1/*-
2 * Copyright (c) 2003-2008 Joseph Koshy
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/types.h>
28#include <sys/cpuset.h>
29#include <sys/event.h>
30#include <sys/param.h>
31#include <sys/socket.h>
32#include <sys/stat.h>
33#include <sys/module.h>
34#include <sys/pmc.h>
35
36#include <assert.h>
37#include <ctype.h>
38#include <err.h>
39#include <errno.h>
40#include <fcntl.h>
41#include <limits.h>
42#include <netdb.h>
43#include <pmc.h>
44#include <pmclog.h>
45#include <signal.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <string.h>
49#include <strings.h>
50#include <sysexits.h>
51#include <unistd.h>
52
53#include "libpmcstat.h"
54
55/*
56 * Associate an AOUT image with a process.
57 */
58
59void
60pmcstat_process_aout_exec(struct pmcstat_process *pp,
61    struct pmcstat_image *image, uintptr_t baseaddr)
62{
63	(void) pp;
64	(void) image;
65	(void) baseaddr;
66	/* TODO Implement a.out handling */
67}
68
69/*
70 * Associate an ELF image with a process.
71 */
72
73void
74pmcstat_process_elf_exec(struct pmcstat_process *pp,
75    struct pmcstat_image *image, uintptr_t baseaddr, uintptr_t dynaddr,
76    struct pmcstat_args *args, struct pmc_plugins *plugins,
77    struct pmcstat_stats *pmcstat_stats)
78{
79	struct pmcstat_image *rtldimage;
80
81	assert(image->pi_type == PMCSTAT_IMAGE_ELF32 ||
82	    image->pi_type == PMCSTAT_IMAGE_ELF64);
83
84	/*
85	 * The exact address where the executable gets mapped in will vary for
86	 * PIEs.  The dynamic address recorded at process exec time corresponds
87	 * to the address where the executable's file object had been mapped to.
88	 */
89	pmcstat_image_link(pp, image, image->pi_vaddr + dynaddr);
90
91	/*
92	 * For dynamically linked executables we need to determine
93	 * where the dynamic linker was mapped to for this process,
94	 * Subsequent executable objects that are mapped in by the
95	 * dynamic linker will be tracked by log events of type
96	 * PMCLOG_TYPE_MAP_IN.
97	 */
98
99	if (image->pi_isdynamic) {
100
101		/*
102		 * The runtime loader gets loaded just after the maximum
103		 * possible heap address.  Like so:
104		 *
105		 * [  TEXT DATA BSS HEAP -->*RTLD  SHLIBS   <--STACK]
106		 * ^					            ^
107		 * 0				   VM_MAXUSER_ADDRESS
108		 *
109		 * The exact address where the loader gets mapped in
110		 * will vary according to the size of the executable
111		 * and the limits on the size of the process'es data
112		 * segment at the time of exec().  The base address
113		 * recorded at process exec time corresponds to the
114		 * address where the runtime loader's file object had
115		 * been mapped to.
116		 */
117		rtldimage = pmcstat_image_from_path(image->pi_dynlinkerpath,
118		    0, args, plugins);
119		if (rtldimage == NULL) {
120			warnx("WARNING: Cannot find image for \"%s\".",
121			    pmcstat_string_unintern(image->pi_dynlinkerpath));
122			pmcstat_stats->ps_exec_errors++;
123			return;
124		}
125
126		if (rtldimage->pi_type == PMCSTAT_IMAGE_UNKNOWN)
127			pmcstat_image_get_elf_params(rtldimage, args);
128
129		if (rtldimage->pi_type != PMCSTAT_IMAGE_ELF32 &&
130		    rtldimage->pi_type != PMCSTAT_IMAGE_ELF64) {
131			warnx("WARNING: rtld not an ELF object \"%s\".",
132			    pmcstat_string_unintern(image->pi_dynlinkerpath));
133			return;
134		}
135
136		pmcstat_image_link(pp, rtldimage, baseaddr);
137	}
138}
139
140/*
141 * Associate an image and a process.
