phnum, ap->arg_interp,
ap->arg_entry));
a->au_id = AUX_phdr;
a->au_v = ap->arg_phaddr;
a++;
a->au_id = AUX_phent;
a->au_v = ap->arg_phentsize;
a++;
a->au_id = AUX_phnum;
a->au_v = ap->arg_phnum;
a++;
a->au_id = AUX_pagesz;
a->au_v = SVR4_PAGESIZE;
a++;
a->au_id = AUX_base;
a->au_v = ap->arg_interp;
a++;
a->au_id = AUX_flags;
a->au_v = 0;
a++;
a->au_id = AUX_entry;
a->au_v = ap->arg_entry;
a++;
a->au_id = AUX_null;
a->au_v = 0;
}
/*
* svr4_check_header():
*
* Check header for validity; return 0 of ok ENOEXEC if error
*/
static int
svr4_check_header(eh, type)
Elf32_Ehdr *eh;
int type;
{
if (memcmp(eh->e_ident, Elf32_e_ident, Elf32_e_siz) != 0) {
DPRINTF(("Not an elf file\n"));
return ENOEXEC;
}
if (eh->e_machine != Elf32_em_386 && eh->e_machine != Elf32_em_486) {
DPRINTF(("Not an elf/386 or 486 executable\n"));
return ENOEXEC;
}
if (eh->e_type != type) {
DPRINTF(("Not an elf executable\n"));
return ENOEXEC;
}
return 0;
}
/*
* svr4_load_psection():
*
* Load a psection at the appropriate address
*/
static void
svr4_load_psection(epp, vp, ph, addr, size, prot)
struct exec_package *epp;
struct vnode *vp;
Elf32_Phdr *ph;
u_long *addr;
u_long *size;
int *prot;
{
u_long uaddr;
long diff;
long offset;
u_long msize;
/*
* If the user specified an address, then we load there.
*/
if (*addr != ~0) {
uaddr = *addr + ph->p_align;
*addr = SVR4_ALIGN(uaddr, ph->p_align);
uaddr = SVR4_ALIGN(ph->p_vaddr, ph->p_align);
diff = ph->p_vaddr - uaddr;
}
else {
uaddr = ph->p_vaddr;
*addr = SVR4_ALIGN(uaddr, ph->p_align);
diff = uaddr - *addr;
}
*prot |= (ph->p_flags & Elf32_pf_r) ? VM_PROT_READ : 0;
*prot |= (ph->p_flags & Elf32_pf_w) ? VM_PROT_WRITE : 0;
*prot |= (ph->p_flags & Elf32_pf_x) ? VM_PROT_EXECUTE : 0;
offset = ph->p_offset - diff;
*size = ph->p_filesz + diff;
msize = ph->p_memsz + diff;
DPRINTF(("Elf Segment@ 0x%x/0x%x sz %d/%d off 0x%x/0x%x[%d] algn 0x%x\n",
ph->p_vaddr, *addr, *size, msize, ph->p_offset, offset,
diff, ph->p_align));
NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, *size,
*addr, vp, offset, *prot);
/*
* Check if we need to extend the size of the segment
*/
{
u_long rm = round_page(*addr + msize);
u_long rf = round_page(*addr + *size);
if (rm != rf) {
DPRINTF(("zeropad 0x%x-0x%x\n", rf, rm));
NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, rm - rf,
rf, NULLVP, 0, *prot);
*size = msize;
}
}
}
/*
* svr4_set_segment():
*
* Decide if the segment is text or data, depending on the protection
* and set it appropriately
*/
static int
svr4_set_segment(epp, vaddr, size, prot)
struct exec_package *epp;
u_long vaddr;
u_long size;
int prot;
{
/*
* Kludge: Unfortunately the current implementation of
* exec package assumes a single text and data segment.
* In Elf we can have more, but here we limit ourselves
* to two and hope :-(
* We also assume that the text is r-x, and data is rwx.
*/
switch (prot) {
case (VM_PROT_READ|VM_PROT_EXECUTE):
if (epp->ep_tsize != ~0) {
DPRINTF(("More than one text segment\n"));
return ENOEXEC;
}
epp->ep_taddr = vaddr;
epp->ep_tsize = size;
DPRINTF(("Elf Text@ 0x%x, size %d\n", vaddr, size));
break;
case (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE):
if (epp->ep_dsize != ~0) {
DPRINTF(("More than one data segment\n"));
return ENOEXEC;
}
epp->ep_daddr = vaddr;
epp->ep_dsize = size;
DPRINTF(("Elf Data@ 0x%x, size %d\n", vaddr, size));
break;
default:
DPRINTF(("Bad protection 0%o\n", prot));
return ENOEXEC;
}
return 0;
}
/*
* svr4_read_from():
*
* Read from vnode into buffer at offset.
