freebsd-dev/sys/kern/sys_process.c

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/*
* Copyright (c) 1994, Sean Eric Fagan
* All rights reserved.
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*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Sean Eric Fagan.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
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*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* 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 OR CONTRIBUTORS BE LIABLE
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* 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.
*
* $Id: sys_process.c,v 1.36 1998/02/06 12:13:27 eivind Exp $
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*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
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#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ptrace.h>
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#include <machine/reg.h>
#include <vm/vm.h>
#include <vm/vm_prot.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_extern.h>
#include <sys/user.h>
#include <miscfs/procfs/procfs.h>
/* use the equivalent procfs code */
#if 0
static int
pread (struct proc *procp, unsigned int addr, unsigned int *retval) {
int rv;
vm_map_t map, tmap;
vm_object_t object;
vm_offset_t kva = 0;
int page_offset; /* offset into page */
vm_offset_t pageno; /* page number */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
VM level code cleanups. 1) Start using TSM. Struct procs continue to point to upages structure, after being freed. Struct vmspace continues to point to pte object and kva space for kstack. u_map is now superfluous. 2) vm_map's don't need to be reference counted. They always exist either in the kernel or in a vmspace. The vmspaces are managed by reference counts. 3) Remove the "wired" vm_map nonsense. 4) No need to keep a cache of kernel stack kva's. 5) Get rid of strange looking ++var, and change to var++. 6) Change more data structures to use our "zone" allocator. Added struct proc, struct vmspace and struct vnode. This saves a significant amount of kva space and physical memory. Additionally, this enables TSM for the zone managed memory. 7) Keep ioopt disabled for now. 8) Remove the now bogus "single use" map concept. 9) Use generation counts or id's for data structures residing in TSM, where it allows us to avoid unneeded restart overhead during traversals, where blocking might occur. 10) Account better for memory deficits, so the pageout daemon will be able to make enough memory available (experimental.) 11) Fix some vnode locking problems. (From Tor, I think.) 12) Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp. (experimental.) 13) Significantly shrink, cleanup, and make slightly faster the vm_fault.c code. Use generation counts, get rid of unneded collpase operations, and clean up the cluster code. 14) Make vm_zone more suitable for TSM. This commit is partially as a result of discussions and contributions from other people, including DG, Tor Egge, PHK, and probably others that I have forgotten to attribute (so let me know, if I forgot.) This is not the infamous, final cleanup of the vnode stuff, but a necessary step. Vnode mgmt should be correct, but things might still change, and there is still some missing stuff (like ioopt, and physical backing of non-merged cache files, debugging of layering concepts.)
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boolean_t wired;
vm_pindex_t pindex;
/* Map page into kernel space */
map = &procp->p_vmspace->vm_map;
page_offset = addr - trunc_page(addr);
pageno = trunc_page(addr);
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tmap = map;
rv = vm_map_lookup (&tmap, pageno, VM_PROT_READ, &out_entry,
VM level code cleanups. 1) Start using TSM. Struct procs continue to point to upages structure, after being freed. Struct vmspace continues to point to pte object and kva space for kstack. u_map is now superfluous. 2) vm_map's don't need to be reference counted. They always exist either in the kernel or in a vmspace. The vmspaces are managed by reference counts. 3) Remove the "wired" vm_map nonsense. 4) No need to keep a cache of kernel stack kva's. 5) Get rid of strange looking ++var, and change to var++. 6) Change more data structures to use our "zone" allocator. Added struct proc, struct vmspace and struct vnode. This saves a significant amount of kva space and physical memory. Additionally, this enables TSM for the zone managed memory. 7) Keep ioopt disabled for now. 8) Remove the now bogus "single use" map concept. 9) Use generation counts or id's for data structures residing in TSM, where it allows us to avoid unneeded restart overhead during traversals, where blocking might occur. 10) Account better for memory deficits, so the pageout daemon will be able to make enough memory available (experimental.) 11) Fix some vnode locking problems. (From Tor, I think.) 12) Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp. (experimental.) 13) Significantly shrink, cleanup, and make slightly faster the vm_fault.c code. Use generation counts, get rid of unneded collpase operations, and clean up the cluster code. 14) Make vm_zone more suitable for TSM. This commit is partially as a result of discussions and contributions from other people, including DG, Tor Egge, PHK, and probably others that I have forgotten to attribute (so let me know, if I forgot.) This is not the infamous, final cleanup of the vnode stuff, but a necessary step. Vnode mgmt should be correct, but things might still change, and there is still some missing stuff (like ioopt, and physical backing of non-merged cache files, debugging of layering concepts.)
