freebsd-nq/sys/kern/sys_process.c
David Xu d7bc12b096 Avoid kernel panic when attaching a process which may not be stopped
by debugger, e.g process is dumping core. Only access p_xthread if
P_STOPPED_TRACE is set, this means thread is ready to exchange signal
with debugger, print a warning if P_STOPPED_TRACE is not set due to
some bugs in other code, if there is.

The patch has been tested by Anish Mistry mistry.7 at osu dot edu, and
is slightly adjusted.
2005-12-24 02:59:29 +00:00

1066 lines
23 KiB
C

/*-
* Copyright (c) 1994, Sean Eric Fagan
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* 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
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ptrace.h>
#include <sys/sx.h>
#include <sys/malloc.h>
#include <sys/signalvar.h>
#include <machine/reg.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#ifdef COMPAT_IA32
#include <sys/procfs.h>
#include <machine/fpu.h>
#include <compat/ia32/ia32_reg.h>
extern struct sysentvec ia32_freebsd_sysvec;
struct ptrace_io_desc32 {
int piod_op;
u_int32_t piod_offs;
u_int32_t piod_addr;
u_int32_t piod_len;
};
#endif
/*
* Functions implemented using PROC_ACTION():
*
* proc_read_regs(proc, regs)
* Get the current user-visible register set from the process
* and copy it into the regs structure (<machine/reg.h>).
* The process is stopped at the time read_regs is called.
*
* proc_write_regs(proc, regs)
* Update the current register set from the passed in regs
* structure. Take care to avoid clobbering special CPU
* registers or privileged bits in the PSL.
* Depending on the architecture this may have fix-up work to do,
* especially if the IAR or PCW are modified.
* The process is stopped at the time write_regs is called.
*
* proc_read_fpregs, proc_write_fpregs
* deal with the floating point register set, otherwise as above.
*
* proc_read_dbregs, proc_write_dbregs
* deal with the processor debug register set, otherwise as above.
*
* proc_sstep(proc)
* Arrange for the process to trap after executing a single instruction.
*/
#define PROC_ACTION(action) do { \
int error; \
\
PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); \
if ((td->td_proc->p_sflag & PS_INMEM) == 0) \
error = EIO; \
else \
error = (action); \
return (error); \
} while(0)
int
proc_read_regs(struct thread *td, struct reg *regs)
{
PROC_ACTION(fill_regs(td, regs));
}
int
proc_write_regs(struct thread *td, struct reg *regs)
{
PROC_ACTION(set_regs(td, regs));
}
int
proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
{
PROC_ACTION(fill_dbregs(td, dbregs));
}
int
proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
{
PROC_ACTION(set_dbregs(td, dbregs));
}
/*
* Ptrace doesn't support fpregs at all, and there are no security holes
* or translations for fpregs, so we can just copy them.
*/
int
proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
{
PROC_ACTION(fill_fpregs(td, fpregs));
}
int
proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
{
PROC_ACTION(set_fpregs(td, fpregs));
}
#ifdef COMPAT_IA32
/* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
int
proc_read_regs32(struct thread *td, struct reg32 *regs32)
{
PROC_ACTION(fill_regs32(td, regs32));
}
int
proc_write_regs32(struct thread *td, struct reg32 *regs32)
{
PROC_ACTION(set_regs32(td, regs32));
}
int
proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
{
PROC_ACTION(fill_dbregs32(td, dbregs32));
}
int
proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
{
PROC_ACTION(set_dbregs32(td, dbregs32));
}
int
proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
{
PROC_ACTION(fill_fpregs32(td, fpregs32));
}
int
proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
{
PROC_ACTION(set_fpregs32(td, fpregs32));
}
#endif
int
proc_sstep(struct thread *td)
{
PROC_ACTION(ptrace_single_step(td));
}
int
proc_rwmem(struct proc *p, struct uio *uio)
{
struct vmspace *vm;
vm_map_t map;
vm_object_t backing_object, object = NULL;
vm_offset_t pageno = 0; /* page number */
vm_prot_t reqprot;
int error, refcnt, writing;
/*
* if the vmspace is in the midst of being deallocated or the
* process is exiting, don't try to grab anything. The page table
* usage in that process can be messed up.
