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NetBSD/sys/kern/kern_ktrace.c

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/* $NetBSD: kern_ktrace.c,v 1.120 2007/03/12 18:18:33 ad Exp $ */
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)kern_ktrace.c 8.5 (Berkeley) 5/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_ktrace.c,v 1.120 2007/03/12 18:18:33 ad Exp $");
#include "opt_ktrace.h"
#include "opt_compat_mach.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/ktrace.h>
#include <sys/kmem.h>
#include <sys/syslog.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/callout.h>
#include <sys/kauth.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#ifdef KTRACE
/*
* XXX:
* - need better error reporting?
* - userland utility to sort ktrace.out by timestamp.
* - keep minimum information in ktrace_entry when rest of alloc failed.
* - enlarge ktrace_entry so that small entry won't require additional
* alloc?
* - per trace control of configurable parameters.
*/
struct ktrace_entry {
TAILQ_ENTRY(ktrace_entry) kte_list;
struct ktr_header kte_kth;
void *kte_buf;
size_t kte_bufsz;
#define KTE_SPACE 32
uint8_t kte_space[KTE_SPACE];
};
struct ktr_desc {
TAILQ_ENTRY(ktr_desc) ktd_list;
int ktd_flags;
#define KTDF_WAIT 0x0001
#define KTDF_DONE 0x0002
#define KTDF_BLOCKING 0x0004
#define KTDF_INTERACTIVE 0x0008
int ktd_error;
#define KTDE_ENOMEM 0x0001
#define KTDE_ENOSPC 0x0002
int ktd_errcnt;
int ktd_ref; /* # of reference */
int ktd_qcount; /* # of entry in the queue */
/*
* Params to control behaviour.
*/
int ktd_delayqcnt; /* # of entry allowed to delay */
int ktd_wakedelay; /* delay of wakeup in *tick* */
int ktd_intrwakdl; /* ditto, but when interactive */
struct file *ktd_fp; /* trace output file */
struct proc *ktd_proc; /* our kernel thread */
TAILQ_HEAD(, ktrace_entry) ktd_queue;
struct callout ktd_wakch; /* delayed wakeup */
kcondvar_t ktd_sync_cv;
kcondvar_t ktd_cv;
};
static int ktealloc(struct ktrace_entry **, void **, struct lwp *, int,
size_t);
static void ktrwrite(struct ktr_desc *, struct ktrace_entry *);
static int ktrace_common(struct lwp *, int, int, int, struct file *);
static int ktrops(struct lwp *, struct proc *, int, int,
struct ktr_desc *);
static int ktrsetchildren(struct lwp *, struct proc *, int, int,
struct ktr_desc *);
static int ktrcanset(struct lwp *, struct proc *);
static int ktrsamefile(struct file *, struct file *);
static struct ktr_desc *
ktd_lookup(struct file *);
static void ktdrel(struct ktr_desc *);
static void ktdref(struct ktr_desc *);
static void ktraddentry(struct lwp *, struct ktrace_entry *, int);
/* Flags for ktraddentry (3rd arg) */
#define KTA_NOWAIT 0x0000
#define KTA_WAITOK 0x0001
#define KTA_LARGE 0x0002
static void ktefree(struct ktrace_entry *);
static void ktd_logerrl(struct ktr_desc *, int);
static void ktrace_thread(void *);
static int ktrderefall(struct ktr_desc *, int);
/*
* Default vaules.
*/
#define KTD_MAXENTRY 1000 /* XXX: tune */
#define KTD_TIMEOUT 5 /* XXX: tune */
#define KTD_DELAYQCNT 100 /* XXX: tune */
#define KTD_WAKEDELAY 5000 /* XXX: tune */
#define KTD_INTRWAKDL 100 /* XXX: tune */
/*
* Patchable variables.
*/
int ktd_maxentry = KTD_MAXENTRY; /* max # of entry in the queue */
int ktd_timeout = KTD_TIMEOUT; /* timeout in seconds */
int ktd_delayqcnt = KTD_DELAYQCNT; /* # of entry allowed to delay */
int ktd_wakedelay = KTD_WAKEDELAY; /* delay of wakeup in *ms* */
int ktd_intrwakdl = KTD_INTRWAKDL; /* ditto, but when interactive */
kmutex_t ktrace_mutex;
static TAILQ_HEAD(, ktr_desc) ktdq = TAILQ_HEAD_INITIALIZER(ktdq);
MALLOC_DEFINE(M_KTRACE, "ktrace", "ktrace data buffer");
POOL_INIT(kte_pool, sizeof(struct ktrace_entry), 0, 0, 0,
"ktepl", &pool_allocator_nointr, IPL_NONE);
static inline void
ktd_wakeup(struct ktr_desc *ktd)
{
callout_stop(&ktd->ktd_wakch);
cv_wakeup(&ktd->ktd_cv); /* XXXSMP */
}
static void
ktd_logerrl(struct ktr_desc *ktd, int error)
{
ktd->ktd_error |= error;
ktd->ktd_errcnt++;
}
#if 0
static void
ktd_logerr(struct proc *p, int error)
{
struct ktr_desc *ktd;
KASSERT(mutex_owned(&ktrace_mutex));
ktd = p->p_tracep;
if (ktd == NULL)
return;
ktd_logerrl(ktd, error);
}
#endif
static inline int
ktrenter(struct lwp *l)
{
if ((l->l_pflag & LP_KTRACTIVE) != 0)
return 1;
l->l_pflag |= LP_KTRACTIVE;
return 0;
}
static inline void
ktrexit(struct lwp *l)
{
l->l_pflag &= ~LP_KTRACTIVE;
}
/*
* Initialise the ktrace system.
