static void
do_fork(struct thread *td, struct fork_req *fr, struct proc *p2, struct thread *td2,
struct vmspace *vm2, struct file *fp_procdesc)
{
struct proc *p1, *pptr;
int trypid;
struct filedesc *fd;
struct filedesc_to_leader *fdtol;
struct sigacts *newsigacts;
sx_assert(&proctree_lock, SX_SLOCKED);
sx_assert(&allproc_lock, SX_XLOCKED);
p1 = td->td_proc;
trypid = fork_findpid(fr->fr_flags);
sx_sunlock(&proctree_lock);
p2->p_state = PRS_NEW; /* protect against others */
p2->p_pid = trypid;
AUDIT_ARG_PID(p2->p_pid);
LIST_INSERT_HEAD(&allproc, p2, p_list);
allproc_gen++;
LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
tidhash_add(td2);
PROC_LOCK(p2);
PROC_LOCK(p1);
sx_xunlock(&allproc_lock);
bcopy(&p1->p_startcopy, &p2->p_startcopy,
__rangeof(struct proc, p_startcopy, p_endcopy));
pargs_hold(p2->p_args);
PROC_UNLOCK(p1);
bzero(&p2->p_startzero,
__rangeof(struct proc, p_startzero, p_endzero));
/* Tell the prison that we exist. */
prison_proc_hold(p2->p_ucred->cr_prison);
PROC_UNLOCK(p2);
/*
* Malloc things while we don't hold any locks.
*/
if (fr->fr_flags & RFSIGSHARE)
newsigacts = NULL;
else
newsigacts = sigacts_alloc();
/*
* Copy filedesc.
*/
if (fr->fr_flags & RFCFDG) {
fd = fdinit(p1->p_fd, false);
fdtol = NULL;
} else if (fr->fr_flags & RFFDG) {
fd = fdcopy(p1->p_fd);
fdtol = NULL;
} else {
fd = fdshare(p1->p_fd);
if (p1->p_fdtol == NULL)
p1->p_fdtol = filedesc_to_leader_alloc(NULL, NULL,
p1->p_leader);
if ((fr->fr_flags & RFTHREAD) != 0) {
/*
* Shared file descriptor table, and shared
* process leaders.
*/
fdtol = p1->p_fdtol;
FILEDESC_XLOCK(p1->p_fd);
fdtol->fdl_refcount++;
FILEDESC_XUNLOCK(p1->p_fd);
} else {
/*
* Shared file descriptor table, and different
* process leaders.
*/
fdtol = filedesc_to_leader_alloc(p1->p_fdtol,
p1->p_fd, p2);
}
}
/*
* Make a proc table entry for the new process.
* Start by zeroing the section of proc that is zero-initialized,
* then copy the section that is copied directly from the parent.
*/
PROC_LOCK(p2);
PROC_LOCK(p1);
bzero(&td2->td_startzero,
__rangeof(struct thread, td_startzero, td_endzero));
bcopy(&td->td_startcopy, &td2->td_startcopy,
__rangeof(struct thread, td_startcopy, td_endcopy));
bcopy(&p2->p_comm, &td2->td_name, sizeof(td2->td_name));
td2->td_sigstk = td->td_sigstk;
td2->td_flags = TDF_INMEM;
td2->td_lend_user_pri = PRI_MAX;
#ifdef VIMAGE
td2->td_vnet = NULL;
td2->td_vnet_lpush = NULL;
#endif
/*
* Allow the scheduler to initialize the child.
*/
thread_lock(td);
sched_fork(td, td2);
thread_unlock(td);
/*
* Duplicate sub-structures as needed.
* Increase reference counts on shared objects.
*/
p2->p_flag = P_INMEM;
p2->p_flag2 = p1->p_flag2 & (P2_NOTRACE | P2_NOTRACE_EXEC | P2_TRAPCAP);
p2->p_swtick = ticks;
if (p1->p_flag & P_PROFIL)
startprofclock(p2);
/*
* Whilst the proc lock is held, copy the VM domain data out
* using the VM domain method.
