When it was inline it made sense to depend on the existing nested check in KTRUSERRET() rather than adding a new td_flags flag. However, since we now have a TDA_KTRACE flag anyway, we might as well check it and avoid the call. Suggested by: jhb Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D35888
1402 lines
33 KiB
C
1402 lines
33 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California.
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* Copyright (c) 2005 Robert N. M. Watson
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_ktrace.c 8.2 (Berkeley) 9/23/93
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_ktrace.h"
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#include <sys/param.h>
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#include <sys/capsicum.h>
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#include <sys/systm.h>
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#include <sys/fcntl.h>
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#include <sys/kernel.h>
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#include <sys/kthread.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/malloc.h>
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#include <sys/mount.h>
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#include <sys/namei.h>
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#include <sys/priv.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/unistd.h>
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#include <sys/vnode.h>
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#include <sys/socket.h>
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#include <sys/stat.h>
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#include <sys/ktrace.h>
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#include <sys/sx.h>
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#include <sys/sysctl.h>
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#include <sys/sysent.h>
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#include <sys/syslog.h>
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#include <sys/sysproto.h>
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#include <security/mac/mac_framework.h>
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/*
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* The ktrace facility allows the tracing of certain key events in user space
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* processes, such as system calls, signal delivery, context switches, and
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* user generated events using utrace(2). It works by streaming event
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* records and data to a vnode associated with the process using the
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* ktrace(2) system call. In general, records can be written directly from
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* the context that generates the event. One important exception to this is
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* during a context switch, where sleeping is not permitted. To handle this
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* case, trace events are generated using in-kernel ktr_request records, and
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* then delivered to disk at a convenient moment -- either immediately, the
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* next traceable event, at system call return, or at process exit.
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*
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* When dealing with multiple threads or processes writing to the same event
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* log, ordering guarantees are weak: specifically, if an event has multiple
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* records (i.e., system call enter and return), they may be interlaced with
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* records from another event. Process and thread ID information is provided
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* in the record, and user applications can de-interlace events if required.
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*/
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static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
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#ifdef KTRACE
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FEATURE(ktrace, "Kernel support for system-call tracing");
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#ifndef KTRACE_REQUEST_POOL
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#define KTRACE_REQUEST_POOL 100
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#endif
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struct ktr_request {
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struct ktr_header ktr_header;
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void *ktr_buffer;
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union {
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struct ktr_proc_ctor ktr_proc_ctor;
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struct ktr_cap_fail ktr_cap_fail;
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struct ktr_syscall ktr_syscall;
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struct ktr_sysret ktr_sysret;
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struct ktr_genio ktr_genio;
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struct ktr_psig ktr_psig;
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struct ktr_csw ktr_csw;
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struct ktr_fault ktr_fault;
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struct ktr_faultend ktr_faultend;
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struct ktr_struct_array ktr_struct_array;
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} ktr_data;
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STAILQ_ENTRY(ktr_request) ktr_list;
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};
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static int data_lengths[] = {
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[KTR_SYSCALL] = offsetof(struct ktr_syscall, ktr_args),
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[KTR_SYSRET] = sizeof(struct ktr_sysret),
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[KTR_NAMEI] = 0,
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[KTR_GENIO] = sizeof(struct ktr_genio),
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[KTR_PSIG] = sizeof(struct ktr_psig),
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[KTR_CSW] = sizeof(struct ktr_csw),
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[KTR_USER] = 0,
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[KTR_STRUCT] = 0,
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[KTR_SYSCTL] = 0,
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[KTR_PROCCTOR] = sizeof(struct ktr_proc_ctor),
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[KTR_PROCDTOR] = 0,
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[KTR_CAPFAIL] = sizeof(struct ktr_cap_fail),
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[KTR_FAULT] = sizeof(struct ktr_fault),
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[KTR_FAULTEND] = sizeof(struct ktr_faultend),
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[KTR_STRUCT_ARRAY] = sizeof(struct ktr_struct_array),
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};
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static STAILQ_HEAD(, ktr_request) ktr_free;
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static SYSCTL_NODE(_kern, OID_AUTO, ktrace, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
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"KTRACE options");
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static u_int ktr_requestpool = KTRACE_REQUEST_POOL;
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TUNABLE_INT("kern.ktrace.request_pool", &ktr_requestpool);
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u_int ktr_geniosize = PAGE_SIZE;
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SYSCTL_UINT(_kern_ktrace, OID_AUTO, genio_size, CTLFLAG_RWTUN, &ktr_geniosize,
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0, "Maximum size of genio event payload");
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/*
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* Allow to not to send signal to traced process, in which context the
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* ktr record is written. The limit is applied from the process that
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* set up ktrace, so killing the traced process is not completely fair.
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*/
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int ktr_filesize_limit_signal = 0;
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SYSCTL_INT(_kern_ktrace, OID_AUTO, filesize_limit_signal, CTLFLAG_RWTUN,
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&ktr_filesize_limit_signal, 0,
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"Send SIGXFSZ to the traced process when the log size limit is exceeded");
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static int print_message = 1;
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static struct mtx ktrace_mtx;
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static struct sx ktrace_sx;
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struct ktr_io_params {
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struct vnode *vp;
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struct ucred *cr;
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off_t lim;
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u_int refs;
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};
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static void ktrace_init(void *dummy);
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static int sysctl_kern_ktrace_request_pool(SYSCTL_HANDLER_ARGS);
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static u_int ktrace_resize_pool(u_int oldsize, u_int newsize);
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static struct ktr_request *ktr_getrequest_entered(struct thread *td, int type);
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static struct ktr_request *ktr_getrequest(int type);
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static void ktr_submitrequest(struct thread *td, struct ktr_request *req);
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static struct ktr_io_params *ktr_freeproc(struct proc *p);
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static void ktr_freerequest(struct ktr_request *req);
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static void ktr_freerequest_locked(struct ktr_request *req);
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static void ktr_writerequest(struct thread *td, struct ktr_request *req);
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static int ktrcanset(struct thread *,struct proc *);
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static int ktrsetchildren(struct thread *, struct proc *, int, int,
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struct ktr_io_params *);
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static int ktrops(struct thread *, struct proc *, int, int,
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struct ktr_io_params *);
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static void ktrprocctor_entered(struct thread *, struct proc *);
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/*
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* ktrace itself generates events, such as context switches, which we do not
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* wish to trace. Maintain a flag, TDP_INKTRACE, on each thread to determine
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* whether or not it is in a region where tracing of events should be
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* suppressed.
