1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 *
21 * Portions Copyright 2006-2008 John Birrell jb@freebsd.org
22 */
23
24 /*
25 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/conf.h>
32 #include <sys/cpuvar.h>
33 #include <sys/dtrace.h>
34 #include <sys/fcntl.h>
35 #include <sys/filio.h>
36 #include <sys/kdb.h>
37 #include <sys/kernel.h>
38 #include <sys/kmem.h>
39 #include <sys/kthread.h>
40 #include <sys/limits.h>
41 #include <sys/linker.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/module.h>
45 #include <sys/mutex.h>
46 #include <sys/poll.h>
47 #include <sys/proc.h>
48 #include <sys/selinfo.h>
49 #include <sys/smp.h>
50 #include <sys/sysent.h>
51 #include <sys/sysproto.h>
52 #include <sys/uio.h>
53 #include <sys/unistd.h>
54
55 #include <cddl/dev/dtrace/dtrace_cddl.h>
56
57 #include <machine/stdarg.h>
58
59 #ifdef LINUX_SYSTRACE
60 #if defined(__amd64__)
61 #include <amd64/linux/linux.h>
62 #include <amd64/linux/linux_proto.h>
63 #include <amd64/linux/linux_syscalls.c>
64 #include <amd64/linux/linux_systrace_args.c>
65 #elif defined(__i386__)
66 #include <i386/linux/linux.h>
67 #include <i386/linux/linux_proto.h>
68 #include <i386/linux/linux_syscalls.c>
69 #include <i386/linux/linux_systrace_args.c>
70 #else
71 #error Only i386 and amd64 are supported.
72 #endif
73 #define MODNAME "linux"
74 extern struct sysent linux_sysent[];
75 #define MAXSYSCALL LINUX_SYS_MAXSYSCALL
76 #define SYSCALLNAMES linux_syscallnames
77 #define SYSENT linux_sysent
78 #elif defined(LINUX32_SYSTRACE)
79 #if defined(__amd64__)
80 #include <amd64/linux32/linux.h>
81 #include <amd64/linux32/linux32_proto.h>
82 #include <amd64/linux32/linux32_syscalls.c>
83 #include <amd64/linux32/linux32_systrace_args.c>
84 #else
85 #error Only amd64 is supported.
86 #endif
87 #define MODNAME "linux32"
88 extern struct sysent linux32_sysent[];
89 #define MAXSYSCALL LINUX32_SYS_MAXSYSCALL
90 #define SYSCALLNAMES linux32_syscallnames
91 #define SYSENT linux32_sysent
92 #elif defined(FREEBSD32_SYSTRACE)
93 /*
94 * The syscall arguments are processed into a DTrace argument array
95 * using a generated function. See sys/tools/syscalls/README.md.
96 */
97 #include <compat/freebsd32/freebsd32_proto.h>
98 #include <compat/freebsd32/freebsd32_util.h>
99 #include <compat/freebsd32/freebsd32_syscall.h>
100 #include <compat/freebsd32/freebsd32_systrace_args.c>
101 extern const char *freebsd32_syscallnames[];
102 #define MODNAME "freebsd32"
103 #define MAXSYSCALL FREEBSD32_SYS_MAXSYSCALL
104 #define SYSCALLNAMES freebsd32_syscallnames
105 #define SYSENT freebsd32_sysent
106 #else
107 /*
108 * The syscall arguments are processed into a DTrace argument array
109 * using a generated function. See sys/tools/syscalls/README.md.