*/
vm_domain_policy_init(&p2->p_vm_dom_policy);
vm_domain_policy_localcopy(&p2->p_vm_dom_policy,
&p1->p_vm_dom_policy);
if (fr->fr_flags & RFSIGSHARE) {
p2->p_sigacts = sigacts_hold(p1->p_sigacts);
} else {
sigacts_copy(newsigacts, p1->p_sigacts);
p2->p_sigacts = newsigacts;
}
if (fr->fr_flags & RFTSIGZMB)
p2->p_sigparent = RFTSIGNUM(fr->fr_flags);
else if (fr->fr_flags & RFLINUXTHPN)
p2->p_sigparent = SIGUSR1;
else
p2->p_sigparent = SIGCHLD;
p2->p_textvp = p1->p_textvp;
p2->p_fd = fd;
p2->p_fdtol = fdtol;
if (p1->p_flag2 & P2_INHERIT_PROTECTED) {
p2->p_flag |= P_PROTECTED;
p2->p_flag2 |= P2_INHERIT_PROTECTED;
}
/*
* p_limit is copy-on-write. Bump its refcount.
*/
lim_fork(p1, p2);
thread_cow_get_proc(td2, p2);
pstats_fork(p1->p_stats, p2->p_stats);
PROC_UNLOCK(p1);
PROC_UNLOCK(p2);
/* Bump references to the text vnode (for procfs). */
if (p2->p_textvp)
vrefact(p2->p_textvp);
/*
* Set up linkage for kernel based threading.
*/
if ((fr->fr_flags & RFTHREAD) != 0) {
mtx_lock(&ppeers_lock);
p2->p_peers = p1->p_peers;
p1->p_peers = p2;
p2->p_leader = p1->p_leader;
mtx_unlock(&ppeers_lock);
PROC_LOCK(p1->p_leader);
if ((p1->p_leader->p_flag & P_WEXIT) != 0) {
PROC_UNLOCK(p1->p_leader);
/*
* The task leader is exiting, so process p1 is
* going to be killed shortly. Since p1 obviously
* isn't dead yet, we know that the leader is either
* sending SIGKILL's to all the processes in this
* task or is sleeping waiting for all the peers to
* exit. We let p1 complete the fork, but we need
* to go ahead and kill the new process p2 since
* the task leader may not get a chance to send
* SIGKILL to it. We leave it on the list so that
* the task leader will wait for this new process
* to commit suicide.
*/
PROC_LOCK(p2);
kern_psignal(p2, SIGKILL);
PROC_UNLOCK(p2);
} else
PROC_UNLOCK(p1->p_leader);
} else {
p2->p_peers = NULL;
p2->p_leader = p2;
}
sx_xlock(&proctree_lock);
PGRP_LOCK(p1->p_pgrp);
PROC_LOCK(p2);
PROC_LOCK(p1);
/*
* Preserve some more flags in subprocess. P_PROFIL has already
* been preserved.
*/
p2->p_flag |= p1->p_flag & P_SUGID;
td2->td_pflags |= (td->td_pflags & TDP_ALTSTACK) | TDP_FORKING;
SESS_LOCK(p1->p_session);
if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
p2->p_flag |= P_CONTROLT;
SESS_UNLOCK(p1->p_session);
if (fr->fr_flags & RFPPWAIT)
p2->p_flag |= P_PPWAIT;
p2->p_pgrp = p1->p_pgrp;
LIST_INSERT_AFTER(p1, p2, p_pglist);
PGRP_UNLOCK(p1->p_pgrp);
LIST_INIT(&p2->p_children);
LIST_INIT(&p2->p_orphans);
callout_init_mtx(&p2->p_itcallout, &p2->p_mtx, 0);
/*
* If PF_FORK is set, the child process inherits the
* procfs ioctl flags from its parent.