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&object, &pindex, &out_prot, &wired);
if (rv != KERN_SUCCESS)
return EINVAL;
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vm_map_lookup_done (tmap, out_entry);
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/* Find space in kernel_map for the page we're interested in */
rv = vm_map_find (kernel_map, object, IDX_TO_OFF(pindex),
&kva, PAGE_SIZE, 0, VM_PROT_ALL, VM_PROT_ALL, 0);
if (!rv) {
vm_object_reference (object);
rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0);
if (!rv) {
*retval = 0;
bcopy ((caddr_t)kva + page_offset,
retval, sizeof *retval);
}
vm_map_remove (kernel_map, kva, kva + PAGE_SIZE);
}
return rv;
}
static int
pwrite (struct proc *procp, unsigned int addr, unsigned int datum) {
int rv;
vm_map_t map, tmap;
vm_object_t object;
vm_offset_t kva = 0;
int page_offset; /* offset into page */
vm_offset_t pageno; /* page number */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
VM level code cleanups. 1) Start using TSM. Struct procs continue to point to upages structure, after being freed. Struct vmspace continues to point to pte object and kva space for kstack. u_map is now superfluous. 2) vm_map's don't need to be reference counted. They always exist either in the kernel or in a vmspace. The vmspaces are managed by reference counts. 3) Remove the "wired" vm_map nonsense. 4) No need to keep a cache of kernel stack kva's. 5) Get rid of strange looking ++var, and change to var++. 6) Change more data structures to use our "zone" allocator. Added struct proc, struct vmspace and struct vnode. This saves a significant amount of kva space and physical memory. Additionally, this enables TSM for the zone managed memory. 7) Keep ioopt disabled for now. 8) Remove the now bogus "single use" map concept. 9) Use generation counts or id's for data structures residing in TSM, where it allows us to avoid unneeded restart overhead during traversals, where blocking might occur. 10) Account better for memory deficits, so the pageout daemon will be able to make enough memory available (experimental.) 11) Fix some vnode locking problems. (From Tor, I think.) 12) Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp. (experimental.) 13) Significantly shrink, cleanup, and make slightly faster the vm_fault.c code. Use generation counts, get rid of unneded collpase operations, and clean up the cluster code. 14) Make vm_zone more suitable for TSM. This commit is partially as a result of discussions and contributions from other people, including DG, Tor Egge, PHK, and probably others that I have forgotten to attribute (so let me know, if I forgot.) This is not the infamous, final cleanup of the vnode stuff, but a necessary step. Vnode mgmt should be correct, but things might still change, and there is still some missing stuff (like ioopt, and physical backing of non-merged cache files, debugging of layering concepts.)
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boolean_t wired;
vm_pindex_t pindex;
boolean_t fix_prot = 0;
/* Map page into kernel space */
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map = &procp->p_vmspace->vm_map;
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page_offset = addr - trunc_page(addr);
pageno = trunc_page(addr);
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/*
* Check the permissions for the area we're interested in.
*/
if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE,
VM_PROT_WRITE) == FALSE) {
/*
* If the page was not writable, we make it so.
* XXX It is possible a page may *not* be read/executable,
* if a process changes that!
