d584ed9598
original system call number, which can be negative for a Mach trap. We cannot just replace code by realcode, because ktrsyscall uses it as an index in the system call table, thus crashing the kernel when the value is negative.
702 lines
16 KiB
C
702 lines
16 KiB
C
/* $NetBSD: kern_ktrace.c,v 1.61 2002/11/15 20:06:04 manu Exp $ */
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/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. 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 8.5 (Berkeley) 5/14/95
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: kern_ktrace.c,v 1.61 2002/11/15 20:06:04 manu Exp $");
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#include "opt_ktrace.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/file.h>
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#include <sys/namei.h>
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#include <sys/vnode.h>
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#include <sys/ktrace.h>
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#include <sys/malloc.h>
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#include <sys/syslog.h>
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#include <sys/filedesc.h>
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#include <sys/ioctl.h>
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#include <sys/mount.h>
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#include <sys/syscallargs.h>
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#ifdef KTRACE
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int ktrace_common(struct proc *, int, int, int, struct file *);
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void ktrinitheader(struct ktr_header *, struct proc *, int);
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int ktrops(struct proc *, struct proc *, int, int, struct file *);
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int ktrsetchildren(struct proc *, struct proc *, int, int,
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struct file *);
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int ktrwrite(struct proc *, struct ktr_header *);
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int ktrcanset(struct proc *, struct proc *);
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int ktrsamefile(struct file *, struct file *);
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/*
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* "deep" compare of two files for the purposes of clearing a trace.
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* Returns true if they're the same open file, or if they point at the
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* same underlying vnode/socket.
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*/
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int
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ktrsamefile(struct file *f1, struct file *f2)
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{
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return ((f1 == f2) ||
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((f1 != NULL) && (f2 != NULL) &&
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(f1->f_type == f2->f_type) &&
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(f1->f_data == f2->f_data)));
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}
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void
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ktrderef(struct proc *p)
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{
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struct file *fp = p->p_tracep;
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p->p_traceflag = 0;
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if (fp == NULL)
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return;
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FILE_USE(fp);
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/*
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* ktrace file descriptor can't be watched (are not visible to
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* userspace), so no kqueue stuff here
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*/
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closef(fp, NULL);
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p->p_tracep = NULL;
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}
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void
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ktradref(struct proc *p)
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{
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struct file *fp = p->p_tracep;
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fp->f_count++;
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}
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void
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ktrinitheader(struct ktr_header *kth, struct proc *p, int type)
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{
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memset(kth, 0, sizeof(*kth));
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kth->ktr_type = type;
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microtime(&kth->ktr_time);
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kth->ktr_pid = p->p_pid;
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memcpy(kth->ktr_comm, p->p_comm, MAXCOMLEN);
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}
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void
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ktrsyscall(struct proc *p, register_t code,
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register_t realcode, register_t args[])
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{
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struct ktr_header kth;
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struct ktr_syscall *ktp;
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register_t *argp;
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int argsize;
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size_t len;
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u_int i;
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argsize = p->p_emul->e_sysent[code].sy_narg * sizeof (register_t);
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len = sizeof(struct ktr_syscall) + argsize;
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p->p_traceflag |= KTRFAC_ACTIVE;
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ktrinitheader(&kth, p, KTR_SYSCALL);
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ktp = malloc(len, M_TEMP, M_WAITOK);
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ktp->ktr_code = realcode;
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ktp->ktr_argsize = argsize;
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argp = (register_t *)((char *)ktp + sizeof(struct ktr_syscall));
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for (i = 0; i < (argsize / sizeof(*argp)); i++)
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*argp++ = args[i];
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kth.ktr_buf = (caddr_t)ktp;
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kth.ktr_len = len;
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(void) ktrwrite(p, &kth);
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free(ktp, M_TEMP);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktrsysret(struct proc *p, register_t code, int error, register_t retval)
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{
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struct ktr_header kth;
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struct ktr_sysret ktp;
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p->p_traceflag |= KTRFAC_ACTIVE;
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ktrinitheader(&kth, p, KTR_SYSRET);
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ktp.ktr_code = code;
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ktp.ktr_eosys = 0; /* XXX unused */
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ktp.ktr_error = error;
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ktp.ktr_retval = retval; /* what about val2 ? */
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kth.ktr_buf = (caddr_t)&ktp;
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kth.ktr_len = sizeof(struct ktr_sysret);
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(void) ktrwrite(p, &kth);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktrnamei(struct proc *p, char *path)
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{
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struct ktr_header kth;