*/
vm = p->p_vmspace;
if ((p->p_flag & P_WEXIT))
return (EFAULT);
do {
if ((refcnt = vm->vm_refcnt) < 1)
return (EFAULT);
} while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1));
/*
* The map we want...
*/
map = &vm->vm_map;
writing = uio->uio_rw == UIO_WRITE;
reqprot = writing ? (VM_PROT_WRITE | VM_PROT_OVERRIDE_WRITE) :
VM_PROT_READ;
/*
* Only map in one page at a time. We don't have to, but it
* makes things easier. This way is trivial - right?
*/
do {
vm_map_t tmap;
vm_offset_t uva;
int page_offset; /* offset into page */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
boolean_t wired;
vm_pindex_t pindex;
u_int len;
vm_page_t m;
object = NULL;
uva = (vm_offset_t)uio->uio_offset;
/*
* Get the page number of this segment.
*/
pageno = trunc_page(uva);
page_offset = uva - pageno;
/*
* How many bytes to copy
*/
len = min(PAGE_SIZE - page_offset, uio->uio_resid);
/*
* Fault the page on behalf of the process
*/
error = vm_fault(map, pageno, reqprot, VM_FAULT_NORMAL);
if (error) {
error = EFAULT;
break;
}
/*
* 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;
error = vm_map_lookup(&tmap, pageno, reqprot, &out_entry,
&object, &pindex, &out_prot, &wired);
if (error) {
error = EFAULT;
break;
}
VM_OBJECT_LOCK(object);
while ((m = vm_page_lookup(object, pindex)) == NULL &&
!writing &&
(backing_object = object->backing_object) != NULL) {
/*
* Allow fallback to backing objects if we are reading.
*/
VM_OBJECT_LOCK(backing_object);
pindex += OFF_TO_IDX(object->backing_object_offset);
VM_OBJECT_UNLOCK(object);
object = backing_object;
}
VM_OBJECT_UNLOCK(object);
if (m == NULL) {
vm_map_lookup_done(tmap, out_entry);
error = EFAULT;
break;
}
/*
* Hold the page in memory.
*/
vm_page_lock_queues();
vm_page_hold(m);
vm_page_unlock_queues();
/*
* We're done with tmap now.
*/
vm_map_lookup_done(tmap, out_entry);
/*
* Now do the i/o move.
*/
error = uiomove_fromphys(&m, page_offset, len, uio);
/*
* Release the page.
*/
vm_page_lock_queues();
vm_page_unhold(m);
vm_page_unlock_queues();
} while (error == 0 && uio->uio_resid > 0);
vmspace_free(vm);
return (error);
}
/*
* Process debugging system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct ptrace_args {
int req;
pid_t pid;
caddr_t addr;
int data;
};
#endif
#ifdef COMPAT_IA32
/*
* This CPP subterfuge is to try and reduce the number of ifdefs in
* the body of the code.
* COPYIN(uap->addr, &r.reg, sizeof r.reg);
* becomes either:
* copyin(uap->addr, &r.reg, sizeof r.reg);
* or
* copyin(uap->addr, &r.reg32, sizeof r.reg32);
* .. except this is done at runtime.
*/
#define COPYIN(u, k, s) wrap32 ? \
copyin(u, k ## 32, s ## 32) : \
copyin(u, k, s)
#define COPYOUT(k, u, s) wrap32 ? \
copyout(k ## 32, u, s ## 32) : \
copyout(k, u, s)
#else
#define COPYIN(u, k, s) copyin(u, k, s)
#define COPYOUT(k, u, s) copyout(k, u, s)
#endif
/*
* MPSAFE
*/
int
ptrace(struct thread *td, struct ptrace_args *uap)
{
/*
* XXX this obfuscation is to reduce stack usage, but the register
* structs may be too large to put on the stack anyway.
