1/* $NetBSD: kern_scdebug.c,v 1.2 2019/03/14 19:51:49 palle Exp $ */
2
3/*
4 * Copyright (c) 2015 Matthew R. Green
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29/*
30 * Copyright (c) 1982, 1986, 1989, 1993
31 * The Regents of the University of California. All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. Neither the name of the University nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55 * SUCH DAMAGE.
56 *
57 * @(#)kern_xxx.c 8.3 (Berkeley) 2/14/95
58 * from: NetBSD: kern_xxx.c,v 1.74 2017/10/28 00:37:11 pgoyette Exp
59 */
60
61#include <sys/cdefs.h>
62__KERNEL_RCSID(0, "$NetBSD: kern_scdebug.c,v 1.2 2019/03/14 19:51:49 palle Exp $");
63
64#ifdef _KERNEL_OPT
65#include "opt_syscall_debug.h"
66#include "opt_kernhist.h"
67#endif
68
69#include <sys/param.h>
70#include <sys/systm.h>
71#include <sys/kernel.h>
72#include <sys/proc.h>
73#include <sys/sysctl.h>
74#include <sys/mount.h>
75#include <sys/syscall.h>
76#include <sys/syscallargs.h>
77#include <sys/kernhist.h>
78
79/*
80 * Pull in the indirect syscall functions here.
81 * They are only actually used if the ports syscall entry code
82 * doesn't special-case SYS_SYSCALL and SYS___SYSCALL
83 *
84 * In some cases the generated code for the two functions is identical,
85 * but there isn't a MI way of determining that - so we don't try.
86 */
87
88#define SYS_SYSCALL sys_syscall
89#include "sys_syscall.c"
90#undef SYS_SYSCALL
91
92#define SYS_SYSCALL sys___syscall
93#include "sys_syscall.c"
94#undef SYS_SYSCALL
95
96#ifdef SYSCALL_DEBUG
97#define SCDEBUG_CALLS 0x0001 /* show calls */
98#define SCDEBUG_RETURNS 0x0002 /* show returns */
99#define SCDEBUG_ALL 0x0004 /* even syscalls that are not implemented */
100#define SCDEBUG_SHOWARGS 0x0008 /* show arguments to calls */
101#define SCDEBUG_KERNHIST 0x0010 /* use kernhist instead of printf */
102
103#ifndef SCDEBUG_DEFAULT
104#define SCDEBUG_DEFAULT (SCDEBUG_CALLS|SCDEBUG_RETURNS|SCDEBUG_SHOWARGS)
105#endif
106
107int scdebug = SCDEBUG_DEFAULT;
108
109#ifdef KERNHIST
110KERNHIST_DEFINE(scdebughist);
111#define SCDEBUG_KERNHIST_FUNC(a) KERNHIST_FUNC(a)
112#define SCDEBUG_KERNHIST_CALLED(a) KERNHIST_CALLED(a)
113#define SCDEBUG_KERNHIST_LOG(a,b,c,d,e,f) KERNHIST_LOG(a,b,c,d,e,f)
114#else
115#define SCDEBUG_KERNHIST_FUNC(a) {} /* nothing */
116#define SCDEBUG_KERNHIST_CALLED(a) {} /* nothing */
117#define SCDEBUG_KERNHIST_LOG(a,b,c,d,e,f) {} /* nothing */
118/* The non-kernhist support version can elide all this code easily. */
119#undef SCDEBUG_KERNHIST
120#define SCDEBUG_KERNHIST 0
121#endif
122
123#ifdef __HAVE_MINIMAL_EMUL
124#define CODE_NOT_OK(code, em) ((int)(code) < 0)
125#else
126#define CODE_NOT_OK(code, em) (((int)(code) < 0) || \
127 ((int)(code) >= (em)->e_nsysent))
128#endif
129
130void
131scdebug_call(register_t code, const register_t args[])
132{
133 SCDEBUG_KERNHIST_FUNC("scdebug_call");
134 struct lwp *l = curlwp;
135 struct proc *p = l->l_proc;
136 const struct sysent *sy;
137 const struct emul *em;
138 int i;
139
140 if ((scdebug & SCDEBUG_CALLS) == 0)
141 return;
142
143 if (scdebug & SCDEBUG_KERNHIST)
144 SCDEBUG_KERNHIST_CALLED(scdebughist);
145
146 em = p->p_emul;
147 sy = &em->e_sysent[code];
148
149 if ((scdebug & SCDEBUG_ALL) == 0 &&
150 (CODE_NOT_OK(code, em) || sy->sy_call == sys_nosys)) {
151 if (scdebug & SCDEBUG_KERNHIST)
152 SCDEBUG_KERNHIST_LOG(scdebughist, "", 0, 0, 0, 0);
153 return;
154 }
155
156 /*
157 * The kernhist version of scdebug needs to restrict the usage
158 * compared to the normal version. histories must avoid these
159 * sorts of usage:
160 *
161 * - the format string *must* be literal, as it is used
162 * at display time in the kernel or userland
163 * - strings in the format will cause vmstat -u to crash
164 * so avoid using %s formats
165 *
166 * to avoid these, we have a fairly long block to print args
167 * as the format needs to change for each, and we can't just
168 * call printf() on each argument until we're done.