*/
void
ktrinit(void)
{
mutex_init(&ktrace_mutex, MUTEX_DEFAULT, IPL_NONE);
}
/*
* Release a reference. Called with ktrace_mutex held.
*/
void
ktdrel(struct ktr_desc *ktd)
{
KASSERT(mutex_owned(&ktrace_mutex));
KDASSERT(ktd->ktd_ref != 0);
KASSERT(ktd->ktd_ref > 0);
if (--ktd->ktd_ref <= 0) {
ktd->ktd_flags |= KTDF_DONE;
cv_broadcast(&ktd->ktd_cv);
}
}
void
ktdref(struct ktr_desc *ktd)
{
KASSERT(mutex_owned(&ktrace_mutex));
ktd->ktd_ref++;
}
struct ktr_desc *
ktd_lookup(struct file *fp)
{
struct ktr_desc *ktd;
KASSERT(mutex_owned(&ktrace_mutex));
for (ktd = TAILQ_FIRST(&ktdq); ktd != NULL;
ktd = TAILQ_NEXT(ktd, ktd_list)) {
if (ktrsamefile(ktd->ktd_fp, fp)) {
ktd->ktd_ref++;
break;
}
}
return (ktd);
}
void
ktraddentry(struct lwp *l, struct ktrace_entry *kte, int flags)
{
struct proc *p = l->l_proc;
struct ktr_desc *ktd;
#ifdef DEBUG
struct timeval t1, t2;
#endif
mutex_enter(&ktrace_mutex);
if (p->p_traceflag & KTRFAC_TRC_EMUL) {
/* Add emulation trace before first entry for this process */
p->p_traceflag &= ~KTRFAC_TRC_EMUL;
mutex_exit(&ktrace_mutex);
ktrexit(l);
ktremul(l);
(void)ktrenter(l);
mutex_enter(&ktrace_mutex);
}
/*
* Tracing may be canceled while we were sleeping waiting for
* memory.
*/
ktd = p->p_tracep;
if (ktd == NULL)
goto freekte;
/*
* Bump reference count so that the object will remain while
* we are here. Note that the trace is controlled by other
* process.
*/
ktdref(ktd);
if (ktd->ktd_flags & KTDF_DONE)
goto relktd;
if (ktd->ktd_qcount > ktd_maxentry) {
ktd_logerrl(ktd, KTDE_ENOSPC);
goto relktd;
}
TAILQ_INSERT_TAIL(&ktd->ktd_queue, kte, kte_list);
ktd->ktd_qcount++;
if (ktd->ktd_flags & KTDF_BLOCKING)
goto skip_sync;
if (flags & KTA_WAITOK &&
(/* flags & KTA_LARGE */0 || ktd->ktd_flags & KTDF_WAIT ||
ktd->ktd_qcount > ktd_maxentry >> 1))
/*
* Sync with writer thread since we're requesting rather
* big one or many requests are pending.
*/
do {
ktd->ktd_flags |= KTDF_WAIT;
ktd_wakeup(ktd);
#ifdef DEBUG
getmicrouptime(&t1);
#endif
if (cv_timedwait(&ktd->ktd_sync_cv, &ktrace_mutex,
ktd_timeout * hz) != 0) {
ktd->ktd_flags |= KTDF_BLOCKING;
/*
* Maybe the writer thread is blocking
* completely for some reason, but
* don't stop target process forever.
