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 *
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 #include <machine/stack.h>
36 #include <machine/trap.h>
37
38 #include "fbt.h"
39
40 #define FBT_PUSHM 0xe92d0000
41 #define FBT_POPM 0xe8bd0000
42 #define FBT_JUMP 0xea000000
43 #define FBT_SUBSP 0xe24dd000
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 = &solaris_cpu[curcpu];
49 fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
50 register_t fifthparam;
51
52 for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
53 if ((uintptr_t)fbt->fbtp_patchpoint != addr)
54 continue;
55
56 cpu->cpu_dtrace_caller = addr;
57
58 if (fbt->fbtp_roffset == 0) {
59 /* Get 5th parameter from stack */
60 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
61 fifthparam = *(register_t *)frame->tf_svc_sp;
62 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
63
64 dtrace_probe(fbt->fbtp_id, frame->tf_r0,
65 frame->tf_r1, frame->tf_r2,
66 frame->tf_r3, fifthparam);
67 } else {
68 dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval,
69 0, 0, 0);
70 }
71
72 cpu->cpu_dtrace_caller = 0;
73 return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT));
74 }
75
76 return (0);
77 }
78
79 void
fbt_patch_tracepoint(fbt_probe_t * fbt,fbt_patchval_t val)80 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val)
81 {
82
83 *fbt->fbtp_patchpoint = val;
84 icache_sync((vm_offset_t)fbt->fbtp_patchpoint, sizeof(val));
85 }
86
87 int
fbt_provide_module_function(linker_file_t lf,int symindx,linker_symval_t * symval,void * opaque)88 fbt_provide_module_function(linker_file_t lf, int symindx,
89 linker_symval_t *symval, void *opaque)
90 {
91 char *modname = opaque;
92 const char *name = symval->name;
93 fbt_probe_t *fbt, *retfbt;
94 uint32_t *instr, *limit;
95 int popm;
96
97 if (fbt_excluded(name))
98 return (0);
99
100 instr = (uint32_t *)symval->value;
101 limit = (uint32_t *)(symval->value + symval->size);
102
103 /*
104 * va_arg functions has first instruction of
105 * sub sp, sp, #?
106 */
107 if ((*instr & 0xfffff000) == FBT_SUBSP)
108 instr++;
109
110 /*
111 * check if insn is a pushm with LR
112 */
113 if ((*instr & 0xffff0000) != FBT_PUSHM ||
114 (*instr & (1 << LR)) == 0)
115 return (0);
116
117 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
118 fbt->fbtp_name = name;
119 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
120 name, FBT_ENTRY, 2, fbt);
121 fbt->fbtp_patchpoint = instr;
122 fbt->fbtp_ctl = lf;
123 fbt->fbtp_loadcnt = lf->loadcnt;
124 fbt->fbtp_savedval = *instr;
125 fbt->fbtp_patchval = FBT_BREAKPOINT;
126 fbt->fbtp_rval = DTRACE_INVOP_PUSHM;
127 fbt->fbtp_symindx = symindx;
128
129 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
130 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
131
132 lf->fbt_nentries++;
133
134 popm = FBT_POPM | ((*instr) & 0x3FFF) | 0x8000;
135
136 retfbt = NULL;
137 again:
138 for (; instr < limit; instr++) {
139 if (*instr == popm)
140 break;
141 else if ((*instr & 0xff000000) == FBT_JUMP) {
142 uint32_t *target, *start;
143 int offset;
144
145 offset = (*instr & 0xffffff);
146 offset <<= 8;
147 offset /= 64;
148 target = instr + (2 + offset);
149 start = (uint32_t *)symval->value;
150 if (target >= limit || target < start)
151 break;
152 }
153 }
154
155 if (instr >= limit)
156 return (0);
157
158 /*
159 * We have a winner!
160 */
161 fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
162 fbt->fbtp_name = name;
163 if (retfbt == NULL) {
164 fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
165 name, FBT_RETURN, 2, fbt);
166 } else {
167 retfbt->fbtp_probenext = fbt;
168 fbt->fbtp_id = retfbt->fbtp_id;
169 }
170 retfbt = fbt;
171
172 fbt->fbtp_patchpoint = instr;
173 fbt->fbtp_ctl = lf;
174 fbt->fbtp_loadcnt = lf->loadcnt;
175 fbt->fbtp_symindx = symindx;
176 if ((*instr & 0xff000000) == FBT_JUMP)
177 fbt->fbtp_rval = DTRACE_INVOP_B;
178 else
179 fbt->fbtp_rval = DTRACE_INVOP_POPM;
180 fbt->fbtp_roffset = (uintptr_t)instr - (uintptr_t)symval->value;
181 fbt->fbtp_savedval = *instr;
182 fbt->fbtp_patchval = FBT_BREAKPOINT;
183 fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
184 fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
185
186 lf->fbt_nentries++;
187
188 instr++;
189 goto again;
190 }
191