169 */
170 if (scdebug & SCDEBUG_KERNHIST) {
171 if (CODE_NOT_OK(code, em)) {
172 SCDEBUG_KERNHIST_LOG(scdebughist,
173 "pid %jd:%jd: OUT OF RANGE (%jd)",
174 p->p_pid, l->l_lid, code, 0);
175 } else {
176 SCDEBUG_KERNHIST_LOG(scdebughist,
177 "pid %jd:%jd: num %jd call %#jx",
178 p->p_pid, l->l_lid, code, (uintptr_t)sy->sy_call);
179 if ((scdebug & SCDEBUG_SHOWARGS) == 0)
180 return;
181
182 if (sy->sy_narg > 7) {
183 SCDEBUG_KERNHIST_LOG(scdebughist,
184 "args[4-7]: (%jx, %jx, %jx, %jx, ...)",
185 (long)args[4], (long)args[5],
186 (long)args[6], (long)args[7]);
187 } else if (sy->sy_narg > 6) {
188 SCDEBUG_KERNHIST_LOG(scdebughist,
189 "args[4-6]: (%jx, %jx, %jx)",
190 (long)args[4], (long)args[5],
191 (long)args[6], 0);
192 } else if (sy->sy_narg > 5) {
193 SCDEBUG_KERNHIST_LOG(scdebughist,
194 "args[4-5]: (%jx, %jx)",
195 (long)args[4], (long)args[5], 0, 0);
196 } else if (sy->sy_narg == 5) {
197 SCDEBUG_KERNHIST_LOG(scdebughist,
198 "args[4]: (%jx)",
199 (long)args[4], 0, 0, 0);
200 }
201
202 if (sy->sy_narg > 3) {
203 SCDEBUG_KERNHIST_LOG(scdebughist,
204 "args[0-3]: (%jx, %jx, %jx, %jx, ...)",
205 (long)args[0], (long)args[1],
206 (long)args[2], (long)args[3]);
207 } else if (sy->sy_narg > 2) {
208 SCDEBUG_KERNHIST_LOG(scdebughist,
209 "args[0-2]: (%jx, %jx, %jx)",
210 (long)args[0], (long)args[1],
211 (long)args[2], 0);
212 } else if (sy->sy_narg > 1) {
213 SCDEBUG_KERNHIST_LOG(scdebughist,
214 "args[0-1]: (%jx, %jx)",
215 (long)args[0], (long)args[1], 0, 0);
216 } else if (sy->sy_narg == 1) {
217 SCDEBUG_KERNHIST_LOG(scdebughist,
218 "args[0]: (%jx)",
219 (long)args[0], 0, 0, 0);
220 }
221 }
222 return;
223 }
224
225 printf("proc %d (%s): %s num ", p->p_pid, p->p_comm, em->e_name);
226 if (CODE_NOT_OK(code, em))
227 printf("OUT OF RANGE (%ld)", (long)code);
228 else {
229 printf("%ld call: %s", (long)code, em->e_syscallnames[code]);
230 if (scdebug & SCDEBUG_SHOWARGS) {
231 printf("(");
232 for (i = 0; i < sy->sy_argsize/sizeof(register_t); i++)
233 printf("%s0x%lx", i == 0 ? "" : ", ",
234 (long)args[i]);
235 printf(")");
236 }
237 }
238 printf("\n");
239}
240
241void
242scdebug_ret(register_t code, int error, const register_t retval[])
243{
244 SCDEBUG_KERNHIST_FUNC("scdebug_ret");
245 struct lwp *l = curlwp;
246 struct proc *p = l->l_proc;
247 const struct sysent *sy;
248 const struct emul *em;
249
250 if ((scdebug & SCDEBUG_RETURNS) == 0)
251 return;
252
253 if (scdebug & SCDEBUG_KERNHIST)
254 SCDEBUG_KERNHIST_CALLED(scdebughist);
255
256 em = p->p_emul;
257 sy = &em->e_sysent[code];
258 if ((scdebug & SCDEBUG_ALL) == 0 &&
259 (CODE_NOT_OK(code, em) || sy->sy_call == sys_nosys)) {
260 if (scdebug & SCDEBUG_KERNHIST)
261 SCDEBUG_KERNHIST_LOG(scdebughist, "", 0, 0, 0, 0);
262 return;
263 }
264
265 if (scdebug & SCDEBUG_KERNHIST) {
266 if (CODE_NOT_OK(code, em)) {
267 SCDEBUG_KERNHIST_LOG(scdebughist,
268 "pid %jd:%jd: OUT OF RANGE (%jd)",
269 p->p_pid, l->l_lid, code, 0);
270 } else {
271 SCDEBUG_KERNHIST_LOG(scdebughist,
272 "pid %jd:%jd: num %jd",
273 p->p_pid, l->l_lid, code, 0);
274 SCDEBUG_KERNHIST_LOG(scdebughist,
275 "ret: err = %jd, rv = 0x%jx,0x%jx",
276 error, (long)retval[0], (long)retval[1], 0);
277 }
278 return;
279 }
280
281 printf("proc %d (%s): %s num ", p->p_pid, p->p_comm, em->e_name);
282 if (CODE_NOT_OK(code, em))
283 printf("OUT OF RANGE (%ld)", (long)code);
284 else
285 printf("%ld ret %s: err = %d, rv = 0x%lx,0x%lx", (long)code,
286 em->e_syscallnames[code], error,
287 (long)retval[0], (long)retval[1]);
288 printf("\n");
289}
290#endif /* SYSCALL_DEBUG */
291
292#ifndef SCDEBUG_KERNHIST_SIZE
293#define SCDEBUG_KERNHIST_SIZE 500
294#endif
295
296void
297scdebug_init(void)
298{
299#if defined(SYSCALL_DEBUG) && defined(KERNHIST)
300 /* Setup scdebughist kernel history */
301 KERNHIST_INIT(scdebughist, SCDEBUG_KERNHIST_SIZE);
302#endif
303}
304