*/
log(LOG_NOTICE, "ktrace timeout\n");
break;
}
#ifdef DEBUG
getmicrouptime(&t2);
timersub(&t2, &t1, &t2);
if (t2.tv_sec > 0)
log(LOG_NOTICE,
"ktrace long wait: %ld.%06ld\n",
t2.tv_sec, t2.tv_usec);
#endif
} while (p->p_tracep == ktd &&
(ktd->ktd_flags & (KTDF_WAIT | KTDF_DONE)) == KTDF_WAIT);
else {
/* Schedule delayed wakeup */
if (ktd->ktd_qcount > ktd->ktd_delayqcnt)
ktd_wakeup(ktd); /* Wakeup now */
else if (!callout_pending(&ktd->ktd_wakch))
callout_reset(&ktd->ktd_wakch,
ktd->ktd_flags & KTDF_INTERACTIVE ?
ktd->ktd_intrwakdl : ktd->ktd_wakedelay,
(void (*)(void *))ktd_wakeup, ktd);
}
skip_sync:
ktdrel(ktd);
mutex_exit(&ktrace_mutex);
ktrexit(l);
return;
relktd:
ktdrel(ktd);
freekte:
mutex_exit(&ktrace_mutex);
ktefree(kte);
ktrexit(l);
}
void
ktefree(struct ktrace_entry *kte)
{
KERNEL_LOCK(1, curlwp); /* XXXSMP */
if (kte->kte_buf != kte->kte_space)
kmem_free(kte->kte_buf, kte->kte_bufsz);
pool_put(&kte_pool, kte);
KERNEL_UNLOCK_ONE(curlwp); /* XXXSMP */
}
/*
* "deep" compare of two files for the purposes of clearing a trace.
* Returns true if they're the same open file, or if they point at the
* same underlying vnode/socket.
*/
int
ktrsamefile(struct file *f1, struct file *f2)
{
return ((f1 == f2) ||
((f1 != NULL) && (f2 != NULL) &&
(f1->f_type == f2->f_type) &&
(f1->f_data == f2->f_data)));
}
void
ktrderef(struct proc *p)
{
struct ktr_desc *ktd = p->p_tracep;
KASSERT(mutex_owned(&ktrace_mutex));
p->p_traceflag = 0;
if (ktd == NULL)
return;
p->p_tracep = NULL;
cv_broadcast(&ktd->ktd_sync_cv);
ktdrel(ktd);
}
void
ktradref(struct proc *p)
{
struct ktr_desc *ktd = p->p_tracep;
KASSERT(mutex_owned(&ktrace_mutex));
ktdref(ktd);
}
int
ktrderefall(struct ktr_desc *ktd, int auth)
{
struct lwp *curl = curlwp;
struct proc *p;
int error = 0;
mutex_enter(&proclist_lock);
PROCLIST_FOREACH(p, &allproc) {
if (p->p_tracep != ktd)
continue;
mutex_enter(&p->p_mutex);
mutex_enter(&ktrace_mutex);
if (p->p_tracep == ktd) {
if (!auth || ktrcanset(curl, p))
ktrderef(p);
else
error = EPERM;
}
mutex_exit(&ktrace_mutex);
mutex_exit(&p->p_mutex);
}
mutex_exit(&proclist_lock);
return error;
}
int
ktealloc(struct ktrace_entry **ktep, void **bufp, struct lwp *l, int type,
size_t sz)
{
struct proc *p = l->l_proc;
struct ktrace_entry *kte;
struct ktr_header *kth;
void *buf;
if (ktrenter(l))
return EAGAIN;
KERNEL_LOCK(1, l); /* XXXSMP */
kte = pool_get(&kte_pool, PR_WAITOK);
if (sz > sizeof(kte->kte_space)) {
if ((buf = kmem_alloc(sz, KM_SLEEP)) == NULL) {
pool_put(&kte_pool, kte);
KERNEL_UNLOCK_ONE(l); /* XXXSMP */
ktrexit(l);
return ENOMEM;
}
} else
buf = kte->kte_space;
KERNEL_UNLOCK_ONE(l); /* XXXSMP */
kte->kte_bufsz = sz;
kte->kte_buf = buf;
kth = &kte->kte_kth;
(void)memset(kth, 0, sizeof(*kth));
kth->ktr_len = sz;
kth->ktr_type = type;
kth->ktr_pid = p->p_pid;
memcpy(kth->ktr_comm, p->p_comm, MAXCOMLEN);
kth->ktr_version = KTRFAC_VERSION(p->p_traceflag);
switch (KTRFAC_VERSION(p->p_traceflag)) {
case 0:
/* This is the original format */
microtime(&kth->ktr_tv);
break;
case 1:
kth->ktr_lid = l->l_lid;
nanotime(&kth->ktr_time);
break;
default:
break;
}
*ktep = kte;
*bufp = buf;
return 0;
}
void
ktrsyscall(struct lwp *l, register_t code, register_t realcode,
const struct sysent *callp, register_t args[])
{
struct proc *p = l->l_proc;
struct ktrace_entry *kte;
struct ktr_syscall *ktp;
register_t *argp;
int argsize;
size_t len;
u_int i;
if (callp == NULL)
callp = p->p_emul->e_sysent;
argsize = callp[code].sy_argsize;
#ifdef _LP64
if (p->p_flag & PK_32)
argsize = argsize << 1;
#endif
len = sizeof(struct ktr_syscall) + argsize;
if (ktealloc(&kte, (void *)&ktp, l, KTR_SYSCALL, len))
return;
ktp->ktr_code = realcode;
ktp->ktr_argsize = argsize;
argp = (register_t *)(ktp + 1);
for (i = 0; i < (argsize / sizeof(*argp)); i++)
*argp++ = args[i];
ktraddentry(l, kte, KTA_WAITOK);
}
void
ktrsysret(struct lwp *l, register_t code, int error, register_t *retval)
{
struct ktrace_entry *kte;
struct ktr_sysret *ktp;
if (ktealloc(&kte, (void *)&ktp, l, KTR_SYSRET,
sizeof(struct ktr_sysret)))
return;
ktp->ktr_code = code;
ktp->ktr_eosys = 0; /* XXX unused */
ktp->ktr_error = error;
ktp->ktr_retval = retval ? retval[0] : 0;
ktp->ktr_retval_1 = retval ? retval[1] : 0;
ktraddentry(l, kte, KTA_WAITOK);
}
/*
* XXX: ndp->ni_pathlen should be passed.
