/*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2015 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License"). You may not use this file except in compliance with the
- * License. Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
- *
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
-/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
+
/*
- * Copyright (c) 1989, 1993
- * The Regents of the University of California. All rights reserved.
+ * This file manages the ownership of ktrace and its subsystems, like kdebug
+ * and kperf, as well as the overall state of the system, whether it is in
+ * foreground or background mode.
*
- * 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 the University of
- * California, Berkeley and its contributors.
- * 4. 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.
+ * When unconfigured or in background mode, any root process can take ownership
+ * of ktrace and configure it, changing the state to foreground and, in the case
+ * of a transition out of background, resetting the background configuration.
*
- * 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.
+ * When in foreground mode, if the owning process is still running, only it may
+ * configure ktrace. If it exits, ktrace keeps running but any root process can
+ * change the configuration. When ktrace is reset, the state changes back to
+ * unconfigured and a notification is sent on the ktrace_background host special
+ * port.
*
- * @(#)kern_ktrace.c 8.2 (Berkeley) 9/23/93
- * $FreeBSD: src/sys/kern/kern_ktrace.c,v 1.35.2.4 2001/03/05 13:09:01 obrien Exp $
+ * If a process has set itself as the background tool, using the init_background
+ * sysctl, it can configure ktrace only when ktrace is off or already in
+ * background mode. The first attempt to configure ktrace by the background pid
+ * when it is off results in the transition to background mode.
*/
+#include <sys/ktrace.h>
+
+#include <mach/host_priv.h>
+#include <mach/mach_types.h>
+#include <mach/ktrace_background.h>
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/types.h>
-#include <sys/proc_internal.h>
#include <sys/kauth.h>
-#include <sys/file_internal.h>
-#include <sys/namei.h>
-#include <sys/vnode_internal.h>
-#if KTRACE
-#include <sys/ktrace.h>
-#endif
-#include <sys/malloc.h>
-#include <sys/syslog.h>
-#include <sys/sysproto.h>
-#include <sys/uio_internal.h>
-
-#include <bsm/audit_kernel.h>
-
-#if KTRACE
-static struct ktr_header *ktrgetheader(int type);
-static void ktrwrite(struct vnode *, struct ktr_header *, struct uio *);
-static int ktrcanset(struct proc *,struct proc *);
-static int ktrsetchildren(struct proc *,struct proc *,
- int, int, struct vnode *);
-static int ktrops(struct proc *,struct proc *,int,int,struct vnode *);
-
-
-static struct ktr_header *
-ktrgetheader(type)
- int type;
+#include <sys/priv.h>
+#include <sys/proc.h>
+char *proc_name_address(void *p);
+#include <sys/sysctl.h>
+#include <sys/vm.h>
+
+#include <kern/locks.h>
+#include <kern/assert.h>
+
+#include <sys/kdebug.h>
+#include <kperf/kperf.h>
+
+#include <kern/host.h>
+
+kern_return_t ktrace_background_available_notify_user(void);
+
+lck_mtx_t *ktrace_lock;
+
+/*
+ * The overall state of ktrace, whether it is unconfigured, in foreground mode,
+ * or in background mode. The state determines which processes can configure
+ * ktrace.
+ */
+static enum ktrace_state ktrace_state = KTRACE_STATE_OFF;
+
+/* The true owner of ktrace, checked by ktrace_access_check(). */
+static uint64_t ktrace_owning_unique_id = 0;
+static pid_t ktrace_owning_pid = 0;
+
+/*
+ * The background pid of ktrace, automatically made the owner when
+ * transitioning to background mode.
+ */
+static uint64_t ktrace_bg_unique_id = 0;
+static pid_t ktrace_bg_pid = 0;
+
+/* The name of the last process to configure ktrace. */
+static char ktrace_last_owner_execname[MAXCOMLEN + 1] = { 0 };
+
+/*
+ * Which subsystems of ktrace (currently kdebug and kperf) are active.