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*/
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static void
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ktrace_enter(struct thread *td)
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{
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KASSERT(!(td->td_pflags & TDP_INKTRACE), ("ktrace_enter: flag set"));
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td->td_pflags |= TDP_INKTRACE;
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}
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static void
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ktrace_exit(struct thread *td)
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{
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KASSERT(td->td_pflags & TDP_INKTRACE, ("ktrace_exit: flag not set"));
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td->td_pflags &= ~TDP_INKTRACE;
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}
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static void
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ktrace_assert(struct thread *td)
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{
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KASSERT(td->td_pflags & TDP_INKTRACE, ("ktrace_assert: flag not set"));
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}
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static void
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ast_ktrace(struct thread *td, int tda __unused)
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{
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KTRUSERRET(td);
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}
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static void
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ktrace_init(void *dummy)
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{
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struct ktr_request *req;
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int i;
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mtx_init(&ktrace_mtx, "ktrace", NULL, MTX_DEF | MTX_QUIET);
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sx_init(&ktrace_sx, "ktrace_sx");
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STAILQ_INIT(&ktr_free);
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for (i = 0; i < ktr_requestpool; i++) {
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req = malloc(sizeof(struct ktr_request), M_KTRACE, M_WAITOK |
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M_ZERO);
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STAILQ_INSERT_HEAD(&ktr_free, req, ktr_list);
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}
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ast_register(TDA_KTRACE, ASTR_ASTF_REQUIRED, 0, ast_ktrace);
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}
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SYSINIT(ktrace_init, SI_SUB_KTRACE, SI_ORDER_ANY, ktrace_init, NULL);
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static int
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sysctl_kern_ktrace_request_pool(SYSCTL_HANDLER_ARGS)
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{
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struct thread *td;
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u_int newsize, oldsize, wantsize;
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int error;
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/* Handle easy read-only case first to avoid warnings from GCC. */
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if (!req->newptr) {
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oldsize = ktr_requestpool;
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return (SYSCTL_OUT(req, &oldsize, sizeof(u_int)));
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}
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error = SYSCTL_IN(req, &wantsize, sizeof(u_int));
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if (error)
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return (error);
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td = curthread;
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ktrace_enter(td);
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oldsize = ktr_requestpool;
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newsize = ktrace_resize_pool(oldsize, wantsize);
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ktrace_exit(td);
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error = SYSCTL_OUT(req, &oldsize, sizeof(u_int));
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if (error)
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return (error);
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if (wantsize > oldsize && newsize < wantsize)
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return (ENOSPC);
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return (0);
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}
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SYSCTL_PROC(_kern_ktrace, OID_AUTO, request_pool,
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CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &ktr_requestpool, 0,
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sysctl_kern_ktrace_request_pool, "IU",
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"Pool buffer size for ktrace(1)");
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static u_int
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ktrace_resize_pool(u_int oldsize, u_int newsize)
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{
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STAILQ_HEAD(, ktr_request) ktr_new;
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struct ktr_request *req;
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int bound;
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print_message = 1;
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bound = newsize - oldsize;
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if (bound == 0)
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return (ktr_requestpool);
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if (bound < 0) {
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mtx_lock(&ktrace_mtx);
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/* Shrink pool down to newsize if possible. */
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while (bound++ < 0) {
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req = STAILQ_FIRST(&ktr_free);
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if (req == NULL)
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break;
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STAILQ_REMOVE_HEAD(&ktr_free, ktr_list);
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ktr_requestpool--;
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free(req, M_KTRACE);
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}
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} else {
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/* Grow pool up to newsize. */
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STAILQ_INIT(&ktr_new);
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while (bound-- > 0) {
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req = malloc(sizeof(struct ktr_request), M_KTRACE,
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M_WAITOK | M_ZERO);
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STAILQ_INSERT_HEAD(&ktr_new, req, ktr_list);
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}
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mtx_lock(&ktrace_mtx);
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STAILQ_CONCAT(&ktr_free, &ktr_new);
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ktr_requestpool += (newsize - oldsize);
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}
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mtx_unlock(&ktrace_mtx);
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return (ktr_requestpool);
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}
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/* ktr_getrequest() assumes that ktr_comm[] is the same size as td_name[]. */
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CTASSERT(sizeof(((struct ktr_header *)NULL)->ktr_comm) ==
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(sizeof((struct thread *)NULL)->td_name));
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static struct ktr_request *
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ktr_getrequest_entered(struct thread *td, int type)
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{
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struct ktr_request *req;
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struct proc *p = td->td_proc;
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int pm;
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mtx_lock(&ktrace_mtx);
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if (!KTRCHECK(td, type)) {
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mtx_unlock(&ktrace_mtx);
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return (NULL);
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}
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req = STAILQ_FIRST(&ktr_free);
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if (req != NULL) {
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STAILQ_REMOVE_HEAD(&ktr_free, ktr_list);
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req->ktr_header.ktr_type = type;
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if (p->p_traceflag & KTRFAC_DROP) {
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req->ktr_header.ktr_type |= KTR_DROP;
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p->p_traceflag &= ~KTRFAC_DROP;
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}
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mtx_unlock(&ktrace_mtx);
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nanotime(&req->ktr_header.ktr_time);
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req->ktr_header.ktr_type |= KTR_VERSIONED;
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req->ktr_header.ktr_pid = p->p_pid;
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req->ktr_header.ktr_tid = td->td_tid;
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req->ktr_header.ktr_cpu = PCPU_GET(cpuid);
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req->ktr_header.ktr_version = KTR_VERSION1;
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bcopy(td->td_name, req->ktr_header.ktr_comm,
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sizeof(req->ktr_header.ktr_comm));
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req->ktr_buffer = NULL;
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req->ktr_header.ktr_len = 0;
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} else {
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p->p_traceflag |= KTRFAC_DROP;
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pm = print_message;
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print_message = 0;
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mtx_unlock(&ktrace_mtx);
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if (pm)
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printf("Out of ktrace request objects.\n");
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}
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return (req);
|
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}
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|
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static struct ktr_request *
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ktr_getrequest(int type)
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{
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struct thread *td = curthread;
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struct ktr_request *req;
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ktrace_enter(td);
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req = ktr_getrequest_entered(td, type);
|
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if (req == NULL)
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ktrace_exit(td);
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|
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return (req);
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}
|
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|
|
/*
|
|
* Some trace generation environments don't permit direct access to VFS,
|
|
* such as during a context switch where sleeping is not allowed. Under these
|
|
* circumstances, queue a request to the thread to be written asynchronously
|
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* later.