*/
void
ktrnamei(struct lwp *l, char *path)
{
ktrkmem(l, KTR_NAMEI, path, strlen(path));
}
void
ktremul(struct lwp *l)
{
const char *emul = l->l_proc->p_emul->e_name;
ktrkmem(l, KTR_EMUL, emul, strlen(emul));
}
void
ktrkmem(struct lwp *l, int type, const void *bf, size_t len)
{
struct ktrace_entry *kte;
void *buf;
if (ktealloc(&kte, &buf, l, type, len))
return;
memcpy(buf, bf, len);
ktraddentry(l, kte, KTA_WAITOK);
}
void
ktrgenio(struct lwp *l, int fd, enum uio_rw rw, struct iovec *iov,
int len, int error)
{
struct ktrace_entry *kte;
struct ktr_genio *ktp;
int resid = len, cnt;
void *cp;
int buflen;
if (error)
return;
next:
buflen = min(PAGE_SIZE, resid + sizeof(struct ktr_genio));
if (ktealloc(&kte, (void *)&ktp, l, KTR_GENIO, buflen))
return;
ktp->ktr_fd = fd;
ktp->ktr_rw = rw;
cp = (void *)(ktp + 1);
buflen -= sizeof(struct ktr_genio);
kte->kte_kth.ktr_len = sizeof(struct ktr_genio);
while (buflen > 0) {
cnt = min(iov->iov_len, buflen);
if (copyin(iov->iov_base, cp, cnt) != 0)
goto out;
kte->kte_kth.ktr_len += cnt;
buflen -= cnt;
resid -= cnt;
iov->iov_len -= cnt;
if (iov->iov_len == 0)
iov++;
else
iov->iov_base = (char *)iov->iov_base + cnt;
}
/*
* Don't push so many entry at once. It will cause kmem map
* shortage.
*/
ktraddentry(l, kte, KTA_WAITOK | KTA_LARGE);
if (resid > 0) {
if (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD) {
(void)ktrenter(l);
preempt();
ktrexit(l);
}
goto next;
}
return;
out:
ktefree(kte);
ktrexit(l);
}
void
ktrpsig(struct lwp *l, int sig, sig_t action, const sigset_t *mask,
const ksiginfo_t *ksi)
{
struct ktrace_entry *kte;
struct {
struct ktr_psig kp;
siginfo_t si;
} *kbuf;
if (ktealloc(&kte, (void *)&kbuf, l, KTR_PSIG, sizeof(*kbuf)))
return;
kbuf->kp.signo = (char)sig;
kbuf->kp.action = action;
kbuf->kp.mask = *mask;
if (ksi) {
kbuf->kp.code = KSI_TRAPCODE(ksi);
(void)memset(&kbuf->si, 0, sizeof(kbuf->si));
kbuf->si._info = ksi->ksi_info;
kte->kte_kth.ktr_len = sizeof(*kbuf);
} else {
kbuf->kp.code = 0;
kte->kte_kth.ktr_len = sizeof(struct ktr_psig);
}
ktraddentry(l, kte, KTA_WAITOK);
}
void
ktrcsw(struct lwp *l, int out, int user)
{
struct proc *p = l->l_proc;
struct ktrace_entry *kte;
struct ktr_csw *kc;
/*
* Don't record context switches resulting from blocking on
* locks; it's too easy to get duff results.