+ */
+static uint32_t ktrace_active_mask = 0;
+
+/*
+ * At boot or when a daemon has been newly loaded, it's necessary to bootstrap
+ * user space background tools by sending a background available notification
+ * when the init_background sysctl is made.
+ *
+ * Background tools must be RunAtLoad daemons.
+ */
+static boolean_t should_notify_on_init = TRUE;
+
+/* Set the owning process of ktrace. */
+static void ktrace_set_owning_proc(proc_t p);
+
+/* Reset ktrace ownership back to unowned. */
+static void ktrace_release_ownership(void);
+
+/* Make the background tool the owner of ktrace. */
+static void ktrace_promote_background(void);
+
+/*
+ * If user space sets a pid manually (through kperf "blessing"), ktrace should
+ * not treat resets as releasing ownership. At that point, ownership is only
+ * released when the owner is set to an invalid pid.
+ *
+ * This is managed by the user space-oriented function ktrace_set_owning_pid
+ * and ktrace_unset_owning_pid.
+ */
+boolean_t ktrace_keep_ownership_on_reset = FALSE;
+
+/* Allow user space to unset the owning pid and potentially reset ktrace. */
+static void ktrace_set_invalid_owning_pid(void);
+
+/*
+ * This flag allows any root process to set a new ktrace owner. It is
+ * currently used by Instruments.
+ */
+int ktrace_root_set_owner_allowed = 0;
+
+static void
+ktrace_reset_internal(uint32_t reset_mask)
{
- register struct ktr_header *kth;
- struct proc *p = current_proc(); /* XXX */
-
- MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
- M_KTRACE, M_WAITOK);
- if (kth != NULL) {
- kth->ktr_type = type;
- microtime(&kth->ktr_time);
- kth->ktr_pid = p->p_pid;
- bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN);
+ if (!ktrace_keep_ownership_on_reset) {
+ ktrace_active_mask &= ~reset_mask;
+ }
+
+ if (reset_mask & KTRACE_KPERF) {
+ kperf_reset();
+ }
+ if (reset_mask & KTRACE_KDEBUG) {
+ kdebug_reset();
+ }
+
+ if (ktrace_active_mask == 0) {
+ if (ktrace_state == KTRACE_STATE_FG) {
+ /* transition from foreground to background */
+ ktrace_promote_background();
+ } else if (ktrace_state == KTRACE_STATE_BG) {
+ /* background tool is resetting ktrace */
+ should_notify_on_init = TRUE;
+ ktrace_release_ownership();
+ ktrace_state = KTRACE_STATE_OFF;
+ }
}
- return (kth);
}
-#endif
void
-ktrsyscall(p, code, narg, args)
- struct proc *p;
- int code, narg;
- syscall_arg_t args[];
+ktrace_reset(uint32_t reset_mask)
{
-#if KTRACE
- struct vnode *vp;
- struct ktr_header *kth;
- struct ktr_syscall *ktp;
- register int len;
- u_int64_t *argp;
- int i;
-
- if (!KTRPOINT(p, KTR_SYSCALL))
- return;
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
- vp = p->p_tracep;
- len = __offsetof(struct ktr_syscall, ktr_args) +
- (narg * sizeof(u_int64_t));
- p->p_traceflag |= KTRFAC_ACTIVE;
- kth = ktrgetheader(KTR_SYSCALL);
- if (kth == NULL) {
- p->p_traceflag &= ~KTRFAC_ACTIVE;
+ if (ktrace_active_mask == 0) {
+ if (!ktrace_keep_ownership_on_reset) {
+ assert(ktrace_state == KTRACE_STATE_OFF);
+ }
return;
}
- MALLOC(ktp, struct ktr_syscall *, len, M_KTRACE, M_WAITOK);
- if (ktp == NULL) {
- FREE(kth, M_KTRACE);
- return;
+
+ ktrace_reset_internal(reset_mask);
+}
+
+static void
+ktrace_promote_background(void)
+{
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+ assert(ktrace_state != KTRACE_STATE_BG);
+
+ /*
+ * Remember to send a background available notification on the next init
+ * if the notification failed (meaning no task holds the receive right
+ * for the host special port).