110 */
111 #include <sys/syscall.h>
112 #include <kern/systrace_args.c>
113 #define MODNAME "freebsd"
114 #define MAXSYSCALL SYS_MAXSYSCALL
115 #define SYSCALLNAMES syscallnames
116 #define SYSENT sysent
117 #define NATIVE_ABI
118 #endif
119
120 #define PROVNAME "syscall"
121 #define DEVNAME "dtrace/systrace/" MODNAME
122
123 #define SYSTRACE_ARTIFICIAL_FRAMES 1
124
125 #define SYSTRACE_SHIFT 16
126 #define SYSTRACE_ISENTRY(x) ((int)(x) >> SYSTRACE_SHIFT)
127 #define SYSTRACE_SYSNUM(x) ((int)(x) & ((1 << SYSTRACE_SHIFT) - 1))
128 #define SYSTRACE_ENTRY(id) ((1 << SYSTRACE_SHIFT) | (id))
129 #define SYSTRACE_RETURN(id) (id)
130
131 #if ((1 << SYSTRACE_SHIFT) <= MAXSYSCALL)
132 #error 1 << SYSTRACE_SHIFT must exceed number of system calls
133 #endif
134
135 static int systrace_enabled_count;
136
137 static void systrace_load(void *);
138 static void systrace_unload(void *);
139
140 static void systrace_getargdesc(void *, dtrace_id_t, void *,
141 dtrace_argdesc_t *);
142 static uint64_t systrace_getargval(void *, dtrace_id_t, void *, int, int);
143 static void systrace_provide(void *, dtrace_probedesc_t *);
144 static void systrace_destroy(void *, dtrace_id_t, void *);
145 static void systrace_enable(void *, dtrace_id_t, void *);
146 static void systrace_disable(void *, dtrace_id_t, void *);
147
148 static union {
149 const char **p_constnames;
150 char **pp_syscallnames;
151 } uglyhack = { SYSCALLNAMES };
152
153 static dtrace_pattr_t systrace_attr = {
154 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
155 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
156 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
157 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
158 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
159 };
160
161 static dtrace_pops_t systrace_pops = {
162 .dtps_provide = systrace_provide,
163 .dtps_provide_module = NULL,
164 .dtps_enable = systrace_enable,
165 .dtps_disable = systrace_disable,
166 .dtps_suspend = NULL,
167 .dtps_resume = NULL,
168 .dtps_getargdesc = systrace_getargdesc,
169 .dtps_getargval = systrace_getargval,
170 .dtps_usermode = NULL,
171 .dtps_destroy = systrace_destroy
172 };
173
174 static dtrace_provider_id_t systrace_id;
175
176 #ifdef NATIVE_ABI
177 /*
178 * Probe callback function.
179 *
180 * Note: This function is called for _all_ syscalls, regardless of which sysent
181 * array the syscall comes from. It could be a standard syscall or a
182 * compat syscall from something like Linux.
183 */
184 static void
systrace_probe(struct syscall_args * sa,enum systrace_probe_t type,int retval)185 systrace_probe(struct syscall_args *sa, enum systrace_probe_t type, int retval)
186 {
187 uint64_t uargs[nitems(sa->args)];
188 dtrace_id_t id;
189 int n_args, sysnum;
190
191 sysnum = sa->code;
192 memset(uargs, 0, sizeof(uargs));
193
194 if (type == SYSTRACE_ENTRY) {
195 if ((id = sa->callp->sy_entry) == DTRACE_IDNONE)
196 return;
197
198 if (sa->callp->sy_systrace_args_func != NULL)
199 /*
200 * Convert the syscall parameters using the registered
201 * function.
202 */
203 (*sa->callp->sy_systrace_args_func)(sysnum, sa->args,
204 uargs, &n_args);
205 else
206 /*
207 * Use the built-in system call argument conversion
208 * function to translate the syscall structure fields
209 * into the array of 64-bit values that DTrace expects.
210 */
211 systrace_args(sysnum, sa->args, uargs, &n_args);
212 /*
213 * Save probe arguments now so that we can retrieve them if
214 * the getargval method is called from further down the stack.