*/
if (l->l_syncobj == &mutex_syncobj || l->l_syncobj == &rw_syncobj)
return;
/*
* We can't sleep if we're already going to sleep (if original
* condition is met during sleep, we hang up).
*
* XXX This is not ideal: it would be better to maintain a pool
* of ktes and actually push this to the kthread when context
* switch happens, however given the points where we are called
* from that is difficult to do.
*/
if (out) {
if (ktrenter(l))
return;
switch (KTRFAC_VERSION(p->p_traceflag)) {
case 0:
/* This is the original format */
microtime(&l->l_ktrcsw.tv);
l->l_pflag |= LP_KTRCSW;
break;
case 1:
nanotime(&l->l_ktrcsw.ts);
l->l_pflag |= LP_KTRCSW;
break;
default:
break;
}
if (user)
l->l_pflag |= LP_KTRCSWUSER;
else
l->l_pflag &= ~LP_KTRCSWUSER;
ktrexit(l);
return;
}
/*
* On the way back in, we need to record twice: once for entry, and
* once for exit.
*/
if ((l->l_pflag & LP_KTRCSW) != 0) {
l->l_pflag &= ~LP_KTRCSW;
if (ktealloc(&kte, (void *)&kc, l, KTR_CSW, sizeof(*kc)))
return;
kc->out = 1;
kc->user = ((l->l_pflag & LP_KTRCSWUSER) != 0);
switch (KTRFAC_VERSION(p->p_traceflag)) {
case 0:
/* This is the original format */
memcpy(&kte->kte_kth.ktr_tv, &l->l_ktrcsw.tv,
sizeof(kte->kte_kth.ktr_tv));
break;
case 1:
memcpy(&kte->kte_kth.ktr_time, &l->l_ktrcsw.ts,
sizeof(kte->kte_kth.ktr_time));
break;
default:
break;
}
ktraddentry(l, kte, KTA_WAITOK);
}
if (ktealloc(&kte, (void *)&kc, l, KTR_CSW, sizeof(*kc)))
return;
kc->out = 0;
kc->user = user;
ktraddentry(l, kte, KTA_WAITOK);
}
int
ktruser(struct lwp *l, const char *id, void *addr, size_t len, int ustr)
{
struct ktrace_entry *kte;
struct ktr_user *ktp;
void *user_dta;
int error;
if (len > KTR_USER_MAXLEN)
return ENOSPC;
error = ktealloc(&kte, (void *)&ktp, l, KTR_USER, sizeof(*ktp) + len);
if (error != 0)
return error;
if (ustr) {
if (copyinstr(id, ktp->ktr_id, KTR_USER_MAXIDLEN, NULL) != 0)
ktp->ktr_id[0] = '\0';
} else
strncpy(ktp->ktr_id, id, KTR_USER_MAXIDLEN);
ktp->ktr_id[KTR_USER_MAXIDLEN-1] = '\0';
user_dta = (void *)(ktp + 1);
if ((error = copyin(addr, (void *)user_dta, len)) != 0)
len = 0;
ktraddentry(l, kte, KTA_WAITOK);
return error;
}
void
ktrmmsg(struct lwp *l, const void *msgh, size_t size)
{
ktrkmem(l, KTR_MMSG, msgh, size);
}
void
ktrmool(struct lwp *l, const void *kaddr, size_t size, const void *uaddr)
{
struct ktrace_entry *kte;
struct ktr_mool *kp;
struct ktr_mool *bf;
if (ktealloc(&kte, (void *)&kp, l, KTR_MOOL, size + sizeof(*kp)))
return;
kp->uaddr = uaddr;
kp->size = size;
bf = kp + 1; /* Skip uaddr and size */
(void)memcpy(bf, kaddr, size);
ktraddentry(l, kte, KTA_WAITOK);
}
void
ktrmib(struct lwp *l, const int *name, u_int namelen)
{
struct ktrace_entry *kte;
int *namep;
size_t size;
size = namelen * sizeof(*name);
if (ktealloc(&kte, (void *)&namep, l, KTR_MIB, size))
return;
(void)memcpy(namep, name, namelen * sizeof(*name));
ktraddentry(l, kte, KTA_WAITOK);
}
/* Interface and common routines */
int
ktrace_common(struct lwp *curl, int ops, int facs, int pid, struct file *fp)
{
struct proc *curp;
struct proc *p;
struct pgrp *pg;
struct ktr_desc *ktd = NULL;
int ret = 0;
int error = 0;
int descend;
curp = curl->l_proc;
descend = ops & KTRFLAG_DESCEND;
facs = facs & ~((unsigned) KTRFAC_ROOT);
(void)ktrenter(curl);
switch (KTROP(ops)) {
case KTROP_CLEARFILE:
/*
* Clear all uses of the tracefile
*/
mutex_enter(&ktrace_mutex);
ktd = ktd_lookup(fp);
mutex_exit(&ktrace_mutex);
if (ktd == NULL)
goto done;
error = ktrderefall(ktd, 1);
goto done;
case KTROP_SET:
mutex_enter(&ktrace_mutex);
ktd = ktd_lookup(fp);
mutex_exit(&ktrace_mutex);
if (ktd == NULL) {
ktd = kmem_alloc(sizeof(*ktd), KM_SLEEP);
TAILQ_INIT(&ktd->ktd_queue);
callout_init(&ktd->ktd_wakch);
cv_init(&ktd->ktd_cv, "ktrwait");
cv_init(&ktd->ktd_sync_cv, "ktrsync");
ktd->ktd_flags = ktd->ktd_qcount =
ktd->ktd_error = ktd->ktd_errcnt = 0;
ktd->ktd_ref = 1;
ktd->ktd_delayqcnt = ktd_delayqcnt;
ktd->ktd_wakedelay = mstohz(ktd_wakedelay);
ktd->ktd_intrwakdl = mstohz(ktd_intrwakdl);
/*
* XXX: not correct. needs an way to detect
* whether ktruss or ktrace.
