/* ARGSUSED */
int
sys_execve(struct proc *p, void *v, register_t *retval)
{
struct sys_execve_args /* {
syscallarg(const char *) path;
syscallarg(char *const *) argp;
syscallarg(char *const *) envp;
} */ *uap = v;
int error;
struct exec_package pack;
struct nameidata nid;
struct vattr attr;
struct ucred *cred = p->p_ucred;
char *argp;
char * const *cpp, *dp, *sp;
struct process *pr = p->p_p;
long argc, envc;
size_t len, sgap;
#ifdef MACHINE_STACK_GROWS_UP
size_t slen;
#endif
char *stack;
struct ps_strings arginfo;
struct vmspace *vm = p->p_vmspace;
char **tmpfap;
extern struct emul emul_native;
#if NSYSTRACE > 0
int wassugid = ISSET(pr->ps_flags, PS_SUGID | PS_SUGIDEXEC);
size_t pathbuflen;
#endif
char *pathbuf = NULL;
struct vnode *otvp;
/* get other threads to stop */
if ((error = single_thread_set(p, SINGLE_UNWIND, 1)))
return (error);
/*
* Cheap solution to complicated problems.
* Mark this process as "leave me alone, I'm execing".
*/
atomic_setbits_int(&pr->ps_flags, PS_INEXEC);
#if NSYSTRACE > 0
if (ISSET(p->p_flag, P_SYSTRACE)) {
systrace_execve0(p);
pathbuf = pool_get(&namei_pool, PR_WAITOK);
error = copyinstr(SCARG(uap, path), pathbuf, MAXPATHLEN,
&pathbuflen);
if (error != 0)
goto clrflag;
}
#endif
if (pathbuf != NULL) {
NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, p);
} else {
NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE,
SCARG(uap, path), p);
}
/*
* initialize the fields of the exec package.
*/
if (pathbuf != NULL)
pack.ep_name = pathbuf;
else
pack.ep_name = (char *)SCARG(uap, path);
pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK);
pack.ep_hdrlen = exec_maxhdrsz;
pack.ep_hdrvalid = 0;
pack.ep_ndp = &nid;
pack.ep_interp = NULL;
pack.ep_emul_arg = NULL;
VMCMDSET_INIT(&pack.ep_vmcmds);
pack.ep_vap = &attr;
pack.ep_emul = &emul_native;
pack.ep_flags = 0;
/* see if we can run it. */
if ((error = check_exec(p, &pack)) != 0) {
goto freehdr;
}
/* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */
/* allocate an argument buffer */
argp = km_alloc(NCARGS, &kv_exec, &kp_pageable, &kd_waitok);
#ifdef DIAGNOSTIC
if (argp == NULL)
panic("execve: argp == NULL");
#endif
dp = argp;
argc = 0;
/* copy the fake args list, if there's one, freeing it as we go */
if (pack.ep_flags & EXEC_HASARGL) {
tmpfap = pack.ep_fa;
while (*tmpfap != NULL) {
char *cp;
cp = *tmpfap;
while (*cp)
*dp++ = *cp++;
*dp++ = '\0';
free(*tmpfap, M_EXEC);
tmpfap++; argc++;
}
free(pack.ep_fa, M_EXEC);
pack.ep_flags &= ~EXEC_HASARGL;
}
/* Now get argv & environment */
if (!(cpp = SCARG(uap, argp))) {
error = EFAULT;
goto bad;
}
if (pack.ep_flags & EXEC_SKIPARG)
cpp++;
while (1) {
len = argp + ARG_MAX - dp;
if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
goto bad;
if (!sp)
break;
if ((error = copyinstr(sp, dp, len, &len)) != 0) {
if (error == ENAMETOOLONG)
error = E2BIG;
goto bad;
}
dp += len;
cpp++;
argc++;
}
envc = 0;
/* environment does not need to be there */
if ((cpp = SCARG(uap, envp)) != NULL ) {
while (1) {
len = argp + ARG_MAX - dp;
if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
goto bad;
if (!sp)
break;
if ((error = copyinstr(sp, dp, len, &len)) != 0) {
if (error == ENAMETOOLONG)
error = E2BIG;
goto bad;
}
dp += len;
cpp++;
envc++;
}
}
dp = (char *)(((long)dp + _STACKALIGNBYTES) & ~_STACKALIGNBYTES);
sgap = STACKGAPLEN;
if (stackgap_random != 0) {
sgap += arc4random() & (stackgap_random - 1);
sgap = (sgap + _STACKALIGNBYTES) & ~_STACKALIGNBYTES;
}
/* Now check if args & environ fit into new stack */
len = ((argc + envc + 2 + pack.ep_emul->e_arglen) * sizeof(char *) +
sizeof(long) + dp + sgap + sizeof(struct ps_strings)) - argp;
len = (len + _STACKALIGNBYTES) &~ _STACKALIGNBYTES;
if (len > pack.ep_ssize) { /* in effect, compare to initial limit */
error = ENOMEM;
goto bad;
}
/* adjust "active stack depth" for process VSZ */
pack.ep_ssize = len; /* maybe should go elsewhere, but... */
/*
* we're committed: any further errors will kill the process, so
* kill the other threads now.
