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Protect proc.p_pptr and proc.p_children/p_sibling with the

Browse Source 
proctree_lock.

linprocfs not locked pending response from informal maintainer.

Reviewed by:	jhb, -smp@
This commit is contained in:
jake 2000-12-23 19:43:10 +00:00
parent 974f411f61
commit fa7a58ab48
22 changed files with 218 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sys/alpha/alpha/sys_machdep.c
View File

@ -173,6 +173,7 @@ alpha_set_uac(struct proc *p, char *args)
if (error)
return (error);
PROCTREE_LOCK(PT_SHARED);
if (p->p_pptr) {
s = splimp();
if (p->p_pptr) {
@ -182,6 +183,7 @@ alpha_set_uac(struct proc *p, char *args)
error = ESRCH;
splx(s);
}
PROCTREE_LOCK(PT_RELEASE);
return error;
}
@ -192,6 +194,7 @@ alpha_get_uac(struct proc *p, char *args)
unsigned long uac;
error = ESRCH;
PROCTREE_LOCK(PT_SHARED);
if (p->p_pptr) {
s = splimp();
if (p->p_pptr) {
@ -200,5 +203,6 @@ alpha_get_uac(struct proc *p, char *args)
}
splx(s);
}
PROCTREE_LOCK(PT_RELEASE);
return error;
}

12
sys/alpha/alpha/vm_machdep.c
View File

@ -256,6 +256,18 @@ cpu_exit(p)
mtx_enter(&sched_lock, MTX_SPIN);
mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
mtx_assert(&Giant, MA_NOTOWNED);
/*
* We have to wait until after releasing all locks before
* changing p_stat. If we block on a mutex then we will be
* back at SRUN when we resume and our parent will never
* harvest us.
*/
p->p_stat = SZOMB;
mp_fixme("assumption: p_pptr won't change at this time");
wakeup(p->p_pptr);
cnt.v_swtch++;
cpu_switch();
panic("cpu_exit");

12
sys/amd64/amd64/vm_machdep.c
View File

@ -259,6 +259,18 @@ cpu_exit(p)
mtx_enter(&sched_lock, MTX_SPIN);
mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
mtx_assert(&Giant, MA_NOTOWNED);
/*
* We have to wait until after releasing all locks before
* changing p_stat. If we block on a mutex then we will be
* back at SRUN when we resume and our parent will never
* harvest us.
*/
p->p_stat = SZOMB;
mp_fixme("assumption: p_pptr won't change at this time");
wakeup(p->p_pptr);
cnt.v_swtch++;
cpu_throw();
panic("cpu_exit");

24
sys/compat/svr4/svr4_misc.c
View File

@ -1205,6 +1205,7 @@ svr4_sys_waitsys(p, uap)
loop:
nfound = 0;
PROCTREE_LOCK(PT_SHARED);
for (q = p->p_children.lh_first; q != 0; q = q->p_sibling.le_next) {
if (SCARG(uap, id) != WAIT_ANY &&
q->p_pid != SCARG(uap, id) &&
@ -1216,6 +1217,7 @@ svr4_sys_waitsys(p, uap)
nfound++;
if (q->p_stat == SZOMB &&
((SCARG(uap, options) & (SVR4_WEXITED|SVR4_WTRAPPED)))) {
PROCTREE_LOCK(PT_RELEASE);
*retval = 0;
DPRINTF(("found %d\n", q->p_pid));
if ((error = svr4_setinfo(q, q->p_xstat,
@ -1236,14 +1238,18 @@ svr4_sys_waitsys(p, uap)
* parent a SIGCHLD. The rest of the cleanup will be
* done when the old parent waits on the child.
*/
if ((q->p_flag & P_TRACED) &&
q->p_oppid != q->p_pptr->p_pid) {
t = pfind(q->p_oppid);
proc_reparent(q, t ? t : initproc);
q->p_oppid = 0;
q->p_flag &= ~(P_TRACED | P_WAITED);
wakeup((caddr_t)q->p_pptr);
return 0;
if (q->p_flag & P_TRACED) {
PROCTREE_LOCK(PT_EXCLUSIVE);
if (q->p_oppid != q->p_pptr->p_pid) {
t = pfind(q->p_oppid);
proc_reparent(q, t ? t : initproc);
q->p_oppid = 0;
q->p_flag &= ~(P_TRACED | P_WAITED);
wakeup((caddr_t)q->p_pptr);
PROCTREE_LOCK(PT_RELEASE);
return 0;
}
PROCTREE_LOCK(PT_RELEASE);
}
q->p_xstat = 0;
ruadd(&p->p_stats->p_cru, q->p_ru);
@ -1260,7 +1266,9 @@ svr4_sys_waitsys(p, uap)
LIST_REMOVE(q, p_list); /* off zombproc */
ALLPROC_LOCK(AP_RELEASE);
PROCTREE_LOCK(PT_EXCLUSIVE);
LIST_REMOVE(q, p_sibling);
PROCTREE_LOCK(PT_RELEASE);
/*
* Decrement the count of procs running with this uid.