+ */
+ if (ktrace_background_available_notify_user() == KERN_FAILURE) {
+ should_notify_on_init = TRUE;
+ } else {
+ should_notify_on_init = FALSE;
}
- ktp->ktr_code = code;
- ktp->ktr_narg = narg;
- argp = &ktp->ktr_args[0];
- for (i = 0; i < narg; i++)
- *argp++ = args[i];
- kth->ktr_buf = (caddr_t)ktp;
- kth->ktr_len = len;
- ktrwrite(vp, kth, NULL);
- FREE(ktp, M_KTRACE);
- FREE(kth, M_KTRACE);
- p->p_traceflag &= ~KTRFAC_ACTIVE;
-#else
- return;
-#endif
+
+ ktrace_release_ownership();
+ ktrace_state = KTRACE_STATE_OFF;
}
-
-void
-ktrsysret(p, code, error, retval)
- struct proc *p;
- int code, error;
- register_t retval;
+
+bool
+ktrace_background_active(void)
{
-#if KTRACE
- struct vnode *vp;
- struct ktr_header *kth;
- struct ktr_sysret ktp;
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+ return (ktrace_state == KTRACE_STATE_BG);
+}
- if (!KTRPOINT(p, KTR_SYSRET))
- return;
+int
+ktrace_read_check(void)
+{
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
- vp = p->p_tracep;
- p->p_traceflag |= KTRFAC_ACTIVE;
- kth = ktrgetheader(KTR_SYSRET);
- if (kth == NULL) {
- p->p_traceflag &= ~KTRFAC_ACTIVE;
- return;
+ if (proc_uniqueid(current_proc()) == ktrace_owning_unique_id)
+ {
+ return 0;
}
- ktp.ktr_code = code;
- ktp.ktr_error = error;
- ktp.ktr_retval = retval; /* what about val2 ? */
-
- kth->ktr_buf = (caddr_t)&ktp;
- kth->ktr_len = sizeof(struct ktr_sysret);
-
- ktrwrite(vp, kth, NULL);
- FREE(kth, M_KTRACE);
- p->p_traceflag &= ~KTRFAC_ACTIVE;
-#else
- return;
-#endif
+
+ return kauth_cred_issuser(kauth_cred_get()) ? 0 : EPERM;
}
-#if KTRACE
-void
-ktrnamei(vp, path)
- struct vnode *vp;
- char *path;
+/* If an owning process has exited, reset the ownership. */
+static void
+ktrace_ownership_maintenance(void)
{
- struct ktr_header *kth;
- struct proc *p = current_proc(); /* XXX */
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
- p->p_traceflag |= KTRFAC_ACTIVE;
- kth = ktrgetheader(KTR_NAMEI);
- if (kth == NULL) {
- p->p_traceflag &= ~KTRFAC_ACTIVE;
+ /* do nothing if ktrace is not owned */
+ if (ktrace_owning_unique_id == 0) {
return;
}
- kth->ktr_len = strlen(path);
- kth->ktr_buf = path;
- ktrwrite(vp, kth, NULL);
- FREE(kth, M_KTRACE);
- p->p_traceflag &= ~KTRFAC_ACTIVE;
+ /* reset ownership if process cannot be found */
+
+ proc_t owning_proc = proc_find(ktrace_owning_pid);
+
+ if (owning_proc != NULL) {
+ /* make sure the pid was not recycled */
+ if (proc_uniqueid(owning_proc) != ktrace_owning_unique_id) {
+ ktrace_release_ownership();
+ }
+
+ proc_rele(owning_proc);
+ } else {
+ ktrace_release_ownership();
+ }
}
-void
-ktrgenio(vp, fd, rw, uio, error)
- struct vnode *vp;
- int fd;
- enum uio_rw rw;
- struct uio *uio;
- int error;
+int
+ktrace_configure(uint32_t config_mask)
