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/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/conf.h>
35 #include <sys/cpuvar.h>
36 #include <sys/dtrace.h>
37 #include <sys/fcntl.h>
38 #include <sys/filio.h>
39 #include <sys/kdb.h>
40 #include <sys/kernel.h>
41 #include <sys/kmem.h>
42 #include <sys/kthread.h>
43 #include <sys/limits.h>
44 #include <sys/linker.h>
45 #include <sys/lock.h>
46 #include <sys/malloc.h>
47 #include <sys/module.h>
48 #include <sys/mutex.h>
49 #include <sys/poll.h>
50 #include <sys/proc.h>
51 #include <sys/selinfo.h>
52 #include <sys/smp.h>
53 #include <sys/sysent.h>
54 #include <sys/sysproto.h>
55 #include <sys/uio.h>
56 #include <sys/unistd.h>
57
58 #include <cddl/dev/dtrace/dtrace_cddl.h>
59
60 #include <machine/stdarg.h>
61
62 #ifdef LINUX_SYSTRACE
63 #if defined(__amd64__)
64 #include <amd64/linux/linux.h>
65 #include <amd64/linux/linux_proto.h>
66 #include <amd64/linux/linux_syscalls.c>
67 #include <amd64/linux/linux_systrace_args.c>
68 #elif defined(__i386__)
69 #include <i386/linux/linux.h>
70 #include <i386/linux/linux_proto.h>
71 #include <i386/linux/linux_syscalls.c>
72 #include <i386/linux/linux_systrace_args.c>
73 #else
74 #error Only i386 and amd64 are supported.
75 #endif
76 #define MODNAME "linux"
77 extern struct sysent linux_sysent[];
78 #define MAXSYSCALL LINUX_SYS_MAXSYSCALL
79 #define SYSCALLNAMES linux_syscallnames
80 #define SYSENT linux_sysent
81 #elif defined(LINUX32_SYSTRACE)
82 #if defined(__amd64__)
83 #include <amd64/linux32/linux.h>
84 #include <amd64/linux32/linux32_proto.h>
85 #include <amd64/linux32/linux32_syscalls.c>
86 #include <amd64/linux32/linux32_systrace_args.c>
87 #else
88 #error Only amd64 is supported.
89 #endif
90 #define MODNAME "linux32"
91 extern struct sysent linux32_sysent[];
92 #define MAXSYSCALL LINUX32_SYS_MAXSYSCALL
93 #define SYSCALLNAMES linux32_syscallnames
94 #define SYSENT linux32_sysent
95 #elif defined(FREEBSD32_SYSTRACE)
96 /*
97 * The syscall arguments are processed into a DTrace argument array
98 * using a generated function. See sys/kern/makesyscalls.sh.
99 */
100 #include <compat/freebsd32/freebsd32_proto.h>
101 #include <compat/freebsd32/freebsd32_util.h>
102 #include <compat/freebsd32/freebsd32_syscall.h>
103 #include <compat/freebsd32/freebsd32_systrace_args.c>
104 extern const char *freebsd32_syscallnames[];
105 #define MODNAME "freebsd32"
106 #define MAXSYSCALL FREEBSD32_SYS_MAXSYSCALL
107 #define SYSCALLNAMES freebsd32_syscallnames
108 #define SYSENT freebsd32_sysent
109 #else
110 /*
111 * The syscall arguments are processed into a DTrace argument array
112 * using a generated function. See sys/kern/makesyscalls.sh.