*/
if (fp->f_type == DTYPE_PIPE)
ktd->ktd_flags |= KTDF_INTERACTIVE;
error = kthread_create1(ktrace_thread, ktd,
&ktd->ktd_proc, "ktr %p", ktd);
if (error != 0) {
kmem_free(ktd, sizeof(*ktd));
goto done;
}
simple_lock(&fp->f_slock);
fp->f_count++;
simple_unlock(&fp->f_slock);
ktd->ktd_fp = fp;
mutex_enter(&ktrace_mutex);
if (ktd_lookup(fp) != NULL) {
ktdrel(ktd);
ktd = NULL;
} else
TAILQ_INSERT_TAIL(&ktdq, ktd, ktd_list);
mutex_exit(&ktrace_mutex);
if (ktd == NULL) {
tsleep(&lbolt, PWAIT, "ktrzzz", 0);
goto done;
}
}
break;
case KTROP_CLEAR:
break;
}
/*
* need something to (un)trace (XXX - why is this here?)
*/
if (!facs) {
error = EINVAL;
goto done;
}
/*
* do it
*/
mutex_enter(&proclist_lock);
if (pid < 0) {
/*
* by process group
*/
pg = pg_find(-pid, PFIND_LOCKED);
if (pg == NULL)
error = ESRCH;
else {
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
if (descend)
ret |= ktrsetchildren(curl, p, ops,
facs, ktd);
else
ret |= ktrops(curl, p, ops, facs,
ktd);
}
}
} else {
/*
* by pid
*/
p = p_find(pid, PFIND_LOCKED);
if (p == NULL)
error = ESRCH;
else if (descend)
ret |= ktrsetchildren(curl, p, ops, facs, ktd);
else
ret |= ktrops(curl, p, ops, facs, ktd);
}
mutex_exit(&proclist_lock); /* taken by p{g}_find */
if (error == 0 && !ret)
error = EPERM;
done:
if (ktd != NULL) {
if (error != 0) {
/*
* Wakeup the thread so that it can be die if we
* can't trace any process.
*/
ktd_wakeup(ktd);
}
if (KTROP(ops) == KTROP_SET || KTROP(ops) == KTROP_CLEARFILE) {
mutex_enter(&ktrace_mutex);
ktdrel(ktd);
mutex_exit(&ktrace_mutex);
}
}
ktrexit(curl);
return (error);
}
/*
* fktrace system call
*/
/* ARGSUSED */
int
sys_fktrace(struct lwp *l, void *v, register_t *retval)
{
struct sys_fktrace_args /* {
syscallarg(int) fd;
syscallarg(int) ops;
syscallarg(int) facs;
syscallarg(int) pid;
} */ *uap = v;
struct file *fp = NULL;
struct filedesc *fdp = l->l_proc->p_fd;
int error;
fdp = l->l_proc->p_fd;
if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL)
return (EBADF);
FILE_USE(fp);
if ((fp->f_flag & FWRITE) == 0)
error = EBADF;
else
error = ktrace_common(l, SCARG(uap, ops),
SCARG(uap, facs), SCARG(uap, pid), fp);
FILE_UNUSE(fp, l);
return error;
}
/*
* ktrace system call
*/
/* ARGSUSED */
int
sys_ktrace(struct lwp *l, void *v, register_t *retval)
{
struct sys_ktrace_args /* {
syscallarg(const char *) fname;
syscallarg(int) ops;
syscallarg(int) facs;
syscallarg(int) pid;
} */ *uap = v;
struct vnode *vp = NULL;
struct file *fp = NULL;
struct nameidata nd;
int error = 0;
int fd;
if (ktrenter(l))
return EAGAIN;
if (KTROP(SCARG(uap, ops)) != KTROP_CLEAR) {
/*
* an operation which requires a file argument.