{
- struct ktr_header *kth;
- struct ktr_genio ktg;
- struct proc *p = current_proc(); /* XXX */
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+ assert(config_mask != 0);
- if (error)
- return;
+ proc_t p = current_proc();
- p->p_traceflag |= KTRFAC_ACTIVE;
- kth = ktrgetheader(KTR_GENIO);
- if (kth == NULL) {
- p->p_traceflag &= ~KTRFAC_ACTIVE;
- return;
+ /* if process clearly owns ktrace, allow */
+ if (proc_uniqueid(p) == ktrace_owning_unique_id) {
+ ktrace_active_mask |= config_mask;
+ return 0;
+ }
+
+ /* background configure while foreground is active is not allowed */
+ if (proc_uniqueid(p) == ktrace_bg_unique_id &&
+ ktrace_state == KTRACE_STATE_FG)
+ {
+ return EBUSY;
+ }
+
+ ktrace_ownership_maintenance();
+
+ /* allow process to gain control when unowned or background */
+ if (ktrace_owning_unique_id == 0 || ktrace_state == KTRACE_STATE_BG) {
+ if (!kauth_cred_issuser(kauth_cred_get())) {
+ return EPERM;
+ }
+
+ ktrace_set_owning_proc(p);
+ ktrace_active_mask |= config_mask;
+ return 0;
}
- ktg.ktr_fd = fd;
- ktg.ktr_rw = rw;
- kth->ktr_buf = (caddr_t)&ktg;
- kth->ktr_len = sizeof(struct ktr_genio);
- uio->uio_offset = 0;
- uio->uio_rw = UIO_WRITE;
-
- ktrwrite(vp, kth, uio);
- FREE(kth, M_KTRACE);
- p->p_traceflag &= ~KTRFAC_ACTIVE;
+
+ /* owned by an existing, different process */
+ return EBUSY;
}
void
-ktrpsig(vp, sig, action, mask, code)
- struct vnode *vp;
- int sig;
- sig_t action;
- sigset_t *mask;
- int code;
+ktrace_disable(enum ktrace_state state_to_match)
{
- struct ktr_header *kth;
- struct ktr_psig kp;
- struct proc *p = current_proc(); /* XXX */
-
- p->p_traceflag |= KTRFAC_ACTIVE;
- kth = ktrgetheader(KTR_PSIG);
- if (kth == NULL) {
- p->p_traceflag &= ~KTRFAC_ACTIVE;
- return;
+ if (ktrace_state == state_to_match) {
+ kernel_debug_disable();
+ kperf_sampling_disable();
}
- kp.signo = (char)sig;
- kp.action = action;
- kp.mask = *mask;
- kp.code = code;
- kth->ktr_buf = (caddr_t)&kp;
- kth->ktr_len = sizeof (struct ktr_psig);
-
- ktrwrite(vp, kth, NULL);
- FREE(kth, M_KTRACE);
- p->p_traceflag &= ~KTRFAC_ACTIVE;
+}
+
+int
+ktrace_get_owning_pid(void)
+{
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+
+ ktrace_ownership_maintenance();
+ return ktrace_owning_pid;
}
void
-ktrcsw(vp, out, user)
- struct vnode *vp;
- int out, user;
+ktrace_kernel_configure(uint32_t config_mask)
{
- struct ktr_header *kth;
- struct ktr_csw kc;
- struct proc *p = current_proc(); /* XXX */
-
- p->p_traceflag |= KTRFAC_ACTIVE;
- kth = ktrgetheader(KTR_CSW);
- if (kth == NULL) {
- p->p_traceflag &= ~KTRFAC_ACTIVE;
- return;
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+
+ if (ktrace_state != KTRACE_STATE_OFF) {
+ if (ktrace_active_mask & KTRACE_KPERF) {
+ kperf_reset();
+ }