|
|
*/
|
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static void
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ktr_enqueuerequest(struct thread *td, struct ktr_request *req)
|
|
{
|
|
|
|
mtx_lock(&ktrace_mtx);
|
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STAILQ_INSERT_TAIL(&td->td_proc->p_ktr, req, ktr_list);
|
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mtx_unlock(&ktrace_mtx);
|
|
ast_sched(td, TDA_KTRACE);
|
|
}
|
|
|
|
/*
|
|
* Drain any pending ktrace records from the per-thread queue to disk. This
|
|
* is used both internally before committing other records, and also on
|
|
* system call return. We drain all the ones we can find at the time when
|
|
* drain is requested, but don't keep draining after that as those events
|
|
* may be approximately "after" the current event.
|
|
*/
|
|
static void
|
|
ktr_drain(struct thread *td)
|
|
{
|
|
struct ktr_request *queued_req;
|
|
STAILQ_HEAD(, ktr_request) local_queue;
|
|
|
|
ktrace_assert(td);
|
|
sx_assert(&ktrace_sx, SX_XLOCKED);
|
|
|
|
STAILQ_INIT(&local_queue);
|
|
|
|
if (!STAILQ_EMPTY(&td->td_proc->p_ktr)) {
|
|
mtx_lock(&ktrace_mtx);
|
|
STAILQ_CONCAT(&local_queue, &td->td_proc->p_ktr);
|
|
mtx_unlock(&ktrace_mtx);
|
|
|
|
while ((queued_req = STAILQ_FIRST(&local_queue))) {
|
|
STAILQ_REMOVE_HEAD(&local_queue, ktr_list);
|
|
ktr_writerequest(td, queued_req);
|
|
ktr_freerequest(queued_req);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Submit a trace record for immediate commit to disk -- to be used only
|
|
* where entering VFS is OK. First drain any pending records that may have
|
|
* been cached in the thread.
|
|
*/
|
|
static void
|
|
ktr_submitrequest(struct thread *td, struct ktr_request *req)
|
|
{
|
|
|
|
ktrace_assert(td);
|
|
|
|
sx_xlock(&ktrace_sx);
|
|
ktr_drain(td);
|
|
ktr_writerequest(td, req);
|
|
ktr_freerequest(req);
|
|
sx_xunlock(&ktrace_sx);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
static void
|
|
ktr_freerequest(struct ktr_request *req)
|
|
{
|
|
|
|
mtx_lock(&ktrace_mtx);
|
|
ktr_freerequest_locked(req);
|
|
mtx_unlock(&ktrace_mtx);
|
|
}
|
|
|
|
static void
|
|
ktr_freerequest_locked(struct ktr_request *req)
|
|
{
|
|
|
|
mtx_assert(&ktrace_mtx, MA_OWNED);
|
|
if (req->ktr_buffer != NULL)
|
|
free(req->ktr_buffer, M_KTRACE);
|
|
STAILQ_INSERT_HEAD(&ktr_free, req, ktr_list);
|
|
}
|
|
|
|
static void
|
|
ktr_io_params_ref(struct ktr_io_params *kiop)
|
|
{
|
|
mtx_assert(&ktrace_mtx, MA_OWNED);
|
|
kiop->refs++;
|
|
}
|
|
|
|
static struct ktr_io_params *
|
|
ktr_io_params_rele(struct ktr_io_params *kiop)
|
|
{
|
|
mtx_assert(&ktrace_mtx, MA_OWNED);
|
|
if (kiop == NULL)
|
|
return (NULL);
|
|
KASSERT(kiop->refs > 0, ("kiop ref == 0 %p", kiop));
|
|
return (--(kiop->refs) == 0 ? kiop : NULL);
|
|
}
|
|
|
|
void
|
|
ktr_io_params_free(struct ktr_io_params *kiop)
|
|
{
|
|
if (kiop == NULL)
|
|
return;
|
|
|
|
MPASS(kiop->refs == 0);
|
|
vn_close(kiop->vp, FWRITE, kiop->cr, curthread);
|
|
crfree(kiop->cr);
|
|
free(kiop, M_KTRACE);
|
|
}
|
|
|
|
static struct ktr_io_params *
|
|
ktr_io_params_alloc(struct thread *td, struct vnode *vp)
|
|
{
|
|
struct ktr_io_params *res;
|
|
|
|
res = malloc(sizeof(struct ktr_io_params), M_KTRACE, M_WAITOK);
|
|
res->vp = vp;
|
|
res->cr = crhold(td->td_ucred);
|
|
res->lim = lim_cur(td, RLIMIT_FSIZE);
|
|
res->refs = 1;
|
|
return (res);
|
|
}
|
|
|
|
/*
|
|
* Disable tracing for a process and release all associated resources.
|
|
* The caller is responsible for releasing a reference on the returned
|
|
* vnode and credentials.