215 */
216 curthread->t_dtrace_systrace_args = uargs;
217 } else {
218 if ((id = sa->callp->sy_return) == DTRACE_IDNONE)
219 return;
220
221 curthread->t_dtrace_systrace_args = NULL;
222 /* Set arg0 and arg1 as the return value of this syscall. */
223 uargs[0] = uargs[1] = retval;
224 }
225
226 /* Process the probe using the converted argments. */
227 dtrace_probe(id, uargs[0], uargs[1], uargs[2], uargs[3], uargs[4]);
228 }
229 #endif
230
231 static void
systrace_getargdesc(void * arg,dtrace_id_t id,void * parg,dtrace_argdesc_t * desc)232 systrace_getargdesc(void *arg, dtrace_id_t id, void *parg,
233 dtrace_argdesc_t *desc)
234 {
235 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
236
237 if (SYSTRACE_ISENTRY((uintptr_t)parg))
238 systrace_entry_setargdesc(sysnum, desc->dtargd_ndx,
239 desc->dtargd_native, sizeof(desc->dtargd_native));
240 else
241 systrace_return_setargdesc(sysnum, desc->dtargd_ndx,
242 desc->dtargd_native, sizeof(desc->dtargd_native));
243
244 if (desc->dtargd_native[0] == '\0')
245 desc->dtargd_ndx = DTRACE_ARGNONE;
246 }
247
248 static uint64_t
systrace_getargval(void * arg __unused,dtrace_id_t id __unused,void * parg __unused,int argno,int aframes __unused)249 systrace_getargval(void *arg __unused, dtrace_id_t id __unused,
250 void *parg __unused, int argno, int aframes __unused)
251 {
252 uint64_t *uargs;
253
254 uargs = curthread->t_dtrace_systrace_args;
255 if (uargs == NULL)
256 /* This is a return probe. */
257 return (0);
258 if (argno >= nitems(((struct syscall_args *)NULL)->args))
259 return (0);
260 return (uargs[argno]);
261 }
262
263 static void
systrace_provide(void * arg,dtrace_probedesc_t * desc)264 systrace_provide(void *arg, dtrace_probedesc_t *desc)
265 {
266 int i;
267
268 if (desc != NULL)
269 return;
270
271 for (i = 0; i < MAXSYSCALL; i++) {
272 if (dtrace_probe_lookup(systrace_id, MODNAME,
273 uglyhack.pp_syscallnames[i], "entry") != 0)
274 continue;
275
276 (void)dtrace_probe_create(systrace_id, MODNAME,
277 uglyhack.pp_syscallnames[i], "entry",
278 SYSTRACE_ARTIFICIAL_FRAMES,
279 (void *)((uintptr_t)SYSTRACE_ENTRY(i)));
280 (void)dtrace_probe_create(systrace_id, MODNAME,
281 uglyhack.pp_syscallnames[i], "return",
282 SYSTRACE_ARTIFICIAL_FRAMES,
283 (void *)((uintptr_t)SYSTRACE_RETURN(i)));
284 }
285 }
286
287 static void
systrace_destroy(void * arg,dtrace_id_t id,void * parg)288 systrace_destroy(void *arg, dtrace_id_t id, void *parg)
289 {
290 #ifdef SYSTRACE_DEBUG
291 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
292
293 /*
294 * There's nothing to do here but assert that we have actually been
295 * disabled.