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p->p_traceflag |= KTRFAC_ACTIVE;
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ktrinitheader(&kth, p, KTR_NAMEI);
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kth.ktr_len = strlen(path);
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kth.ktr_buf = path;
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(void) ktrwrite(p, &kth);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktremul(struct proc *p)
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{
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struct ktr_header kth;
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const char *emul = p->p_emul->e_name;
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p->p_traceflag |= KTRFAC_ACTIVE;
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ktrinitheader(&kth, p, KTR_EMUL);
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kth.ktr_len = strlen(emul);
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kth.ktr_buf = (caddr_t)emul;
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(void) ktrwrite(p, &kth);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktrgenio(struct proc *p, int fd, enum uio_rw rw, struct iovec *iov,
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int len, int error)
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{
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struct ktr_header kth;
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struct ktr_genio *ktp;
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caddr_t cp;
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int resid = len, cnt;
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int buflen;
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if (error)
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return;
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p->p_traceflag |= KTRFAC_ACTIVE;
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buflen = min(PAGE_SIZE, len + sizeof(struct ktr_genio));
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ktrinitheader(&kth, p, KTR_GENIO);
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ktp = malloc(buflen, M_TEMP, M_WAITOK);
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ktp->ktr_fd = fd;
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ktp->ktr_rw = rw;
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kth.ktr_buf = (caddr_t)ktp;
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cp = (caddr_t)((char *)ktp + sizeof(struct ktr_genio));
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buflen -= sizeof(struct ktr_genio);
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while (resid > 0) {
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KDASSERT(p->p_cpu != NULL);
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KDASSERT(p->p_cpu == curcpu());
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if (p->p_cpu->ci_schedstate.spc_flags & SPCF_SHOULDYIELD)
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preempt(NULL);
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cnt = min(iov->iov_len, buflen);
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if (cnt > resid)
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cnt = resid;
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if (copyin(iov->iov_base, cp, cnt))
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break;
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kth.ktr_len = cnt + sizeof(struct ktr_genio);
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if (__predict_false(ktrwrite(p, &kth) != 0))
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break;
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iov->iov_base = (caddr_t)iov->iov_base + cnt;
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iov->iov_len -= cnt;
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if (iov->iov_len == 0)
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iov++;
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resid -= cnt;
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}
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free(ktp, M_TEMP);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktrpsig(struct proc *p, int sig, sig_t action, sigset_t *mask, int code)
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{
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struct ktr_header kth;
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struct ktr_psig kp;
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p->p_traceflag |= KTRFAC_ACTIVE;
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ktrinitheader(&kth, p, KTR_PSIG);
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kp.signo = (char)sig;
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kp.action = action;
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kp.mask = *mask;
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kp.code = code;
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kth.ktr_buf = (caddr_t)&kp;
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kth.ktr_len = sizeof(struct ktr_psig);
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(void) ktrwrite(p, &kth);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktrcsw(struct proc *p, int out, int user)
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{
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struct ktr_header kth;
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struct ktr_csw kc;
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p->p_traceflag |= KTRFAC_ACTIVE;
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ktrinitheader(&kth, p, KTR_CSW);
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kc.out = out;
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kc.user = user;
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kth.ktr_buf = (caddr_t)&kc;
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kth.ktr_len = sizeof(struct ktr_csw);
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(void) ktrwrite(p, &kth);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktruser(p, id, addr, len, ustr)
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struct proc *p;
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const char *id;
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void *addr;
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size_t len;
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int ustr;
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{
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struct ktr_header kth;
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struct ktr_user *ktp;
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caddr_t user_dta;
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p->p_traceflag |= KTRFAC_ACTIVE;
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ktrinitheader(&kth, p, KTR_USER);
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ktp = malloc(sizeof(struct ktr_user) + len, M_TEMP, M_WAITOK);
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if (ustr) {
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if (copyinstr(id, ktp->ktr_id, KTR_USER_MAXIDLEN, NULL) != 0)
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ktp->ktr_id[0] = '\0';
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} else
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strncpy(ktp->ktr_id, id, KTR_USER_MAXIDLEN);
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ktp->ktr_id[KTR_USER_MAXIDLEN-1] = '\0';
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user_dta = (caddr_t) ((char *)ktp + sizeof(struct ktr_user));
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if (copyin(addr, (void *) user_dta, len) != 0)
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len = 0;
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kth.ktr_buf = (void *)ktp;
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kth.ktr_len = sizeof(struct ktr_user) + len;
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(void) ktrwrite(p, &kth);
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free(ktp, M_TEMP);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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/* Interface and common routines */
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int
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ktrace_common(struct proc *curp, int ops, int facs, int pid, struct file *fp)
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{
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int ret = 0;
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int error = 0;
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int one = 1;