|
|
*/
|
|
static struct ktr_io_params *
|
|
ktr_freeproc(struct proc *p)
|
|
{
|
|
struct ktr_io_params *kiop;
|
|
struct ktr_request *req;
|
|
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
mtx_assert(&ktrace_mtx, MA_OWNED);
|
|
kiop = ktr_io_params_rele(p->p_ktrioparms);
|
|
p->p_ktrioparms = NULL;
|
|
p->p_traceflag = 0;
|
|
while ((req = STAILQ_FIRST(&p->p_ktr)) != NULL) {
|
|
STAILQ_REMOVE_HEAD(&p->p_ktr, ktr_list);
|
|
ktr_freerequest_locked(req);
|
|
}
|
|
return (kiop);
|
|
}
|
|
|
|
struct vnode *
|
|
ktr_get_tracevp(struct proc *p, bool ref)
|
|
{
|
|
struct vnode *vp;
|
|
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
|
|
if (p->p_ktrioparms != NULL) {
|
|
vp = p->p_ktrioparms->vp;
|
|
if (ref)
|
|
vrefact(vp);
|
|
} else {
|
|
vp = NULL;
|
|
}
|
|
return (vp);
|
|
}
|
|
|
|
void
|
|
ktrsyscall(int code, int narg, syscallarg_t args[])
|
|
{
|
|
struct ktr_request *req;
|
|
struct ktr_syscall *ktp;
|
|
size_t buflen;
|
|
char *buf = NULL;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
|
|
buflen = sizeof(register_t) * narg;
|
|
if (buflen > 0) {
|
|
buf = malloc(buflen, M_KTRACE, M_WAITOK);
|
|
bcopy(args, buf, buflen);
|
|
}
|
|
req = ktr_getrequest(KTR_SYSCALL);
|
|
if (req == NULL) {
|
|
if (buf != NULL)
|
|
free(buf, M_KTRACE);
|
|
return;
|
|
}
|
|
ktp = &req->ktr_data.ktr_syscall;
|
|
ktp->ktr_code = code;
|
|
ktp->ktr_narg = narg;
|
|
if (buflen > 0) {
|
|
req->ktr_header.ktr_len = buflen;
|
|
req->ktr_buffer = buf;
|
|
}
|
|
ktr_submitrequest(curthread, req);
|
|
}
|
|
|
|
void
|
|
ktrsysret(int code, int error, register_t retval)
|
|
{
|
|
struct ktr_request *req;
|
|
struct ktr_sysret *ktp;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
|
|
req = ktr_getrequest(KTR_SYSRET);
|
|
if (req == NULL)
|
|
return;
|
|
ktp = &req->ktr_data.ktr_sysret;
|
|
ktp->ktr_code = code;
|
|
ktp->ktr_error = error;
|
|
ktp->ktr_retval = ((error == 0) ? retval: 0); /* what about val2 ? */
|
|
ktr_submitrequest(curthread, req);
|
|
}
|
|
|
|
/*
|
|
* When a setuid process execs, disable tracing.
|
|
*
|
|
* XXX: We toss any pending asynchronous records.
|
|
*/
|
|
struct ktr_io_params *
|
|
ktrprocexec(struct proc *p)
|
|
{
|
|
struct ktr_io_params *kiop;
|
|
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
|
|
kiop = p->p_ktrioparms;
|
|
if (kiop == NULL || priv_check_cred(kiop->cr, PRIV_DEBUG_DIFFCRED))
|
|
return (NULL);
|
|
|
|
mtx_lock(&ktrace_mtx);
|
|
kiop = ktr_freeproc(p);
|
|
mtx_unlock(&ktrace_mtx);
|
|
return (kiop);
|
|
}
|
|
|
|
/*
|
|
* When a process exits, drain per-process asynchronous trace records
|
|
* and disable tracing.
|
|
*/
|
|
void
|
|
ktrprocexit(struct thread *td)
|
|
{
|
|
struct ktr_request *req;
|
|
struct proc *p;
|
|
struct ktr_io_params *kiop;
|
|
|
|
p = td->td_proc;
|
|
if (p->p_traceflag == 0)
|
|
return;
|
|
|
|
ktrace_enter(td);
|
|
req = ktr_getrequest_entered(td, KTR_PROCDTOR);
|
|
if (req != NULL)
|
|
ktr_enqueuerequest(td, req);
|
|
sx_xlock(&ktrace_sx);
|
|
ktr_drain(td);
|
|
sx_xunlock(&ktrace_sx);
|
|
PROC_LOCK(p);
|
|
mtx_lock(&ktrace_mtx);
|
|
kiop = ktr_freeproc(p);
|
|
mtx_unlock(&ktrace_mtx);
|
|
PROC_UNLOCK(p);
|
|
ktr_io_params_free(kiop);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
static void
|
|
ktrprocctor_entered(struct thread *td, struct proc *p)
|
|
{
|
|
struct ktr_proc_ctor *ktp;
|
|
struct ktr_request *req;
|
|
struct thread *td2;
|
|
|
|
ktrace_assert(td);
|
|
td2 = FIRST_THREAD_IN_PROC(p);
|
|
req = ktr_getrequest_entered(td2, KTR_PROCCTOR);
|
|
if (req == NULL)
|
|
return;
|
|
ktp = &req->ktr_data.ktr_proc_ctor;
|
|
ktp->sv_flags = p->p_sysent->sv_flags;
|
|
ktr_enqueuerequest(td2, req);
|
|
}
|
|
|
|
void
|
|
ktrprocctor(struct proc *p)
|
|
{
|
|
struct thread *td = curthread;
|
|
|
|
if ((p->p_traceflag & KTRFAC_MASK) == 0)
|
|
return;
|
|
|
|
ktrace_enter(td);
|
|
ktrprocctor_entered(td, p);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
/*
|
|
* When a process forks, enable tracing in the new process if needed.
|
|
*/
|
|
void
|
|
ktrprocfork(struct proc *p1, struct proc *p2)
|
|
{
|
|
|
|
MPASS(p2->p_ktrioparms == NULL);
|
|
MPASS(p2->p_traceflag == 0);
|
|
|
|
if (p1->p_traceflag == 0)
|
|
return;
|
|
|
|
PROC_LOCK(p1);
|
|
mtx_lock(&ktrace_mtx);
|
|
if (p1->p_traceflag & KTRFAC_INHERIT) {
|
|
p2->p_traceflag = p1->p_traceflag;
|
|
if ((p2->p_ktrioparms = p1->p_ktrioparms) != NULL)
|
|
p1->p_ktrioparms->refs++;
|
|
}
|
|
mtx_unlock(&ktrace_mtx);
|
|
PROC_UNLOCK(p1);
|
|
|
|
ktrprocctor(p2);
|
|
}
|
|
|
|
/*
|
|
* When a thread returns, drain any asynchronous records generated by the
|
|
* system call.
