d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
3aecd7a21e
freebsd-skq/sys/kern/sys_process.c
kib 4d78ed404a Swap in WKILLED processes. 
Swapped-out process that is WKILLED must be swapped in as soon as
possible.  The reason is that such process can be killed by OOM and
its pages can be only freed if the process exits.  To exit, the kernel
stack of the process must be mapped.

When allocating pages for the stack of the WKILLED process on swap in,
use VM_ALLOC_SYSTEM requests to increase the chance of the allocation
to succeed.

Add counter of the swapped out processes to avoid unneeded iteration
over the allprocs list when there is no work to do, reducing the
allproc_lock ownership.

Reviewed by:	alc, markj (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D16489
2018-08-04 20:45:43 +00:00

1487 lines
34 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-4-Clause
*
* 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/pioctl.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ptrace.h>
#include <sys/rwlock.h>
#include <sys/sx.h>
#include <sys/malloc.h>
#include <sys/signalvar.h>
#include <machine/reg.h>
#include <security/audit/audit.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>
#include <vm/vm_param.h>
#ifdef COMPAT_FREEBSD32
#include <sys/procfs.h>
#include <compat/freebsd32/freebsd32_signal.h>
struct ptrace_io_desc32 {
int piod_op;
uint32_t piod_offs;
uint32_t piod_addr;
uint32_t piod_len;
};
struct ptrace_vm_entry32 {
int pve_entry;
int pve_timestamp;
uint32_t pve_start;
uint32_t pve_end;
uint32_t pve_offset;
u_int pve_prot;
u_int pve_pathlen;
int32_t pve_fileid;
u_int pve_fsid;
uint32_t pve_path;
};
#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_flag & P_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_FREEBSD32
/* 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)
{
vm_map_t map;
vm_offset_t pageno; /* page number */
vm_prot_t reqprot;
int error, fault_flags, page_offset, writing;
/*
* Assert that someone has locked this vmspace. (Should be
* curthread but we can't assert that.) This keeps the process
* from exiting out from under us until this operation completes.
*/
PROC_ASSERT_HELD(p);
PROC_LOCK_ASSERT(p, MA_NOTOWNED);
/*
* The map we want...
*/
map = &p->p_vmspace->vm_map;
/*
* If we are writing, then we request vm_fault() to create a private
* copy of each page. Since these copies will not be writeable by the
* process, we must explicity request that they be dirtied.
*/
writing = uio->uio_rw == UIO_WRITE;
reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
/*
* 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_offset_t uva;
u_int len;
vm_page_t m;
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 and hold the page on behalf of the process.
*/
error = vm_fault_hold(map, pageno, reqprot, fault_flags, &m);
if (error != KERN_SUCCESS) {
if (error == KERN_RESOURCE_SHORTAGE)
error = ENOMEM;
else
error = EFAULT;
break;
}
/*
* Now do the i/o move.
*/
error = uiomove_fromphys(&m, page_offset, len, uio);
/* Make the I-cache coherent for breakpoints. */
if (writing && error == 0) {
vm_map_lock_read(map);
if (vm_map_check_protection(map, pageno, pageno +
PAGE_SIZE, VM_PROT_EXECUTE))
vm_sync_icache(map, uva, len);
vm_map_unlock_read(map);
}
/*
* Release the page.