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int descend;
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struct proc *p;
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struct pgrp *pg;
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curp->p_traceflag |= KTRFAC_ACTIVE;
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descend = ops & KTRFLAG_DESCEND;
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facs = facs & ~((unsigned) KTRFAC_ROOT);
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/*
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* Clear all uses of the tracefile
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*/
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if (KTROP(ops) == KTROP_CLEARFILE) {
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proclist_lock_read();
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for (p = LIST_FIRST(&allproc); p != NULL;
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p = LIST_NEXT(p, p_list)) {
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if (ktrsamefile(p->p_tracep, fp)) {
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if (ktrcanset(curp, p))
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ktrderef(p);
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else
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error = EPERM;
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}
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}
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proclist_unlock_read();
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goto done;
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}
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/*
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* Mark fp non-blocking, to avoid problems from possible deadlocks.
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*/
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if (fp != NULL) {
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fp->f_flag |= FNONBLOCK;
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(*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&one, curp);
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}
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/*
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* need something to (un)trace (XXX - why is this here?)
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*/
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if (!facs) {
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error = EINVAL;
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goto done;
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}
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/*
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* do it
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*/
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if (pid < 0) {
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/*
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* by process group
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*/
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pg = pgfind(-pid);
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if (pg == NULL) {
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error = ESRCH;
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goto done;
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}
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for (p = LIST_FIRST(&pg->pg_members); p != NULL;
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p = LIST_NEXT(p, p_pglist)) {
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if (descend)
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ret |= ktrsetchildren(curp, p, ops, facs, fp);
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else
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ret |= ktrops(curp, p, ops, facs, fp);
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}
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} else {
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/*
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* by pid
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*/
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p = pfind(pid);
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if (p == NULL) {
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error = ESRCH;
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goto done;
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}
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if (descend)
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ret |= ktrsetchildren(curp, p, ops, facs, fp);
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else
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ret |= ktrops(curp, p, ops, facs, fp);
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}
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if (!ret)
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error = EPERM;
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done:
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curp->p_traceflag &= ~KTRFAC_ACTIVE;
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return (error);
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}
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/*
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* ktrace system call
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*/
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/* ARGSUSED */
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int
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sys_fktrace(struct proc *curp, void *v, register_t *retval)
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{
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struct sys_fktrace_args /* {
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syscallarg(int) fd;
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syscallarg(int) ops;
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syscallarg(int) facs;
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syscallarg(int) pid;
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} */ *uap = v;
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struct file *fp = NULL;
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struct filedesc *fdp = curp->p_fd;
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if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL)
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return (EBADF);
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if ((fp->f_flag & FWRITE) == 0)
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return (EBADF);
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return ktrace_common(curp, SCARG(uap, ops),
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SCARG(uap, facs), SCARG(uap, pid), fp);
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}
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/*
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* ktrace system call
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*/
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/* ARGSUSED */
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int
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sys_ktrace(struct proc *curp, void *v, register_t *retval)
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{
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struct sys_ktrace_args /* {
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syscallarg(const char *) fname;
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syscallarg(int) ops;
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syscallarg(int) facs;
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syscallarg(int) pid;
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} */ *uap = v;
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struct vnode *vp = NULL;
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struct file *fp = NULL;
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int fd;
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int ops = SCARG(uap, ops);
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int error = 0;
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struct nameidata nd;
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ops = KTROP(ops) | (ops & KTRFLAG_DESCEND);
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curp->p_traceflag |= KTRFAC_ACTIVE;
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if (ops != KTROP_CLEAR) {
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/*
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* an operation which requires a file argument.