|
|
*/
|
|
void
|
|
ktruserret(struct thread *td)
|
|
{
|
|
|
|
ktrace_enter(td);
|
|
sx_xlock(&ktrace_sx);
|
|
ktr_drain(td);
|
|
sx_xunlock(&ktrace_sx);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
void
|
|
ktrnamei(const char *path)
|
|
{
|
|
struct ktr_request *req;
|
|
int namelen;
|
|
char *buf = NULL;
|
|
|
|
namelen = strlen(path);
|
|
if (namelen > 0) {
|
|
buf = malloc(namelen, M_KTRACE, M_WAITOK);
|
|
bcopy(path, buf, namelen);
|
|
}
|
|
req = ktr_getrequest(KTR_NAMEI);
|
|
if (req == NULL) {
|
|
if (buf != NULL)
|
|
free(buf, M_KTRACE);
|
|
return;
|
|
}
|
|
if (namelen > 0) {
|
|
req->ktr_header.ktr_len = namelen;
|
|
req->ktr_buffer = buf;
|
|
}
|
|
ktr_submitrequest(curthread, req);
|
|
}
|
|
|
|
void
|
|
ktrsysctl(int *name, u_int namelen)
|
|
{
|
|
struct ktr_request *req;
|
|
u_int mib[CTL_MAXNAME + 2];
|
|
char *mibname;
|
|
size_t mibnamelen;
|
|
int error;
|
|
|
|
/* Lookup name of mib. */
|
|
KASSERT(namelen <= CTL_MAXNAME, ("sysctl MIB too long"));
|
|
mib[0] = 0;
|
|
mib[1] = 1;
|
|
bcopy(name, mib + 2, namelen * sizeof(*name));
|
|
mibnamelen = 128;
|
|
mibname = malloc(mibnamelen, M_KTRACE, M_WAITOK);
|
|
error = kernel_sysctl(curthread, mib, namelen + 2, mibname, &mibnamelen,
|
|
NULL, 0, &mibnamelen, 0);
|
|
if (error) {
|
|
free(mibname, M_KTRACE);
|
|
return;
|
|
}
|
|
req = ktr_getrequest(KTR_SYSCTL);
|
|
if (req == NULL) {
|
|
free(mibname, M_KTRACE);
|
|
return;
|
|
}
|
|
req->ktr_header.ktr_len = mibnamelen;
|
|
req->ktr_buffer = mibname;
|
|
ktr_submitrequest(curthread, req);
|
|
}
|
|
|
|
void
|
|
ktrgenio(int fd, enum uio_rw rw, struct uio *uio, int error)
|
|
{
|
|
struct ktr_request *req;
|
|
struct ktr_genio *ktg;
|
|
int datalen;
|
|
char *buf;
|
|
|
|
if (error) {
|
|
free(uio, M_IOV);
|
|
return;
|
|
}
|
|
uio->uio_offset = 0;
|
|
uio->uio_rw = UIO_WRITE;
|
|
datalen = MIN(uio->uio_resid, ktr_geniosize);
|
|
buf = malloc(datalen, M_KTRACE, M_WAITOK);
|
|
error = uiomove(buf, datalen, uio);
|
|
free(uio, M_IOV);
|
|
if (error) {
|
|
free(buf, M_KTRACE);
|
|
return;
|
|
}
|
|
req = ktr_getrequest(KTR_GENIO);
|
|
if (req == NULL) {
|
|
free(buf, M_KTRACE);
|
|
return;
|
|
}
|
|
ktg = &req->ktr_data.ktr_genio;
|
|
ktg->ktr_fd = fd;
|
|
ktg->ktr_rw = rw;
|
|
req->ktr_header.ktr_len = datalen;
|
|
req->ktr_buffer = buf;
|
|
ktr_submitrequest(curthread, req);
|
|
}
|
|
|
|
void
|
|
ktrpsig(int sig, sig_t action, sigset_t *mask, int code)
|
|
{
|
|
struct thread *td = curthread;
|
|
struct ktr_request *req;
|
|
struct ktr_psig *kp;
|
|
|
|
req = ktr_getrequest(KTR_PSIG);
|
|
if (req == NULL)
|
|
return;
|
|
kp = &req->ktr_data.ktr_psig;
|
|
kp->signo = (char)sig;
|
|
kp->action = action;
|
|
kp->mask = *mask;
|
|
kp->code = code;
|
|
ktr_enqueuerequest(td, req);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
void
|
|
ktrcsw(int out, int user, const char *wmesg)
|
|
{
|
|
struct thread *td = curthread;
|
|
struct ktr_request *req;
|
|
struct ktr_csw *kc;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
|
|
req = ktr_getrequest(KTR_CSW);
|
|
if (req == NULL)
|
|
return;
|
|
kc = &req->ktr_data.ktr_csw;
|
|
kc->out = out;
|
|
kc->user = user;
|
|
if (wmesg != NULL)
|
|
strlcpy(kc->wmesg, wmesg, sizeof(kc->wmesg));
|
|
else
|
|
bzero(kc->wmesg, sizeof(kc->wmesg));
|
|
ktr_enqueuerequest(td, req);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
void
|
|
ktrstruct(const char *name, const void *data, size_t datalen)
|
|
{
|
|
struct ktr_request *req;
|
|
char *buf;
|
|
size_t buflen, namelen;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
|
|
if (data == NULL)
|
|
datalen = 0;
|
|
namelen = strlen(name) + 1;
|
|
buflen = namelen + datalen;
|
|
buf = malloc(buflen, M_KTRACE, M_WAITOK);
|
|
strcpy(buf, name);
|
|
bcopy(data, buf + namelen, datalen);
|
|
if ((req = ktr_getrequest(KTR_STRUCT)) == NULL) {
|
|
free(buf, M_KTRACE);
|
|
return;
|
|
}
|
|
req->ktr_buffer = buf;
|
|
req->ktr_header.ktr_len = buflen;
|
|
ktr_submitrequest(curthread, req);
|
|
}
|
|
|
|
void
|
|
ktrstruct_error(const char *name, const void *data, size_t datalen, int error)