* XXX wait until threads are reaped to make uvmspace_exec() cheaper?
*/
single_thread_set(p, SINGLE_EXIT, 0);
/*
* Prepare vmspace for remapping. Note that uvmspace_exec can replace
* p_vmspace!
*/
uvmspace_exec(p, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS);
vm = p->p_vmspace;
/* Now map address space */
vm->vm_taddr = (char *)pack.ep_taddr;
vm->vm_tsize = atop(round_page(pack.ep_tsize));
vm->vm_daddr = (char *)pack.ep_daddr;
vm->vm_dsize = atop(round_page(pack.ep_dsize));
vm->vm_dused = 0;
vm->vm_ssize = atop(round_page(pack.ep_ssize));
vm->vm_maxsaddr = (char *)pack.ep_maxsaddr;
vm->vm_minsaddr = (char *)pack.ep_minsaddr;
/* create the new process's VM space by running the vmcmds */
#ifdef DIAGNOSTIC
if (pack.ep_vmcmds.evs_used == 0)
panic("execve: no vmcmds");
#endif
error = exec_process_vmcmds(p, &pack);
/* if an error happened, deallocate and punt */
if (error)
goto exec_abort;
/* remember information about the process */
arginfo.ps_nargvstr = argc;
arginfo.ps_nenvstr = envc;
#ifdef MACHINE_STACK_GROWS_UP
stack = (char *)USRSTACK + sizeof(arginfo) + sgap;
slen = len - sizeof(arginfo) - sgap;
#else
stack = (char *)(USRSTACK - len);
#endif
/* Now copy argc, args & environ to new stack */
if (!(*pack.ep_emul->e_copyargs)(&pack, &arginfo, stack, argp))
goto exec_abort;
/* copy out the process's ps_strings structure */
if (copyout(&arginfo, (char *)PS_STRINGS, sizeof(arginfo)))
goto exec_abort;
stopprofclock(pr); /* stop profiling */
fdcloseexec(p); /* handle close on exec */
execsigs(p); /* reset caught signals */
TCB_SET(p, NULL); /* reset the TCB address */
/* set command name & other accounting info */
memset(p->p_comm, 0, sizeof(p->p_comm));
len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN);
bcopy(nid.ni_cnd.cn_nameptr, p->p_comm, len);
pr->ps_acflag &= ~AFORK;
/* record proc's vnode, for use by procfs and others */
otvp = pr->ps_textvp;
vref(pack.ep_vp);
pr->ps_textvp = pack.ep_vp;
if (otvp)
vrele(otvp);
atomic_setbits_int(&pr->ps_flags, PS_EXEC);
if (pr->ps_flags & PS_PPWAIT) {
atomic_clearbits_int(&pr->ps_flags, PS_PPWAIT);
atomic_clearbits_int(&pr->ps_pptr->ps_flags, PS_ISPWAIT);
wakeup(pr->ps_pptr);
}
/*
* If process does execve() while it has a mismatched real,
* effective, or saved uid/gid, we set PS_SUGIDEXEC.
*/
if (cred->cr_uid != cred->cr_ruid ||
cred->cr_uid != cred->cr_svuid ||
cred->cr_gid != cred->cr_rgid ||
cred->cr_gid != cred->cr_svgid)
atomic_setbits_int(&pr->ps_flags, PS_SUGIDEXEC);
else
atomic_clearbits_int(&pr->ps_flags, PS_SUGIDEXEC);
/*
* deal with set[ug]id.
* MNT_NOEXEC has already been used to disable s[ug]id.
*/
if ((attr.va_mode & (VSUID | VSGID)) && proc_cansugid(p)) {
int i;
atomic_setbits_int(&pr->ps_flags, PS_SUGID|PS_SUGIDEXEC);
#ifdef KTRACE
/*
* If process is being ktraced, turn off - unless
* root set it.