+ if (ktrace_active_mask & KTRACE_KDEBUG) {
+ kdebug_reset();
+ }
}
- kc.out = out;
- kc.user = user;
- kth->ktr_buf = (caddr_t)&kc;
- kth->ktr_len = sizeof (struct ktr_csw);
-
- ktrwrite(vp, kth, NULL);
- FREE(kth, M_KTRACE);
- p->p_traceflag &= ~KTRFAC_ACTIVE;
-}
-#endif /* KTRACE */
-/* Interface and common routines */
+ ktrace_active_mask = config_mask;
+ ktrace_state = KTRACE_STATE_FG;
-/*
- * ktrace system call
- */
-/* ARGSUSED */
-int
-ktrace(struct proc *curp, register struct ktrace_args *uap, __unused register_t *retval)
+ ktrace_release_ownership();
+ strlcpy(ktrace_last_owner_execname, "kernel_task",
+ sizeof(ktrace_last_owner_execname));
+}
+
+static errno_t
+ktrace_init_background(void)
{
-#if KTRACE
- register struct vnode *vp = NULL;
- register struct proc *p;
- struct pgrp *pg;
- int facs = uap->facs & ~KTRFAC_ROOT;
- int ops = KTROP(uap->ops);
- int descend = uap->ops & KTRFLAG_DESCEND;
- int ret = 0;
- int error = 0;
- struct nameidata nd;
- struct vfs_context context;
-
- AUDIT_ARG(cmd, uap->ops);
- AUDIT_ARG(pid, uap->pid);
- AUDIT_ARG(value, uap->facs);
-
- context.vc_proc = curp;
- context.vc_ucred = kauth_cred_get();
-
- curp->p_traceflag |= KTRFAC_ACTIVE;
- if (ops != KTROP_CLEAR) {
- /*
- * an operation which requires a file argument.
- */
- NDINIT(&nd, LOOKUP, (NOFOLLOW|LOCKLEAF), UIO_USERSPACE,
- uap->fname, &context);
- error = vn_open(&nd, FREAD|FWRITE|O_NOFOLLOW, 0);
- if (error) {
- curp->p_traceflag &= ~KTRFAC_ACTIVE;
- return (error);
- }
- vp = nd.ni_vp;
+ int err = 0;
- if (vp->v_type != VREG) {
- (void) vn_close(vp, FREAD|FWRITE, kauth_cred_get(), curp);
- (void) vnode_put(vp);
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
- curp->p_traceflag &= ~KTRFAC_ACTIVE;
- return (EACCES);
- }
+ if ((err = priv_check_cred(kauth_cred_get(), PRIV_KTRACE_BACKGROUND, 0))) {
+ return err;
}
+
/*
- * Clear all uses of the tracefile
+ * When a background tool first checks in, send a notification if ktrace
+ * is available.
*/
- if (ops == KTROP_CLEARFILE) {
- LIST_FOREACH(p, &allproc, p_list) {
- if (p->p_tracep == vp) {
- if (ktrcanset(curp, p)) {
- struct vnode *tvp = p->p_tracep;
- /* no more tracing */
- p->p_traceflag = 0;
- if (tvp != NULL) {
- p->p_tracep = NULL;
- vnode_rele(tvp);
- }
- } else
- error = EPERM;
+ if (should_notify_on_init) {
+ if (ktrace_state == KTRACE_STATE_OFF) {
+ /*
+ * This notification can only fail if a process does not
+ * hold the receive right for the host special port.
+ * Return an error and don't make the current process
+ * the background tool.
+ */
+ if (ktrace_background_available_notify_user() == KERN_FAILURE) {
+ return EINVAL;
}
}
- goto done;
+ should_notify_on_init = FALSE;
}
- /*
- * need something to (un)trace (XXX - why is this here?)
