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 * Portions Copyright 2013 Justin Hibbits jhibbits@freebsd.org
23 * Portions Copyright 2013 Howard Su howardsu@freebsd.org
24 * Portions Copyright 2016-2018 Ruslan Bukin <br@bsdpad.com>
25 */
26
27 /*
28 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
29 * Use is subject to license terms.
30 */
31
32 #include <sys/param.h>
33
34 #include <sys/dtrace.h>
35
36 #include <machine/riscvreg.h>
37 #include <machine/encoding.h>
38
39 #include "fbt.h"
40
41 #define FBT_C_PATCHVAL MATCH_C_EBREAK
42 #define FBT_PATCHVAL MATCH_EBREAK
43 #define FBT_AFRAMES 5
44
45 int
fbt_invop(uintptr_t addr,struct trapframe * frame,uintptr_t rval)46 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval)
47 {
48 solaris_cpu_t *cpu;
49 fbt_probe_t *fbt;
50
51 cpu = &solaris_cpu[curcpu];
52 fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
53
54 for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
55 if ((uintptr_t)fbt->fbtp_patchpoint == addr) {
56 cpu->cpu_dtrace_caller = frame->tf_ra - INSN_SIZE;
57
58 if (fbt->fbtp_roffset == 0) {
59 dtrace_probe(fbt->fbtp_id, frame->tf_a[0],
60 frame->tf_a[1], frame->tf_a[2],
61 frame->tf_a[3], frame->tf_a[4]);
62 } else {
63 dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset,
64 frame->tf_a[0], frame->tf_a[1], 0, 0);
65 }
66
67 cpu->cpu_dtrace_caller = 0;
68 return (fbt->fbtp_savedval);
69 }
70 }
71
72 return (0);
73 }
74
75 void
fbt_patch_tracepoint(fbt_probe_t * fbt,fbt_patchval_t val)76 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val)
77 {
78
79 switch(fbt->fbtp_patchval) {
80 case FBT_C_PATCHVAL:
81 *(uint16_t *)fbt->fbtp_patchpoint = (uint16_t)val;
82 fence_i();
83 break;
84 case FBT_PATCHVAL:
85 *fbt->fbtp_patchpoint = val;
86 fence_i();
87 break;
88 };
89 }
90
91 int
fbt_provide_module_function(linker_file_t lf,int symindx,linker_symval_t * symval,void * opaque)92 fbt_provide_module_function(linker_file_t lf, int symindx,
93 linker_symval_t *symval, void *opaque)
94 {
95 fbt_probe_t *fbt, *retfbt;
96 uint32_t *instr, *limit;
97 const char *name;
98 char *modname;
99 int patchval;
100 int rval;
101
102 modname = opaque;
103 name = symval->name;
104
105 /* Check if function is excluded from instrumentation */
106 if (fbt_excluded(name))
107 return (0);
108
109 /*
110 * Some assembly-language exception handlers are not suitable for
111 * instrumentation.
112 */
113 if (strcmp(name, "cpu_exception_handler") == 0)
114 return (0);
115 if (strcmp(name, "cpu_exception_handler_user") == 0)
116 return (0);
117 if (strcmp(name, "cpu_exception_handler_supervisor") == 0)
118 return (0);
119 if (strcmp(name, "do_trap_supervisor") == 0)
120 return (0);
121
122 instr = (uint32_t *)(symval->value);
123 limit = (uint32_t *)(symval->value + symval->size);
124
125 /* Look for sd operation */
126 for (; instr < limit; instr++) {
127 /* Look for a non-compressed store of ra to sp */
128 if (dtrace_instr_sdsp(&instr)) {
129 rval = DTRACE_INVOP_SD;
130 patchval = FBT_PATCHVAL;
131 break;
132 }
133
134 /* Look for a 'C'-compressed store of ra to sp. */
135 if (dtrace_instr_c_sdsp(&instr)) {
136 rval = DTRACE_INVOP_C_SDSP;
137 patchval = FBT_C_PATCHVAL;
138 break;
139 }
140 }
141
142 if (instr >= limit)
143 return (0);
144
145 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
146 fbt->fbtp_name = name;
147 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
148 name, FBT_ENTRY, FBT_AFRAMES, fbt);
149 fbt->fbtp_patchpoint = instr;
150 fbt->fbtp_ctl = lf;
151 fbt->fbtp_loadcnt = lf->loadcnt;
152 fbt->fbtp_savedval = *instr;
153 fbt->fbtp_patchval = patchval;
154 fbt->fbtp_rval = rval;
155 fbt->fbtp_symindx = symindx;
156
157 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
158 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
159
160 lf->fbt_nentries++;
161
162 retfbt = NULL;
163 again:
164 for (; instr < limit; instr++) {
165 /* Look for non-compressed return */
166 if (dtrace_instr_ret(&instr)) {
167 rval = DTRACE_INVOP_RET;
168 patchval = FBT_PATCHVAL;
169 break;
170 }
171
172 /* Look for 'C'-compressed return */
173 if (dtrace_instr_c_ret(&instr)) {
174 rval = DTRACE_INVOP_C_RET;
175 patchval = FBT_C_PATCHVAL;
176 break;
177 }
178 }
179
180 if (instr >= limit)
181 return (0);
182
183 /*
184 * We have a winner!
185 */
186 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
187 fbt->fbtp_name = name;
188 if (retfbt == NULL) {
189 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
190 name, FBT_RETURN, FBT_AFRAMES, fbt);
191 } else {
192 retfbt->fbtp_probenext = fbt;
193 fbt->fbtp_id = retfbt->fbtp_id;
194 }
195 retfbt = fbt;
196
197 fbt->fbtp_patchpoint = instr;
198 fbt->fbtp_ctl = lf;
199 fbt->fbtp_loadcnt = lf->loadcnt;
200 fbt->fbtp_symindx = symindx;
201 fbt->fbtp_rval = rval;
202 fbt->fbtp_roffset = (uintptr_t)instr - (uintptr_t)symval->value;
203 fbt->fbtp_savedval = *instr;
204 fbt->fbtp_patchval = patchval;
205 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
206 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
207
208 lf->fbt_nentries++;
209
210 instr++;
211 goto again;
212 }
213