*/
if (pr->ps_tracevp && !(pr->ps_traceflag & KTRFAC_ROOT))
ktrcleartrace(pr);
#endif
p->p_ucred = cred = crcopy(cred);
if (attr.va_mode & VSUID)
cred->cr_uid = attr.va_uid;
if (attr.va_mode & VSGID)
cred->cr_gid = attr.va_gid;
/*
* For set[ug]id processes, a few caveats apply to
* stdin, stdout, and stderr.
*/
error = 0;
fdplock(p->p_fd);
for (i = 0; i < 3; i++) {
struct file *fp = NULL;
/*
* NOTE - This will never return NULL because of
* immature fds. The file descriptor table is not
* shared because we're suid.
*/
fp = fd_getfile(p->p_fd, i);
/*
* Ensure that stdin, stdout, and stderr are already
* allocated. We do not want userland to accidentally
* allocate descriptors in this range which has implied
* meaning to libc.
*/
if (fp == NULL) {
short flags = FREAD | (i == 0 ? 0 : FWRITE);
struct vnode *vp;
int indx;
if ((error = falloc(p, &fp, &indx)) != 0)
break;
#ifdef DIAGNOSTIC
if (indx != i)
panic("sys_execve: falloc indx != i");
#endif
if ((error = cdevvp(getnulldev(), &vp)) != 0) {
fdremove(p->p_fd, indx);
closef(fp, p);
break;
}
if ((error = VOP_OPEN(vp, flags, cred)) != 0) {
fdremove(p->p_fd, indx);
closef(fp, p);
vrele(vp);
break;
}
if (flags & FWRITE)
vp->v_writecount++;
fp->f_flag = flags;
fp->f_type = DTYPE_VNODE;
fp->f_ops = &vnops;
fp->f_data = (caddr_t)vp;
FILE_SET_MATURE(fp, p);
}
}
fdpunlock(p->p_fd);
if (error)
goto exec_abort;
} else
atomic_clearbits_int(&pr->ps_flags, PS_SUGID);
/* reset the saved ugids */
if (cred->cr_uid != cred->cr_svuid ||
cred->cr_gid != cred->cr_svgid) {
/* make sure we have unshared ucreds */
p->p_ucred = cred = crcopy(cred);
cred->cr_svuid = cred->cr_uid;
cred->cr_svgid = cred->cr_gid;
}
if (pr->ps_flags & PS_SUGIDEXEC) {
int i, s = splclock();
timeout_del(&pr->ps_realit_to);
for (i = 0; i < nitems(pr->ps_timer); i++) {
timerclear(&pr->ps_timer[i].it_interval);
timerclear(&pr->ps_timer[i].it_value);
}
splx(s);
}
/* reset CPU time usage for the thread, but not the process */
timespecclear(&p->p_tu.tu_runtime);
p->p_tu.tu_uticks = p->p_tu.tu_sticks = p->p_tu.tu_iticks = 0;
km_free(argp, NCARGS, &kv_exec, &kp_pageable);
pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf);
vn_close(pack.ep_vp, FREAD, cred, p);
/*
* notify others that we exec'd
*/
KNOTE(&pr->ps_klist, NOTE_EXEC);
/* setup new registers and do misc. setup. */
if (pack.ep_emul->e_fixup != NULL) {
if ((*pack.ep_emul->e_fixup)(p, &pack) != 0)
goto free_pack_abort;
}
#ifdef MACHINE_STACK_GROWS_UP
(*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack + slen, retval);
#else
(*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack, retval);
#endif
/* map the process's signal trampoline code */
if (exec_sigcode_map(p, pack.ep_emul))
goto free_pack_abort;
#ifdef __HAVE_EXEC_MD_MAP
/* perform md specific mappings that process might need */
if (exec_md_map(p, &pack))
goto free_pack_abort;
#endif
if (pr->ps_flags & PS_TRACED)
psignal(p, SIGTRAP);
free(pack.ep_hdr, M_EXEC);
/*
* Call emulation specific exec hook. This can setup per-process
* p->p_emuldata or do any other per-process stuff an emulation needs.
*
* If we are executing process of different emulation than the
* original forked process, call e_proc_exit() of the old emulation
* first, then e_proc_exec() of new emulation. If the emulation is
* same, the exec hook code should deallocate any old emulation
* resources held previously by this process.