|
|
{
|
|
|
|
if (error == 0)
|
|
ktrstruct(name, data, datalen);
|
|
}
|
|
|
|
void
|
|
ktrstructarray(const char *name, enum uio_seg seg, const void *data,
|
|
int num_items, size_t struct_size)
|
|
{
|
|
struct ktr_request *req;
|
|
struct ktr_struct_array *ksa;
|
|
char *buf;
|
|
size_t buflen, datalen, namelen;
|
|
int max_items;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
if (num_items < 0)
|
|
return;
|
|
|
|
/* Trim array length to genio size. */
|
|
max_items = ktr_geniosize / struct_size;
|
|
if (num_items > max_items) {
|
|
if (max_items == 0)
|
|
num_items = 1;
|
|
else
|
|
num_items = max_items;
|
|
}
|
|
datalen = num_items * struct_size;
|
|
|
|
if (data == NULL)
|
|
datalen = 0;
|
|
|
|
namelen = strlen(name) + 1;
|
|
buflen = namelen + datalen;
|
|
buf = malloc(buflen, M_KTRACE, M_WAITOK);
|
|
strcpy(buf, name);
|
|
if (seg == UIO_SYSSPACE)
|
|
bcopy(data, buf + namelen, datalen);
|
|
else {
|
|
if (copyin(data, buf + namelen, datalen) != 0) {
|
|
free(buf, M_KTRACE);
|
|
return;
|
|
}
|
|
}
|
|
if ((req = ktr_getrequest(KTR_STRUCT_ARRAY)) == NULL) {
|
|
free(buf, M_KTRACE);
|
|
return;
|
|
}
|
|
ksa = &req->ktr_data.ktr_struct_array;
|
|
ksa->struct_size = struct_size;
|
|
req->ktr_buffer = buf;
|
|
req->ktr_header.ktr_len = buflen;
|
|
ktr_submitrequest(curthread, req);
|
|
}
|
|
|
|
void
|
|
ktrcapfail(enum ktr_cap_fail_type type, const cap_rights_t *needed,
|
|
const cap_rights_t *held)
|
|
{
|
|
struct thread *td = curthread;
|
|
struct ktr_request *req;
|
|
struct ktr_cap_fail *kcf;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
|
|
req = ktr_getrequest(KTR_CAPFAIL);
|
|
if (req == NULL)
|
|
return;
|
|
kcf = &req->ktr_data.ktr_cap_fail;
|
|
kcf->cap_type = type;
|
|
if (needed != NULL)
|
|
kcf->cap_needed = *needed;
|
|
else
|
|
cap_rights_init(&kcf->cap_needed);
|
|
if (held != NULL)
|
|
kcf->cap_held = *held;
|
|
else
|
|
cap_rights_init(&kcf->cap_held);
|
|
ktr_enqueuerequest(td, req);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
void
|
|
ktrfault(vm_offset_t vaddr, int type)
|
|
{
|
|
struct thread *td = curthread;
|
|
struct ktr_request *req;
|
|
struct ktr_fault *kf;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
|
|
req = ktr_getrequest(KTR_FAULT);
|
|
if (req == NULL)
|
|
return;
|
|
kf = &req->ktr_data.ktr_fault;
|
|
kf->vaddr = vaddr;
|
|
kf->type = type;
|
|
ktr_enqueuerequest(td, req);
|
|
ktrace_exit(td);
|
|
}
|
|
|
|
void
|
|
ktrfaultend(int result)
|
|
{
|
|
struct thread *td = curthread;
|
|
struct ktr_request *req;
|
|
struct ktr_faultend *kf;
|
|
|
|
if (__predict_false(curthread->td_pflags & TDP_INKTRACE))
|
|
return;
|
|
|
|
req = ktr_getrequest(KTR_FAULTEND);
|
|
if (req == NULL)
|
|
return;
|
|
kf = &req->ktr_data.ktr_faultend;
|
|
kf->result = result;
|
|
ktr_enqueuerequest(td, req);
|
|
ktrace_exit(td);
|
|
}
|
|
#endif /* KTRACE */
|
|
|
|
/* Interface and common routines */
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct ktrace_args {
|
|
char *fname;
|
|
int ops;
|
|
int facs;
|
|
int pid;
|
|
};
|
|
#endif
|
|
/* ARGSUSED */
|
|
int
|
|
sys_ktrace(struct thread *td, struct ktrace_args *uap)
|
|
{
|
|
#ifdef KTRACE
|
|
struct vnode *vp = NULL;
|
|
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 flags, error = 0;
|
|
struct nameidata nd;
|
|
struct ktr_io_params *kiop, *old_kiop;
|
|
|
|
/*
|
|
* Need something to (un)trace.
|
|
*/
|
|
if (ops != KTROP_CLEARFILE && facs == 0)
|
|
return (EINVAL);
|
|
|
|
kiop = NULL;
|
|
if (ops != KTROP_CLEAR) {
|
|
/*
|
|
* an operation which requires a file argument.
|
|
*/
|
|
NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->fname);
|
|
flags = FREAD | FWRITE | O_NOFOLLOW;
|
|
error = vn_open(&nd, &flags, 0, NULL);
|
|
if (error)
|
|
return (error);
|
|
NDFREE_PNBUF(&nd);
|
|
vp = nd.ni_vp;
|
|
VOP_UNLOCK(vp);
|
|
if (vp->v_type != VREG) {
|
|
(void)vn_close(vp, FREAD|FWRITE, td->td_ucred, td);
|
|
return (EACCES);
|
|
}
|
|
kiop = ktr_io_params_alloc(td, vp);
|
|
}
|
|
|
|
/*
|
|
* Clear all uses of the tracefile.
