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Process tracing code. Written by Sean Eric Fagan.

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Submitted by:	Sean Eric Fagan
This commit is contained in:
dg 1994-08-08 13:00:27 +00:00
parent 8bdddcb065
commit b3b331ada7
2 changed files with 323 additions and 33 deletions
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351
sys/kern/sys_process.c
View File

@ -1,11 +1,6 @@
/*-
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
/*
* Copyright (c) 1994, Sean Eric Fagan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@ -17,16 +12,14 @@
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* This product includes software developed by Sean Eric Fagan.
* 4. The name of the author may not 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
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR 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)
@ -35,14 +28,163 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93
* $Id$
* $Id$
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ptrace.h>
#include <sys/errno.h>
#include <machine/reg.h>
#include <machine/psl.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#include "user.h"
int
pread (struct proc *procp, unsigned int addr, unsigned int *retval) {
int rv;
vm_map_t map, tmap;
vm_object_t object;
vm_offset_t kva = 0;
int page_offset; /* offset into page */
vm_offset_t pageno; /* page number */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
boolean_t wired, single_use;
vm_offset_t off;
/* Map page into kernel space */
map = &procp->p_vmspace->vm_map;
page_offset = addr - trunc_page(addr);
pageno = trunc_page(addr);
tmap = map;
rv = vm_map_lookup (&tmap, pageno, VM_PROT_READ, &out_entry,
&object, &off, &out_prot, &wired, &single_use);
if (rv != KERN_SUCCESS)
return EINVAL;
vm_map_lookup_done (tmap, out_entry);
/* Find space in kernel_map for the page we're interested in */
rv = vm_map_find (kernel_map, object, off, &kva, PAGE_SIZE, 1);
if (!rv) {
vm_object_reference (object);
rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0);
if (!rv) {
*retval = 0;
bcopy (kva + page_offset, retval, sizeof *retval);
}
vm_map_remove (kernel_map, kva, kva + PAGE_SIZE);
}
return rv;
}
int
pwrite (struct proc *procp, unsigned int addr, unsigned int datum) {
int rv;
vm_map_t map, tmap;
vm_object_t object;
vm_offset_t kva = 0;
int page_offset; /* offset into page */
vm_offset_t pageno; /* page number */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
boolean_t wired, single_use;
vm_offset_t off;
boolean_t fix_prot = 0;
/* Map page into kernel space */
map = &procp->p_vmspace->vm_map;
page_offset = addr - trunc_page(addr);
pageno = trunc_page(addr);
/*
* Check the permissions for the area we're interested in.
*/
if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE,
VM_PROT_WRITE) == FALSE) {
/*
* If the page was not writable, we make it so.
* XXX It is possible a page may *not* be read/executable,
* if a process changes that!
*/
fix_prot = 1;
/* The page isn't writable, so let's try making it so... */
if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE,
VM_PROT_ALL, 0)) != KERN_SUCCESS)
return EFAULT; /* I guess... */
}
/*
* Now we need to get the page. out_entry, out_prot, wired, and
* single_use aren't used. One would think the vm code would be
* a *bit* nicer... We use tmap because vm_map_lookup() can
* change the map argument.
*/
tmap = map;
rv = vm_map_lookup (&tmap, pageno, VM_PROT_WRITE, &out_entry,
&object, &off, &out_prot, &wired, &single_use);
if (rv != KERN_SUCCESS) {
return EINVAL;
}
/*
* Okay, we've got the page. Let's release tmap.
*/
vm_map_lookup_done (tmap, out_entry);
/*
* Fault the page in...
*/
rv = vm_fault (map, pageno, VM_PROT_WRITE, FALSE);
if (rv != KERN_SUCCESS)
return EFAULT;
/*
* The page may need to be faulted in again, it seems.
* This covers COW pages, I believe.
*/
if (!rv)
rv = vm_fault (map, pageno, VM_PROT_WRITE, 0);
/* Find space in kernel_map for the page we're interested in */
rv = vm_map_find (kernel_map, object, off, &kva, PAGE_SIZE, 1);
if (!rv) {
vm_object_reference (object);
rv = vm_map_pageable (kernel_map, kva, kva + PAGE_SIZE, 0);
if (!rv) {
bcopy (&datum, kva + page_offset, sizeof datum);
}
vm_map_remove (kernel_map, kva, kva + PAGE_SIZE);
}
if (fix_prot)