*/
if (pr->ps_emul && pr->ps_emul->e_proc_exit &&
pr->ps_emul != pack.ep_emul)
(*pr->ps_emul->e_proc_exit)(p);
p->p_descfd = 255;
if ((pack.ep_flags & EXEC_HASFD) && pack.ep_fd < 255)
p->p_descfd = pack.ep_fd;
/*
* Call exec hook. Emulation code may NOT store reference to anything
* from &pack.
*/
if (pack.ep_emul->e_proc_exec)
(*pack.ep_emul->e_proc_exec)(p, &pack);
/* update ps_emul, the old value is no longer needed */
pr->ps_emul = pack.ep_emul;
#ifdef KTRACE
if (KTRPOINT(p, KTR_EMUL))
ktremul(p);
#endif
atomic_clearbits_int(&pr->ps_flags, PS_INEXEC);
single_thread_clear(p, P_SUSPSIG);
#if NSYSTRACE > 0
if (ISSET(p->p_flag, P_SYSTRACE) &&
wassugid && !ISSET(pr->ps_flags, PS_SUGID | PS_SUGIDEXEC))
systrace_execve1(pathbuf, p);
#endif
if (pathbuf != NULL)
pool_put(&namei_pool, pathbuf);
return (0);
bad:
/* free the vmspace-creation commands, and release their references */
kill_vmcmds(&pack.ep_vmcmds);
/* kill any opened file descriptor, if necessary */
if (pack.ep_flags & EXEC_HASFD) {
pack.ep_flags &= ~EXEC_HASFD;
fdplock(p->p_fd);
(void) fdrelease(p, pack.ep_fd);
fdpunlock(p->p_fd);
}
if (pack.ep_interp != NULL)
pool_put(&namei_pool, pack.ep_interp);
if (pack.ep_emul_arg != NULL)
free(pack.ep_emul_arg, M_TEMP);
/* close and put the exec'd file */
vn_close(pack.ep_vp, FREAD, cred, p);
pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf);
km_free(argp, NCARGS, &kv_exec, &kp_pageable);
freehdr:
free(pack.ep_hdr, M_EXEC);
#if NSYSTRACE > 0
clrflag:
#endif
atomic_clearbits_int(&pr->ps_flags, PS_INEXEC);
single_thread_clear(p, P_SUSPSIG);
if (pathbuf != NULL)
pool_put(&namei_pool, pathbuf);
return (error);
exec_abort:
/*
* the old process doesn't exist anymore. exit gracefully.
* get rid of the (new) address space we have created, if any, get rid
* of our namei data and vnode, and exit noting failure
*/
uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS,
VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS);
if (pack.ep_interp != NULL)
pool_put(&namei_pool, pack.ep_interp);
if (pack.ep_emul_arg != NULL)
free(pack.ep_emul_arg, M_TEMP);
pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf);
vn_close(pack.ep_vp, FREAD, cred, p);
km_free(argp, NCARGS, &kv_exec, &kp_pageable);
free_pack_abort:
free(pack.ep_hdr, M_EXEC);
exit1(p, W_EXITCODE(0, SIGABRT), EXIT_NORMAL);
/* NOTREACHED */
atomic_clearbits_int(&pr->ps_flags, PS_INEXEC);
if (pathbuf != NULL)
pool_put(&namei_pool, pathbuf);
return (0);
}
/*
* Phase II of load. It is now safe to load the interpreter. Info collected
* when loading the program is available for setup of the interpreter.
*/
int
ELFNAME2(exec,fixup)(struct proc *p, struct exec_package *epp)
{
char *interp;
int error;
struct elf_args *ap;
AuxInfo ai[ELF_AUX_ENTRIES], *a;
Elf_Addr pos = epp->ep_interp_pos;
if (epp->ep_interp == NULL) {
return (0);
}
interp = (char *)epp->ep_interp;
ap = (struct elf_args *)epp->ep_emul_arg;
if ((error = ELFNAME(load_file)(p, interp, epp, ap, &pos)) != 0) {
free((char *)ap, M_TEMP);
free((char *)interp, M_TEMP);
kill_vmcmds(&epp->ep_vmcmds);
return (error);
}
/*
* We have to do this ourselves...
*/
error = exec_process_vmcmds(p, epp);
/*
* Push extra arguments on the stack needed by dynamically
* linked binaries
*/
if (error == 0) {
a = ai;
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 = PAGE_SIZE;
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;
a++;
error = copyout(ai, epp->ep_emul_argp, sizeof ai);
}
free((char *)ap, M_TEMP);
free((char *)interp, M_TEMP);
return (error);
}