|
|
*/
|
|
ktrace_enter(td);
|
|
if (ops == KTROP_CLEARFILE) {
|
|
restart:
|
|
sx_slock(&allproc_lock);
|
|
FOREACH_PROC_IN_SYSTEM(p) {
|
|
old_kiop = NULL;
|
|
PROC_LOCK(p);
|
|
if (p->p_ktrioparms != NULL &&
|
|
p->p_ktrioparms->vp == vp) {
|
|
if (ktrcanset(td, p)) {
|
|
mtx_lock(&ktrace_mtx);
|
|
old_kiop = ktr_freeproc(p);
|
|
mtx_unlock(&ktrace_mtx);
|
|
} else
|
|
error = EPERM;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
if (old_kiop != NULL) {
|
|
sx_sunlock(&allproc_lock);
|
|
ktr_io_params_free(old_kiop);
|
|
goto restart;
|
|
}
|
|
}
|
|
sx_sunlock(&allproc_lock);
|
|
goto done;
|
|
}
|
|
/*
|
|
* do it
|
|
*/
|
|
sx_slock(&proctree_lock);
|
|
if (uap->pid < 0) {
|
|
/*
|
|
* by process group
|
|
*/
|
|
pg = pgfind(-uap->pid);
|
|
if (pg == NULL) {
|
|
sx_sunlock(&proctree_lock);
|
|
error = ESRCH;
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* ktrops() may call vrele(). Lock pg_members
|
|
* by the proctree_lock rather than pg_mtx.
|
|
*/
|
|
PGRP_UNLOCK(pg);
|
|
if (LIST_EMPTY(&pg->pg_members)) {
|
|
sx_sunlock(&proctree_lock);
|
|
error = ESRCH;
|
|
goto done;
|
|
}
|
|
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
|
|
PROC_LOCK(p);
|
|
if (descend)
|
|
ret |= ktrsetchildren(td, p, ops, facs, kiop);
|
|
else
|
|
ret |= ktrops(td, p, ops, facs, kiop);
|
|
}
|
|
} else {
|
|
/*
|
|
* by pid
|
|
*/
|
|
p = pfind(uap->pid);
|
|
if (p == NULL) {
|
|
error = ESRCH;
|
|
sx_sunlock(&proctree_lock);
|
|
goto done;
|
|
}
|
|
if (descend)
|
|
ret |= ktrsetchildren(td, p, ops, facs, kiop);
|
|
else
|
|
ret |= ktrops(td, p, ops, facs, kiop);
|
|
}
|
|
sx_sunlock(&proctree_lock);
|
|
if (!ret)
|
|
error = EPERM;
|
|
done:
|
|
if (kiop != NULL) {
|
|
mtx_lock(&ktrace_mtx);
|
|
kiop = ktr_io_params_rele(kiop);
|
|
mtx_unlock(&ktrace_mtx);
|
|
ktr_io_params_free(kiop);
|
|
}
|
|
ktrace_exit(td);
|
|
return (error);
|
|
#else /* !KTRACE */
|
|
return (ENOSYS);
|
|
#endif /* KTRACE */
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
int
|
|
sys_utrace(struct thread *td, struct utrace_args *uap)
|
|
{
|
|
|
|
#ifdef KTRACE
|
|
struct ktr_request *req;
|
|
void *cp;
|
|
int error;
|
|
|
|
if (!KTRPOINT(td, KTR_USER))
|
|
return (0);
|
|
if (uap->len > KTR_USER_MAXLEN)
|
|
return (EINVAL);
|
|
cp = malloc(uap->len, M_KTRACE, M_WAITOK);
|
|
error = copyin(uap->addr, cp, uap->len);
|
|
if (error) {
|
|
free(cp, M_KTRACE);
|
|
return (error);
|
|
}
|
|
req = ktr_getrequest(KTR_USER);
|
|
if (req == NULL) {
|
|
free(cp, M_KTRACE);
|
|
return (ENOMEM);
|
|
}
|
|
req->ktr_buffer = cp;
|
|
req->ktr_header.ktr_len = uap->len;
|
|
ktr_submitrequest(td, req);
|
|
return (0);
|
|
#else /* !KTRACE */
|
|
return (ENOSYS);
|
|
#endif /* KTRACE */
|
|
}
|
|
|
|
#ifdef KTRACE
|
|
static int
|
|
ktrops(struct thread *td, struct proc *p, int ops, int facs,
|
|
struct ktr_io_params *new_kiop)
|
|
{
|
|
struct ktr_io_params *old_kiop;
|
|
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
if (!ktrcanset(td, p)) {
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
if ((ops == KTROP_SET && p->p_state == PRS_NEW) ||
|
|
p_cansee(td, p) != 0) {
|
|
/*
|
|
* Disallow setting trace points if the process is being born.
|
|
* This avoids races with trace point inheritance in
|
|
* ktrprocfork().
|
|
*/
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
if ((p->p_flag & P_WEXIT) != 0) {
|
|
/*
|
|
* There's nothing to do if the process is exiting, but avoid
|
|
* signaling an error.