*/
NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, fname),
l);
if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) {
ktrexit(l);
return (error);
}
vp = nd.ni_vp;
VOP_UNLOCK(vp, 0);
if (vp->v_type != VREG) {
(void) vn_close(vp, FREAD|FWRITE, l->l_cred, l);
ktrexit(l);
return (EACCES);
}
/*
* XXX This uses up a file descriptor slot in the
* tracing process for the duration of this syscall.
* This is not expected to be a problem. If
* falloc(NULL, ...) DTRT we could skip that part, but
* that would require changing its interface to allow
* the caller to pass in a ucred..
*
* This will FILE_USE the fp it returns, if any.
* Keep it in use until we return.
*/
if ((error = falloc(l, &fp, &fd)) != 0)
goto done;
fp->f_flag = FWRITE;
fp->f_type = DTYPE_VNODE;
fp->f_ops = &vnops;
fp->f_data = (void *)vp;
FILE_SET_MATURE(fp);
vp = NULL;
}
error = ktrace_common(l, SCARG(uap, ops), SCARG(uap, facs),
SCARG(uap, pid), fp);
done:
if (vp != NULL)
(void) vn_close(vp, FWRITE, l->l_cred, l);
if (fp != NULL) {
FILE_UNUSE(fp, l); /* release file */
fdrelease(l, fd); /* release fd table slot */
}
return (error);
}
int
ktrops(struct lwp *curl, struct proc *p, int ops, int facs,
struct ktr_desc *ktd)
{
int vers = ops & KTRFAC_VER_MASK;
int error = 0;
mutex_enter(&p->p_mutex);
mutex_enter(&ktrace_mutex);
if (!ktrcanset(curl, p))
goto out;
switch (vers) {
case KTRFACv0:
case KTRFACv1:
break;
default:
error = EINVAL;
goto out;
}
if (KTROP(ops) == KTROP_SET) {
if (p->p_tracep != ktd) {
/*
* if trace file already in use, relinquish
*/
ktrderef(p);
p->p_tracep = ktd;
ktradref(p);
}
p->p_traceflag |= facs;
if (kauth_authorize_generic(curl->l_cred,
KAUTH_GENERIC_ISSUSER, NULL) == 0)
p->p_traceflag |= KTRFAC_ROOT;
} else {
/* KTROP_CLEAR */
if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
/* no more tracing */
ktrderef(p);
}
}
if (p->p_traceflag)
p->p_traceflag |= vers;
/*
* Emit an emulation record, every time there is a ktrace
* change/attach request.
*/
if (KTRPOINT(p, KTR_EMUL))
p->p_traceflag |= KTRFAC_TRC_EMUL;
#ifdef __HAVE_SYSCALL_INTERN
(*p->p_emul->e_syscall_intern)(p);
#endif
out:
mutex_exit(&ktrace_mutex);
mutex_exit(&p->p_mutex);
return (1);
}
int
ktrsetchildren(struct lwp *curl, struct proc *top, int ops, int facs,
struct ktr_desc *ktd)
{
struct proc *p;
int ret = 0;
KASSERT(mutex_owned(&proclist_lock));
p = top;
for (;;) {
ret |= ktrops(curl, p, ops, facs, ktd);
/*
* If this process has children, descend to them next,
* otherwise do any siblings, and if done with this level,
* follow back up the tree (but not past top).
