xref: /illumos-gate/usr/src/lib/libdtrace/sparc/dt_isadep.c (revision 1da57d551424de5a9d469760be7c4b4d4f10a755)
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 #include <stdlib.h>
28 #include <assert.h>
29 #include <errno.h>
30 #include <string.h>
31 #include <libgen.h>
32 
33 #include <dt_impl.h>
34 #include <dt_pid.h>
35 
36 #define	OP(x)		((x) >> 30)
37 #define	OP2(x)		(((x) >> 22) & 0x07)
38 #define	COND(x)		(((x) >> 25) & 0x0f)
39 #define	A(x)		(((x) >> 29) & 0x01)
40 
41 #define	OP_BRANCH	0
42 
43 #define	OP2_BPcc	0x1
44 #define	OP2_Bicc	0x2
45 #define	OP2_BPr		0x3
46 #define	OP2_FBPfcc	0x5
47 #define	OP2_FBfcc	0x6
48 
49 /*ARGSUSED*/
50 int
dt_pid_create_entry_probe(struct ps_prochandle * P,dtrace_hdl_t * dtp,fasttrap_probe_spec_t * ftp,const GElf_Sym * symp)51 dt_pid_create_entry_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
52     fasttrap_probe_spec_t *ftp, const GElf_Sym *symp)
53 {
54 	ftp->ftps_type = DTFTP_ENTRY;
55 	ftp->ftps_pc = (uintptr_t)symp->st_value;
56 	ftp->ftps_size = (size_t)symp->st_size;
57 	ftp->ftps_noffs = 1;
58 	ftp->ftps_offs[0] = 0;
59 
60 	if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
61 		dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
62 		    strerror(errno));
63 		return (dt_set_errno(dtp, errno));
64 	}
65 
66 	return (1);
67 }
68 
69 int
dt_pid_create_return_probe(struct ps_prochandle * P,dtrace_hdl_t * dtp,fasttrap_probe_spec_t * ftp,const GElf_Sym * symp,uint64_t * stret)70 dt_pid_create_return_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
71     fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, uint64_t *stret)
72 {
73 
74 	uint32_t *text;
75 	int i;
76 	int srdepth = 0;
77 
78 	if ((text = malloc(symp->st_size + 4)) == NULL) {
79 		dt_dprintf("mr sparkle: malloc() failed\n");
80 		return (DT_PROC_ERR);
81 	}
82 
83 	if (Pread(P, text, symp->st_size, symp->st_value) != symp->st_size) {
84 		dt_dprintf("mr sparkle: Pread() failed\n");
85 		free(text);
86 		return (DT_PROC_ERR);
87 	}
88 
89 	/*
90 	 * Leave a dummy instruction in the last slot to simplify edge
91 	 * conditions.
92 	 */
93 	text[symp->st_size / 4] = 0;
94 
95 	ftp->ftps_type = DTFTP_RETURN;
96 	ftp->ftps_pc = symp->st_value;
97 	ftp->ftps_size = symp->st_size;
98 	ftp->ftps_noffs = 0;
99 
100 	for (i = 0; i < symp->st_size / 4; i++) {
101 		/*
102 		 * If we encounter an existing tracepoint, query the
103 		 * kernel to find out the instruction that was
104 		 * replaced at this spot.