113 */
114 #include <sys/syscall.h>
115 #include <kern/systrace_args.c>
116 #define MODNAME "freebsd"
117 #define MAXSYSCALL SYS_MAXSYSCALL
118 #define SYSCALLNAMES syscallnames
119 #define SYSENT sysent
120 #define NATIVE_ABI
121 #endif
122
123 #define PROVNAME "syscall"
124 #define DEVNAME "dtrace/systrace/" MODNAME
125
126 #define SYSTRACE_ARTIFICIAL_FRAMES 1
127
128 #define SYSTRACE_SHIFT 16
129 #define SYSTRACE_ISENTRY(x) ((int)(x) >> SYSTRACE_SHIFT)
130 #define SYSTRACE_SYSNUM(x) ((int)(x) & ((1 << SYSTRACE_SHIFT) - 1))
131 #define SYSTRACE_ENTRY(id) ((1 << SYSTRACE_SHIFT) | (id))
132 #define SYSTRACE_RETURN(id) (id)
133
134 #if ((1 << SYSTRACE_SHIFT) <= MAXSYSCALL)
135 #error 1 << SYSTRACE_SHIFT must exceed number of system calls
136 #endif
137
138 static void systrace_load(void *);
139 static void systrace_unload(void *);
140
141 static void systrace_getargdesc(void *, dtrace_id_t, void *,
142 dtrace_argdesc_t *);
143 static uint64_t systrace_getargval(void *, dtrace_id_t, void *, int, int);
144 static void systrace_provide(void *, dtrace_probedesc_t *);
145 static void systrace_destroy(void *, dtrace_id_t, void *);
146 static void systrace_enable(void *, dtrace_id_t, void *);
147 static void systrace_disable(void *, dtrace_id_t, void *);
148
149 static union {
150 const char **p_constnames;
151 char **pp_syscallnames;
152 } uglyhack = { SYSCALLNAMES };
153
154 static dtrace_pattr_t systrace_attr = {
155 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
156 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
157 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
158 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
159 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_ISA },
160 };
161
162 static dtrace_pops_t systrace_pops = {
163 systrace_provide,
164 NULL,
165 systrace_enable,
166 systrace_disable,
167 NULL,
168 NULL,
169 systrace_getargdesc,
170 systrace_getargval,
171 NULL,
172 systrace_destroy
173 };
174
175 static dtrace_provider_id_t systrace_id;
176
177 #ifdef NATIVE_ABI
178 /*
179 * Probe callback function.
180 *
181 * Note: This function is called for _all_ syscalls, regardless of which sysent
182 * array the syscall comes from. It could be a standard syscall or a
183 * compat syscall from something like Linux.
184 */
185 static void
systrace_probe(struct syscall_args * sa,enum systrace_probe_t type,int retval)186 systrace_probe(struct syscall_args *sa, enum systrace_probe_t type, int retval)
187 {
188 uint64_t uargs[nitems(sa->args)];
189 dtrace_id_t id;
190 int n_args, sysnum;
191
192 sysnum = sa->code;
193 memset(uargs, 0, sizeof(uargs));
194
195 if (type == SYSTRACE_ENTRY) {
196 id = sa->callp->sy_entry;
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 id = sa->callp->sy_return;
219
220 curthread->t_dtrace_systrace_args = NULL;
221 /* Set arg0 and arg1 as the return value of this syscall. */
222 uargs[0] = uargs[1] = retval;
223 }
224
225 /* Process the probe using the converted argments. */
226 dtrace_probe(id, uargs[0], uargs[1], uargs[2], uargs[3], uargs[4]);
227 }
228 #endif
229
230 static void
systrace_getargdesc(void * arg,dtrace_id_t id,void * parg,dtrace_argdesc_t * desc)231 systrace_getargdesc(void *arg, dtrace_id_t id, void *parg,
232 dtrace_argdesc_t *desc)
233 {
234 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
235
236 if (SYSTRACE_ISENTRY((uintptr_t)parg))
237 systrace_entry_setargdesc(sysnum, desc->dtargd_ndx,
238 desc->dtargd_native, sizeof(desc->dtargd_native));
239 else
240 systrace_return_setargdesc(sysnum, desc->dtargd_ndx,
241 desc->dtargd_native, sizeof(desc->dtargd_native));
242
243 if (desc->dtargd_native[0] == '\0')
244 desc->dtargd_ndx = DTRACE_ARGNONE;
245 }
246
247 static uint64_t
systrace_getargval(void * arg __unused,dtrace_id_t id __unused,void * parg __unused,int argno,int aframes __unused)248 systrace_getargval(void *arg __unused, dtrace_id_t id __unused,
249 void *parg __unused, int argno, int aframes __unused)
250 {
251 uint64_t *uargs;
252
253 uargs = curthread->t_dtrace_systrace_args;
254 if (uargs == NULL)
255 /* This is a return probe. */
256 return (0);
257 if (argno >= nitems(((struct syscall_args *)NULL)->args))
258 return (0);
259 return (uargs[argno]);
260 }
261
262 static void
systrace_provide(void * arg,dtrace_probedesc_t * desc)263 systrace_provide(void *arg, dtrace_probedesc_t *desc)
264 {
265 int i;
266
267 if (desc != NULL)
268 return;
269
270 for (i = 0; i < MAXSYSCALL; i++) {
271 if (dtrace_probe_lookup(systrace_id, MODNAME,
272 uglyhack.pp_syscallnames[i], "entry") != 0)
273 continue;
274
275 (void)dtrace_probe_create(systrace_id, MODNAME,
276 uglyhack.pp_syscallnames[i], "entry",
277 SYSTRACE_ARTIFICIAL_FRAMES,
278 (void *)((uintptr_t)SYSTRACE_ENTRY(i)));
279 (void)dtrace_probe_create(systrace_id, MODNAME,
280 uglyhack.pp_syscallnames[i], "return",
281 SYSTRACE_ARTIFICIAL_FRAMES,
282 (void *)((uintptr_t)SYSTRACE_RETURN(i)));
283 }
284 }
285
286 static void
systrace_destroy(void * arg,dtrace_id_t id,void * parg)287 systrace_destroy(void *arg, dtrace_id_t id, void *parg)
288 {
289 #ifdef DEBUG
290 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
291
292 /*
293 * There's nothing to do here but assert that we have actually been
294 * disabled.