*/
vm_page_lock(m);
vm_page_unhold(m);
vm_page_unlock(m);
} while (error == 0 && uio->uio_resid > 0);
return (error);
}
static ssize_t
proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
size_t len, enum uio_rw rw)
{
struct iovec iov;
struct uio uio;
ssize_t slen;
MPASS(len < SSIZE_MAX);
slen = (ssize_t)len;
iov.iov_base = (caddr_t)buf;
iov.iov_len = len;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = va;
uio.uio_resid = slen;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_rw = rw;
uio.uio_td = td;
proc_rwmem(p, &uio);
if (uio.uio_resid == slen)
return (-1);
return (slen - uio.uio_resid);
}
ssize_t
proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
size_t len)
{
return (proc_iop(td, p, va, buf, len, UIO_READ));
}
ssize_t
proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
size_t len)
{
return (proc_iop(td, p, va, buf, len, UIO_WRITE));
}
static int
ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
{
struct vattr vattr;
vm_map_t map;
vm_map_entry_t entry;
vm_object_t obj, tobj, lobj;
struct vmspace *vm;
struct vnode *vp;
char *freepath, *fullpath;
u_int pathlen;
int error, index;
error = 0;
obj = NULL;
vm = vmspace_acquire_ref(p);
map = &vm->vm_map;
vm_map_lock_read(map);
do {
entry = map->header.next;
index = 0;
while (index < pve->pve_entry && entry != &map->header) {
entry = entry->next;
index++;
}
if (index != pve->pve_entry) {
error = EINVAL;
break;
}
while (entry != &map->header &&
(entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
entry = entry->next;
index++;
}
if (entry == &map->header) {
error = ENOENT;
break;
}
/* We got an entry. */
pve->pve_entry = index + 1;
pve->pve_timestamp = map->timestamp;
pve->pve_start = entry->start;
pve->pve_end = entry->end - 1;
pve->pve_offset = entry->offset;
pve->pve_prot = entry->protection;
/* Backing object's path needed? */
if (pve->pve_pathlen == 0)
break;
pathlen = pve->pve_pathlen;
pve->pve_pathlen = 0;
obj = entry->object.vm_object;
if (obj != NULL)
VM_OBJECT_RLOCK(obj);
} while (0);
vm_map_unlock_read(map);
pve->pve_fsid = VNOVAL;
pve->pve_fileid = VNOVAL;
if (error == 0 && obj != NULL) {
lobj = obj;
for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
if (tobj != obj)
VM_OBJECT_RLOCK(tobj);
if (lobj != obj)
VM_OBJECT_RUNLOCK(lobj);
lobj = tobj;
pve->pve_offset += tobj->backing_object_offset;
}
vp = vm_object_vnode(lobj);
if (vp != NULL)
vref(vp);
if (lobj != obj)
VM_OBJECT_RUNLOCK(lobj);
VM_OBJECT_RUNLOCK(obj);
if (vp != NULL) {
freepath = NULL;
fullpath = NULL;
vn_fullpath(td, vp, &fullpath, &freepath);
vn_lock(vp, LK_SHARED | LK_RETRY);
if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
pve->pve_fileid = vattr.va_fileid;
pve->pve_fsid = vattr.va_fsid;
}
vput(vp);
if (fullpath != NULL) {
pve->pve_pathlen = strlen(fullpath) + 1;
if (pve->pve_pathlen <= pathlen) {
error = copyout(fullpath, pve->pve_path,
pve->pve_pathlen);
} else
error = ENAMETOOLONG;
}
if (freepath != NULL)
free(freepath, M_TEMP);
}
}
vmspace_free(vm);
if (error == 0)
CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
p->p_pid, pve->pve_entry, pve->pve_start);
return (error);
}
#ifdef COMPAT_FREEBSD32
static int
ptrace_vm_entry32(struct thread *td, struct proc *p,
struct ptrace_vm_entry32 *pve32)
{
struct ptrace_vm_entry pve;
int error;
pve.pve_entry = pve32->pve_entry;
pve.pve_pathlen = pve32->pve_pathlen;
pve.pve_path = (void *)(uintptr_t)pve32->pve_path;
error = ptrace_vm_entry(td, p, &pve);
if (error == 0) {
pve32->pve_entry = pve.pve_entry;
pve32->pve_timestamp = pve.pve_timestamp;
pve32->pve_start = pve.pve_start;
pve32->pve_end = pve.pve_end;
pve32->pve_offset = pve.pve_offset;
pve32->pve_prot = pve.pve_prot;
pve32->pve_fileid = pve.pve_fileid;
pve32->pve_fsid = pve.pve_fsid;
}
pve32->pve_pathlen = pve.pve_pathlen;
return (error);
}
static void
