static int do_exec(int proc_e, char *exec, size_t exec_len, char *progname,
char *frame, int frame_len)
{
int r;
vir_bytes vsp;
struct exec_info execi;
int i;
memset(&execi, 0, sizeof(execi));
execi.stack_size = DEFAULT_STACK_LIMIT;
execi.proc_e = proc_e;
execi.hdr = exec;
execi.hdr_len = exec_len;
strncpy(execi.progname, progname, PROC_NAME_LEN-1);
execi.progname[PROC_NAME_LEN-1] = '\0';
execi.frame_len = frame_len;
/* callback functions and data */
execi.copymem = read_seg;
execi.clearproc = libexec_clearproc_vm_procctl;
execi.clearmem = libexec_clear_sys_memset;
execi.allocmem_prealloc = libexec_alloc_mmap_prealloc;
execi.allocmem_ondemand = libexec_alloc_mmap_ondemand;
for(i = 0; exec_loaders[i].load_object != NULL; i++) {
r = (*exec_loaders[i].load_object)(&execi);
/* Loaded successfully, so no need to try other loaders */
if (r == OK) break;
}
/* No exec loader could load the object */
if (r != OK) {
printf("RS: do_exec: loading error %d\n", r);
return r;
}
/* Inform PM */
if((r = libexec_pm_newexec(execi.proc_e, &execi)) != OK)
return r;
/* Patch up stack and copy it from RS to new core image. */
vsp = execi.stack_high;
vsp -= frame_len;
libexec_patch_ptr(frame, vsp);
r = sys_datacopy(SELF, (vir_bytes) frame,
proc_e, (vir_bytes) vsp, (phys_bytes)frame_len);
if (r != OK) {
printf("do_exec: copying out new stack failed: %d\n", r);
exec_restart(proc_e, r, execi.pc);
return r;
}
return exec_restart(proc_e, OK, execi.pc);
}
/*===========================================================================*
* pm_exec *
*===========================================================================*/
int pm_exec(endpoint_t proc_e, vir_bytes path, size_t path_len,
vir_bytes frame, size_t frame_len, vir_bytes *pc,
vir_bytes *newsp, int user_exec_flags)
{
/* Perform the execve(name, argv, envp) call. The user library builds a
* complete stack image, including pointers, args, environ, etc. The stack
* is copied to a buffer inside VFS, and then to the new core image.
*/
int r, slot;
vir_bytes vsp;
struct fproc *rfp;
int extrabase = 0;
static char mbuf[ARG_MAX]; /* buffer for stack and zeroes */
struct vfs_exec_info execi;
int i;
static char fullpath[PATH_MAX],
elf_interpreter[PATH_MAX],
firstexec[PATH_MAX],
finalexec[PATH_MAX];
struct lookup resolve;
struct fproc *vmfp = &fproc[VM_PROC_NR];
stackhook_t makestack = NULL;
static int n;
n++;
struct filp *newfilp = NULL;
lock_exec();
lock_proc(vmfp, 0);
/* unset execi values are 0. */
memset(&execi, 0, sizeof(execi));
execi.vmfd = -1;
/* passed from exec() libc code */
execi.userflags = user_exec_flags;
execi.args.stack_high = kinfo.user_sp;
execi.args.stack_size = DEFAULT_STACK_LIMIT;
okendpt(proc_e, &slot);
rfp = fp = &fproc[slot];
lookup_init(&resolve, fullpath, PATH_NOFLAGS, &execi.vmp, &execi.vp);
resolve.l_vmnt_lock = VMNT_READ;
resolve.l_vnode_lock = VNODE_READ;
/* Fetch the stack from the user before destroying the old core image. */
if (frame_len > ARG_MAX)
FAILCHECK(ENOMEM); /* stack too big */
r = sys_datacopy(proc_e, (vir_bytes) frame, SELF, (vir_bytes) mbuf,
(size_t) frame_len);
if (r != OK) { /* can't fetch stack (e.g. bad virtual addr) */
printf("VFS: pm_exec: sys_datacopy failed\n");
FAILCHECK(r);
}
/* The default is to keep the original user and group IDs */
execi.args.new_uid = rfp->fp_effuid;
execi.args.new_gid = rfp->fp_effgid;
/* Get the exec file name. */
FAILCHECK(fetch_name(path, path_len, fullpath));
strlcpy(finalexec, fullpath, PATH_MAX);
strlcpy(firstexec, fullpath, PATH_MAX);
/* Get_read_vp will return an opened vn in execi.
* if necessary it releases the existing vp so we can
* switch after we find out what's inside the file.
* It reads the start of the file.
*/
Get_read_vp(execi, fullpath, 1, 1, &resolve, fp);
/* If this is a script (i.e. has a #!/interpreter line),
* retrieve the name of the interpreter and open that
* executable instead.
*/
if(is_script(&execi)) {
/* patch_stack will add interpreter name and
* args to stack and retrieve the new binary
* name into fullpath.