*/
fix_prot = 1;
/* The page isn't writable, so let's try making it so... */
if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE,
VM_PROT_ALL, 0)) != KERN_SUCCESS)
return EFAULT; /* I guess... */
}
/*
* Now we need to get the page. out_entry, out_prot, wired, and
* single_use aren't used. One would think the vm code would be
* a *bit* nicer... We use tmap because vm_map_lookup() can
* change the map argument.
*/
tmap = map;
rv = vm_map_lookup (&tmap, pageno, VM_PROT_WRITE, &out_entry,
VM level code cleanups. 1) Start using TSM. Struct procs continue to point to upages structure, after being freed. Struct vmspace continues to point to pte object and kva space for kstack. u_map is now superfluous. 2) vm_map's don't need to be reference counted. They always exist either in the kernel or in a vmspace. The vmspaces are managed by reference counts. 3) Remove the "wired" vm_map nonsense. 4) No need to keep a cache of kernel stack kva's. 5) Get rid of strange looking ++var, and change to var++. 6) Change more data structures to use our "zone" allocator. Added struct proc, struct vmspace and struct vnode. This saves a significant amount of kva space and physical memory. Additionally, this enables TSM for the zone managed memory. 7) Keep ioopt disabled for now. 8) Remove the now bogus "single use" map concept. 9) Use generation counts or id's for data structures residing in TSM, where it allows us to avoid unneeded restart overhead during traversals, where blocking might occur. 10) Account better for memory deficits, so the pageout daemon will be able to make enough memory available (experimental.) 11) Fix some vnode locking problems. (From Tor, I think.) 12) Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp. (experimental.) 13) Significantly shrink, cleanup, and make slightly faster the vm_fault.c code. Use generation counts, get rid of unneded collpase operations, and clean up the cluster code. 14) Make vm_zone more suitable for TSM. This commit is partially as a result of discussions and contributions from other people, including DG, Tor Egge, PHK, and probably others that I have forgotten to attribute (so let me know, if I forgot.) This is not the infamous, final cleanup of the vnode stuff, but a necessary step. Vnode mgmt should be correct, but things might still change, and there is still some missing stuff (like ioopt, and physical backing of non-merged cache files, debugging of layering concepts.)
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&object, &pindex, &out_prot, &wired);
if (rv != KERN_SUCCESS) {
return EINVAL;
}
/*
* Okay, we've got the page. Let's release tmap.
*/
vm_map_lookup_done (tmap, out_entry);
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/*
* Fault the page in...
*/
rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE);
if (rv != KERN_SUCCESS)
return EFAULT;
/* Find space in kernel_map for the page we're interested in */
rv = vm_map_find (kernel_map, object, IDX_TO_OFF(pindex),
&kva, PAGE_SIZE, 0,
VM_PROT_ALL, VM_PROT_ALL, 0);
if (!rv) {
vm_object_reference (object);
rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0);
if (!rv) {
bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum);
}
vm_map_remove (kernel_map, kva, kva + PAGE_SIZE);
}
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if (fix_prot)
vm_map_protect (map, pageno, pageno + PAGE_SIZE,
VM_PROT_READ|VM_PROT_EXECUTE, 0);
return rv;
}
#endif
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/*
* Process debugging system call.
