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, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29#include <stdlib.h>
30#include <assert.h>
31#include <errno.h>
32#include <string.h>
33#include <libgen.h>
34
35#include <dt_impl.h>
36#include <dt_pid.h>
37
38#define	OP(x)		((x) >> 30)
39#define	OP2(x)		(((x) >> 22) & 0x07)
40#define	COND(x)		(((x) >> 25) & 0x0f)
41#define	A(x)		(((x) >> 29) & 0x01)
42
43#define	OP_BRANCH	0
44
45#define	OP2_BPcc	0x1
46#define	OP2_Bicc	0x2
47#define	OP2_BPr		0x3
48#define	OP2_FBPfcc	0x5
49#define	OP2_FBfcc	0x6
50
51/*ARGSUSED*/
52int
53dt_pid_create_entry_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
54    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp)
55{
56	ftp->ftps_type = DTFTP_ENTRY;
57	ftp->ftps_pc = (uintptr_t)symp->st_value;
58	ftp->ftps_size = (size_t)symp->st_size;
59	ftp->ftps_noffs = 1;
60	ftp->ftps_offs[0] = 0;
61
62	if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
63		dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
64		    strerror(errno));
65		return (dt_set_errno(dtp, errno));
66	}
67
68	return (1);
69}
70
71int
72dt_pid_create_return_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
73    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, uint64_t *stret)
74{
75
76	uint32_t *text;
77	int i;
78	int srdepth = 0;
79
80	if ((text = malloc(symp->st_size + 4)) == NULL) {
81		dt_dprintf("mr sparkle: malloc() failed\n");
82		return (DT_PROC_ERR);
83	}
84
85	if (Pread(P, text, symp->st_size, symp->st_value) != symp->st_size) {
86		dt_dprintf("mr sparkle: Pread() failed\n");
87		free(text);
88		return (DT_PROC_ERR);
89	}
90
91	/*
92	 * Leave a dummy instruction in the last slot to simplify edge
93	 * conditions.
94	 */
95	text[symp->st_size / 4] = 0;
96
97	ftp->ftps_type = DTFTP_RETURN;
98	ftp->ftps_pc = symp->st_value;
99	ftp->ftps_size = symp->st_size;
100	ftp->ftps_noffs = 0;
101
102	for (i = 0; i < symp->st_size / 4; i++) {
103		/*
104		 * If we encounter an existing tracepoint, query the
105		 * kernel to find out the instruction that was
106		 * replaced at this spot.
107		 */
108		while (text[i] == FASTTRAP_INSTR) {
109			fasttrap_instr_query_t instr;
110
111			instr.ftiq_pid = Pstatus(P)->pr_pid;
112			instr.ftiq_pc = symp->st_value + i * 4;
113
114			if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_GETINSTR,
115			    &instr) != 0) {
116
117				if (errno == ESRCH || errno == ENOENT) {
118					if (Pread(P, &text[i], 4,
119					    instr.ftiq_pc) != 4) {
120						dt_dprintf("mr sparkle: "
121						    "Pread() failed\n");
122						free(text);
123						return (DT_PROC_ERR);
124					}
125					continue;
126				}
127
128				free(text);
129				dt_dprintf("mr sparkle: getinstr query "
130				    "failed: %s\n", strerror(errno));
131				return (DT_PROC_ERR);
132			}
133
134			text[i] = instr.ftiq_instr;
135			break;
136		}
137
138		/* save */
139		if ((text[i] & 0xc1f80000) == 0x81e00000) {
140			srdepth++;
141			continue;
142		}
143
144		/* restore */
145		if ((text[i] & 0xc1f80000) == 0x81e80000) {
146			srdepth--;
147			continue;
148		}
149
150		if (srdepth > 0) {
151			/* ret */
152			if (text[i] == 0x81c7e008)
153				goto is_ret;
154
155			/* return */
156			if (text[i] == 0x81cfe008)
157				goto is_ret;
158
159			/* call or jmpl w/ restore in the slot */
160			if (((text[i] & 0xc0000000) == 0x40000000 ||
161			    (text[i] & 0xc1f80000) == 0x81c00000) &&
162			    (text[i + 1] & 0xc1f80000) == 0x81e80000)
163				goto is_ret;
164
165			/* call to one of the stret routines */
166			if ((text[i] & 0xc0000000) == 0x40000000) {
167				int32_t	disp = text[i] << 2;
168				uint64_t dest = ftp->ftps_pc + i * 4 + disp;
169
170				dt_dprintf("dest = %llx\n", (u_longlong_t)dest);
171
172				if (dest == stret[0] || dest == stret[1] ||
173				    dest == stret[2] || dest == stret[3])
174					goto is_ret;
175			}
176		} else {
177			/* external call */
178			if ((text[i] & 0xc0000000) == 0x40000000) {
179				int32_t dst = text[i] << 2;
180