105 		 */
106 		while (text[i] == FASTTRAP_INSTR) {
107 			fasttrap_instr_query_t instr;
108 
109 			instr.ftiq_pid = Pstatus(P)->pr_pid;
110 			instr.ftiq_pc = symp->st_value + i * 4;
111 
112 			if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_GETINSTR,
113 			    &instr) != 0) {
114 
115 				if (errno == ESRCH || errno == ENOENT) {
116 					if (Pread(P, &text[i], 4,
117 					    instr.ftiq_pc) != 4) {
118 						dt_dprintf("mr sparkle: "
119 						    "Pread() failed\n");
120 						free(text);
121 						return (DT_PROC_ERR);
122 					}
123 					continue;
124 				}
125 
126 				free(text);
127 				dt_dprintf("mr sparkle: getinstr query "
128 				    "failed: %s\n", strerror(errno));
129 				return (DT_PROC_ERR);
130 			}
131 
132 			text[i] = instr.ftiq_instr;
133 			break;
134 		}
135 
136 		/* save */
137 		if ((text[i] & 0xc1f80000) == 0x81e00000) {
138 			srdepth++;
139 			continue;
140 		}
141 
142 		/* restore */
143 		if ((text[i] & 0xc1f80000) == 0x81e80000) {
144 			srdepth--;
145 			continue;
146 		}
147 
148 		if (srdepth > 0) {
149 			/* ret */
150 			if (text[i] == 0x81c7e008)
151 				goto is_ret;
152 
153 			/* return */
154 			if (text[i] == 0x81cfe008)
155 				goto is_ret;
156 
157 			/* call or jmpl w/ restore in the slot */
158 			if (((text[i] & 0xc0000000) == 0x40000000 ||
159 			    (text[i] & 0xc1f80000) == 0x81c00000) &&
160 			    (text[i + 1] & 0xc1f80000) == 0x81e80000)
161 				goto is_ret;
162 
163 			/* call to one of the stret routines */
164 			if ((text[i] & 0xc0000000) == 0x40000000) {
165 				int32_t	disp = text[i] << 2;
166 				uint64_t dest = ftp->ftps_pc + i * 4 + disp;
167 
168 				dt_dprintf("dest = %llx\n", (u_longlong_t)dest);
169 
170 				if (dest == stret[0] || dest == stret[1] ||
171 				    dest == stret[2] || dest == stret[3])
172 					goto is_ret;
173 			}
174 		} else {
175 			/* external call */
176 			if ((text[i] & 0xc0000000) == 0x40000000) {
177 				int32_t dst = text[i] << 2;
178 
179 				dst += i * 4;
180 
181 				if ((uintptr_t)dst >= (uintptr_t)symp->st_size)
182 					goto is_ret;
183 			}
184 
185 			/* jmpl into %g0 -- this includes the retl pseudo op */
186 			if ((text[i] & 0xfff80000) == 0x81c00000)
187 				goto is_ret;
188 
189 			/* external branch -- possible return site */
190 			if (OP(text[i]) == OP_BRANCH) {
191 				int32_t dst;
192 				int baa;
193 
194 				switch (OP2(text[i])) {
195 				case OP2_BPcc:
196 					dst = text[i] & 0x7ffff;
197 					dst <<= 13;
198 					dst >>= 11;
199 
200 					baa = COND(text[i]) == 8 && A(text[i]);
201 					break;
202 				case OP2_Bicc:
203 					dst = text[i] & 0x3fffff;
204 					dst <<= 10;
205 					dst >>= 8;
206 
207 					baa = COND(text[i]) == 8 && A(text[i]);
208 					break;
209 				case OP2_BPr:
210 					dst = (((text[i]) >> 6) & 0xc000) |
211 					    ((text[i]) & 0x3fff);
212 					dst <<= 16;
213 					dst >>= 14;
214 
215 					baa = 0;
216 					break;
217 				case OP2_FBPfcc:
218 					dst = text[i] & 0x7ffff;
219 					dst <<= 13;
220 					dst >>= 11;
221 
222 					baa = COND(text[i]) == 8 && A(text[i]);
223 					break;
224 				case OP2_FBfcc:
225 					dst = text[i] & 0x3fffff;
226 					dst <<= 10;
227 					dst >>= 8;
228 
229 					baa = COND(text[i]) == 8 && A(text[i]);
230 					break;
231 				default:
232 					continue;
233 				}
234 
235 				dst += i * 4;
236 
237 				/*
238 				 * Interpret branches outside of the function's
239 				 * bounds as potential return sites. If the
240 				 * branch is a ba,a don't skip the instruction
241 				 * in the delay slot.