14
sys/fs/procfs/procfs_ctl.c
View File

@ -144,10 +144,12 @@ procfs_control(curp, p, op)
p->p_flag |= P_TRACED;
faultin(p);
p->p_xstat = 0; /* XXX ? */
PROCTREE_LOCK(PT_EXCLUSIVE);
if (p->p_pptr != curp) {
p->p_oppid = p->p_pptr->p_pid;
proc_reparent(p, curp);
}
PROCTREE_LOCK(PT_RELEASE);
psignal(p, SIGSTOP);
return (0);
}
@ -164,12 +166,15 @@ procfs_control(curp, p, op)
break;
default:
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
if (!TRACE_WAIT_P(curp, p)) {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
return (EBUSY);
}
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
}
@ -204,6 +209,7 @@ procfs_control(curp, p, op)
SIGDELSET(p->p_siglist, SIGTRAP);
/* give process back to original parent */
PROCTREE_LOCK(PT_EXCLUSIVE);
if (p->p_oppid != p->p_pptr->p_pid) {
struct proc *pp;
@ -211,6 +217,7 @@ procfs_control(curp, p, op)
if (pp)
proc_reparent(p, pp);
}
PROCTREE_LOCK(PT_RELEASE);
p->p_oppid = 0;
p->p_flag &= ~P_WAITED; /* XXX ? */
@ -244,19 +251,23 @@ procfs_control(curp, p, op)
case PROCFS_CTL_WAIT:
error = 0;
if (p->p_flag & P_TRACED) {
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
while (error == 0 &&
(p->p_stat != SSTOP) &&
(p->p_flag & P_TRACED) &&
(p->p_pptr == curp)) {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
error = tsleep((caddr_t) p,
PWAIT|PCATCH, "procfsx", 0);
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
}
if (error == 0 && !TRACE_WAIT_P(curp, p))
error = EBUSY;
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
} else {
mtx_enter(&sched_lock, MTX_SPIN);
while (error == 0 && p->p_stat != SSTOP) {
@ -317,6 +328,7 @@ procfs_doctl(curp, p, pfs, uio)
} else {
nm = vfs_findname(signames, msg, xlen);
if (nm) {
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
if (TRACE_WAIT_P(curp, p)) {
p->p_xstat = nm->nm_val;
@ -325,8 +337,10 @@ procfs_doctl(curp, p, pfs, uio)
#endif
setrunnable(p);
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
} else {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
psignal(p, nm->nm_val);
}
error = 0;

2
sys/fs/procfs/procfs_status.c
View File

@ -78,7 +78,9 @@ procfs_dostatus(curp, p, pfs, uio)
return (EOPNOTSUPP);
pid = p->p_pid;
PROCTREE_LOCK(PT_SHARED);
ppid = p->p_pptr ? p->p_pptr->p_pid : 0;
PROCTREE_LOCK(PT_RELEASE);
pgid = p->p_pgrp->pg_id;
sess = p->p_pgrp->pg_session;
sid = sess->s_leader ? sess->s_leader->p_pid : 0;