*/
static int
svr4_read_from(vp, off, p, buf, size)
struct vnode *vp;
u_long off;
struct proc *p;
caddr_t buf;
int size;
{
int error;
int resid;
DPRINTF(("read from 0x%x to 0x%x size %d\n",
off, buf, size));
if ((error = vn_rdwr(UIO_READ, vp, buf, size,
off, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred,
&resid, p)) != 0) {
DPRINTF(("Bad read error %d\n", error));
return error;
}
/*
* See if we got all of it
*/
if (resid != 0) {
DPRINTF(("Incomplete read for header ask=%d, rem=%d\n",
size, resid));
return error;
}
return 0;
}
/*
* svr4_load_interp():
*
* Load an interpreter pointed to by path [stolen from coff_load_shlib()]
*/
static int
svr4_load_interp(p, path, epp, ap, last)
struct proc *p;
char *path;
struct exec_package *epp;
struct svr4_args *ap;
u_long* last;
{
int error, i;
struct nameidata nd;
Elf32_Ehdr eh;
Elf32_Phdr *ph = NULL;
u_long phsize;
char *bp = NULL;
/*
* Start loading just after the data segment
*/
u_long addr = *last;
DPRINTF(("Loading interpreter %s\n", path));
if ((error = svr4_emul_find(p, UIO_SYSSPACE, svr4_emul_path, path,
&bp)) != 0)
bp = NULL;
else
path = bp;
/*
* 1. open interp file
* 2. read filehdr
* 3. map text, data, and bss out of it using VM_*
*/
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, p);
/* first get the vnode */
if ((error = namei(&nd)) != 0) {
DPRINTF(("Can't find interpreter %s\n", path));
if (bp != NULL)
free((char *) bp, M_TEMP);
return error;
}
if ((error = svr4_read_from(nd.ni_vp, 0, p,
(caddr_t) &eh, sizeof(eh))) != 0)
goto bad;
#ifdef DEBUG_EXEC_SVR4
print_Ehdr(&eh);
#endif
if ((error = svr4_check_header(&eh, Elf32_et_dyn)) != 0)
goto bad;
phsize = eh.e_phnum * sizeof(Elf32_Phdr);
ph = (Elf32_Phdr *) malloc(phsize, M_TEMP, M_WAITOK);
if ((error = svr4_read_from(nd.ni_vp, eh.e_phoff, p,
(caddr_t) ph, phsize)) != 0)
goto bad;
/*
* Load all the necessary sections
*/
for (i = 0; i < eh.e_phnum; i++) {
u_long size = 0;
int prot = 0;
#ifdef DEBUG_EXEC_SVR4
print_Phdr(&ph[i]);
#endif
switch (ph[i].p_type) {
case Elf32_pt_load:
svr4_load_psection(epp, nd.ni_vp, &ph[i], &addr, &size,
&prot);
/* Assume that the text segment is r-x only */
if ((prot & PROT_WRITE) == 0) {
epp->ep_entry = addr + eh.e_entry;
ap->arg_interp = addr;
DPRINTF(("Interpreter@ 0x%x\n", addr));
}
addr += size;
break;
case Elf32_pt_dynamic:
case Elf32_pt_phdr:
case Elf32_pt_note:
break;
default:
DPRINTF(("interp: Unexpected program header type %d\n",
ph[i].p_type));
break;
}
}
bad:
if (ph != NULL)
free((char *) ph, M_TEMP);
if (bp != NULL)
free((char *) bp, M_TEMP);
*last = addr;
vrele(nd.ni_vp);
return error;
}
/*
* exec_svr4_elf_makecmds(): Prepare an Elf binary's exec package
*
* First, set of the various offsets/lengths in the exec package.
*
* Then, mark the text image busy (so it can be demand paged) or error
* out if this is not possible. Finally, set up vmcmds for the
* text, data, bss, and stack segments.