295 */
296 if (SYSTRACE_ISENTRY((uintptr_t)parg)) {
297 ASSERT(sysent[sysnum].sy_entry == 0);
298 } else {
299 ASSERT(sysent[sysnum].sy_return == 0);
300 }
301 #endif
302 }
303
304 static void
systrace_enable(void * arg,dtrace_id_t id,void * parg)305 systrace_enable(void *arg, dtrace_id_t id, void *parg)
306 {
307 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
308
309 if (SYSENT[sysnum].sy_systrace_args_func == NULL)
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 }
317
318 static void
systrace_disable(void * arg,dtrace_id_t id,void * parg)319 systrace_disable(void *arg, dtrace_id_t id, void *parg)
320 {
321 int sysnum = SYSTRACE_SYSNUM((uintptr_t)parg);
322
323 SYSENT[sysnum].sy_entry = 0;
324 SYSENT[sysnum].sy_return = 0;
325 }
326
327 static void
systrace_load(void * dummy __unused)328 systrace_load(void *dummy __unused)
329 {
330
331 if (dtrace_register(PROVNAME, &systrace_attr, DTRACE_PRIV_USER, NULL,
332 &systrace_pops, NULL, &systrace_id) != 0)
333 return;
334
335 #ifdef NATIVE_ABI
336 systrace_probe_func = systrace_probe;
337 #endif
338 }
339
340 static void
systrace_unload(void * dummy __unused)341 systrace_unload(void *dummy __unused)
342 {
343
344 #ifdef NATIVE_ABI
345 systrace_probe_func = NULL;
346 #endif
347
348 if (dtrace_unregister(systrace_id) != 0)
349 return;
350 }
351
352 static int
systrace_modevent(module_t mod __unused,int type,void * data __unused)353 systrace_modevent(module_t mod __unused, int type, void *data __unused)
354 {
355 int error;
356
357 error = 0;
358 switch (type) {
359 case MOD_LOAD:
360 break;
361
362 case MOD_UNLOAD:
363 break;
364
365 case MOD_SHUTDOWN:
366 break;
367
368 default:
369 error = EOPNOTSUPP;
370 break;
371
372 }
373 return (error);
374 }
375
376 SYSINIT(systrace_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY,
377 systrace_load, NULL);
378 SYSUNINIT(systrace_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY,
379 systrace_unload, NULL);
380
381 #ifdef LINUX_SYSTRACE
382 DEV_MODULE(systrace_linux, systrace_modevent, NULL);
383 MODULE_VERSION(systrace_linux, 1);
384 #ifdef __amd64__
385 MODULE_DEPEND(systrace_linux, linux64, 1, 1, 1);
386 #else
387 MODULE_DEPEND(systrace_linux, linux, 1, 1, 1);
388 #endif
389 MODULE_DEPEND(systrace_linux, dtrace, 1, 1, 1);
390 MODULE_DEPEND(systrace_linux, opensolaris, 1, 1, 1);
391 #elif defined(LINUX32_SYSTRACE)
392 DEV_MODULE(systrace_linux32, systrace_modevent, NULL);
393 MODULE_VERSION(systrace_linux32, 1);
394 MODULE_DEPEND(systrace_linux32, linux, 1, 1, 1);
395 MODULE_DEPEND(systrace_linux32, dtrace, 1, 1, 1);
396 MODULE_DEPEND(systrace_linux32, opensolaris, 1, 1, 1);
397 #elif defined(FREEBSD32_SYSTRACE)
398 DEV_MODULE(systrace_freebsd32, systrace_modevent, NULL);
399 MODULE_VERSION(systrace_freebsd32, 1);
400 MODULE_DEPEND(systrace_freebsd32, dtrace, 1, 1, 1);
401 MODULE_DEPEND(systrace_freebsd32, opensolaris, 1, 1, 1);
402 #else
403 DEV_MODULE(systrace, systrace_modevent, NULL);
404 MODULE_VERSION(systrace, 1);
405 MODULE_DEPEND(systrace, dtrace, 1, 1, 1);
406 MODULE_DEPEND(systrace, opensolaris, 1, 1, 1);
407 #endif
408