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 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <kern/cpu_data.h>
27 #include <kern/thread.h>
28 #include <mach/thread_status.h>
29 #include <mach/vm_param.h>
30
31 #include <sys/dtrace.h>
32 #include <sys/dtrace_impl.h>
33
34 #include <sys/dtrace_glue.h>
35
36 #include <sys/sdt_impl.h>
37
38 extern sdt_probe_t **sdt_probetab;
39
40 /*ARGSUSED*/
41 int
sdt_invop(uintptr_t addr,uintptr_t * stack,uintptr_t eax)42 sdt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
43 {
44 #pragma unused(eax)
45 sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
46
47 for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
48 if ((uintptr_t)sdt->sdp_patchpoint == addr) {
49 x86_saved_state64_t *regs = (x86_saved_state64_t *)stack;
50
51 dtrace_probe(sdt->sdp_id, regs->rdi, regs->rsi, regs->rdx, regs->rcx, regs->r8);
52
53 return DTRACE_INVOP_NOP;
54 }
55 }
56
57 return 0;
58 }
59
60
61 struct frame {
62 struct frame *backchain;
63 uintptr_t retaddr;
64 };
65
66 /*ARGSUSED*/
67 uint64_t
sdt_getarg(void * arg,dtrace_id_t id,void * parg,int argno,int aframes)68 sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
69 {
70 #pragma unused(arg, id, parg)
71 uint64_t val;
72 struct frame *fp = (struct frame *)__builtin_frame_address(0);
73 uintptr_t *stack;
74 uintptr_t pc;
75 int i;
76
77 /*
78 * A total of 6 arguments are passed via registers; any argument with
79 * index of 5 or lower is therefore in a register.
80 */
81 int inreg = 5;
82
83 for (i = 1; i <= aframes; i++) {
84 fp = fp->backchain;
85 pc = fp->retaddr;
86
87 if (dtrace_invop_callsite_pre != NULL
88 && pc > (uintptr_t)dtrace_invop_callsite_pre
89 && pc <= (uintptr_t)dtrace_invop_callsite_post) {
90 /*
91 * In the case of x86_64, we will use the pointer to the
92 * save area structure that was pushed when we took the
93 * trap. To get this structure, we must increment
94 * beyond the frame structure. If the
95 * argument that we're seeking is passed on the stack,
96 * we'll pull the true stack pointer out of the saved
97 * registers and decrement our argument by the number
98 * of arguments passed in registers; if the argument
99 * we're seeking is passed in regsiters, we can just
100 * load it directly.
101 */
102
103 /* fp points to frame of dtrace_invop() activation. */
104 fp = fp->backchain; /* to fbt_perfcallback() activation. */
105 fp = fp->backchain; /* to kernel_trap() activation. */
106 fp = fp->backchain; /* to trap_from_kernel() activation. */
107
108 x86_saved_state_t *tagged_regs = (x86_saved_state_t *)&fp[1];
109 x86_saved_state64_t *saved_state = saved_state64(tagged_regs);
110
111 if (argno <= inreg) {
112 stack = (uintptr_t *)(void*)&saved_state->rdi;
113 } else {
114 fp = (struct frame *)(saved_state->isf.rsp);
115 stack = (uintptr_t *)&fp[0]; /* Find marshalled
116 * arguments */
117 argno -= (inreg + 1);
118 }
119 goto load;
120 }
121 }
122
123 /*
124 * We know that we did not come through a trap to get into
125 * dtrace_probe() -- We arrive here when the provider has
126 * called dtrace_probe() directly.
127 * The probe ID is the first argument to dtrace_probe().
128 * We must advance beyond that to get the argX.
129 */
130 argno++; /* Advance past probeID */
131
132 if (argno <= inreg) {
133 /*
134 * This shouldn't happen. If the argument is passed in a
135 * register then it should have been, well, passed in a
136 * register...
137 */
138 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
139 return 0;
140 }
141
142 argno -= (inreg + 1);
143 stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
144
145 load:
146 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
147 /* dtrace_probe arguments arg0 ... arg4 are 64bits wide */
148 val = (uint64_t)(*(((uintptr_t *)stack) + argno));
149 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
150
151 return val;
152 }
153