242 				 */
243 				if ((uintptr_t)dst >=
244 				    (uintptr_t)symp->st_size) {
245 					if (baa)
246 						goto is_ret_baa;
247 					else
248 						goto is_ret;
249 				}
250 			}
251 		}
252 
253 		continue;
254 is_ret:
255 		i++;
256 is_ret_baa:
257 		dt_dprintf("return at offset %x\n", i * 4);
258 		ftp->ftps_offs[ftp->ftps_noffs++] = i * 4;
259 	}
260 
261 	free(text);
262 	if (ftp->ftps_noffs > 0) {
263 		if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
264 			dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
265 			    strerror(errno));
266 			return (dt_set_errno(dtp, errno));
267 		}
268 	}
269 
270 
271 	return (ftp->ftps_noffs);
272 }
273 
274 /*ARGSUSED*/
275 int
dt_pid_create_offset_probe(struct ps_prochandle * P,dtrace_hdl_t * dtp,fasttrap_probe_spec_t * ftp,const GElf_Sym * symp,ulong_t off)276 dt_pid_create_offset_probe(struct ps_prochandle *P, dtrace_hdl_t *dtp,
277     fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, ulong_t off)
278 {
279 	if (off & 0x3)
280 		return (DT_PROC_ALIGN);
281 
282 	ftp->ftps_type = DTFTP_OFFSETS;
283 	ftp->ftps_pc = (uintptr_t)symp->st_value;
284 	ftp->ftps_size = (size_t)symp->st_size;
285 	ftp->ftps_noffs = 1;
286 	ftp->ftps_offs[0] = off;
287 
288 	if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
289 		dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
290 		    strerror(errno));
291 		return (dt_set_errno(dtp, errno));
292 	}
293 
294 	return (1);
295 }
296 
297 /*ARGSUSED*/
298 int
dt_pid_create_glob_offset_probes(struct ps_prochandle * P,dtrace_hdl_t * dtp,fasttrap_probe_spec_t * ftp,const GElf_Sym * symp,const char * pattern)299 dt_pid_create_glob_offset_probes(struct ps_prochandle *P, dtrace_hdl_t *dtp,
300     fasttrap_probe_spec_t *ftp, const GElf_Sym *symp, const char *pattern)
301 {
302 	ulong_t i;
303 
304 	ftp->ftps_type = DTFTP_OFFSETS;
305 	ftp->ftps_pc = (uintptr_t)symp->st_value;
306 	ftp->ftps_size = (size_t)symp->st_size;
307 	ftp->ftps_noffs = 0;
308 
309 	/*
310 	 * If we're matching against everything, just iterate through each
311 	 * instruction in the function, otherwise look for matching offset
312 	 * names by constructing the string and comparing it against the
313 	 * pattern.
314 	 */
315 	if (strcmp("*", pattern) == 0) {
316 		for (i = 0; i < symp->st_size; i += 4) {
317 			ftp->ftps_offs[ftp->ftps_noffs++] = i;
318 		}
319 	} else {
320 		char name[sizeof (i) * 2 + 1];
321 
322 		for (i = 0; i < symp->st_size; i += 4) {
323 			(void) sprintf(name, "%lx", i);
324 			if (gmatch(name, pattern))
325 				ftp->ftps_offs[ftp->ftps_noffs++] = i;
326 		}
327 	}
328 
329 	if (ioctl(dtp->dt_ftfd, FASTTRAPIOC_MAKEPROBE, ftp) != 0) {
330 		dt_dprintf("fasttrap probe creation ioctl failed: %s\n",
331 		    strerror(errno));
332 		return (dt_set_errno(dtp, errno));
333 	}
334 
335 	return (ftp->ftps_noffs);
336 }
337