*/
if (p1->p_pfsflags & PF_FORK) {
p2->p_stops = p1->p_stops;
p2->p_pfsflags = p1->p_pfsflags;
}
/*
* This begins the section where we must prevent the parent
* from being swapped.
*/
_PHOLD(p1);
PROC_UNLOCK(p1);
/*
* Attach the new process to its parent.
*
* If RFNOWAIT is set, the newly created process becomes a child
* of init. This effectively disassociates the child from the
* parent.
*/
if ((fr->fr_flags & RFNOWAIT) != 0) {
pptr = p1->p_reaper;
p2->p_reaper = pptr;
} else {
p2->p_reaper = (p1->p_treeflag & P_TREE_REAPER) != 0 ?
p1 : p1->p_reaper;
pptr = p1;
}
p2->p_pptr = pptr;
LIST_INSERT_HEAD(&pptr->p_children, p2, p_sibling);
LIST_INIT(&p2->p_reaplist);
LIST_INSERT_HEAD(&p2->p_reaper->p_reaplist, p2, p_reapsibling);
if (p2->p_reaper == p1)
p2->p_reapsubtree = p2->p_pid;
sx_xunlock(&proctree_lock);
/* Inform accounting that we have forked. */
p2->p_acflag = AFORK;
PROC_UNLOCK(p2);
#ifdef KTRACE
ktrprocfork(p1, p2);
#endif
/*
* Finish creating the child process. It will return via a different
* execution path later. (ie: directly into user mode)
*/
vm_forkproc(td, p2, td2, vm2, fr->fr_flags);
if (fr->fr_flags == (RFFDG | RFPROC)) {
VM_CNT_INC(v_forks);
VM_CNT_ADD(v_forkpages, p2->p_vmspace->vm_dsize +
p2->p_vmspace->vm_ssize);
} else if (fr->fr_flags == (RFFDG | RFPROC | RFPPWAIT | RFMEM)) {
VM_CNT_INC(v_vforks);
VM_CNT_ADD(v_vforkpages, p2->p_vmspace->vm_dsize +
p2->p_vmspace->vm_ssize);
} else if (p1 == &proc0) {
VM_CNT_INC(v_kthreads);
VM_CNT_ADD(v_kthreadpages, p2->p_vmspace->vm_dsize +
p2->p_vmspace->vm_ssize);
} else {
VM_CNT_INC(v_rforks);
VM_CNT_ADD(v_rforkpages, p2->p_vmspace->vm_dsize +
p2->p_vmspace->vm_ssize);
}
/*
* Associate the process descriptor with the process before anything
* can happen that might cause that process to need the descriptor.
* However, don't do this until after fork(2) can no longer fail.
*/
if (fr->fr_flags & RFPROCDESC)
procdesc_new(p2, fr->fr_pd_flags);
/*
* Both processes are set up, now check if any loadable modules want
* to adjust anything.
*/
EVENTHANDLER_INVOKE(process_fork, p1, p2, fr->fr_flags);
/*
* Set the child start time and mark the process as being complete.
*/
PROC_LOCK(p2);
PROC_LOCK(p1);
microuptime(&p2->p_stats->p_start);
PROC_SLOCK(p2);
p2->p_state = PRS_NORMAL;
PROC_SUNLOCK(p2);
#ifdef KDTRACE_HOOKS
/*
* Tell the DTrace fasttrap provider about the new process so that any
* tracepoints inherited from the parent can be removed. We have to do
* this only after p_state is PRS_NORMAL since the fasttrap module will
* use pfind() later on.
*/
if ((fr->fr_flags & RFMEM) == 0 && dtrace_fasttrap_fork)
dtrace_fasttrap_fork(p1, p2);
#endif
/*
* Hold the process so that it cannot exit after we make it runnable,
* but before we wait for the debugger.
*/
_PHOLD(p2);
if (p1->p_ptevents & PTRACE_FORK) {
/*
* Arrange for debugger to receive the fork event.
*
* We can report PL_FLAG_FORKED regardless of
* P_FOLLOWFORK settings, but it does not make a sense
* for runaway child.