12
sys/i386/i386/vm_machdep.c
View File

@ -259,6 +259,18 @@ cpu_exit(p)
mtx_enter(&sched_lock, MTX_SPIN);
mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
mtx_assert(&Giant, MA_NOTOWNED);
/*
* We have to wait until after releasing all locks before
* changing p_stat. If we block on a mutex then we will be
* back at SRUN when we resume and our parent will never
* harvest us.
*/
p->p_stat = SZOMB;
mp_fixme("assumption: p_pptr won't change at this time");
wakeup(p->p_pptr);
cnt.v_swtch++;
cpu_throw();
panic("cpu_exit");

12
sys/ia64/ia64/vm_machdep.c
View File

@ -306,6 +306,18 @@ cpu_exit(p)
mtx_enter(&sched_lock, MTX_SPIN);
mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
mtx_assert(&Giant, MA_NOTOWNED);
/*
* We have to wait until after releasing all locks before
* changing p_stat. If we block on a mutex then we will be
* back at SRUN when we resume and our parent will never
* harvest us.
*/
p->p_stat = SZOMB;
mp_fixme("assumption: p_pptr won't change at this time");
wakeup(p->p_pptr);
cnt.v_swtch++;
cpu_switch();
panic("cpu_exit");

2
sys/kern/kern_exec.c
View File

@ -267,10 +267,12 @@ execve(p, uap)
* it that it now has its own resources back
*/
p->p_flag |= P_EXEC;
PROCTREE_LOCK(PT_SHARED);
if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
p->p_flag &= ~P_PPWAIT;
wakeup((caddr_t)p->p_pptr);
}
PROCTREE_LOCK(PT_RELEASE);
/*
* Implement image setuid/setgid.

40
sys/kern/kern_exit.c
View File

@ -267,17 +267,10 @@ exit1(p, rv)
ALLPROC_LOCK(AP_EXCLUSIVE);
LIST_REMOVE(p, p_list);
LIST_INSERT_HEAD(&zombproc, p, p_list);
LIST_REMOVE(p, p_hash);
ALLPROC_LOCK(AP_RELEASE);
/*
* We have to wait until after releasing this lock before
* changing p_stat. If we block on a mutex while waiting to
* release the allproc_lock, then we will be back at SRUN when
* we resume here and our parent will never harvest us.
*/
p->p_stat = SZOMB;
PROCTREE_LOCK(PT_EXCLUSIVE);
q = LIST_FIRST(&p->p_children);
if (q) /* only need this if any child is S_ZOMB */
wakeup((caddr_t) initproc);
@ -343,7 +336,7 @@ exit1(p, rv)
psignal(p->p_pptr, SIGCHLD);
}
wakeup((caddr_t)p->p_pptr);
PROCTREE_LOCK(PT_RELEASE);
/*
* Clear curproc after we've done all operations
* that could block, and before tearing down the rest
@ -419,6 +412,7 @@ wait1(q, uap, compat)
return (EINVAL);
loop:
nfound = 0;
PROCTREE_LOCK(PT_SHARED);
LIST_FOREACH(p, &q->p_children, p_sibling) {
if (uap->pid != WAIT_ANY &&
p->p_pid != uap->pid && p->p_pgid != -uap->pid)
@ -440,6 +434,7 @@ wait1(q, uap, compat)
mtx_enter(&sched_lock, MTX_SPIN);
if (p->p_stat == SZOMB) {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
/* charge childs scheduling cpu usage to parent */
if (curproc->p_pid != 1) {
@ -466,12 +461,17 @@ wait1(q, uap, compat)
* If we got the child via a ptrace 'attach',
* we need to give it back to the old parent.
*/
if (p->p_oppid && (t = pfind(p->p_oppid))) {
p->p_oppid = 0;
proc_reparent(p, t);
psignal(t, SIGCHLD);
wakeup((caddr_t)t);
return (0);
if (p->p_oppid) {
PROCTREE_LOCK(PT_EXCLUSIVE);
if ((t = pfind(p->p_oppid)) != NULL) {
p->p_oppid = 0;
proc_reparent(p, t);
psignal(t, SIGCHLD);
wakeup((caddr_t)t);
PROCTREE_LOCK(PT_RELEASE);
return (0);
}
PROCTREE_LOCK(PT_RELEASE);
}
p->p_xstat = 0;
ruadd(&q->p_stats->p_cru, p->p_ru);
@ -519,10 +519,14 @@ wait1(q, uap, compat)
* Unlink it from its process group and free it.
*/
leavepgrp(p);
ALLPROC_LOCK(AP_EXCLUSIVE);
LIST_REMOVE(p, p_list); /* off zombproc */
ALLPROC_LOCK(AP_RELEASE);
PROCTREE_LOCK(PT_EXCLUSIVE);
LIST_REMOVE(p, p_sibling);
PROCTREE_LOCK(PT_RELEASE);
if (--p->p_procsig->ps_refcnt == 0) {
if (p->p_sigacts != &p->p_addr->u_sigacts)
@ -545,6 +549,7 @@ wait1(q, uap, compat)
if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
(p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
p->p_flag |= P_WAITED;
q->p_retval[0] = p->p_pid;
#ifdef COMPAT_43
@ -563,6 +568,7 @@ wait1(q, uap, compat)
}
mtx_exit(&sched_lock, MTX_SPIN);
}
PROCTREE_LOCK(PT_RELEASE);
if (nfound == 0)
return (ECHILD);
if (uap->options & WNOHANG) {
@ -575,7 +581,8 @@ wait1(q, uap, compat)
}
/*
* make process 'parent' the new parent of process 'child'.
* Make process 'parent' the new parent of process 'child'.
* Must be called with an exclusive hold of proctree lock.
*/
void
proc_reparent(child, parent)
@ -583,6 +590,7 @@ proc_reparent(child, parent)
register struct proc *parent;
{
PROCTREE_ASSERT(PT_EXCLUSIVE);
if (child->p_pptr == parent)
return;

