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freebsd/sys/fs/procfs/procfs_dbregs.c
Dag-Erling Smørgrav 66cd74a611 Don't reset uio_offset to 0 before returning. Instead, refuse to service
requests where uio_offset is not 0 to begin with.  This fixes a long-
standing bug where e.g. 'cat /proc/$$/regs' would loop forever.

MFC after:	3 weeks
2007-04-15 13:24:03 +00:00

136 lines
4.0 KiB
C

/*-
* Copyright (c) 1999 Brian Scott Dean, brdean@unx.sas.com.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry under the following copyrights and conditions:
*
* Copyright (c) 1993 Jan-Simon Pendry
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* From: @(#)procfs_regs.c 8.4 (Berkeley) 6/15/94
*
* From:
* $Id: procfs_regs.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
* $FreeBSD$
*/
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/ptrace.h>
#include <sys/uio.h>
#include <machine/reg.h>
#include <fs/pseudofs/pseudofs.h>
#include <fs/procfs/procfs.h>
#ifdef COMPAT_IA32
#include <sys/procfs.h>
#include <machine/fpu.h>
#include <compat/ia32/ia32_reg.h>
extern struct sysentvec ia32_freebsd_sysvec;
/*
* PROC(write, dbregs, td2, &r) becomes
* proc_write_dbregs(td2, &r) or
* proc_write_dbregs32(td2, &r32)
*
* UIOMOVE_FROMBUF(r, uio) becomes
* uiomove_frombuf(&r, sizeof(r), uio) or
* uiomove_frombuf(&r32, sizeof(r32), uio)
*/
#define PROC(d, w, t, r) wrap32 ? \
proc_ ## d ## _ ## w ## 32(t, r ## 32) : \
proc_ ## d ## _ ## w(t, r)
#define UIOMOVE_FROMBUF(k, u) wrap32 ? \
uiomove_frombuf(& k ## 32, sizeof(k ## 32), u) : \
uiomove_frombuf(& k, sizeof(k), u)
#else
#define PROC(d, w, t, r) proc_ ## d ## _ ## w(t, r)
#define UIOMOVE_FROMBUF(k, u) uiomove_frombuf(& k, sizeof(k), u)
#endif
int
procfs_doprocdbregs(PFS_FILL_ARGS)
{
int error;
struct dbreg r;
struct thread *td2;
#ifdef COMPAT_IA32
struct dbreg32 r32;
int wrap32 = 0;
#endif
if (uio->uio_offset != 0)
return (0);
PROC_LOCK(p);
KASSERT(p->p_lock > 0, ("proc not held"));
if (p_candebug(td, p) != 0) {
PROC_UNLOCK(p);
return (EPERM);
}
/* XXXKSE: */
td2 = FIRST_THREAD_IN_PROC(p);
#ifdef COMPAT_IA32
if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) {
if (td2->td_proc->p_sysent != &ia32_freebsd_sysvec) {
PROC_UNLOCK(p);
return (EINVAL);
}
wrap32 = 1;
}
#endif
error = PROC(read, dbregs, td2, &r);
if (error == 0) {
PROC_UNLOCK(p);
error = UIOMOVE_FROMBUF(r, uio);
PROC_LOCK(p);
}
if (error == 0 && uio->uio_rw == UIO_WRITE) {
if (!P_SHOULDSTOP(p)) /* XXXKSE should be P_TRACED? */
error = EBUSY;
else
/* XXXKSE: */
error = PROC(write, dbregs, td2, &r);
}
PROC_UNLOCK(p);
return (error);
}