*/
td->td_dbgflags |= TDB_FORK;
td->td_dbg_forked = p2->p_pid;
td2->td_dbgflags |= TDB_STOPATFORK;
}
if (fr->fr_flags & RFPPWAIT) {
td->td_pflags |= TDP_RFPPWAIT;
td->td_rfppwait_p = p2;
td->td_dbgflags |= TDB_VFORK;
}
PROC_UNLOCK(p2);
/*
* Now can be swapped.
*/
_PRELE(p1);
PROC_UNLOCK(p1);
/*
* Tell any interested parties about the new process.
*/
knote_fork(p1->p_klist, p2->p_pid);
SDT_PROBE3(proc, , , create, p2, p1, fr->fr_flags);
if (fr->fr_flags & RFPROCDESC) {
procdesc_finit(p2->p_procdesc, fp_procdesc);
fdrop(fp_procdesc, td);
}
if ((fr->fr_flags & RFSTOPPED) == 0) {
/*
* If RFSTOPPED not requested, make child runnable and
* add to run queue.
*/
thread_lock(td2);
TD_SET_CAN_RUN(td2);
sched_add(td2, SRQ_BORING);
thread_unlock(td2);
if (fr->fr_pidp != NULL)
*fr->fr_pidp = p2->p_pid;
} else {
*fr->fr_procp = p2;
}
PROC_LOCK(p2);
/*
* Wait until debugger is attached to child.
*/
while (td2->td_proc == p2 && (td2->td_dbgflags & TDB_STOPATFORK) != 0)
cv_wait(&p2->p_dbgwait, &p2->p_mtx);
_PRELE(p2);
racct_proc_fork_done(p2);
PROC_UNLOCK(p2);
}
/*
* In-kernel implementation of execve(). All arguments are assumed to be
* userspace pointers from the passed thread.
*/
static int
do_execve(struct thread *td, struct image_args *args, struct mac *mac_p)
{
struct proc *p = td->td_proc;
struct nameidata nd;
struct ucred *oldcred;
struct uidinfo *euip = NULL;
register_t *stack_base;
int error, i;
struct image_params image_params, *imgp;
struct vattr attr;
int (*img_first)(struct image_params *);
struct pargs *oldargs = NULL, *newargs = NULL;
struct sigacts *oldsigacts = NULL, *newsigacts = NULL;
#ifdef KTRACE
struct vnode *tracevp = NULL;
struct ucred *tracecred = NULL;
#endif
struct vnode *oldtextvp = NULL, *newtextvp;
int credential_changing;
int textset;
#ifdef MAC
struct label *interpvplabel = NULL;
int will_transition;
#endif
#ifdef HWPMC_HOOKS
struct pmckern_procexec pe;
#endif
static const char fexecv_proc_title[] = "(fexecv)";
imgp = &image_params;
/*
* Lock the process and set the P_INEXEC flag to indicate that
* it should be left alone until we're done here. This is
* necessary to avoid race conditions - e.g. in ptrace() -
* that might allow a local user to illicitly obtain elevated
* privileges.
*/
PROC_LOCK(p);
KASSERT((p->p_flag & P_INEXEC) == 0,
("%s(): process already has P_INEXEC flag", __func__));
p->p_flag |= P_INEXEC;
PROC_UNLOCK(p);
/*
* Initialize part of the common data
*/
bzero(imgp, sizeof(*imgp));
imgp->proc = p;
imgp->attr = &attr;
imgp->args = args;
oldcred = p->p_ucred;
#ifdef MAC
error = mac_execve_enter(imgp, mac_p);
if (error)
goto exec_fail;
#endif
/*
* Translate the file name. namei() returns a vnode pointer
* in ni_vp among other things.
*
* XXXAUDIT: It would be desirable to also audit the name of the
* interpreter if this is an interpreted binary.
