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/* #pragma ident "@(#)sdt.c 1.9 08/07/01 SMI" */
27
28#ifdef KERNEL
29#ifndef _KERNEL
30#define _KERNEL /* Solaris vs. Darwin */
31#endif
32#endif
33
34#define MACH__POSIX_C_SOURCE_PRIVATE 1 /* pulls in suitable savearea from mach/ppc/thread_status.h */
35#include <kern/cpu_data.h>
36#include <kern/thread.h>
37#include <mach/thread_status.h>
38#include <mach/vm_param.h>
39
40#include <sys/dtrace.h>
41#include <sys/dtrace_impl.h>
42
43#include <sys/dtrace_glue.h>
44
45#include <sys/sdt_impl.h>
46
47extern sdt_probe_t **sdt_probetab;
48
49/*ARGSUSED*/
50int
51sdt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
52{
53#pragma unused(eax)
54 sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
55
56 for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
57 if ((uintptr_t)sdt->sdp_patchpoint == addr) {
58 x86_saved_state64_t *regs = (x86_saved_state64_t *)stack;
59
60 dtrace_probe(sdt->sdp_id, regs->rdi, regs->rsi, regs->rdx, regs->rcx, regs->r8);
61
62 return (DTRACE_INVOP_NOP);
63 }
64 }
65
66 return (0);
67}
68
69
70struct frame {
71 struct frame *backchain;
72 uintptr_t retaddr;
73};
74
75/*ARGSUSED*/
76uint64_t
77sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
78{
79#pragma unused(arg, id, parg)
80 uint64_t val;
81 struct frame *fp = (struct frame *)__builtin_frame_address(0);
82 uintptr_t *stack;
83 uintptr_t pc;
84 int i;
85
86 /*
87 * A total of 6 arguments are passed via registers; any argument with
88 * index of 5 or lower is therefore in a register.
89 */
90 int inreg = 5;
91
92 for (i = 1; i <= aframes; i++) {
93 fp = fp->backchain;
94 pc = fp->retaddr;
95
96 if (dtrace_invop_callsite_pre != NULL
97 && pc > (uintptr_t)dtrace_invop_callsite_pre
98 && pc <= (uintptr_t)dtrace_invop_callsite_post) {
99 /*
100 * In the case of x86_64, we will use the pointer to the
101 * save area structure that was pushed when we took the
102 * trap. To get this structure, we must increment
103 * beyond the frame structure. If the
104 * argument that we're seeking is passed on the stack,
105 * we'll pull the true stack pointer out of the saved
106 * registers and decrement our argument by the number
107 * of arguments passed in registers; if the argument
108 * we're seeking is passed in regsiters, we can just
109 * load it directly.
110 */
111
112 /* fp points to frame of dtrace_invop() activation. */
113 fp = fp->backchain; /* to fbt_perfcallback() activation. */
114 fp = fp->backchain; /* to kernel_trap() activation. */
115 fp = fp->backchain; /* to trap_from_kernel() activation. */
116
117 x86_saved_state_t *tagged_regs = (x86_saved_state_t *)&fp[1];
118 x86_saved_state64_t *saved_state = saved_state64(tagged_regs);
119
120 if (argno <= inreg) {
121 stack = (uintptr_t *)(void*)&saved_state->rdi;
122 } else {
123 fp = (struct frame *)(saved_state->isf.rsp);
124 stack = (uintptr_t *)&fp[0]; /* Find marshalled
125 arguments */
126 argno -= (inreg +1);
127 }
128 goto load;
129 }
130 }
131
132 /*
133 * We know that we did not come through a trap to get into
134 * dtrace_probe() -- We arrive here when the provider has
135 * called dtrace_probe() directly.
136 * The probe ID is the first argument to dtrace_probe().
137 * We must advance beyond that to get the argX.
138 */
139 argno++; /* Advance past probeID */
140
141 if (argno <= inreg) {
142 /*
143 * This shouldn't happen. If the argument is passed in a
144 * register then it should have been, well, passed in a
145 * register...
146 */
147 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
148 return (0);
149 }
150
151 argno -= (inreg + 1);
152 stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
153
154load:
155 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
156 /* dtrace_probe arguments arg0 ... arg4 are 64bits wide */
157 val = (uint64_t)(*(((uintptr_t *)stack) + argno));
158 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
159
160 return (val);
161}
162
163