*/
#ifndef _SYS_SYSPROTO_H_
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struct ptrace_args {
int req;
pid_t pid;
caddr_t addr;
int data;
};
#endif
int
ptrace(curp, uap)
struct proc *curp;
struct ptrace_args *uap;
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{
struct proc *p;
struct iovec iov;
struct uio uio;
int error = 0;
int write;
int s;
if (uap->req == PT_TRACE_ME)
p = curp;
else {
if ((p = pfind(uap->pid)) == NULL)
return ESRCH;
}
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/*
* Permissions check
*/
switch (uap->req) {
case PT_TRACE_ME:
/* Always legal. */
break;
case PT_ATTACH:
/* Self */
if (p->p_pid == curp->p_pid)
return EINVAL;
/* Already traced */
if (p->p_flag & P_TRACED)
return EBUSY;
/* not owned by you, has done setuid (unless you're root) */
if ((p->p_cred->p_ruid != curp->p_cred->p_ruid) ||
(p->p_flag & P_SUGID)) {
if (error = suser(curp->p_ucred, &curp->p_acflag))
return error;
}
/* can't trace init when securelevel > 0 */
if (securelevel > 0 && p->p_pid == 1)
return EPERM;
/* OK */
break;
case PT_READ_I:
case PT_READ_D:
case PT_READ_U:
case PT_WRITE_I:
case PT_WRITE_D:
case PT_WRITE_U:
case PT_CONTINUE:
case PT_KILL:
case PT_STEP:
case PT_DETACH:
#ifdef PT_GETREGS
case PT_GETREGS:
#endif
#ifdef PT_SETREGS
case PT_SETREGS:
#endif
#ifdef PT_GETFPREGS
case PT_GETFPREGS:
#endif
#ifdef PT_SETFPREGS
case PT_SETFPREGS:
#endif
/* not being traced... */
if ((p->p_flag & P_TRACED) == 0)
return EPERM;
/* not being traced by YOU */
if (p->p_pptr != curp)
return EBUSY;
/* not currently stopped */
if (p->p_stat != SSTOP || (p->p_flag & P_WAITED) == 0)
return EBUSY;
/* OK */
break;
default:
return EINVAL;
}
#ifdef FIX_SSTEP
/*
* Single step fixup ala procfs
*/
FIX_SSTEP(p);
#endif
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/*
* Actually do the requests
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*/
write = 0;
curp->p_retval[0] = 0;
switch (uap->req) {
case PT_TRACE_ME:
/* set my trace flag and "owner" so it can read/write me */
p->p_flag |= P_TRACED;
p->p_oppid = p->p_pptr->p_pid;
return 0;
case PT_ATTACH:
/* security check done above */
p->p_flag |= P_TRACED;
p->p_oppid = p->p_pptr->p_pid;
if (p->p_pptr != curp)
proc_reparent(p, curp);
uap->data = SIGSTOP;
goto sendsig; /* in PT_CONTINUE below */
case PT_STEP:
case PT_CONTINUE:
case PT_DETACH:
if ((unsigned)uap->data >= NSIG)
return EINVAL;
PHOLD(p);
if (uap->req == PT_STEP) {
if ((error = ptrace_single_step (p))) {
PRELE(p);
return error;
}
}
if (uap->addr != (caddr_t)1) {
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
if ((error = ptrace_set_pc (p, (u_int)uap->addr))) {
PRELE(p);
return error;
}
}
PRELE(p);
if (uap->req == PT_DETACH) {
/* reset process parent */
if (p->p_oppid != p->p_pptr->p_pid) {
struct proc *pp;
pp = pfind(p->p_oppid);
proc_reparent(p, pp ? pp : initproc);
}
p->p_flag &= ~(P_TRACED | P_WAITED);
p->p_oppid = 0;
/* should we send SIGCHLD? */
}
sendsig:
/* deliver or queue signal */
s = splhigh();
if (p->p_stat == SSTOP) {
p->p_xstat = uap->data;
setrunnable(p);
} else if (uap->data) {
psignal(p, uap->data);
}
splx(s);
return 0;
case PT_WRITE_I:
case PT_WRITE_D:
write = 1;
/* fallthrough */
case PT_READ_I:
case PT_READ_D:
/* write = 0 set above */
iov.iov_base = write ? (caddr_t)&uap->data : (caddr_t)curp->p_retval;
iov.iov_len = sizeof(int);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = (off_t)(u_long)uap->addr;
uio.uio_resid = sizeof(int);
uio.uio_segflg = UIO_SYSSPACE; /* ie: the uap */
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_procp = p;
error = procfs_domem(curp, p, NULL, &uio);
if (uio.uio_resid != 0) {
/*
* XXX procfs_domem() doesn't currently return ENOSPC,
* so I think write() can bogusly return 0.