- */
- if (!facs) {
- error = EINVAL;
- goto done;
- }
- /*
- * do it
- */
- if (uap->pid < 0) {
- /*
- * by process group
- */
- pg = pgfind(-uap->pid);
- if (pg == NULL) {
- error = ESRCH;
- goto done;
- }
- LIST_FOREACH(p, &pg->pg_members, p_pglist)
- if (descend)
- ret |= ktrsetchildren(curp, p, ops, facs, vp);
- else
- ret |= ktrops(curp, p, ops, facs, vp);
+ proc_t p = current_proc();
- } else {
- /*
- * by pid
- */
- p = pfind(uap->pid);
- if (p == NULL) {
- error = ESRCH;
- goto done;
- }
- AUDIT_ARG(process, p);
- if (descend)
- ret |= ktrsetchildren(curp, p, ops, facs, vp);
- else
- ret |= ktrops(curp, p, ops, facs, vp);
- }
- if (!ret)
- error = EPERM;
-done:
- if (vp != NULL) {
- (void) vn_close(vp, FWRITE, kauth_cred_get(), curp);
- (void) vnode_put(vp);
+ ktrace_bg_unique_id = proc_uniqueid(p);
+ ktrace_bg_pid = proc_pid(p);
+
+ if (ktrace_state == KTRACE_STATE_BG) {
+ ktrace_set_owning_proc(p);
}
- curp->p_traceflag &= ~KTRFAC_ACTIVE;
- return (error);
-#else
- return ENOSYS;
-#endif
+
+ return 0;
}
-/*
- * utrace system call
- */
+void
+ktrace_set_invalid_owning_pid(void)
+{
+ if (ktrace_keep_ownership_on_reset) {
+ ktrace_keep_ownership_on_reset = FALSE;
+ ktrace_reset_internal(ktrace_active_mask);
+ }
+}
-/* ARGSUSED */
int
-utrace(__unused struct proc *curp, register struct utrace_args *uap, __unused register_t *retval)
+ktrace_set_owning_pid(int pid)
{
-#if KTRACE
- struct ktr_header *kth;
- struct proc *p = current_proc(); /* XXX */
- register caddr_t cp;
-
- if (!KTRPOINT(p, KTR_USER))
- return (0);
- if (uap->len > KTR_USER_MAXLEN)
- return (EINVAL);
- p->p_traceflag |= KTRFAC_ACTIVE;
- kth = ktrgetheader(KTR_USER);
- if (kth == NULL) {
- p->p_traceflag &= ~KTRFAC_ACTIVE;
- return(ENOMEM);
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+
+ /* allow user space to successfully unset owning pid */
+ if (pid == -1) {
+ ktrace_set_invalid_owning_pid();
+ return 0;
}
- MALLOC(cp, caddr_t, uap->len, M_KTRACE, M_WAITOK);
- if (cp == NULL) {
- FREE(kth, M_KTRACE);
- return(ENOMEM);
+
+ /* use ktrace_reset or ktrace_release_ownership, not this */
+ if (pid == 0) {
+ ktrace_set_invalid_owning_pid();
+ return EINVAL;
}
- if (copyin(uap->addr, cp, uap->len) == 0) {
- kth->ktr_buf = cp;
- kth->ktr_len = uap->len;
- ktrwrite(p->p_tracep, kth, NULL);
+
+ proc_t p = proc_find(pid);
+ if (!p) {
+ ktrace_set_invalid_owning_pid();
+ return ESRCH;
}
- FREE(kth, M_KTRACE);
- FREE(cp, M_KTRACE);
- p->p_traceflag &= ~KTRFAC_ACTIVE;
-
- return (0);
-#else
- return (ENOSYS);
-#endif
+
+ ktrace_keep_ownership_on_reset = TRUE;
+ ktrace_set_owning_proc(p);
+
+ proc_rele(p);
+ return 0;
}
-#if KTRACE
-static int
-ktrops(curp, p, ops, facs, vp)
- struct proc *p, *curp;
- int ops, facs;
- struct vnode *vp;
+static void
+ktrace_set_owning_proc(proc_t p)
{
- struct vnode *tvp;
-
- if (!ktrcanset(curp, p))