*/
if (args->fname != NULL) {
NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | FOLLOW | SAVENAME
| AUDITVNODE1, UIO_SYSSPACE, args->fname, td);
}
SDT_PROBE1(proc, , , exec, args->fname);
interpret:
if (args->fname != NULL) {
#ifdef CAPABILITY_MODE
/*
* While capability mode can't reach this point via direct
* path arguments to execve(), we also don't allow
* interpreters to be used in capability mode (for now).
* Catch indirect lookups and return a permissions error.
*/
if (IN_CAPABILITY_MODE(td)) {
error = ECAPMODE;
goto exec_fail;
}
#endif
error = namei(&nd);
if (error)
goto exec_fail;
newtextvp = nd.ni_vp;
imgp->vp = newtextvp;
} else {
AUDIT_ARG_FD(args->fd);
/*
* Descriptors opened only with O_EXEC or O_RDONLY are allowed.
*/
error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, &newtextvp);
if (error)
goto exec_fail;
vn_lock(newtextvp, LK_EXCLUSIVE | LK_RETRY);
AUDIT_ARG_VNODE1(newtextvp);
imgp->vp = newtextvp;
}
/*
* Check file permissions (also 'opens' file)
*/
error = exec_check_permissions(imgp);
if (error)
goto exec_fail_dealloc;
imgp->object = imgp->vp->v_object;
if (imgp->object != NULL)
vm_object_reference(imgp->object);
/*
* Set VV_TEXT now so no one can write to the executable while we're
* activating it.
*
* Remember if this was set before and unset it in case this is not
* actually an executable image.
*/
textset = VOP_IS_TEXT(imgp->vp);
VOP_SET_TEXT(imgp->vp);
error = exec_map_first_page(imgp);
if (error)
goto exec_fail_dealloc;
imgp->proc->p_osrel = 0;
imgp->proc->p_fctl0 = 0;
/*
* Implement image setuid/setgid.
*
* Determine new credentials before attempting image activators
* so that it can be used by process_exec handlers to determine
* credential/setid changes.
*
* Don't honor setuid/setgid if the filesystem prohibits it or if
* the process is being traced.
*
* We disable setuid/setgid/etc in capability mode on the basis
* that most setugid applications are not written with that
* environment in mind, and will therefore almost certainly operate
* incorrectly. In principle there's no reason that setugid
* applications might not be useful in capability mode, so we may want
* to reconsider this conservative design choice in the future.
*
* XXXMAC: For the time being, use NOSUID to also prohibit
* transitions on the file system.
*/
credential_changing = 0;
credential_changing |= (attr.va_mode & S_ISUID) &&
oldcred->cr_uid != attr.va_uid;
credential_changing |= (attr.va_mode & S_ISGID) &&
oldcred->cr_gid != attr.va_gid;
#ifdef MAC
will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp,
interpvplabel, imgp);
credential_changing |= will_transition;
#endif
/* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */
if (credential_changing)
imgp->proc->p_pdeathsig = 0;
if (credential_changing &&
#ifdef CAPABILITY_MODE
((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) &&
#endif
(imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
(p->p_flag & P_TRACED) == 0) {
imgp->credential_setid = true;
VOP_UNLOCK(imgp->vp, 0);
imgp->newcred = crdup(oldcred);
if (attr.va_mode & S_ISUID) {
euip = uifind(attr.va_uid);
change_euid(imgp->newcred, euip);
}
vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
if (attr.va_mode & S_ISGID)
change_egid(imgp->newcred, attr.va_gid);
/*
* Implement correct POSIX saved-id behavior.
*
* XXXMAC: Note that the current logic will save the
* uid and gid if a MAC domain transition occurs, even
* though maybe it shouldn't.
*/
change_svuid(imgp->newcred, imgp->newcred->cr_uid);
change_svgid(imgp->newcred, imgp->newcred->cr_gid);
} else {
/*
* Implement correct POSIX saved-id behavior.