ptrace_lwpinfo_to32(const struct ptrace_lwpinfo *pl,
struct ptrace_lwpinfo32 *pl32)
{
bzero(pl32, sizeof(*pl32));
pl32->pl_lwpid = pl->pl_lwpid;
pl32->pl_event = pl->pl_event;
pl32->pl_flags = pl->pl_flags;
pl32->pl_sigmask = pl->pl_sigmask;
pl32->pl_siglist = pl->pl_siglist;
siginfo_to_siginfo32(&pl->pl_siginfo, &pl32->pl_siginfo);
strcpy(pl32->pl_tdname, pl->pl_tdname);
pl32->pl_child_pid = pl->pl_child_pid;
pl32->pl_syscall_code = pl->pl_syscall_code;
pl32->pl_syscall_narg = pl->pl_syscall_narg;
}
#endif /* COMPAT_FREEBSD32 */
/*
* Process debugging system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct ptrace_args {
int req;
pid_t pid;
caddr_t addr;
int data;
};
#endif
#ifdef COMPAT_FREEBSD32
/*
* 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
int
sys_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 ptrace_vm_entry pve;
struct dbreg dbreg;
struct fpreg fpreg;
struct reg reg;
#ifdef COMPAT_FREEBSD32
struct dbreg32 dbreg32;
struct fpreg32 fpreg32;
struct reg32 reg32;
struct ptrace_io_desc32 piod32;
struct ptrace_lwpinfo32 pl32;
struct ptrace_vm_entry32 pve32;
#endif
char args[nitems(td->td_sa.args) * sizeof(register_t)];
int ptevents;
} r;
void *addr;
int error = 0;
#ifdef COMPAT_FREEBSD32
int wrap32 = 0;
if (SV_CURPROC_FLAG(SV_ILP32))
wrap32 = 1;
#endif
AUDIT_ARG_PID(uap->pid);
AUDIT_ARG_CMD(uap->req);
AUDIT_ARG_VALUE(uap->data);
addr = &r;
switch (uap->req) {
case PT_GET_EVENT_MASK:
case PT_GETREGS:
case PT_GETFPREGS:
case PT_GETDBREGS:
case PT_LWPINFO:
case PT_GET_SC_ARGS:
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_SET_EVENT_MASK:
if (uap->data != sizeof(r.ptevents))
error = EINVAL;
else
error = copyin(uap->addr, &r.ptevents, uap->data);
break;
case PT_IO:
error = COPYIN(uap->addr, &r.piod, sizeof r.piod);
break;
case PT_VM_ENTRY:
error = COPYIN(uap->addr, &r.pve, sizeof r.pve);
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_VM_ENTRY:
error = COPYOUT(&r.pve, uap->addr, sizeof r.pve);
break;
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_GET_EVENT_MASK:
/* NB: The size in uap->data is validated in kern_ptrace(). */
error = copyout(&r.ptevents, uap->addr, uap->data);
break;
case PT_LWPINFO:
/* NB: The size in uap->data is validated in kern_ptrace(). */
error = copyout(&r.pl, uap->addr, uap->data);
break;
case PT_GET_SC_ARGS:
error = copyout(r.args, uap->addr, MIN(uap->data,
sizeof(r.args)));
break;
}
return (error);
}
#undef COPYIN
#undef COPYOUT
#ifdef COMPAT_FREEBSD32
/*
* 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
void
proc_set_traced(struct proc *p, bool stop)
{
sx_assert(&proctree_lock, SX_XLOCKED);
PROC_LOCK_ASSERT(p, MA_OWNED);
p->p_flag |= P_TRACED;
if (stop)
p->p_flag2 |= P2_PTRACE_FSTP;
p->p_ptevents = PTRACE_DEFAULT;
p->p_oppid = p->p_pptr->p_pid;
}
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, *td3;
struct ptrace_io_desc *piod = NULL;
struct ptrace_lwpinfo *pl;
int error, num, tmp;
int proctree_locked = 0;
lwpid_t tid = 0, *buf;
#ifdef COMPAT_FREEBSD32
int wrap32 = 0, safe = 0;
struct ptrace_io_desc32 *piod32 = NULL;
struct ptrace_lwpinfo32 *pl32 = NULL;
struct ptrace_lwpinfo plr;
#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_FOLLOW_FORK:
case PT_LWP_EVENTS:
case PT_GET_EVENT_MASK:
case PT_SET_EVENT_MASK:
case PT_DETACH:
case PT_GET_SC_ARGS:
sx_xlock(&proctree_lock);
proctree_locked = 1;
break;
default:
break;
}
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 {
td2 = tdfind(pid, -1);
if (td2 == NULL) {
if (proctree_locked)
sx_xunlock(&proctree_lock);
return (ESRCH);
}
p = td2->td_proc;
tid = pid;
pid = p->p_pid;
}
}
AUDIT_ARG_PROCESS(p);
if ((p->p_flag & P_WEXIT) != 0) {
error = ESRCH;
goto fail;
}
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_FREEBSD32
/*
* Test if we're a 32 bit client and what the target is.