*/
if (LIST_FIRST(&p->p_children) != NULL) {
p = LIST_FIRST(&p->p_children);
continue;
}
for (;;) {
if (p == top)
return (ret);
if (LIST_NEXT(p, p_sibling) != NULL) {
p = LIST_NEXT(p, p_sibling);
break;
}
p = p->p_pptr;
}
}
/*NOTREACHED*/
}
void
ktrwrite(struct ktr_desc *ktd, struct ktrace_entry *kte)
{
struct uio auio;
struct iovec aiov[64], *iov;
struct ktrace_entry *top = kte;
struct ktr_header *kth;
struct file *fp = ktd->ktd_fp;
int error;
next:
auio.uio_iov = iov = &aiov[0];
auio.uio_offset = 0;
auio.uio_rw = UIO_WRITE;
auio.uio_resid = 0;
auio.uio_iovcnt = 0;
UIO_SETUP_SYSSPACE(&auio);
do {
kth = &kte->kte_kth;
if (kth->ktr_version == 0) {
/*
* Convert back to the old format fields
*/
TIMESPEC_TO_TIMEVAL(&kth->ktr_tv, &kth->ktr_time);
kth->ktr_unused = NULL;
}
iov->iov_base = (void *)kth;
iov++->iov_len = sizeof(struct ktr_header);
auio.uio_resid += sizeof(struct ktr_header);
auio.uio_iovcnt++;
if (kth->ktr_len > 0) {
iov->iov_base = kte->kte_buf;
iov++->iov_len = kth->ktr_len;
auio.uio_resid += kth->ktr_len;
auio.uio_iovcnt++;
}
} while ((kte = TAILQ_NEXT(kte, kte_list)) != NULL &&
auio.uio_iovcnt < sizeof(aiov) / sizeof(aiov[0]) - 1);
again:
simple_lock(&fp->f_slock);
FILE_USE(fp);
error = (*fp->f_ops->fo_write)(fp, &fp->f_offset, &auio,
fp->f_cred, FOF_UPDATE_OFFSET);
FILE_UNUSE(fp, NULL);
switch (error) {
case 0:
if (auio.uio_resid > 0)
goto again;
if (kte != NULL)
goto next;
break;
case EWOULDBLOCK:
kpause("ktrzzz", false, 1, NULL);
goto again;
default:
/*
* If error encountered, give up tracing on this
* vnode. Don't report EPIPE as this can easily
* happen with fktrace()/ktruss.
*/
#ifndef DEBUG
if (error != EPIPE)
#endif
log(LOG_NOTICE,
"ktrace write failed, errno %d, tracing stopped\n",
error);
(void)ktrderefall(ktd, 0);
}
while ((kte = top) != NULL) {
top = TAILQ_NEXT(top, kte_list);
ktefree(kte);
}
}
void
ktrace_thread(void *arg)
{
struct ktr_desc *ktd = arg;
struct file *fp = ktd->ktd_fp;
struct ktrace_entry *kte;
int ktrerr, errcnt;
mutex_enter(&ktrace_mutex);
for (;;) {
kte = TAILQ_FIRST(&ktd->ktd_queue);
if (kte == NULL) {
if (ktd->ktd_flags & KTDF_WAIT) {
ktd->ktd_flags &= ~(KTDF_WAIT | KTDF_BLOCKING);
cv_broadcast(&ktd->ktd_sync_cv);
}
if (ktd->ktd_ref == 0)
break;
cv_wait(&ktd->ktd_cv, &ktrace_mutex);
continue;
}
TAILQ_INIT(&ktd->ktd_queue);
ktd->ktd_qcount = 0;
ktrerr = ktd->ktd_error;
errcnt = ktd->ktd_errcnt;
ktd->ktd_error = ktd->ktd_errcnt = 0;
mutex_exit(&ktrace_mutex);
if (ktrerr) {
log(LOG_NOTICE,
"ktrace failed, fp %p, error 0x%x, total %d\n",
fp, ktrerr, errcnt);
}
ktrwrite(ktd, kte);
mutex_enter(&ktrace_mutex);
}
TAILQ_REMOVE(&ktdq, ktd, ktd_list);
mutex_exit(&ktrace_mutex);
simple_lock(&fp->f_slock);
FILE_USE(fp);
/*
* ktrace file descriptor can't be watched (are not visible to
* userspace), so no kqueue stuff here
* XXX: The above comment is wrong, because the fktrace file
* descriptor is available in userland.
*/
closef(fp, NULL);
callout_stop(&ktd->ktd_wakch);
kmem_free(ktd, sizeof(*ktd));
kthread_exit(0);
}
/*
* Return true if caller has permission to set the ktracing state
* of target. Essentially, the target can't possess any
* more permissions than the caller. KTRFAC_ROOT signifies that
* root previously set the tracing status on the target process, and
* so, only root may further change it.
*
* TODO: check groups. use caller effective gid.
*/
int
ktrcanset(struct lwp *calll, struct proc *targetp)
{
KASSERT(mutex_owned(&targetp->p_mutex));
KASSERT(mutex_owned(&ktrace_mutex));
if (kauth_authorize_process(calll->l_cred, KAUTH_PROCESS_CANKTRACE,
targetp, NULL, NULL, NULL) == 0)
return (1);
return (0);
}
#endif /* KTRACE */
/*
* Put user defined entry to ktrace records.
*/
int
sys_utrace(struct lwp *l, void *v, register_t *retval)
{
#ifdef KTRACE
struct sys_utrace_args /* {
syscallarg(const char *) label;
syscallarg(void *) addr;
syscallarg(size_t) len;
} */ *uap = v;
struct proc *p = l->l_proc;
if (!KTRPOINT(p, KTR_USER))
return (0);
return ktruser(l, SCARG(uap, label), SCARG(uap, addr),
SCARG(uap, len), 1);
#else /* !KTRACE */
return ENOSYS;
#endif /* KTRACE */
}
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