2
sys/kern/kern_fork.c
View File

@ -476,8 +476,10 @@ fork1(p1, flags, procp)
pptr = initproc;
else
pptr = p1;
PROCTREE_LOCK(PT_EXCLUSIVE);
p2->p_pptr = pptr;
LIST_INSERT_HEAD(&pptr->p_children, p2, p_sibling);
PROCTREE_LOCK(PT_RELEASE);
LIST_INIT(&p2->p_children);
LIST_INIT(&p2->p_heldmtx);
LIST_INIT(&p2->p_contested);

4
sys/kern/kern_kthread.c
View File

@ -30,6 +30,7 @@
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/unistd.h>
@ -113,7 +114,10 @@ kthread_create(void (*func)(void *), void *arg,
void
kthread_exit(int ecode)
{
PROCTREE_LOCK(PT_EXCLUSIVE);
proc_reparent(curproc, initproc);
PROCTREE_LOCK(PT_RELEASE);
exit1(curproc, W_EXITCODE(ecode, 0));
}

6
sys/kern/kern_ktrace.c
View File

@ -317,7 +317,6 @@ ktrace(curp, uap)
ret |= ktrsetchildren(curp, p, ops, facs, vp);
else
ret |= ktrops(curp, p, ops, facs, vp);
} else {
/*
* by pid
@ -426,6 +425,7 @@ ktrsetchildren(curp, top, ops, facs, vp)
register int ret = 0;
p = top;
PROCTREE_LOCK(PT_SHARED);
for (;;) {
ret |= ktrops(curp, p, ops, facs, vp);
/*
@ -436,8 +436,10 @@ ktrsetchildren(curp, top, ops, facs, vp)
if (!LIST_EMPTY(&p->p_children))
p = LIST_FIRST(&p->p_children);
else for (;;) {
if (p == top)
if (p == top) {
PROCTREE_LOCK(PT_RELEASE);
return (ret);
}
if (LIST_NEXT(p, p_sibling)) {
p = LIST_NEXT(p, p_sibling);
break;