* Set the wrap controls accordingly.
*/
if (SV_CURPROC_FLAG(SV_ILP32)) {
if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
safe = 1;
wrap32 = 1;
}
#endif
/*
* Permissions check
*/
switch (req) {
case PT_TRACE_ME:
/*
* Always legal, when there is a parent process which
* could trace us. Otherwise, reject.
*/
if ((p->p_flag & P_TRACED) != 0) {
error = EBUSY;
goto fail;
}
if (p->p_pptr == initproc) {
error = EPERM;
goto fail;
}
break;
case PT_ATTACH:
/* Self */
if (p == td->td_proc) {
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_TRACE) == 0 ||
p->p_suspcount != p->p_numthreads ||
(p->p_flag & P_WAITED) == 0) {
error = EBUSY;
goto fail;
}
/* OK */
break;
}
/* Keep this process around until we finish this request. */
_PHOLD(p);
#ifdef FIX_SSTEP
/*
* Single step fixup ala procfs
*/
FIX_SSTEP(td2);
#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 */
proc_set_traced(p, false);
if (p->p_flag & P_PPWAIT)
p->p_flag |= P_PPTRACE;
CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
break;
case PT_ATTACH:
/* security check done above */
/*
* It would be nice if the tracing relationship was separate
* from the parent relationship but that would require
* another set of links in the proc struct or for "wait"
* to scan the entire proc table. To make life easier,
* we just re-parent the process we're trying to trace.
* The old parent is remembered so we can put things back
* on a "detach".
*/
proc_set_traced(p, true);
if (p->p_pptr != td->td_proc) {
proc_reparent(p, td->td_proc);
}
CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
p->p_oppid);
sx_xunlock(&proctree_lock);
proctree_locked = 0;
MPASS(p->p_xthread == NULL);
MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
/*
* If already stopped due to a stop signal, clear the
* existing stop before triggering a traced SIGSTOP.
*/
if ((p->p_flag & P_STOPPED_SIG) != 0) {
PROC_SLOCK(p);
p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
thread_unsuspend(p);
PROC_SUNLOCK(p);
}
kern_psignal(p, SIGSTOP);
break;
case PT_CLEARSTEP:
CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
p->p_pid);
error = ptrace_clear_single_step(td2);
break;
case PT_SETSTEP:
CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
p->p_pid);
error = ptrace_single_step(td2);
break;
case PT_SUSPEND:
CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
p->p_pid);
td2->td_dbgflags |= TDB_SUSPEND;
thread_lock(td2);
td2->td_flags |= TDF_NEEDSUSPCHK;
thread_unlock(td2);
break;
case PT_RESUME:
CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
p->p_pid);
td2->td_dbgflags &= ~TDB_SUSPEND;
break;
case PT_FOLLOW_FORK:
CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
data ? "enabled" : "disabled");
if (data)
p->p_ptevents |= PTRACE_FORK;
else
p->p_ptevents &= ~PTRACE_FORK;
break;
case PT_LWP_EVENTS:
CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
data ? "enabled" : "disabled");
if (data)
p->p_ptevents |= PTRACE_LWP;
else
p->p_ptevents &= ~PTRACE_LWP;
break;
case PT_GET_EVENT_MASK:
if (data != sizeof(p->p_ptevents)) {
error = EINVAL;
break;
}
CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
p->p_ptevents);
*(int *)addr = p->p_ptevents;
break;
case PT_SET_EVENT_MASK:
if (data != sizeof(p->p_ptevents)) {