*
* XXX: It's not clear that the existing behavior is
* POSIX-compliant. A number of sources indicate that the
* saved uid/gid should only be updated if the new ruid is
* not equal to the old ruid, or the new euid is not equal
* to the old euid and the new euid is not equal to the old
* ruid. The FreeBSD code always updates the saved uid/gid.
* Also, this code uses the new (replaced) euid and egid as
* the source, which may or may not be the right ones to use.
*/
if (oldcred->cr_svuid != oldcred->cr_uid ||
oldcred->cr_svgid != oldcred->cr_gid) {
VOP_UNLOCK(imgp->vp, 0);
imgp->newcred = crdup(oldcred);
vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
change_svuid(imgp->newcred, imgp->newcred->cr_uid);
change_svgid(imgp->newcred, imgp->newcred->cr_gid);
}
}
/* The new credentials are installed into the process later. */
/*
* Do the best to calculate the full path to the image file.
*/
if (args->fname != NULL && args->fname[0] == '/')
imgp->execpath = args->fname;
else {
VOP_UNLOCK(imgp->vp, 0);
if (vn_fullpath(td, imgp->vp, &imgp->execpath,
&imgp->freepath) != 0)
imgp->execpath = args->fname;
vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
}
/*
* If the current process has a special image activator it
* wants to try first, call it. For example, emulating shell
* scripts differently.
*/
error = -1;
if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
error = img_first(imgp);
/*
* Loop through the list of image activators, calling each one.
* An activator returns -1 if there is no match, 0 on success,
* and an error otherwise.
*/
for (i = 0; error == -1 && execsw[i]; ++i) {
if (execsw[i]->ex_imgact == NULL ||
execsw[i]->ex_imgact == img_first) {
continue;
}
error = (*execsw[i]->ex_imgact)(imgp);
}
if (error) {
if (error == -1) {
if (textset == 0)
VOP_UNSET_TEXT(imgp->vp);
error = ENOEXEC;
}
goto exec_fail_dealloc;
}
/*
* Special interpreter operation, cleanup and loop up to try to
* activate the interpreter.
*/
if (imgp->interpreted) {
exec_unmap_first_page(imgp);
/*
* VV_TEXT needs to be unset for scripts. There is a short
* period before we determine that something is a script where
* VV_TEXT will be set. The vnode lock is held over this
* entire period so nothing should illegitimately be blocked.
*/
VOP_UNSET_TEXT(imgp->vp);
/* free name buffer and old vnode */
if (args->fname != NULL)
NDFREE(&nd, NDF_ONLY_PNBUF);
#ifdef MAC
mac_execve_interpreter_enter(newtextvp, &interpvplabel);
#endif
if (imgp->opened) {
VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td);
imgp->opened = 0;
}
vput(newtextvp);
vm_object_deallocate(imgp->object);
imgp->object = NULL;
imgp->credential_setid = false;
if (imgp->newcred != NULL) {
crfree(imgp->newcred);
imgp->newcred = NULL;
}
imgp->execpath = NULL;
free(imgp->freepath, M_TEMP);
imgp->freepath = NULL;
/* set new name to that of the interpreter */
NDINIT(&nd, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
UIO_SYSSPACE, imgp->interpreter_name, td);
args->fname = imgp->interpreter_name;
goto interpret;
}
/*
* NB: We unlock the vnode here because it is believed that none
* of the sv_copyout_strings/sv_fixup operations require the vnode.
*/
VOP_UNLOCK(imgp->vp, 0);
if (disallow_high_osrel &&
P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) {
error = ENOEXEC;
uprintf("Osrel %d for image %s too high\n", p->p_osrel,
imgp->execpath != NULL ? imgp->execpath : "<unresolved>");
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
goto exec_fail_dealloc;
}
/* ABI enforces the use of Capsicum. Switch into capabilities mode. */
if (SV_PROC_FLAG(p, SV_CAPSICUM))
sys_cap_enter(td, NULL);
/*
* Copy out strings (args and env) and initialize stack base.