*/
union {
struct ptrace_io_desc piod;
struct ptrace_lwpinfo pl;
struct dbreg dbreg;
struct fpreg fpreg;
struct reg reg;
#ifdef COMPAT_IA32
struct dbreg32 dbreg32;
struct fpreg32 fpreg32;
struct reg32 reg32;
struct ptrace_io_desc32 piod32;
#endif
} r;
void *addr;
int error = 0;
#ifdef COMPAT_IA32
int wrap32 = 0;
if (td->td_proc->p_sysent == &ia32_freebsd_sysvec)
wrap32 = 1;
#endif
addr = &r;
switch (uap->req) {
case PT_GETREGS:
case PT_GETFPREGS:
case PT_GETDBREGS:
case PT_LWPINFO:
break;
case PT_SETREGS:
error = COPYIN(uap->addr, &r.reg, sizeof r.reg);
break;
case PT_SETFPREGS:
error = COPYIN(uap->addr, &r.fpreg, sizeof r.fpreg);
break;
case PT_SETDBREGS:
error = COPYIN(uap->addr, &r.dbreg, sizeof r.dbreg);
break;
case PT_IO:
error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
break;
default:
addr = uap->addr;
break;
}
if (error)
return (error);
error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
if (error)
return (error);
switch (uap->req) {
case PT_IO:
error = COPYOUT(&r.piod, uap->addr, sizeof r.piod);
break;
case PT_GETREGS:
error = COPYOUT(&r.reg, uap->addr, sizeof r.reg);
break;
case PT_GETFPREGS:
error = COPYOUT(&r.fpreg, uap->addr, sizeof r.fpreg);
break;
case PT_GETDBREGS:
error = COPYOUT(&r.dbreg, uap->addr, sizeof r.dbreg);
break;
case PT_LWPINFO:
error = copyout(&r.pl, uap->addr, uap->data);
break;
}
return (error);
}
#undef COPYIN
#undef COPYOUT
#ifdef COMPAT_IA32
/*
* PROC_READ(regs, td2, addr);
* becomes either:
* proc_read_regs(td2, addr);
* or
* proc_read_regs32(td2, addr);
* .. except this is done at runtime. There is an additional
* complication in that PROC_WRITE disallows 32 bit consumers
* from writing to 64 bit address space targets.
*/
#define PROC_READ(w, t, a) wrap32 ? \
proc_read_ ## w ## 32(t, a) : \
proc_read_ ## w (t, a)
#define PROC_WRITE(w, t, a) wrap32 ? \
(safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
proc_write_ ## w (t, a)
#else
#define PROC_READ(w, t, a) proc_read_ ## w (t, a)
#define PROC_WRITE(w, t, a) proc_write_ ## w (t, a)
#endif
int
kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
{
struct iovec iov;
struct uio uio;
struct proc *curp, *p, *pp;
struct thread *td2 = NULL;
struct ptrace_io_desc *piod = NULL;
struct ptrace_lwpinfo *pl;
int error, write, tmp, num;
int proctree_locked = 0;
lwpid_t tid = 0, *buf;
#ifdef COMPAT_IA32
int wrap32 = 0, safe = 0;
struct ptrace_io_desc32 *piod32 = NULL;
#endif
curp = td->td_proc;
/* Lock proctree before locking the process. */
switch (req) {
case PT_TRACE_ME:
case PT_ATTACH:
case PT_STEP:
case PT_CONTINUE:
case PT_TO_SCE:
case PT_TO_SCX:
case PT_SYSCALL:
case PT_DETACH:
sx_xlock(&proctree_lock);
proctree_locked = 1;
break;
default:
break;
}
write = 0;
if (req == PT_TRACE_ME) {
p = td->td_proc;
PROC_LOCK(p);
} else {
if (pid <= PID_MAX) {
if ((p = pfind(pid)) == NULL) {
if (proctree_locked)
sx_xunlock(&proctree_lock);
return (ESRCH);
}
} else {
/* this is slow, should be optimized */
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td2) {
if (td2->td_tid == pid)
break;
}
mtx_unlock_spin(&sched_lock);
if (td2 != NULL)
break; /* proc lock held */
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
if (p == NULL) {
if (proctree_locked)
sx_xunlock(&proctree_lock);
return (ESRCH);
}
tid = pid;
pid = p->p_pid;
}
}
if ((error = p_cansee(td, p)) != 0)
goto fail;
if ((error = p_candebug(td, p)) != 0)
goto fail;
/*
* System processes can't be debugged.