17
sys/kern/kern_proc.c
View File

@ -73,6 +73,7 @@ u_long pgrphash;
struct proclist allproc;
struct proclist zombproc;
struct lock allproc_lock;
struct lock proctree_lock;
vm_zone_t proc_zone;
vm_zone_t ithread_zone;
@ -84,6 +85,7 @@ procinit()
{
lockinit(&allproc_lock, PZERO, "allproc", 0, 0);
lockinit(&proctree_lock, PZERO, "proctree", 0, 0);
LIST_INIT(&allproc);
LIST_INIT(&zombproc);
pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
@ -106,11 +108,16 @@ int
inferior(p)
register struct proc *p;
{
int rval = 1;
PROCTREE_LOCK(PT_SHARED);
for (; p != curproc; p = p->p_pptr)
if (p->p_pid == 0)
return (0);
return (1);
if (p->p_pid == 0) {
rval = 0;
break;
}
PROCTREE_LOCK(PT_RELEASE);
return (rval);
}
/*
@ -281,6 +288,7 @@ fixjobc(p, pgrp, entering)
* Check p's parent to see whether p qualifies its own process
* group; if so, adjust count for p's process group.
*/
PROCTREE_LOCK(PT_SHARED);
if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
hispgrp->pg_session == mysession) {
if (entering)
@ -303,6 +311,7 @@ fixjobc(p, pgrp, entering)
else if (--hispgrp->pg_jobc == 0)
orphanpg(hispgrp);
}
PROCTREE_LOCK(PT_RELEASE);
}
/*
@ -414,8 +423,10 @@ fill_kinfo_proc(p, kp)
kp->ki_rtprio = p->p_rtprio;
kp->ki_runtime = p->p_runtime;
kp->ki_pid = p->p_pid;
PROCTREE_LOCK(PT_SHARED);
if (p->p_pptr)
kp->ki_ppid = p->p_pptr->p_pid;
PROCTREE_LOCK(PT_RELEASE);
sp = NULL;
if (p->p_pgrp) {
kp->ki_pgid = p->p_pgrp->pg_id;

12
sys/kern/kern_prot.c
View File

@ -50,6 +50,7 @@
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/pioctl.h>
@ -65,8 +66,9 @@ struct getpid_args {
#endif
/*
* NOT MP SAFE due to p_pptr access
* getpid - MP SAFE
*/
/* ARGSUSED */
int
getpid(p, uap)
@ -76,11 +78,17 @@ getpid(p, uap)
p->p_retval[0] = p->p_pid;
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
PROCTREE_LOCK(PT_SHARED);
p->p_retval[1] = p->p_pptr->p_pid;
PROCTREE_LOCK(PT_RELEASE);
#endif
return (0);
}
/*
* getppid - MP SAFE
*/
#ifndef _SYS_SYSPROTO_H_
struct getppid_args {
int dummy;
@ -93,7 +101,9 @@ getppid(p, uap)
struct getppid_args *uap;
{
PROCTREE_LOCK(PT_SHARED);
p->p_retval[0] = p->p_pptr->p_pid;
PROCTREE_LOCK(PT_RELEASE);
return (0);
}

11
sys/kern/kern_sig.c
View File

@ -1158,9 +1158,11 @@ psignal(p, sig)
goto out;
SIGDELSET(p->p_siglist, sig);
p->p_xstat = sig;
PROCTREE_LOCK(PT_SHARED);
if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
psignal(p->p_pptr, SIGCHLD);
stop(p);
PROCTREE_LOCK(PT_RELEASE);
goto out;
} else
goto runfast;
@ -1296,14 +1298,17 @@ issignal(p)
* stopped until released by the parent.
*/
p->p_xstat = sig;
PROCTREE_LOCK(PT_SHARED);
psignal(p->p_pptr, SIGCHLD);
do {
stop(p);
PROCTREE_LOCK(PT_RELEASE);
mtx_enter(&sched_lock, MTX_SPIN);
DROP_GIANT_NOSWITCH();
mi_switch();
mtx_exit(&sched_lock, MTX_SPIN);
PICKUP_GIANT();
PROCTREE_LOCK(PT_SHARED);
} while (!trace_req(p)
&& p->p_flag & P_TRACED);
@ -1369,9 +1374,11 @@ issignal(p)
prop & SA_TTYSTOP))
break; /* == ignore */
p->p_xstat = sig;
PROCTREE_LOCK(PT_SHARED);
stop(p);
if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
psignal(p->p_pptr, SIGCHLD);
PROCTREE_LOCK(PT_RELEASE);
mtx_enter(&sched_lock, MTX_SPIN);
DROP_GIANT_NOSWITCH();
mi_switch();
@ -1414,13 +1421,15 @@ issignal(p)
/*
* Put the argument process into the stopped state and notify the parent
* via wakeup. Signals are handled elsewhere. The process must not be
* on the run queue.
* on the run queue. Must be called with at least a shared hold of the
* proctree lock.
*/
void
stop(p)
register struct proc *p;
{
PROCTREE_ASSERT(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
p->p_stat = SSTOP;
p->p_flag &= ~P_WAITED;