- return (0);
- if (ops == KTROP_SET) {
- if (p->p_tracep != vp) {
- tvp = p->p_tracep;
- vnode_ref(vp);
- p->p_tracep = vp;
-
- if (tvp != NULL) {
- /*
- * if trace file already in use, relinquish
- */
- vnode_rele(tvp);
- }
- }
- p->p_traceflag |= facs;
- if (!suser(kauth_cred_get(), NULL))
- p->p_traceflag |= KTRFAC_ROOT;
- } else {
- /* KTROP_CLEAR */
- if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
- /* no more tracing */
- tvp = p->p_tracep;
- p->p_traceflag = 0;
- if (tvp != NULL) {
- p->p_tracep = NULL;
- vnode_rele(tvp);
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+ assert(p);
+
+ if (ktrace_state != KTRACE_STATE_FG) {
+ if (proc_uniqueid(p) == ktrace_bg_unique_id) {
+ ktrace_state = KTRACE_STATE_BG;
+ } else {
+ if (ktrace_state == KTRACE_STATE_BG) {
+ if (ktrace_active_mask & KTRACE_KPERF) {
+ kperf_reset();
+ }
+ if (ktrace_active_mask & KTRACE_KDEBUG) {
+ kdebug_reset();
+ }
+
+ ktrace_active_mask = 0;
}
+ ktrace_state = KTRACE_STATE_FG;
+ should_notify_on_init = FALSE;
}
}
- return (1);
+ ktrace_owning_unique_id = proc_uniqueid(p);
+ ktrace_owning_pid = proc_pid(p);
+ strlcpy(ktrace_last_owner_execname, proc_name_address(p),
+ sizeof(ktrace_last_owner_execname));
}
-static int
-ktrsetchildren(curp, top, ops, facs, vp)
- struct proc *curp, *top;
- int ops, facs;
- struct vnode *vp;
+static void
+ktrace_release_ownership(void)
{
- register struct proc *p;
- register int ret = 0;
-
- p = top;
- for (;;) {
- ret |= ktrops(curp, p, ops, facs, vp);
- /*
- * 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_EMPTY(&p->p_children))
- p = LIST_FIRST(&p->p_children);
- else for (;;) {
- if (p == top)
- return (ret);
- if (LIST_NEXT(p, p_sibling)) {
- p = LIST_NEXT(p, p_sibling);
- break;
- }
- p = p->p_pptr;
- }
- }
- /*NOTREACHED*/
+ lck_mtx_assert(ktrace_lock, LCK_MTX_ASSERT_OWNED);
+
+ ktrace_owning_unique_id = 0;
+ ktrace_owning_pid = 0;
}
-static void
-ktrwrite(struct vnode *vp, struct ktr_header *kth, struct uio *uio)
+#define SYSCTL_INIT_BACKGROUND (1)
+
+static int ktrace_sysctl SYSCTL_HANDLER_ARGS;
+
+SYSCTL_NODE(, OID_AUTO, ktrace, CTLFLAG_RW | CTLFLAG_LOCKED, 0, "ktrace");
+
+SYSCTL_UINT(_ktrace, OID_AUTO, state, CTLFLAG_RD | CTLFLAG_LOCKED,
+ &ktrace_state, 0,
+ "");
+
+SYSCTL_INT(_ktrace, OID_AUTO, owning_pid, CTLFLAG_RD | CTLFLAG_LOCKED,
+ &ktrace_owning_pid, 0,
+ "pid of the process that owns ktrace");
+
+SYSCTL_INT(_ktrace, OID_AUTO, background_pid, CTLFLAG_RD | CTLFLAG_LOCKED,
+ &ktrace_bg_pid, 0,
+ "pid of the background ktrace tool");
+
+SYSCTL_STRING(_ktrace, OID_AUTO, configured_by, CTLFLAG_RD | CTLFLAG_LOCKED,
+ ktrace_last_owner_execname, 0,
+ "execname of process that last configured ktrace");
+
+SYSCTL_PROC(_ktrace, OID_AUTO, init_background, CTLFLAG_RW | CTLFLAG_LOCKED,
+ (void *)SYSCTL_INIT_BACKGROUND, sizeof(int),
+ ktrace_sysctl, "I", "initialize calling process as background");