vm_map_protect (map, pageno, pageno + PAGE_SIZE,
VM_PROT_READ|VM_PROT_EXECUTE, 0);
return rv;
}
/*
* Process debugging system call.
*/
@ -52,26 +194,171 @@ struct ptrace_args {
caddr_t addr;
int data;
};
int
ptrace(a1, a2, a3)
struct proc *a1;
struct ptrace_args *a2;
int *a3;
{
int
ptrace(curp, uap, retval)
struct proc *curp;
struct ptrace_args *uap;
int *retval;
{
struct proc *p;
int s, error = 0;
*retval = 0;
if (uap->req == PT_TRACE_ME) {
curp->p_flag |= P_TRACED;
return 0;
}
if ((p = pfind(uap->pid)) == NULL) {
return ESRCH;
}
#ifdef PT_ATTACH
if (uap->req != PT_ATTACH && (
(p->p_flag & P_TRACED) == 0 ||
(p->p_tptr && curp != p->p_tptr) ||
(!p->p_tptr && curp != p->p_pptr)))
return ESRCH;
#endif
#ifdef PT_ATTACH
if (uap->req != PT_ATTACH) {
#endif
if ((p->p_flag & P_TRACED) == 0)
return EPERM;
if (p->p_stat != SSTOP || (p->p_flag & P_WAITED) == 0)
return EBUSY;
#ifdef PT_ATTACH
}
#endif
/*
* Body deleted.
* XXX The PT_ATTACH code is completely broken. It will
* be obsoleted by a /proc filesystem, so is it worth it
* to fix it? (Answer, probably. So that'll be next,
* I guess.)
*/
return (ENOSYS);
switch (uap->req) {
#ifdef PT_ATTACH
case PT_ATTACH:
if (curp->p_ucred->cr_uid != 0 && (
curp->p_ucred->cr_uid != p->p_ucred->cr_uid ||
curp->p_ucred->cr_uid != p->p_cred->p_svuid))
return EACCES;
p->p_tptr = curp;
p->p_flag |= P_TRACED;
psignal(p, SIGSTOP);
return 0;
case PT_DETACH:
if ((unsigned)uap->data >= NSIG)
return EINVAL;
p->p_flag &= ~P_TRACED;
p->p_tptr = NULL;
psignal(p->p_pptr, SIGCHLD);
wakeup((caddr_t)p->p_pptr);
s = splhigh();
if (p->p_stat == SSTOP) {
p->p_xstat = uap->data;
setrunnable(p);
} else if (uap->data) {
psignal(p, uap->data);
}
splx(s);
return 0;
# ifdef PT_INHERIT
case PT_INHERIT:
if ((p->p_flag & P_TRACED) == 0)
return ESRCH;
return 0;
# endif /* PT_INHERIT */
#endif /* PT_ATTACH */
case PT_READ_I:
case PT_READ_D:
if (error = pread (p, (unsigned int)uap->addr, retval))
return error;
return 0;
case PT_WRITE_I:
case PT_WRITE_D:
if (error = pwrite (p, (unsigned int)uap->addr,
(unsigned int)uap->data))
return error;
return 0;
case PT_STEP:
if (error = ptrace_single_step (p))
return error;
/* fallthrough */
case PT_CONTINUE:
/*
* Continue at addr uap->addr with signal
* uap->data; if uap->addr is 1, then we just
* let the chips fall where they may.
*
* The only check I'll make right now is for
* uap->data to be larger than NSIG; if so, we return
* EINVAL.
*/
if (uap->data >= NSIG)
return EINVAL;
if (uap->addr != (caddr_t)1) {
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
if (error = ptrace_set_pc (p, uap->addr))
return error;
}
p->p_xstat = uap->data;
/* if (p->p_stat == SSTOP) */
setrunnable (p);
return 0;
case PT_READ_U:
if ((u_int)uap->addr > (UPAGES * NBPG - sizeof(int))) {
return EFAULT;
}
p->p_addr->u_kproc.kp_proc = *p;
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
*retval = *(int*)((u_int)p->p_addr + (u_int)uap->addr);
return 0;
case PT_WRITE_U:
if ((u_int)uap->addr > (UPAGES * NBPG - sizeof(int))) {
return EFAULT;
}
p->p_addr->u_kproc.kp_proc = *p;
fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
*(int*)((u_int)p->p_addr + (u_int)uap->addr) = uap->data;
return 0;
case PT_KILL:
p->p_xstat = SIGKILL;
setrunnable(p);
return 0;
#ifdef PT_GETREGS
case PT_GETREGS:
/*
* copyout the registers into addr. There's no
* size constraint!!! *GRRR*
*/
return ptrace_getregs(p, uap->addr);
case PT_SETREGS:
/*
* copyin the registers from addr. Again, no
* size constraint!!! *GRRRR*
*/
return ptrace_setregs (p, uap->addr);
#endif /* PT_GETREGS */
default:
break;
}
return 0;
}
int
trace_req(a1)
struct proc *a1;
trace_req(p)
struct proc *p;
{
/*
* Body deleted.
*/
return (0);
return 1;
}

5
sys/sys/ptrace.h
View File

@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)ptrace.h 8.2 (Berkeley) 1/4/94
* $Id$
* $Id: ptrace.h,v 1.2 1994/08/02 07:53:24 davidg Exp $
*/
#ifndef _SYS_PTRACE_H_
@ -47,8 +47,11 @@
#define PT_CONTINUE 7 /* continue the child */
#define PT_KILL 8 /* kill the child process */
#define PT_STEP 9 /* single step the child */
#ifdef notdef
#define PT_ATTACH 10 /* trace some running process */
#define PT_DETACH 11 /* stop tracing a process */
#endif
#define PT_FIRSTMACH 32 /* for machine-specific requests */
#include <machine/ptrace.h> /* machine-specific requests, if any */