*/
FAILCHECK(fetch_name(path, path_len, fullpath));
FAILCHECK(patch_stack(execi.vp, mbuf, &frame_len, fullpath));
strlcpy(finalexec, fullpath, PATH_MAX);
strlcpy(firstexec, fullpath, PATH_MAX);
Get_read_vp(execi, fullpath, 1, 0, &resolve, fp);
}
/* If this is a dynamically linked executable, retrieve
* the name of that interpreter in elf_interpreter and open that
* executable instead. But open the current executable in an
* fd for the current process.
*/
if(elf_has_interpreter(execi.args.hdr, execi.args.hdr_len,
elf_interpreter, sizeof(elf_interpreter))) {
/* Switch the executable vnode to the interpreter */
execi.is_dyn = 1;
/* The interpreter (loader) needs an fd to the main program,
* which is currently in finalexec
*/
if((r = execi.elf_main_fd = common_open(finalexec, O_RDONLY, 0)) < 0) {
printf("VFS: exec: dynamic: open main exec failed %s (%d)\n",
fullpath, r);
FAILCHECK(r);
}
/* ld.so is linked at 0, but it can relocate itself; we
* want it higher to trap NULL pointer dereferences.
*/
execi.args.load_offset = 0x10000;
/* Remember it */
strlcpy(execi.execname, finalexec, PATH_MAX);
/* The executable we need to execute first (loader)
* is in elf_interpreter, and has to be in fullpath to
* be looked up
*/
strlcpy(fullpath, elf_interpreter, PATH_MAX);
strlcpy(firstexec, elf_interpreter, PATH_MAX);
Get_read_vp(execi, fullpath, 0, 0, &resolve, fp);
}
/* We also want an FD for VM to mmap() the process in if possible. */
{
struct vnode *vp = execi.vp;
assert(vp);
if(vp->v_vmnt->m_haspeek && major(vp->v_dev) != MEMORY_MAJOR) {
int newfd = -1;
if(get_fd(vmfp, 0, R_BIT, &newfd, &newfilp) == OK) {
assert(newfd >= 0 && newfd < OPEN_MAX);
assert(!vmfp->fp_filp[newfd]);
newfilp->filp_count = 1;
newfilp->filp_vno = vp;
newfilp->filp_flags = O_RDONLY;
FD_SET(newfd, &vmfp->fp_filp_inuse);
vmfp->fp_filp[newfd] = newfilp;
/* dup_vnode(vp); */
execi.vmfd = newfd;
execi.args.memmap = vfs_memmap;
}
}
}
/* callback functions and data */
execi.args.copymem = read_seg;
execi.args.clearproc = libexec_clearproc_vm_procctl;
execi.args.clearmem = libexec_clear_sys_memset;
execi.args.allocmem_prealloc_cleared = libexec_alloc_mmap_prealloc_cleared;
execi.args.allocmem_prealloc_junk = libexec_alloc_mmap_prealloc_junk;
execi.args.allocmem_ondemand = libexec_alloc_mmap_ondemand;
execi.args.opaque = &execi;
execi.args.proc_e = proc_e;
execi.args.frame_len = frame_len;
execi.args.filesize = execi.vp->v_size;
for (i = 0; exec_loaders[i].load_object != NULL; i++) {
r = (*exec_loaders[i].load_object)(&execi.args);
/* Loaded successfully, so no need to try other loaders */
if (r == OK) { makestack = exec_loaders[i].setup_stack; break; }
}
FAILCHECK(r);
/* Inform PM */
FAILCHECK(libexec_pm_newexec(proc_e, &execi.args));
/* Save off PC */
*pc = execi.args.pc;
/* call a stack-setup function if this executable type wants it */
vsp = execi.args.stack_high - frame_len;
if(makestack) FAILCHECK(makestack(&execi, mbuf, &frame_len, &vsp, &extrabase));
/* Patch up stack and copy it from VFS to new core image. */
libexec_patch_ptr(mbuf, vsp + extrabase);
FAILCHECK(sys_datacopy(SELF, (vir_bytes) mbuf, proc_e, (vir_bytes) vsp,
(phys_bytes)frame_len));
/* Return new stack pointer to caller */
*newsp = vsp;
clo_exec(rfp);
if (execi.args.allow_setuid) {
/* If after loading the image we're still allowed to run with
* setuid or setgid, change credentials now */
rfp->fp_effuid = execi.args.new_uid;
rfp->fp_effgid = execi.args.new_gid;
}
/* Remember the new name of the process */
strlcpy(rfp->fp_name, execi.args.progname, PROC_NAME_LEN);
pm_execfinal:
if(newfilp) unlock_filp(newfilp);
else if (execi.vp != NULL) {
unlock_vnode(execi.vp);
put_vnode(execi.vp);
}
if(execi.vmfd >= 0 && !execi.vmfd_used) {
if(OK != close_fd(vmfp, execi.vmfd)) {
printf("VFS: unexpected close fail of vm fd\n");
}
}
unlock_proc(vmfp);
unlock_exec();
return(r);
}