142 */
143
144void
145pmcstat_process_exec(struct pmcstat_process *pp,
146    pmcstat_interned_string path, uintptr_t baseaddr, uintptr_t dynaddr,
147    struct pmcstat_args *args, struct pmc_plugins *plugins,
148    struct pmcstat_stats *pmcstat_stats)
149{
150	struct pmcstat_image *image;
151
152	if ((image = pmcstat_image_from_path(path, 0,
153	    args, plugins)) == NULL) {
154		pmcstat_stats->ps_exec_errors++;
155		return;
156	}
157
158	if (image->pi_type == PMCSTAT_IMAGE_UNKNOWN)
159		pmcstat_image_determine_type(image, args);
160
161	assert(image->pi_type != PMCSTAT_IMAGE_UNKNOWN);
162
163	switch (image->pi_type) {
164	case PMCSTAT_IMAGE_ELF32:
165	case PMCSTAT_IMAGE_ELF64:
166		pmcstat_stats->ps_exec_elf++;
167		pmcstat_process_elf_exec(pp, image, baseaddr, dynaddr,
168		    args, plugins, pmcstat_stats);
169		break;
170
171	case PMCSTAT_IMAGE_AOUT:
172		pmcstat_stats->ps_exec_aout++;
173		pmcstat_process_aout_exec(pp, image, baseaddr);
174		break;
175
176	case PMCSTAT_IMAGE_INDETERMINABLE:
177		pmcstat_stats->ps_exec_indeterminable++;
178		break;
179
180	default:
181		err(EX_SOFTWARE,
182		    "ERROR: Unsupported executable type for \"%s\"",
183		    pmcstat_string_unintern(path));
184	}
185}
186
187/*
188 * Find the map entry associated with process 'p' at PC value 'pc'.
189 */
190
191struct pmcstat_pcmap *
192pmcstat_process_find_map(struct pmcstat_process *p, uintfptr_t pc)
193{
194	struct pmcstat_pcmap *ppm;
195
196	TAILQ_FOREACH(ppm, &p->pp_map, ppm_next) {
197		if (pc >= ppm->ppm_lowpc && pc < ppm->ppm_highpc)
198			return (ppm);
199		if (pc < ppm->ppm_lowpc)
200			return (NULL);
201	}
202
203	return (NULL);
204}
205
206/*
207 * Find the process descriptor corresponding to a PID.  If 'allocate'
208 * is zero, we return a NULL if a pid descriptor could not be found or
209 * a process descriptor process.  If 'allocate' is non-zero, then we
210 * will attempt to allocate a fresh process descriptor.  Zombie
211 * process descriptors are only removed if a fresh allocation for the
212 * same PID is requested.
213 */
214
215struct pmcstat_process *
216pmcstat_process_lookup(pid_t pid, int allocate)
217{
218	uint32_t hash;
219	struct pmcstat_pcmap *ppm, *ppmtmp;
220	struct pmcstat_process *pp, *pptmp;
221
222	hash = (uint32_t) pid & PMCSTAT_HASH_MASK;	/* simplicity wins */
223
224	LIST_FOREACH_SAFE(pp, &pmcstat_process_hash[hash], pp_next, pptmp)
225		if (pp->pp_pid == pid) {
226			/* Found a descriptor, check and process zombies */
227			if (allocate && pp->pp_isactive == 0) {
228				/* remove maps */
229				TAILQ_FOREACH_SAFE(ppm, &pp->pp_map, ppm_next,
230				    ppmtmp) {
231					TAILQ_REMOVE(&pp->pp_map, ppm,
232					    ppm_next);
233					free(ppm);
234				}
235				/* remove process entry */
236				LIST_REMOVE(pp, pp_next);
237				free(pp);
238				break;
239			}
240			return (pp);
241		}
242
243	if (!allocate)
244		return (NULL);
245
246	if ((pp = malloc(sizeof(*pp))) == NULL)
247		err(EX_OSERR, "ERROR: Cannot allocate pid descriptor");
248
249	pp->pp_pid = pid;
250	pp->pp_isactive = 1;
251
252	TAILQ_INIT(&pp->pp_map);
253
254	LIST_INSERT_HEAD(&pmcstat_process_hash[hash], pp, pp_next);
255	return (pp);
256}