*/
if ((p->p_flag & P_SYSTEM) != 0) {
error = EINVAL;
goto fail;
}
if (tid == 0) {
if ((p->p_flag & P_STOPPED_TRACE) != 0) {
KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
td2 = p->p_xthread;
} else {
td2 = FIRST_THREAD_IN_PROC(p);
}
tid = td2->td_tid;
}
#ifdef COMPAT_IA32
/*
* Test if we're a 32 bit client and what the target is.
* Set the wrap controls accordingly.
*/
if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) {
if (td2->td_proc->p_sysent == &ia32_freebsd_sysvec)
safe = 1;
wrap32 = 1;
}
#endif
/*
* Permissions check
*/
switch (req) {
case PT_TRACE_ME:
/* Always legal. */
break;
case PT_ATTACH:
/* Self */
if (p->p_pid == td->td_proc->p_pid) {
error = EINVAL;
goto fail;
}
/* Already traced */
if (p->p_flag & P_TRACED) {
error = EBUSY;
goto fail;
}
/* Can't trace an ancestor if you're being traced. */
if (curp->p_flag & P_TRACED) {
for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
if (pp == p) {
error = EINVAL;
goto fail;
}
}
}
/* OK */
break;
case PT_CLEARSTEP:
/* Allow thread to clear single step for itself */
if (td->td_tid == tid)
break;
/* FALLTHROUGH */
default:
/* not being traced... */
if ((p->p_flag & P_TRACED) == 0) {
error = EPERM;
goto fail;
}
/* not being traced by YOU */
if (p->p_pptr != td->td_proc) {
error = EBUSY;
goto fail;
}
/* not currently stopped */
if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) == 0 ||
p->p_suspcount != p->p_numthreads ||
(p->p_flag & P_WAITED) == 0) {
error = EBUSY;
goto fail;
}
if ((p->p_flag & P_STOPPED_TRACE) == 0) {
static int count = 0;
if (count++ == 0)
printf("P_STOPPED_TRACE not set.\n");
}
/* OK */
break;
}
#ifdef FIX_SSTEP
/*
* Single step fixup ala procfs
*/
FIX_SSTEP(td2); /* XXXKSE */
#endif
/*
* Actually do the requests
*/
td->td_retval[0] = 0;
switch (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;
PROC_UNLOCK(p);
sx_xunlock(&proctree_lock);
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 != td->td_proc) {
PROC_LOCK(p->p_pptr);
sigqueue_take(p->p_ksi);
PROC_UNLOCK(p->p_pptr);
proc_reparent(p, td->td_proc);
}
data = SIGSTOP;
goto sendsig; /* in PT_CONTINUE below */
case PT_CLEARSTEP:
_PHOLD(p);
error = ptrace_clear_single_step(td2);
_PRELE(p);
if (error)
goto fail;
PROC_UNLOCK(p);
return (0);
case PT_SETSTEP:
_PHOLD(p);
error = ptrace_single_step(td2);
_PRELE(p);
if (error)
goto fail;
PROC_UNLOCK(p);
return (0);
case PT_SUSPEND:
_PHOLD(p);
mtx_lock_spin(&sched_lock);
td2->td_flags |= TDF_DBSUSPEND;
mtx_unlock_spin(&sched_lock);
_PRELE(p);
PROC_UNLOCK(p);
return (0);
case PT_RESUME:
_PHOLD(p);
mtx_lock_spin(&sched_lock);
td2->td_flags &= ~TDF_DBSUSPEND;
mtx_unlock_spin(&sched_lock);
_PRELE(p);
PROC_UNLOCK(p);
return (0);
case PT_STEP:
case PT_CONTINUE:
case PT_TO_SCE:
case PT_TO_SCX:
case PT_SYSCALL:
case PT_DETACH:
/* Zero means do not send any signal */
if (data < 0 || data > _SIG_MAXSIG) {
error = EINVAL;
goto fail;
}
_PHOLD(p);
switch (req) {
case PT_STEP:
PROC_UNLOCK(p);
error = ptrace_single_step(td2);
if (error) {
PRELE(p);
goto fail_noproc;
}
PROC_LOCK(p);
break;
case PT_TO_SCE:
p->p_stops |= S_PT_SCE;
break;
case PT_TO_SCX:
p->p_stops |= S_PT_SCX;
break;
case PT_SYSCALL:
p->p_stops |= S_PT_SCE | S_PT_SCX;
break;
}
if (addr != (void *)1) {
PROC_UNLOCK(p);
error = ptrace_set_pc(td2, (u_long)(uintfptr_t)addr);
if (error) {
PRELE(p);
goto fail_noproc;
}
PROC_LOCK(p);
}
_PRELE(p);
if (req == PT_DETACH) {
/* reset process parent */
if (p->p_oppid != p->p_pptr->p_pid) {
struct proc *pp;
PROC_LOCK(p->p_pptr);
sigqueue_take(p->p_ksi);
PROC_UNLOCK(p->p_pptr);
PROC_UNLOCK(p);
pp = pfind(p->p_oppid);
if (pp == NULL)
pp = initproc;
else
PROC_UNLOCK(pp);
PROC_LOCK(p);
proc_reparent(p, pp);
if (pp == initproc)
p->p_sigparent = SIGCHLD;
}
p->p_flag &= ~(P_TRACED | P_WAITED);
p->p_oppid = 0;
/* should we send SIGCHLD? */
/* childproc_continued(p); */
}
sendsig:
if (proctree_locked)
sx_xunlock(&proctree_lock);
/* deliver or queue signal */
mtx_lock_spin(&sched_lock);
td2->td_flags &= ~TDF_XSIG;
mtx_unlock_spin(&sched_lock);
td2->td_xsig = data;
p->p_xstat = data;
p->p_xthread = NULL;
if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
mtx_lock_spin(&sched_lock);
if (req == PT_DETACH) {
struct thread *td3;
FOREACH_THREAD_IN_PROC(p, td3)
td3->td_flags &= ~TDF_DBSUSPEND;
}
/*
* unsuspend all threads, to not let a thread run,
* you should use PT_SUSPEND to suspend it before
* continuing process.
*/
mtx_unlock_spin(&sched_lock);
thread_continued(p);
p->p_flag &= ~(P_STOPPED_TRACE|P_STOPPED_SIG|P_WAITED);
mtx_lock_spin(&sched_lock);
thread_unsuspend(p);
mtx_unlock_spin(&sched_lock);
}
if (data)
psignal(p, data);
PROC_UNLOCK(p);
return (0);
case PT_WRITE_I:
case PT_WRITE_D:
write = 1;
/* FALLTHROUGH */
case PT_READ_I:
case PT_READ_D:
PROC_UNLOCK(p);
tmp = 0;
/* write = 0 set above */
iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
iov.iov_len = sizeof(int);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = (off_t)(uintptr_t)addr;
uio.uio_resid = sizeof(int);
uio.uio_segflg = UIO_SYSSPACE; /* i.e.: the uap */
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_td = td;
error = proc_rwmem(p, &uio);
if (uio.uio_resid != 0) {
/*
* XXX proc_rwmem() 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 proc_rwmem() 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 */
}
if (!write)
td->td_retval[0] = tmp;
return (error);
case PT_IO:
PROC_UNLOCK(p);
#ifdef COMPAT_IA32
if (wrap32) {
piod32 = addr;
iov.iov_base = (void *)(uintptr_t)piod32->piod_addr;
iov.iov_len = piod32->piod_len;
uio.uio_offset = (off_t)(uintptr_t)piod32->piod_offs;
uio.uio_resid = piod32->piod_len;
} else
#endif
{
piod = addr;
iov.iov_base = piod->piod_addr;
iov.iov_len = piod->piod_len;
uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
uio.uio_resid = piod->piod_len;
}
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_segflg = UIO_USERSPACE;