*/
stack_base = (*p->p_sysent->sv_copyout_strings)(imgp);
/*
* Stack setup.
*/
error = (*p->p_sysent->sv_fixup)(&stack_base, imgp);
if (error != 0) {
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
goto exec_fail_dealloc;
}
if (args->fdp != NULL) {
/* Install a brand new file descriptor table. */
fdinstall_remapped(td, args->fdp);
args->fdp = NULL;
} else {
/*
* Keep on using the existing file descriptor table. For
* security and other reasons, the file descriptor table
* cannot be shared after an exec.
*/
fdunshare(td);
/* close files on exec */
fdcloseexec(td);
}
/*
* Malloc things before we need locks.
*/
i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv;
/* Cache arguments if they fit inside our allowance */
if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
newargs = pargs_alloc(i);
bcopy(imgp->args->begin_argv, newargs->ar_args, i);
}
/*
* For security and other reasons, signal handlers cannot
* be shared after an exec. The new process gets a copy of the old
* handlers. In execsigs(), the new process will have its signals
* reset.
*/
if (sigacts_shared(p->p_sigacts)) {
oldsigacts = p->p_sigacts;
newsigacts = sigacts_alloc();
sigacts_copy(newsigacts, oldsigacts);
}
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
PROC_LOCK(p);
if (oldsigacts)
p->p_sigacts = newsigacts;
/* Stop profiling */
stopprofclock(p);
/* reset caught signals */
execsigs(p);
/* name this process - nameiexec(p, ndp) */
bzero(p->p_comm, sizeof(p->p_comm));
if (args->fname)
bcopy(nd.ni_cnd.cn_nameptr, p->p_comm,
min(nd.ni_cnd.cn_namelen, MAXCOMLEN));
else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0)
bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title));
bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
#ifdef KTR
sched_clear_tdname(td);
#endif
/*
* mark as execed, wakeup the process that vforked (if any) and tell
* it that it now has its own resources back
*/
p->p_flag |= P_EXEC;
if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0)
p->p_flag2 &= ~P2_NOTRACE;
if (p->p_flag & P_PPWAIT) {
p->p_flag &= ~(P_PPWAIT | P_PPTRACE);
cv_broadcast(&p->p_pwait);
/* STOPs are no longer ignored, arrange for AST */
signotify(td);
}
/*
* Implement image setuid/setgid installation.
*/
if (imgp->credential_setid) {
/*
* Turn off syscall tracing for set-id programs, except for
* root. Record any set-id flags first to make sure that
* we do not regain any tracing during a possible block.
*/
setsugid(p);
#ifdef KTRACE
if (p->p_tracecred != NULL &&
priv_check_cred(p->p_tracecred, PRIV_DEBUG_DIFFCRED))
ktrprocexec(p, &tracecred, &tracevp);
#endif
/*
* Close any file descriptors 0..2 that reference procfs,
* then make sure file descriptors 0..2 are in use.
*
* Both fdsetugidsafety() and fdcheckstd() may call functions
* taking sleepable locks, so temporarily drop our locks.
*/
PROC_UNLOCK(p);
VOP_UNLOCK(imgp->vp, 0);
fdsetugidsafety(td);
error = fdcheckstd(td);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
if (error != 0)
goto exec_fail_dealloc;
PROC_LOCK(p);
#ifdef MAC
if (will_transition) {
mac_vnode_execve_transition(oldcred, imgp->newcred,
imgp->vp, interpvplabel, imgp);
}
#endif
} else {
if (oldcred->cr_uid == oldcred->cr_ruid &&
oldcred->cr_gid == oldcred->cr_rgid)
p->p_flag &= ~P_SUGID;
}
/*
* Set the new credentials.
*/
if (imgp->newcred != NULL) {
proc_set_cred(p, imgp->newcred);
crfree(oldcred);
oldcred = NULL;
}
/*
* Store the vp for use in procfs. This vnode was referenced by namei
* or fgetvp_exec.