error = EINVAL;
break;
}
tmp = *(int *)addr;
if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
error = EINVAL;
break;
}
CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
p->p_pid, p->p_ptevents, tmp);
p->p_ptevents = tmp;
break;
case PT_GET_SC_ARGS:
CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
#ifdef COMPAT_FREEBSD32
|| (wrap32 && !safe)
#endif
) {
error = EINVAL;
break;
}
bzero(addr, sizeof(td2->td_sa.args));
#ifdef COMPAT_FREEBSD32
if (wrap32)
for (num = 0; num < nitems(td2->td_sa.args); num++)
((uint32_t *)addr)[num] = (uint32_t)
td2->td_sa.args[num];
else
#endif
bcopy(td2->td_sa.args, addr, td2->td_sa.narg *
sizeof(register_t));
break;
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;
break;
}
switch (req) {
case PT_STEP:
CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
td2->td_tid, p->p_pid, data);
error = ptrace_single_step(td2);
if (error)
goto out;
break;
case PT_CONTINUE:
case PT_TO_SCE:
case PT_TO_SCX:
case PT_SYSCALL:
if (addr != (void *)1) {
error = ptrace_set_pc(td2,
(u_long)(uintfptr_t)addr);
if (error)
goto out;
}
switch (req) {
case PT_TO_SCE:
p->p_ptevents |= PTRACE_SCE;
CTR4(KTR_PTRACE,
"PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
p->p_pid, p->p_ptevents,
(u_long)(uintfptr_t)addr, data);
break;
case PT_TO_SCX:
p->p_ptevents |= PTRACE_SCX;
CTR4(KTR_PTRACE,
"PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
p->p_pid, p->p_ptevents,
(u_long)(uintfptr_t)addr, data);
break;
case PT_SYSCALL:
p->p_ptevents |= PTRACE_SYSCALL;
CTR4(KTR_PTRACE,
"PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
p->p_pid, p->p_ptevents,
(u_long)(uintfptr_t)addr, data);
break;
case PT_CONTINUE:
CTR3(KTR_PTRACE,
"PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
p->p_pid, (u_long)(uintfptr_t)addr, data);
break;
}
break;
case PT_DETACH:
/*
* Reset the process parent.
*
* NB: This clears P_TRACED before reparenting
* a detached process back to its original
* parent. Otherwise the debugee will be set
* as an orphan of the debugger.
*/
p->p_flag &= ~(P_TRACED | P_WAITED);
if (p->p_oppid != p->p_pptr->p_pid) {
PROC_LOCK(p->p_pptr);
sigqueue_take(p->p_ksi);
PROC_UNLOCK(p->p_pptr);
pp = proc_realparent(p);
proc_reparent(p, pp);
if (pp == initproc)
p->p_sigparent = SIGCHLD;
CTR3(KTR_PTRACE,
"PT_DETACH: pid %d reparented to pid %d, sig %d",
p->p_pid, pp->p_pid, data);
} else
CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
p->p_pid, data);
p->p_oppid = 0;
p->p_ptevents = 0;
FOREACH_THREAD_IN_PROC(p, td3) {
if ((td3->td_dbgflags & TDB_FSTP) != 0) {
sigqueue_delete(&td3->td_sigqueue,
SIGSTOP);
}
td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
TDB_SUSPEND);
}
if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
sigqueue_delete(&p->p_sigqueue, SIGSTOP);
p->p_flag2 &= ~P2_PTRACE_FSTP;
}
/* should we send SIGCHLD? */
/* childproc_continued(p); */
break;
}
sx_xunlock(&proctree_lock);
proctree_locked = 0;
sendsig:
MPASS(proctree_locked == 0);
/*
* Clear the pending event for the thread that just
* reported its event (p_xthread). This may not be
* the thread passed to PT_CONTINUE, PT_STEP, etc. if
* the debugger is resuming a different thread.
*
* Deliver any pending signal via the reporting thread.