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*/
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NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, fname),
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curp);
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if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) {
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curp->p_traceflag &= ~KTRFAC_ACTIVE;
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return (error);
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}
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vp = nd.ni_vp;
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VOP_UNLOCK(vp, 0);
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if (vp->v_type != VREG) {
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(void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp);
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curp->p_traceflag &= ~KTRFAC_ACTIVE;
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return (EACCES);
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}
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/*
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* XXX This uses up a file descriptor slot in the
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* tracing process for the duration of this syscall.
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* This is not expected to be a problem. If
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* falloc(NULL, ...) DTRT we could skip that part, but
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* that would require changing its interface to allow
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* the caller to pass in a ucred..
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*
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* This will FILE_USE the fp it returns, if any.
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* Keep it in use until we return.
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*/
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if ((error = falloc(curp, &fp, &fd)) != 0)
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goto done;
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fp->f_flag = FWRITE|FAPPEND;
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fp->f_type = DTYPE_VNODE;
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fp->f_ops = &vnops;
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fp->f_data = (caddr_t)vp;
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FILE_SET_MATURE(fp);
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vp = NULL;
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}
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error = ktrace_common(curp, SCARG(uap, ops), SCARG(uap, facs),
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SCARG(uap, pid), fp);
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done:
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if (vp != NULL)
|
|
(void) vn_close(vp, FWRITE, curp->p_ucred, curp);
|
|
if (fp != NULL) {
|
|
FILE_UNUSE(fp, curp); /* release file */
|
|
fdrelease(curp, fd); /* release fd table slot */
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
ktrops(struct proc *curp, struct proc *p, int ops, int facs, struct file *fp)
|
|
{
|
|
|
|
if (!ktrcanset(curp, p))
|
|
return (0);
|
|
if (KTROP(ops) == KTROP_SET) {
|
|
if (p->p_tracep != fp) {
|
|
/*
|
|
* if trace file already in use, relinquish
|
|
*/
|
|
ktrderef(p);
|
|
p->p_tracep = fp;
|
|
ktradref(p);
|
|
}
|
|
p->p_traceflag |= facs;
|
|
if (curp->p_ucred->cr_uid == 0)
|
|
p->p_traceflag |= KTRFAC_ROOT;
|
|
} else {
|
|
/* KTROP_CLEAR */
|
|
if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
|
|
/* no more tracing */
|
|
ktrderef(p);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Emit an emulation record, every time there is a ktrace
|
|
* change/attach request.