|
|
*/
|
|
PROC_UNLOCK(p);
|
|
return (1);
|
|
}
|
|
old_kiop = NULL;
|
|
mtx_lock(&ktrace_mtx);
|
|
if (ops == KTROP_SET) {
|
|
if (p->p_ktrioparms != NULL &&
|
|
p->p_ktrioparms->vp != new_kiop->vp) {
|
|
/* if trace file already in use, relinquish below */
|
|
old_kiop = ktr_io_params_rele(p->p_ktrioparms);
|
|
p->p_ktrioparms = NULL;
|
|
}
|
|
if (p->p_ktrioparms == NULL) {
|
|
p->p_ktrioparms = new_kiop;
|
|
ktr_io_params_ref(new_kiop);
|
|
}
|
|
p->p_traceflag |= facs;
|
|
if (priv_check(td, PRIV_KTRACE) == 0)
|
|
p->p_traceflag |= KTRFAC_ROOT;
|
|
} else {
|
|
/* KTROP_CLEAR */
|
|
if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0)
|
|
/* no more tracing */
|
|
old_kiop = ktr_freeproc(p);
|
|
}
|
|
mtx_unlock(&ktrace_mtx);
|
|
if ((p->p_traceflag & KTRFAC_MASK) != 0)
|
|
ktrprocctor_entered(td, p);
|
|
PROC_UNLOCK(p);
|
|
ktr_io_params_free(old_kiop);
|
|
|
|
return (1);
|
|
}
|
|
|
|
static int
|
|
ktrsetchildren(struct thread *td, struct proc *top, int ops, int facs,
|
|
struct ktr_io_params *new_kiop)
|
|
{
|
|
struct proc *p;
|
|
int ret = 0;
|
|
|
|
p = top;
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
sx_assert(&proctree_lock, SX_LOCKED);
|
|
for (;;) {
|
|
ret |= ktrops(td, p, ops, facs, new_kiop);
|
|
/*
|
|
* 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;
|
|
}
|
|
PROC_LOCK(p);
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
static void
|
|
ktr_writerequest(struct thread *td, struct ktr_request *req)
|
|
{
|
|
struct ktr_io_params *kiop, *kiop1;
|
|
struct ktr_header *kth;
|
|
struct vnode *vp;
|
|
struct proc *p;
|
|
struct ucred *cred;
|
|
struct uio auio;
|
|
struct iovec aiov[3];
|
|
struct mount *mp;
|
|
off_t lim;
|
|
int datalen, buflen;
|
|
int error;
|
|
|
|
p = td->td_proc;
|
|
|
|
/*
|
|
* We reference the kiop for use in I/O in case ktrace is
|
|
* disabled on the process as we write out the request.
|
|
*/
|
|
mtx_lock(&ktrace_mtx);
|
|
kiop = p->p_ktrioparms;
|
|
|
|
/*
|
|
* If kiop is NULL, it has been cleared out from under this
|
|
* request, so just drop it.
|
|
*/
|
|
if (kiop == NULL) {
|
|
mtx_unlock(&ktrace_mtx);
|
|
return;
|
|
}
|
|
|
|
ktr_io_params_ref(kiop);
|
|
vp = kiop->vp;
|
|
cred = kiop->cr;
|
|
lim = kiop->lim;
|
|
|
|
KASSERT(cred != NULL, ("ktr_writerequest: cred == NULL"));
|
|
mtx_unlock(&ktrace_mtx);
|
|
|
|
kth = &req->ktr_header;
|
|
KASSERT(((u_short)kth->ktr_type & ~KTR_TYPE) < nitems(data_lengths),
|
|
("data_lengths array overflow"));
|
|
datalen = data_lengths[(u_short)kth->ktr_type & ~KTR_TYPE];
|
|
buflen = kth->ktr_len;
|
|
auio.uio_iov = &aiov[0];
|
|
auio.uio_offset = 0;
|
|
auio.uio_segflg = UIO_SYSSPACE;
|
|
auio.uio_rw = UIO_WRITE;
|
|
aiov[0].iov_base = (caddr_t)kth;
|
|
aiov[0].iov_len = sizeof(struct ktr_header);
|
|
auio.uio_resid = sizeof(struct ktr_header);
|
|
auio.uio_iovcnt = 1;
|
|
auio.uio_td = td;
|
|
if (datalen != 0) {
|
|
aiov[1].iov_base = (caddr_t)&req->ktr_data;
|
|
aiov[1].iov_len = datalen;
|
|
auio.uio_resid += datalen;
|
|
auio.uio_iovcnt++;
|
|
kth->ktr_len += datalen;
|
|
}
|
|
if (buflen != 0) {
|
|
KASSERT(req->ktr_buffer != NULL, ("ktrace: nothing to write"));
|
|
aiov[auio.uio_iovcnt].iov_base = req->ktr_buffer;
|
|
aiov[auio.uio_iovcnt].iov_len = buflen;
|
|
auio.uio_resid += buflen;
|
|
auio.uio_iovcnt++;
|
|
}
|
|
|
|
vn_start_write(vp, &mp, V_WAIT);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
|
|
td->td_ktr_io_lim = lim;
|
|
#ifdef MAC
|
|
error = mac_vnode_check_write(cred, NOCRED, vp);
|
|
if (error == 0)
|
|
#endif
|
|
error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, cred);
|
|
VOP_UNLOCK(vp);
|
|
vn_finished_write(mp);
|
|
if (error == 0) {
|
|
mtx_lock(&ktrace_mtx);
|
|
kiop = ktr_io_params_rele(kiop);
|
|
mtx_unlock(&ktrace_mtx);
|
|
ktr_io_params_free(kiop);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If error encountered, give up tracing on this vnode on this
|
|
* process. Other processes might still be suitable for
|
|
* writes to this vnode.
|
|
*/
|
|
log(LOG_NOTICE,
|
|
"ktrace write failed, errno %d, tracing stopped for pid %d\n",
|
|
error, p->p_pid);
|
|
|
|
kiop1 = NULL;
|
|
PROC_LOCK(p);
|
|
mtx_lock(&ktrace_mtx);
|
|
if (p->p_ktrioparms != NULL && p->p_ktrioparms->vp == vp)
|
|
kiop1 = ktr_freeproc(p);
|
|
kiop = ktr_io_params_rele(kiop);
|
|
mtx_unlock(&ktrace_mtx);
|
|
PROC_UNLOCK(p);
|
|
ktr_io_params_free(kiop1);
|
|
ktr_io_params_free(kiop);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int
|
|
ktrcanset(struct thread *td, struct proc *targetp)
|
|
{
|
|
|
|
PROC_LOCK_ASSERT(targetp, MA_OWNED);
|
|
if (targetp->p_traceflag & KTRFAC_ROOT &&
|
|
priv_check(td, PRIV_KTRACE))
|
|
return (0);
|
|
|
|
if (p_candebug(td, targetp) != 0)
|
|
return (0);
|
|
|
|
return (1);
|
|
}
|
|
|
|
#endif /* KTRACE */
|