*/
MPASS(p->p_xthread != NULL);
p->p_xthread->td_dbgflags &= ~TDB_XSIG;
p->p_xthread->td_xsig = data;
p->p_xthread = NULL;
p->p_xsig = data;
/*
* P_WKILLED is insurance that a PT_KILL/SIGKILL
* always works immediately, even if another thread is
* unsuspended first and attempts to handle a
* different signal or if the POSIX.1b style signal
* queue cannot accommodate any new signals.
*/
if (data == SIGKILL)
proc_wkilled(p);
/*
* Unsuspend all threads. To leave a thread
* suspended, use PT_SUSPEND to suspend it before
* continuing the process.
*/
PROC_SLOCK(p);
p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
thread_unsuspend(p);
PROC_SUNLOCK(p);
break;
case PT_WRITE_I:
case PT_WRITE_D:
td2->td_dbgflags |= TDB_USERWR;
PROC_UNLOCK(p);
error = 0;
if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
sizeof(int)) != sizeof(int))
error = ENOMEM;
else
CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
p->p_pid, addr, data);
PROC_LOCK(p);
break;
case PT_READ_I:
case PT_READ_D:
PROC_UNLOCK(p);
error = tmp = 0;
if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
sizeof(int)) != sizeof(int))
error = ENOMEM;
else
CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
p->p_pid, addr, tmp);
td->td_retval[0] = tmp;
PROC_LOCK(p);
break;
case PT_IO:
#ifdef COMPAT_FREEBSD32
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_FREEBSD32
tmp = wrap32 ? piod32->piod_op : piod->piod_op;
#else
tmp = piod->piod_op;
#endif
switch (tmp) {
case PIOD_READ_D:
case PIOD_READ_I:
CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
uio.uio_rw = UIO_READ;
break;
case PIOD_WRITE_D:
case PIOD_WRITE_I:
CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
td2->td_dbgflags |= TDB_USERWR;
uio.uio_rw = UIO_WRITE;
break;
default:
error = EINVAL;
goto out;
}
PROC_UNLOCK(p);
error = proc_rwmem(p, &uio);
#ifdef COMPAT_FREEBSD32
if (wrap32)
piod32->piod_len -= uio.uio_resid;
else
#endif
piod->piod_len -= uio.uio_resid;
PROC_LOCK(p);
break;
case PT_KILL:
CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
data = SIGKILL;
goto sendsig; /* in PT_CONTINUE above */
case PT_SETREGS:
CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
p->p_pid);
td2->td_dbgflags |= TDB_USERWR;
error = PROC_WRITE(regs, td2, addr);
break;
case PT_GETREGS:
CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
p->p_pid);
error = PROC_READ(regs, td2, addr);
break;
case PT_SETFPREGS:
CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
p->p_pid);
td2->td_dbgflags |= TDB_USERWR;
error = PROC_WRITE(fpregs, td2, addr);
break;
case PT_GETFPREGS:
CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
p->p_pid);
error = PROC_READ(fpregs, td2, addr);
break;
case PT_SETDBREGS:
CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
p->p_pid);
td2->td_dbgflags |= TDB_USERWR;
error = PROC_WRITE(dbregs, td2, addr);
break;
case PT_GETDBREGS:
CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
p->p_pid);
error = PROC_READ(dbregs, td2, addr);
break;
case PT_LWPINFO:
if (data <= 0 ||
#ifdef COMPAT_FREEBSD32
(!wrap32 && data > sizeof(*pl)) ||
(wrap32 && data > sizeof(*pl32))) {
#else
data > sizeof(*pl)) {
#endif
error = EINVAL;
break;
}
#ifdef COMPAT_FREEBSD32
if (wrap32) {
pl = &plr;
pl32 = addr;
} else
#endif
pl = addr;
bzero(pl, sizeof(*pl));
pl->pl_lwpid = td2->td_tid;