296 */
297 if (SYSTRACE_ISENTRY((uintptr_t)parg)) {
298 ASSERT(sysent[sysnum].sy_entry == DTRACE_IDNONE);
299 } else {
300 ASSERT(sysent[sysnum].sy_return == DTRACE_IDNONE);
301 }
302 #endif
303 }
304
305 static void
systrace_enable(void * arg,dtrace_id_t id,void * parg)306 systrace_enable(void *arg, dtrace_id_t id, void *parg)
307 {
308 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
309
310 SYSENT[sysnum].sy_systrace_args_func = systrace_args;
311
312 if (SYSTRACE_ISENTRY((uintptr_t)parg))
313 SYSENT[sysnum].sy_entry = id;
314 else
315 SYSENT[sysnum].sy_return = id;
316 systrace_enabled_count++;
317 if (systrace_enabled_count == 1)
318 systrace_enabled = true;
319 }
320
321 static void
systrace_disable(void * arg,dtrace_id_t id,void * parg)322 systrace_disable(void *arg, dtrace_id_t id, void *parg)
323 {
324 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
325
326 SYSENT[sysnum].sy_systrace_args_func = NULL;
327 SYSENT[sysnum].sy_entry = DTRACE_IDNONE;
328 SYSENT[sysnum].sy_return = DTRACE_IDNONE;
329 systrace_enabled_count--;
330 if (systrace_enabled_count == 0)
331 systrace_enabled = false;
332 }
333
334 static void
systrace_load(void * dummy __unused)335 systrace_load(void *dummy __unused)
336 {
337
338 if (dtrace_register(PROVNAME, &systrace_attr, DTRACE_PRIV_USER, NULL,
339 &systrace_pops, NULL, &systrace_id) != 0)
340 return;
341
342 #ifdef NATIVE_ABI
343 systrace_probe_func = systrace_probe;
344 #endif
345 }
346
347 static void
systrace_unload(void * dummy __unused)348 systrace_unload(void *dummy __unused)
349 {
350
351 #ifdef NATIVE_ABI
352 systrace_probe_func = NULL;
353 #endif
354
355 if (dtrace_unregister(systrace_id) != 0)
356 return;
357 }
358
359 static int
systrace_modevent(module_t mod __unused,int type,void * data __unused)360 systrace_modevent(module_t mod __unused, int type, void *data __unused)
361 {
362 int error;
363
364 error = 0;
365 switch (type) {
366 case MOD_LOAD:
367 break;
368
369 case MOD_UNLOAD:
370 break;
371
372 case MOD_SHUTDOWN:
373 break;
374
375 default:
376 error = EOPNOTSUPP;
377 break;
378
379 }
380 return (error);
381 }
382
383 SYSINIT(systrace_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY,
384 systrace_load, NULL);
385 SYSUNINIT(systrace_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY,
386 systrace_unload, NULL);
387
388 #ifdef LINUX_SYSTRACE
389 DEV_MODULE(systrace_linux, systrace_modevent, NULL);
390 MODULE_VERSION(systrace_linux, 1);
391 #ifdef __amd64__
392 MODULE_DEPEND(systrace_linux, linux64, 1, 1, 1);
393 #else
394 MODULE_DEPEND(systrace_linux, linux, 1, 1, 1);
395 #endif
396 MODULE_DEPEND(systrace_linux, dtrace, 1, 1, 1);
397 MODULE_DEPEND(systrace_linux, opensolaris, 1, 1, 1);
398 #elif defined(LINUX32_SYSTRACE)
399 DEV_MODULE(systrace_linux32, systrace_modevent, NULL);
400 MODULE_VERSION(systrace_linux32, 1);
401 MODULE_DEPEND(systrace_linux32, linux, 1, 1, 1);
402 MODULE_DEPEND(systrace_linux32, dtrace, 1, 1, 1);
403 MODULE_DEPEND(systrace_linux32, opensolaris, 1, 1, 1);
404 #elif defined(FREEBSD32_SYSTRACE)
405 DEV_MODULE(systrace_freebsd32, systrace_modevent, NULL);
406 MODULE_VERSION(systrace_freebsd32, 1);
407 MODULE_DEPEND(systrace_freebsd32, dtrace, 1, 1, 1);
408 MODULE_DEPEND(systrace_freebsd32, opensolaris, 1, 1, 1);
409 #else
410 DEV_MODULE(systrace, systrace_modevent, NULL);
411 MODULE_VERSION(systrace, 1);
412 MODULE_DEPEND(systrace, dtrace, 1, 1, 1);
413 MODULE_DEPEND(systrace, opensolaris, 1, 1, 1);
414 #endif
415