257
258void
259pmcstat_create_process(int *pmcstat_sockpair, struct pmcstat_args *args,
260    int pmcstat_kq)
261{
262	char token;
263	pid_t pid;
264	struct kevent kev;
265	struct pmcstat_target *pt;
266
267	if (socketpair(AF_UNIX, SOCK_STREAM, 0, pmcstat_sockpair) < 0)
268		err(EX_OSERR, "ERROR: cannot create socket pair");
269
270	switch (pid = fork()) {
271	case -1:
272		err(EX_OSERR, "ERROR: cannot fork");
273		/*NOTREACHED*/
274
275	case 0:		/* child */
276		(void) close(pmcstat_sockpair[PARENTSOCKET]);
277
278		/* Write a token to tell our parent we've started executing. */
279		if (write(pmcstat_sockpair[CHILDSOCKET], "+", 1) != 1)
280			err(EX_OSERR, "ERROR (child): cannot write token");
281
282		/* Wait for our parent to signal us to start. */
283		if (read(pmcstat_sockpair[CHILDSOCKET], &token, 1) < 0)
284			err(EX_OSERR, "ERROR (child): cannot read token");
285		(void) close(pmcstat_sockpair[CHILDSOCKET]);
286
287		/* exec() the program requested */
288		execvp(*args->pa_argv, args->pa_argv);
289		/* and if that fails, notify the parent */
290		kill(getppid(), SIGCHLD);
291		err(EX_OSERR, "ERROR: execvp \"%s\" failed", *args->pa_argv);
292		/*NOTREACHED*/
293
294	default:	/* parent */
295		(void) close(pmcstat_sockpair[CHILDSOCKET]);
296		break;
297	}
298
299	/* Ask to be notified via a kevent when the target process exits. */
300	EV_SET(&kev, pid, EVFILT_PROC, EV_ADD | EV_ONESHOT, NOTE_EXIT, 0,
301	    NULL);
302	if (kevent(pmcstat_kq, &kev, 1, NULL, 0, NULL) < 0)
303		err(EX_OSERR, "ERROR: cannot monitor child process %d", pid);
304
305	if ((pt = malloc(sizeof(*pt))) == NULL)
306		errx(EX_SOFTWARE, "ERROR: Out of memory.");
307
308	pt->pt_pid = pid;
309	SLIST_INSERT_HEAD(&args->pa_targets, pt, pt_next);
310
311	/* Wait for the child to signal that its ready to go. */
312	if (read(pmcstat_sockpair[PARENTSOCKET], &token, 1) < 0)
313		err(EX_OSERR, "ERROR (parent): cannot read token");
314
315	return;
316}
317
318/*
319 * Do process profiling
320 *
321 * If a pid was specified, attach each allocated PMC to the target
322 * process.  Otherwise, fork a child and attach the PMCs to the child,
323 * and have the child exec() the target program.
324 */
325
326void
327pmcstat_start_process(int *pmcstat_sockpair)
328{
329	/* Signal the child to proceed. */
330	if (write(pmcstat_sockpair[PARENTSOCKET], "!", 1) != 1)
331		err(EX_OSERR, "ERROR (parent): write of token failed");
332
333	(void) close(pmcstat_sockpair[PARENTSOCKET]);
334}
335
336void
337pmcstat_attach_pmcs(struct pmcstat_args *args)
338{
339	struct pmcstat_ev *ev;
340	struct pmcstat_target *pt;
341	int count;
342
343	/* Attach all process PMCs to target processes. */
344	count = 0;
345	STAILQ_FOREACH(ev, &args->pa_events, ev_next) {
346		if (PMC_IS_SYSTEM_MODE(ev->ev_mode))
347			continue;
348		SLIST_FOREACH(pt, &args->pa_targets, pt_next) {
349			if (pmc_attach(ev->ev_pmcid, pt->pt_pid) == 0)
350				count++;
351			else if (errno != ESRCH)
352				err(EX_OSERR,
353"ERROR: cannot attach pmc \"%s\" to process %d",
354				    ev->ev_name, (int)pt->pt_pid);
355		}
356	}
357
358	if (count == 0)
359		errx(EX_DATAERR, "ERROR: No processes were attached to.");
360}
361