pl->pl_event = PL_EVENT_NONE;
pl->pl_flags = 0;
if (td2->td_dbgflags & TDB_XSIG) {
pl->pl_event = PL_EVENT_SIGNAL;
if (td2->td_si.si_signo != 0 &&
#ifdef COMPAT_FREEBSD32
((!wrap32 && data >= offsetof(struct ptrace_lwpinfo,
pl_siginfo) + sizeof(pl->pl_siginfo)) ||
(wrap32 && data >= offsetof(struct ptrace_lwpinfo32,
pl_siginfo) + sizeof(struct siginfo32)))
#else
data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
+ sizeof(pl->pl_siginfo)
#endif
){
pl->pl_flags |= PL_FLAG_SI;
pl->pl_siginfo = td2->td_si;
}
}
if (td2->td_dbgflags & TDB_SCE)
pl->pl_flags |= PL_FLAG_SCE;
else if (td2->td_dbgflags & TDB_SCX)
pl->pl_flags |= PL_FLAG_SCX;
if (td2->td_dbgflags & TDB_EXEC)
pl->pl_flags |= PL_FLAG_EXEC;
if (td2->td_dbgflags & TDB_FORK) {
pl->pl_flags |= PL_FLAG_FORKED;
pl->pl_child_pid = td2->td_dbg_forked;
if (td2->td_dbgflags & TDB_VFORK)
pl->pl_flags |= PL_FLAG_VFORKED;
} else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
TDB_VFORK)
pl->pl_flags |= PL_FLAG_VFORK_DONE;
if (td2->td_dbgflags & TDB_CHILD)
pl->pl_flags |= PL_FLAG_CHILD;
if (td2->td_dbgflags & TDB_BORN)
pl->pl_flags |= PL_FLAG_BORN;
if (td2->td_dbgflags & TDB_EXIT)
pl->pl_flags |= PL_FLAG_EXITED;
pl->pl_sigmask = td2->td_sigmask;
pl->pl_siglist = td2->td_siglist;
strcpy(pl->pl_tdname, td2->td_name);
if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
pl->pl_syscall_code = td2->td_sa.code;
pl->pl_syscall_narg = td2->td_sa.narg;
} else {
pl->pl_syscall_code = 0;
pl->pl_syscall_narg = 0;
}
#ifdef COMPAT_FREEBSD32
if (wrap32)
ptrace_lwpinfo_to32(pl, pl32);
#endif
CTR6(KTR_PTRACE,
"PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
pl->pl_child_pid, pl->pl_syscall_code);
break;
case PT_GETNUMLWPS:
CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
p->p_numthreads);
td->td_retval[0] = p->p_numthreads;
break;
case PT_GETLWPLIST:
CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
p->p_pid, data, p->p_numthreads);
if (data <= 0) {
error = EINVAL;
break;
}
num = imin(p->p_numthreads, data);
PROC_UNLOCK(p);
buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
tmp = 0;
PROC_LOCK(p);
FOREACH_THREAD_IN_PROC(p, td2) {
if (tmp >= num)
break;
buf[tmp++] = td2->td_tid;
}
PROC_UNLOCK(p);
error = copyout(buf, addr, tmp * sizeof(lwpid_t));
free(buf, M_TEMP);
if (!error)
td->td_retval[0] = tmp;
PROC_LOCK(p);
break;
case PT_VM_TIMESTAMP:
CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
p->p_pid, p->p_vmspace->vm_map.timestamp);
td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
break;
case PT_VM_ENTRY:
PROC_UNLOCK(p);
#ifdef COMPAT_FREEBSD32
if (wrap32)
error = ptrace_vm_entry32(td, p, addr);
else
#endif
error = ptrace_vm_entry(td, p, addr);
PROC_LOCK(p);
break;
default:
#ifdef __HAVE_PTRACE_MACHDEP
if (req >= PT_FIRSTMACH) {
PROC_UNLOCK(p);
error = cpu_ptrace(td2, req, addr, data);
PROC_LOCK(p);
} else
#endif
/* Unknown request. */
error = EINVAL;
break;
}
out:
/* Drop our hold on this process now that the request has completed. */
_PRELE(p);
fail:
PROC_UNLOCK(p);
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;
CTR3(KTR_PTRACE, "stopevent: pid %d event %u val %u", p->p_pid, event,
val);
do {
if (event != S_EXIT)
p->p_xsig = 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);
}
Reference in New Issue View Git Blame Copy Permalink