181				dst += i * 4;
182
183				if ((uintptr_t)dst >= (uintptr_t)symp->st_size)
184					goto is_ret;
185			}
186
187			/* jmpl into %g0 -- this includes the retl pseudo op */
188			if ((text[i] & 0xfff80000) == 0x81c00000)
189				goto is_ret;
190
191			/* external branch -- possible return site */
192			if (OP(text[i]) == OP_BRANCH) {
193				int32_t dst;
194				int baa;
195
196				switch (OP2(text[i])) {
197				case OP2_BPcc:
198					dst = text[i] & 0x7ffff;
199					dst <<= 13;
200					dst >>= 11;
201
202					baa = COND(text[i]) == 8 && A(text[i]);
203					break;
204				case OP2_Bicc:
205					dst = text[i] & 0x3fffff;
206					dst <<= 10;
207					dst >>= 8;
208
209					baa = COND(text[i]) == 8 && A(text[i]);
210					break;
211				case OP2_BPr:
212					dst = (((text[i]) >> 6) & 0xc000) |
213					    ((text[i]) & 0x3fff);
214					dst <<= 16;
215					dst >>= 14;
216
217					baa = 0;
218					break;
219				case OP2_FBPfcc:
220					dst = text[i] & 0x7ffff;
221					dst <<= 13;
222					dst >>= 11;
223
224					baa = COND(text[i]) == 8 && A(text[i]);
225					break;
226				case OP2_FBfcc:
227					dst = text[i] & 0x3fffff;
228					dst <<= 10;
229					dst >>= 8;
230
231					baa = COND(text[i]) == 8 && A(text[i]);
232					break;
233				default:
234					continue;
235				}
236
237				dst += i * 4;
238
239				/*
240				 * Interpret branches outside of the function's
241				 * bounds as potential return sites. If the
242				 * branch is a ba,a don't skip the instruction
243				 * in the delay slot.
244				 */
245				if ((uintptr_t)dst >=
246				    (uintptr_t)symp->st_size) {
247					if (baa)
248						goto is_ret_baa;
249					else
250						goto is_ret;
251				}
252			}
253		}
254
255		continue;
256is_ret:
257		i++;
258is_ret_baa:
259		dt_dprintf("return at offset %x\n", i * 4);
260		ftp->ftps_offs[ftp->ftps_noffs++] = i * 4;
261	}
262
263	free(text);
264	if (ftp->ftps_noffs > 0) {
265		if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
266			dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
267			    strerror(errno));
268			return (dt_set_errno(dtp, errno));
269		}
270	}
271
272
273	return (ftp->ftps_noffs);
274}
275
276/*ARGSUSED*/
277int
278dt_pid_create_offset_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
279    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, ulong_t off)
280{
281	if (off & 0x3)
282		return (DT_PROC_ALIGN);
283
284	ftp->ftps_type = DTFTP_OFFSETS;
285	ftp->ftps_pc = (uintptr_t)symp->st_value;
286	ftp->ftps_size = (size_t)symp->st_size;
287	ftp->ftps_noffs = 1;
288	ftp->ftps_offs[0] = off;
289
290	if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
291		dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
292		    strerror(errno));
293		return (dt_set_errno(dtp, errno));
294	}
295
296	return (1);
297}
298
299/*ARGSUSED*/
300int
301dt_pid_create_glob_offset_probes(struct ps_prochandle *P, dtrace_hdl_t *dtp,
302    fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, const char *pattern)
303{
304	ulong_t i;
305
306	ftp->ftps_type = DTFTP_OFFSETS;
307	ftp->ftps_pc = (uintptr_t)symp->st_value;
308	ftp->ftps_size = (size_t)symp->st_size;
309	ftp->ftps_noffs = 0;
310
311	/*
312	 * If we're matching against everything, just iterate through each
313	 * instruction in the function, otherwise look for matching offset
314	 * names by constructing the string and comparing it against the
315	 * pattern.
316	 */
317	if (strcmp("*", pattern) == 0) {
318		for (i = 0; i < symp->st_size; i += 4) {
319			ftp->ftps_offs[ftp->ftps_noffs++] = i;
320		}
321	} else {
322		char name[sizeof (i) * 2 + 1];
323
324		for (i = 0; i < symp->st_size; i += 4) {
325			(void) sprintf(name, "%lx", i);
326			if (gmatch(name, pattern))
327				ftp->ftps_offs[ftp->ftps_noffs++] = i;
328		}
329	}
330
331	if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
332		dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
333		    strerror(errno));
334		return (dt_set_errno(dtp, errno));
335	}
336
337	return (ftp->ftps_noffs);
338}
339