*/
int
exec_svr4_elf_makecmds(p, epp)
struct proc *p;
struct exec_package *epp;
{
Elf32_Ehdr *eh = epp->ep_hdr;
Elf32_Phdr *ph;
int error;
int i;
char interp[MAXPATHLEN];
u_long pos = 0;
u_long phsize;
#ifdef DEBUG_EXEC_SVR4
print_Ehdr(eh);
#endif
if (epp->ep_hdrvalid < sizeof(Elf32_Ehdr))
return ENOEXEC;
if (svr4_check_header(eh, Elf32_et_exec))
return ENOEXEC;
/*
* check if vnode is in open for writing, because we want to
* demand-page out of it. if it is, don't do it, for various
* reasons
*/
if (epp->ep_vp->v_writecount != 0) {
#ifdef DIAGNOSTIC
if (epp->ep_vp->v_flag & VTEXT)
panic("exec: a VTEXT vnode has writecount != 0\n");
#endif
return ETXTBSY;
}
/*
* Allocate space to hold all the program headers, and read them
* from the file
*/
phsize = eh->e_phnum * sizeof(Elf32_Phdr);
ph = (Elf32_Phdr *) malloc(phsize, M_TEMP, M_WAITOK);
if ((error = svr4_read_from(epp->ep_vp, eh->e_phoff, p,
(caddr_t) ph, phsize)) != 0)
goto bad;
epp->ep_emul = EMUL_IBCS2_ELF;
epp->ep_tsize = ~0;
epp->ep_dsize = ~0;
interp[0] = '\0';
/*
* Load all the necessary sections
*/
for (i = 0; i < eh->e_phnum; i++) {
u_long addr = ~0, size = 0;
int prot = 0;
Elf32_Phdr *pp = &ph[i];
#ifdef DEBUG_EXEC_SVR4
print_Phdr(pp);
#endif
switch (ph[i].p_type) {
case Elf32_pt_load:
svr4_load_psection(epp, epp->ep_vp, &ph[i], &addr, &size,
&prot);
if ((error = svr4_set_segment(epp, addr, size, prot)) != 0)
goto bad;
break;
case Elf32_pt_shlib:
DPRINTF(("COFF Shared libraries not supported (yet)\n"));
error = ENOEXEC;
goto bad;
case Elf32_pt_interp:
if (pp->p_filesz >= sizeof(interp)) {
DPRINTF(("Interpreter path too long %d\n", pp->p_filesz));
goto bad;
}
if ((error = svr4_read_from(epp->ep_vp, pp->p_offset, p,
(caddr_t) interp, pp->p_filesz)) != 0)
goto bad;
break;
case Elf32_pt_dynamic:
case Elf32_pt_phdr:
case Elf32_pt_note:
break;
default:
/* Not fatal, we don't need to understand everything :-) */
DPRINTF(("Unsupported program header type %d\n", pp->p_type));
break;
}
}
/*
* Check if we found a dynamically linked binary and arrange to load
* it's interpreter
*/
if (interp[0]) {
struct svr4_args *ap;
pos = SVR4_INTERP_ADDR;
ap = (struct svr4_args *) malloc(sizeof(struct svr4_args),
M_TEMP, M_WAITOK);
if ((error = svr4_load_interp(p, interp, epp, ap, &pos)) != 0) {
free((char *) ap, M_TEMP);
goto bad;
}
/* Arrange to load the program headers. */
pos = SVR4_ALIGN(pos + SVR4_PAGESIZE, SVR4_PAGESIZE);
DPRINTF(("Program header @0x%x\n", pos));
ap->arg_phaddr = pos;
NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, phsize,
pos, epp->ep_vp, eh->e_phoff,
VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
pos += phsize;
ap->arg_phentsize = eh->e_phentsize;
ap->arg_phnum = eh->e_phnum;
ap->arg_entry = eh->e_entry;
epp->ep_setup = svr4_setup_args;
epp->ep_setup_arg = ap;
epp->ep_setup_arglen = SVR4_AUX_ARGSIZ / sizeof(char *);
}
else
epp->ep_entry = eh->e_entry;
DPRINTF(("taddr 0x%x tsize 0x%x daddr 0x%x dsize 0x%x\n",
epp->ep_taddr, epp->ep_tsize, epp->ep_daddr, epp->ep_dsize));
free((char *) ph, M_TEMP);
DPRINTF(("Elf entry@ 0x%x\n", epp->ep_entry));
epp->ep_vp->v_flag |= VTEXT;
return exec_aout_setup_stack(p, epp);
bad:
free((char *) ph, M_TEMP);
return ENOEXEC;
}