aboutsummaryrefslogtreecommitdiff
path: root/sys/kern/sys_process.c
blob: 350433cb910ce84c6ea7adb1576f1e1130eba69e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
/*
 * 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
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by 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 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 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)
 * 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.
 *
 *	$Id: sys_process.c,v 1.12 1995/03/16 18:12:42 bde Exp $
 */

#include <sys/param.h>
#include <sys/systm.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 <sys/user.h>

static 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 ((caddr_t)kva + page_offset,
			       retval, sizeof *retval);
		}
		vm_map_remove (kernel_map, kva, kva + PAGE_SIZE);
	}

	return rv;
}

static 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...
	 */

	vm_map_pageable(map, trunc_page(vtopte(pageno)),
		trunc_page(vtopte(pageno)) + PAGE_SIZE, FALSE);
	rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE);
	vm_map_pageable(map, trunc_page(vtopte(pageno)),
		trunc_page(vtopte(pageno)) + PAGE_SIZE, TRUE);
	if (rv != KERN_SUCCESS)
		return EFAULT;

	/* 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, (caddr_t)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.
 */
struct ptrace_args {
	int	req;
	pid_t	pid;
	caddr_t	addr;
	int	data;
};

int
ptrace(curp, uap, retval)
	struct proc *curp;
	struct ptrace_args *uap;
	int *retval;
{
	struct proc *p;
	int 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
	/*
	 * 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.)
	 */

	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, (u_int)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:
		p->p_addr->u_kproc.kp_proc = *p;
		fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
		return ptrace_write_u(p, (vm_offset_t)uap->addr, uap->data);
	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(p)
	struct proc *p;
{
	return 1;
}