+
+static int
+ktrace_sysctl SYSCTL_HANDLER_ARGS
{
- uio_t auio;
- register struct proc *p = current_proc(); /* XXX */
- struct vfs_context context;
- int error;
- char uio_buf[ UIO_SIZEOF(2) ];
+#pragma unused(oidp, arg2)
+ int ret = 0;
+ uintptr_t type = (uintptr_t)arg1;
- if (vp == NULL)
- return;
+ lck_mtx_lock(ktrace_lock);
- auio = uio_createwithbuffer(2, 0, UIO_SYSSPACE, UIO_WRITE,
- &uio_buf[0], sizeof(uio_buf));
- uio_addiov(auio, CAST_USER_ADDR_T(kth), sizeof(struct ktr_header));
- context.vc_proc = p;
- context.vc_ucred = kauth_cred_get();
-
- if (kth->ktr_len > 0) {
- uio_addiov(auio, CAST_USER_ADDR_T(kth->ktr_buf), kth->ktr_len);
- if (uio != NULL)
- kth->ktr_len += uio_resid(uio);
- }
- if ((error = vnode_getwithref(vp)) == 0) {
- error = VNOP_WRITE(vp, auio, IO_UNIT | IO_APPEND, &context);
- if (error == 0 && uio != NULL) {
- error = VNOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, &context);
- }
- vnode_put(vp);
+ if (!kauth_cred_issuser(kauth_cred_get())) {
+ ret = EPERM;
+ goto out;
}
- if (error) {
- /*
- * If error encountered, give up tracing on this vnode.
- */
- log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
- error);
- LIST_FOREACH(p, &allproc, p_list) {
- if (p->p_tracep == vp) {
- p->p_tracep = NULL;
- p->p_traceflag = 0;
- vnode_rele(vp);
- }
+
+ if (type == SYSCTL_INIT_BACKGROUND) {
+ if (req->newptr != USER_ADDR_NULL) {
+ ret = ktrace_init_background();
+ goto out;
+ } else {
+ ret = EINVAL;
+ goto out;
}
+ } else {
+ ret = EINVAL;
+ goto out;
}
+
+out:
+ lck_mtx_unlock(ktrace_lock);
+ return ret;
}
-/*
- * 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.
- */
-static int
-ktrcanset(__unused struct proc *callp, struct proc *targetp)
+/* This should only be called from the bootstrap thread. */
+void
+ktrace_init(void)
{
- kauth_cred_t caller = kauth_cred_get();
- kauth_cred_t target = targetp->p_ucred; /* XXX */
-
-#if 0
- /* PRISON_CHECK was defined to 1 always .... */
- if (!PRISON_CHECK(callp, targetp))
- return (0);
-#endif
- if ((kauth_cred_getuid(caller) == target->cr_ruid &&
- target->cr_ruid == target->cr_svuid &&
- caller->cr_rgid == target->cr_rgid && /* XXX */
- target->cr_rgid == target->cr_svgid &&
- (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
- (targetp->p_flag & P_SUGID) == 0) ||
- !suser(caller, NULL))
- return (1);
-
- return (0);
-}
+ static lck_grp_attr_t *lock_grp_attr = NULL;
+ static lck_grp_t *lock_grp = NULL;
+ static boolean_t initialized = FALSE;
-#endif /* KTRACE */
+ if (initialized) {
+ return;
+ }
+
+ lock_grp_attr = lck_grp_attr_alloc_init();
+ lock_grp = lck_grp_alloc_init("ktrace", lock_grp_attr);
+ lck_grp_attr_free(lock_grp_attr);
+
+ ktrace_lock = lck_mtx_alloc_init(lock_grp, LCK_ATTR_NULL);
+ assert(ktrace_lock);
+ initialized = TRUE;
+}
projects / apple / xnu.git / blobdiff