|
|
*/
|
|
if (KTRPOINT(p, KTR_EMUL))
|
|
ktremul(p);
|
|
#ifdef __HAVE_SYSCALL_INTERN
|
|
(*p->p_emul->e_syscall_intern)(p);
|
|
#endif
|
|
|
|
return (1);
|
|
}
|
|
|
|
int
|
|
ktrsetchildren(struct proc *curp, struct proc *top, int ops, int facs,
|
|
struct file *fp)
|
|
{
|
|
struct proc *p;
|
|
int ret = 0;
|
|
|
|
p = top;
|
|
for (;;) {
|
|
ret |= ktrops(curp, p, ops, facs, fp);
|
|
/*
|
|
* 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);
|
|
else 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*/
|
|
}
|
|
|
|
int
|
|
ktrwrite(struct proc *p, struct ktr_header *kth)
|
|
{
|
|
struct uio auio;
|
|
struct iovec aiov[2];
|
|
int error, tries;
|
|
struct file *fp = p->p_tracep;
|
|
|
|
if (fp == NULL)
|
|
return 0;
|
|
|
|
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_procp = (struct proc *)0;
|
|
if (kth->ktr_len > 0) {
|
|
auio.uio_iovcnt++;
|
|
aiov[1].iov_base = kth->ktr_buf;
|
|
aiov[1].iov_len = kth->ktr_len;
|
|
auio.uio_resid += kth->ktr_len;
|
|
}
|
|
|
|
FILE_USE(fp);
|
|
|
|
tries = 0;
|
|
do {
|
|
error = (*fp->f_ops->fo_write)(fp, &fp->f_offset, &auio,
|
|
fp->f_cred, FOF_UPDATE_OFFSET);
|
|
tries++;
|
|
if (error == EWOULDBLOCK)
|
|
yield();
|
|
} while ((error == EWOULDBLOCK) && (tries < 3));
|
|
FILE_UNUSE(fp, NULL);
|
|
|
|
if (__predict_true(error == 0))
|
|
return (0);
|
|
/*
|
|
* If error encountered, give up tracing on this vnode. Don't report
|
|
* EPIPE as this can easily happen with fktrace()/ktruss.
|
|
*/
|
|
if (error != EPIPE)
|
|
log(LOG_NOTICE,
|
|
"ktrace write failed, errno %d, tracing stopped\n",
|
|
error);
|
|
proclist_lock_read();
|
|
for (p = LIST_FIRST(&allproc); p != NULL; p = LIST_NEXT(p, p_list)) {
|
|
if (ktrsamefile(p->p_tracep, fp))
|
|
ktrderef(p);
|
|
}
|
|
proclist_unlock_read();
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* 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 proc *callp, struct proc *targetp)
|
|
{
|
|
struct pcred *caller = callp->p_cred;
|
|
struct pcred *target = targetp->p_cred;
|
|
|
|
if ((caller->pc_ucred->cr_uid == target->p_ruid &&
|
|
target->p_ruid == target->p_svuid &&
|
|
caller->p_rgid == target->p_rgid && /* XXX */
|
|
target->p_rgid == target->p_svgid &&
|
|
(targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
|
|
(targetp->p_flag & P_SUGID) == 0) ||
|
|
caller->pc_ucred->cr_uid == 0)
|
|
return (1);
|
|
|
|
return (0);
|
|
}
|
|
#endif /* KTRACE */
|
|
|
|
/*
|
|
* Put user defined entry to ktrace records.
|
|
*/
|
|
int
|
|
sys_utrace(p, v, retval)
|
|
struct proc *p;
|
|
void *v;
|
|
register_t *retval;
|
|
{
|
|
#ifdef KTRACE
|
|
struct sys_utrace_args /* {
|
|
syscallarg(const char *) label;
|
|
syscallarg(void *) addr;
|
|
syscallarg(size_t) len;
|
|
} */ *uap = v;
|
|
|
|
if (!KTRPOINT(p, KTR_USER))
|
|
return (0);
|
|
|
|
if (SCARG(uap, len) > KTR_USER_MAXLEN)
|
|
return (EINVAL);
|
|
|
|
ktruser(p, SCARG(uap, label), SCARG(uap, addr), SCARG(uap, len), 1);
|
|
|
|
return (0);
|
|
#else /* !KTRACE */
|
|
return ENOSYS;
|
|
#endif /* KTRACE */
|
|
}
|