12
sys/kern/sys_process.c
View File

@ -276,8 +276,12 @@ ptrace(curp, uap)
return EPERM;
/* not being traced by YOU */
if (p->p_pptr != curp)
PROCTREE_LOCK(PT_SHARED);
if (p->p_pptr != curp) {
PROCTREE_LOCK(PT_RELEASE);
return EBUSY;
}
PROCTREE_LOCK(PT_RELEASE);
/* not currently stopped */
mtx_enter(&sched_lock, MTX_SPIN);
@ -311,15 +315,19 @@ ptrace(curp, uap)
case PT_TRACE_ME:
/* set my trace flag and "owner" so it can read/write me */
p->p_flag |= P_TRACED;
PROCTREE_LOCK(PT_SHARED);
p->p_oppid = p->p_pptr->p_pid;
PROCTREE_LOCK(PT_RELEASE);
return 0;
case PT_ATTACH:
/* security check done above */
p->p_flag |= P_TRACED;
PROCTREE_LOCK(PT_EXCLUSIVE);
p->p_oppid = p->p_pptr->p_pid;
if (p->p_pptr != curp)
proc_reparent(p, curp);
PROCTREE_LOCK(PT_RELEASE);
uap->data = SIGSTOP;
goto sendsig; /* in PT_CONTINUE below */
@ -350,12 +358,14 @@ ptrace(curp, uap)
if (uap->req == PT_DETACH) {
/* reset process parent */
PROCTREE_LOCK(PT_EXCLUSIVE);
if (p->p_oppid != p->p_pptr->p_pid) {
struct proc *pp;
pp = pfind(p->p_oppid);
proc_reparent(p, pp ? pp : initproc);
}
PROCTREE_LOCK(PT_RELEASE);
p->p_flag &= ~(P_TRACED | P_WAITED);
p->p_oppid = 0;

14
sys/miscfs/procfs/procfs_ctl.c
View File

@ -144,10 +144,12 @@ procfs_control(curp, p, op)
p->p_flag |= P_TRACED;
faultin(p);
p->p_xstat = 0; /* XXX ? */
PROCTREE_LOCK(PT_EXCLUSIVE);
if (p->p_pptr != curp) {
p->p_oppid = p->p_pptr->p_pid;
proc_reparent(p, curp);
}
PROCTREE_LOCK(PT_RELEASE);
psignal(p, SIGSTOP);
return (0);
}
@ -164,12 +166,15 @@ procfs_control(curp, p, op)
break;
default:
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
if (!TRACE_WAIT_P(curp, p)) {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
return (EBUSY);
}
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
}
@ -204,6 +209,7 @@ procfs_control(curp, p, op)
SIGDELSET(p->p_siglist, SIGTRAP);
/* give process back to original parent */
PROCTREE_LOCK(PT_EXCLUSIVE);
if (p->p_oppid != p->p_pptr->p_pid) {
struct proc *pp;
@ -211,6 +217,7 @@ procfs_control(curp, p, op)
if (pp)
proc_reparent(p, pp);
}
PROCTREE_LOCK(PT_RELEASE);
p->p_oppid = 0;
p->p_flag &= ~P_WAITED; /* XXX ? */
@ -244,19 +251,23 @@ procfs_control(curp, p, op)
case PROCFS_CTL_WAIT:
error = 0;
if (p->p_flag & P_TRACED) {
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
while (error == 0 &&
(p->p_stat != SSTOP) &&
(p->p_flag & P_TRACED) &&
(p->p_pptr == curp)) {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
error = tsleep((caddr_t) p,
PWAIT|PCATCH, "procfsx", 0);
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
}
if (error == 0 && !TRACE_WAIT_P(curp, p))
error = EBUSY;
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
} else {
mtx_enter(&sched_lock, MTX_SPIN);
while (error == 0 && p->p_stat != SSTOP) {
@ -317,6 +328,7 @@ procfs_doctl(curp, p, pfs, uio)
} else {
nm = vfs_findname(signames, msg, xlen);
if (nm) {
PROCTREE_LOCK(PT_SHARED);
mtx_enter(&sched_lock, MTX_SPIN);
if (TRACE_WAIT_P(curp, p)) {
p->p_xstat = nm->nm_val;
@ -325,8 +337,10 @@ procfs_doctl(curp, p, pfs, uio)
#endif
setrunnable(p);
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
} else {
mtx_exit(&sched_lock, MTX_SPIN);
PROCTREE_LOCK(PT_RELEASE);
psignal(p, nm->nm_val);
}
error = 0;