uio.uio_td = td;
#ifdef COMPAT_IA32
tmp = wrap32 ? piod32->piod_op : piod->piod_op;
#else
tmp = piod->piod_op;
#endif
switch (tmp) {
case PIOD_READ_D:
case PIOD_READ_I:
uio.uio_rw = UIO_READ;
break;
case PIOD_WRITE_D:
case PIOD_WRITE_I:
uio.uio_rw = UIO_WRITE;
break;
default:
return (EINVAL);
}
error = proc_rwmem(p, &uio);
#ifdef COMPAT_IA32
if (wrap32)
piod32->piod_len -= uio.uio_resid;
else
#endif
piod->piod_len -= uio.uio_resid;
return (error);
case PT_KILL:
data = SIGKILL;
goto sendsig; /* in PT_CONTINUE above */
case PT_SETREGS:
_PHOLD(p);
error = PROC_WRITE(regs, td2, addr);
_PRELE(p);
PROC_UNLOCK(p);
return (error);
case PT_GETREGS:
_PHOLD(p);
error = PROC_READ(regs, td2, addr);
_PRELE(p);
PROC_UNLOCK(p);
return (error);
case PT_SETFPREGS:
_PHOLD(p);
error = PROC_WRITE(fpregs, td2, addr);
_PRELE(p);
PROC_UNLOCK(p);
return (error);
case PT_GETFPREGS:
_PHOLD(p);
error = PROC_READ(fpregs, td2, addr);
_PRELE(p);
PROC_UNLOCK(p);
return (error);
case PT_SETDBREGS:
_PHOLD(p);
error = PROC_WRITE(dbregs, td2, addr);
_PRELE(p);
PROC_UNLOCK(p);
return (error);
case PT_GETDBREGS:
_PHOLD(p);
error = PROC_READ(dbregs, td2, addr);
_PRELE(p);
PROC_UNLOCK(p);
return (error);
case PT_LWPINFO:
if (data == 0 || data > sizeof(*pl))
return (EINVAL);
pl = addr;
_PHOLD(p);
pl->pl_lwpid = td2->td_tid;
if (td2->td_flags & TDF_XSIG)
pl->pl_event = PL_EVENT_SIGNAL;
else
pl->pl_event = 0;
if (td2->td_pflags & TDP_SA) {
pl->pl_flags = PL_FLAG_SA;
if (td2->td_upcall && !TD_CAN_UNBIND(td2))
pl->pl_flags |= PL_FLAG_BOUND;
} else {
pl->pl_flags = 0;
}
_PRELE(p);
PROC_UNLOCK(p);
return (0);
case PT_GETNUMLWPS:
td->td_retval[0] = p->p_numthreads;
PROC_UNLOCK(p);
return (0);
case PT_GETLWPLIST:
if (data <= 0) {
PROC_UNLOCK(p);
return (EINVAL);
}
num = imin(p->p_numthreads, data);
PROC_UNLOCK(p);
buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
tmp = 0;
PROC_LOCK(p);
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td2) {
if (tmp >= num)
break;
buf[tmp++] = td2->td_tid;
}
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
error = copyout(buf, addr, tmp * sizeof(lwpid_t));
free(buf, M_TEMP);
if (!error)
td->td_retval[0] = num;
return (error);
default:
#ifdef __HAVE_PTRACE_MACHDEP
if (req >= PT_FIRSTMACH) {
_PHOLD(p);
PROC_UNLOCK(p);
error = cpu_ptrace(td2, req, addr, data);
PRELE(p);
return (error);
}
#endif
break;
}
/* Unknown request. */
error = EINVAL;
fail:
PROC_UNLOCK(p);
fail_noproc:
if (proctree_locked)
sx_xunlock(&proctree_lock);
return (error);
}
#undef PROC_READ
#undef PROC_WRITE
/*
* Stop a process because of a debugging 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)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
p->p_step = 1;
do {
p->p_xstat = val;
p->p_xthread = NULL;
p->p_stype = event; /* Which event caused the stop? */
wakeup(&p->p_stype); /* Wake up any PIOCWAIT'ing procs */
msleep(&p->p_step, &p->p_mtx, PWAIT, "stopevent", 0);
} while (p->p_step);
}