*/
oldtextvp = p->p_textvp;
p->p_textvp = newtextvp;
#ifdef KDTRACE_HOOKS
/*
* Tell the DTrace fasttrap provider about the exec if it
* has declared an interest.
*/
if (dtrace_fasttrap_exec)
dtrace_fasttrap_exec(p);
#endif
/*
* Notify others that we exec'd, and clear the P_INEXEC flag
* as we're now a bona fide freshly-execed process.
*/
KNOTE_LOCKED(p->p_klist, NOTE_EXEC);
p->p_flag &= ~P_INEXEC;
/* clear "fork but no exec" flag, as we _are_ execing */
p->p_acflag &= ~AFORK;
/*
* Free any previous argument cache and replace it with
* the new argument cache, if any.
*/
oldargs = p->p_args;
p->p_args = newargs;
newargs = NULL;
PROC_UNLOCK(p);
#ifdef HWPMC_HOOKS
/*
* Check if system-wide sampling is in effect or if the
* current process is using PMCs. If so, do exec() time
* processing. This processing needs to happen AFTER the
* P_INEXEC flag is cleared.
*/
if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
VOP_UNLOCK(imgp->vp, 0);
pe.pm_credentialschanged = credential_changing;
pe.pm_entryaddr = imgp->entry_addr;
PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
}
#endif
/* Set values passed into the program in registers. */
(*p->p_sysent->sv_setregs)(td, imgp, (u_long)(uintptr_t)stack_base);
vfs_mark_atime(imgp->vp, td->td_ucred);
SDT_PROBE1(proc, , , exec__success, args->fname);
exec_fail_dealloc:
if (imgp->firstpage != NULL)
exec_unmap_first_page(imgp);
if (imgp->vp != NULL) {
if (args->fname)
NDFREE(&nd, NDF_ONLY_PNBUF);
if (imgp->opened)
VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td);
if (error != 0)
vput(imgp->vp);
else
VOP_UNLOCK(imgp->vp, 0);
}
if (imgp->object != NULL)
vm_object_deallocate(imgp->object);
free(imgp->freepath, M_TEMP);
if (error == 0) {
if (p->p_ptevents & PTRACE_EXEC) {
PROC_LOCK(p);
if (p->p_ptevents & PTRACE_EXEC)
td->td_dbgflags |= TDB_EXEC;
PROC_UNLOCK(p);
}
/*
* Stop the process here if its stop event mask has
* the S_EXEC bit set.
*/
STOPEVENT(p, S_EXEC, 0);
} else {
exec_fail:
/* we're done here, clear P_INEXEC */
PROC_LOCK(p);
p->p_flag &= ~P_INEXEC;
PROC_UNLOCK(p);
SDT_PROBE1(proc, , , exec__failure, error);
}
if (imgp->newcred != NULL && oldcred != NULL)
crfree(imgp->newcred);
#ifdef MAC
mac_execve_exit(imgp);
mac_execve_interpreter_exit(interpvplabel);
#endif
exec_free_args(args);
/*
* Handle deferred decrement of ref counts.
*/
if (oldtextvp != NULL)
vrele(oldtextvp);
#ifdef KTRACE
if (tracevp != NULL)
vrele(tracevp);
if (tracecred != NULL)
crfree(tracecred);
#endif
pargs_drop(oldargs);
pargs_drop(newargs);
if (oldsigacts != NULL)
sigacts_free(oldsigacts);
if (euip != NULL)
uifree(euip);
if (error && imgp->vmspace_destroyed) {
/* sorry, no more process anymore. exit gracefully */
exit1(td, 0, SIGABRT);
/* NOT REACHED */
}
#ifdef KTRACE
if (error == 0)
ktrprocctor(p);
#endif
/*
* We don't want cpu_set_syscall_retval() to overwrite any of
* the register values put in place by exec_setregs().
* Implementations of cpu_set_syscall_retval() will leave
* registers unmodified when returning EJUSTRETURN.
*/
return (error == 0 ? EJUSTRETURN : error);
}