2
sys/miscfs/procfs/procfs_status.c
View File

@ -78,7 +78,9 @@ procfs_dostatus(curp, p, pfs, uio)
return (EOPNOTSUPP);
pid = p->p_pid;
PROCTREE_LOCK(PT_SHARED);
ppid = p->p_pptr ? p->p_pptr->p_pid : 0;
PROCTREE_LOCK(PT_RELEASE);
pgid = p->p_pgrp->pg_id;
sess = p->p_pgrp->pg_session;
sid = sess->s_leader ? sess->s_leader->p_pid : 0;

12
sys/powerpc/aim/vm_machdep.c
View File

@ -256,6 +256,18 @@ cpu_exit(p)
mtx_enter(&sched_lock, MTX_SPIN);
mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
mtx_assert(&Giant, MA_NOTOWNED);
/*
* We have to wait until after releasing all locks before
* changing p_stat. If we block on a mutex then we will be
* back at SRUN when we resume and our parent will never
* harvest us.
*/
p->p_stat = SZOMB;
mp_fixme("assumption: p_pptr won't change at this time");
wakeup(p->p_pptr);
cnt.v_swtch++;
cpu_switch();
panic("cpu_exit");

12
sys/powerpc/powerpc/vm_machdep.c
View File

@ -256,6 +256,18 @@ cpu_exit(p)
mtx_enter(&sched_lock, MTX_SPIN);
mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH);
mtx_assert(&Giant, MA_NOTOWNED);
/*
* We have to wait until after releasing all locks before
* changing p_stat. If we block on a mutex then we will be
* back at SRUN when we resume and our parent will never
* harvest us.
*/
p->p_stat = SZOMB;
mp_fixme("assumption: p_pptr won't change at this time");
wakeup(p->p_pptr);
cnt.v_swtch++;
cpu_switch();
panic("cpu_exit");

12
sys/sys/proc.h
View File

@ -415,6 +415,17 @@ sigonstack(size_t sp)
#define AP_EXCLUSIVE LK_EXCLUSIVE
#define AP_RELEASE LK_RELEASE
/* Lock and unlock the proc child and sibling lists. */
#define PROCTREE_LOCK(how) \
lockmgr(&proctree_lock, (how), NULL, CURPROC)
#define PROCTREE_ASSERT(what) \
LOCKMGR_ASSERT(&proctree_lock, (what), CURPROC)
#define PT_SHARED LK_SHARED
#define PT_EXCLUSIVE LK_EXCLUSIVE
#define PT_RELEASE LK_RELEASE
/* Hold process U-area in memory, normally for ptrace/procfs work. */
#define PHOLD(p) do { \
PROC_LOCK(p); \
@ -439,6 +450,7 @@ extern LIST_HEAD(pgrphashhead, pgrp) *pgrphashtbl;
extern u_long pgrphash;
extern struct lock allproc_lock;
extern struct lock proctree_lock;
extern struct proc proc0; /* Process slot for swapper. */
extern int hogticks; /* Limit on kernel cpu hogs. */
extern int nprocs, maxproc; /* Current and max number of procs. */