* XXX what happens for short writes? We don't want
* to write partial data.
* XXX procfs_domem() returns EPERM for other invalid
* addresses. Convert this to EINVAL. Does this
* clobber returns of EPERM for other reasons?
*/
if (error == 0 || error == ENOSPC || error == EPERM)
error = EINVAL; /* EOF */
}
return (error);
case PT_READ_U:
if ((u_int)uap->addr > (UPAGES * PAGE_SIZE - sizeof(int))) {
return EFAULT;
}
if (ptrace_read_u_check(p,(vm_offset_t) uap->addr,
sizeof(int)) &&
!procfs_kmemaccess(curp)) {
return EFAULT;
}
error = 0;
PHOLD(p); /* user had damn well better be incore! */
if (p->p_flag & P_INMEM) {
p->p_addr->u_kproc.kp_proc = *p;
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
curp->p_retval[0] = *(int*)((u_int)p->p_addr + (u_int)uap->addr);
} else {
curp->p_retval[0] = 0;
error = EFAULT;
}
PRELE(p);
return error;
case PT_WRITE_U:
PHOLD(p); /* user had damn well better be incore! */
if (p->p_flag & P_INMEM) {
p->p_addr->u_kproc.kp_proc = *p;
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
error = ptrace_write_u(p, (vm_offset_t)uap->addr, uap->data);
} else {
error = EFAULT;
}
PRELE(p);
return error;
case PT_KILL:
uap->data = SIGKILL;
goto sendsig; /* in PT_CONTINUE above */
#ifdef PT_SETREGS
case PT_SETREGS:
write = 1;
/* fallthrough */
#endif /* PT_SETREGS */
#ifdef PT_GETREGS
case PT_GETREGS:
/* write = 0 above */
#endif /* PT_SETREGS */
#if defined(PT_SETREGS) || defined(PT_GETREGS)
if (!procfs_validregs(p)) /* no P_SYSTEM procs please */
return EINVAL;
else {
iov.iov_base = uap->addr;
iov.iov_len = sizeof(struct reg);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = 0;
uio.uio_resid = sizeof(struct reg);
uio.uio_segflg = UIO_USERSPACE;
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_procp = curp;
return (procfs_doregs(curp, p, NULL, &uio));
}
#endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */
#ifdef PT_SETFPREGS
case PT_SETFPREGS:
write = 1;
/* fallthrough */
#endif /* PT_SETFPREGS */
#ifdef PT_GETFPREGS
case PT_GETFPREGS:
/* write = 0 above */
#endif /* PT_SETFPREGS */
#if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
if (!procfs_validfpregs(p)) /* no P_SYSTEM procs please */
return EINVAL;
else {
iov.iov_base = uap->addr;
iov.iov_len = sizeof(struct fpreg);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = 0;
uio.uio_resid = sizeof(struct fpreg);
uio.uio_segflg = UIO_USERSPACE;
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_procp = curp;
return (procfs_dofpregs(curp, p, NULL, &uio));
}
#endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */
default:
break;
}
return 0;
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}
int
trace_req(p)
struct proc *p;
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{
return 1;
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}
/*
* stopevent()
* Stop a process because of a procfs event;
* stay stopped until p->p_step is cleared
* (cleared by PIOCCONT in procfs).
*/
void
stopevent(struct proc *p, unsigned int event, unsigned int val) {
p->p_step = 1;
do {
p->p_xstat = val;
p->p_stype = event; /* Which event caused the stop? */
wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */
tsleep(&p->p_step, PWAIT, "stopevent", 0);
} while (p->p_step);
}