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#if defined(__i386__)
50/*ARGSUSED*/
51int
52sdt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
53{
54#pragma unused(eax)
55	uintptr_t stack0 = 0, stack1 = 0, stack2 = 0, stack3 = 0, stack4 = 0;
56	sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
57
58	for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
59		if ((uintptr_t)sdt->sdp_patchpoint == addr) {
60                        uintptr_t *stacktop;
61                        if (CPU_ON_INTR(CPU))
62                                stacktop = (uintptr_t *)dtrace_get_cpu_int_stack_top();
63                        else
64                                stacktop = (uintptr_t *)(dtrace_get_kernel_stack(current_thread()) + kernel_stack_size);
65
66            if (stack <= stacktop)
67                stack0 = *stack++;
68            if (stack <= stacktop)
69                stack1 = *stack++;
70            if (stack <= stacktop)
71                stack2 = *stack++;
72            if (stack <= stacktop)
73                stack3 = *stack++;
74            if (stack <= stacktop)
75                stack4 = *stack++;
76
77			dtrace_probe(sdt->sdp_id, stack0, stack1, stack2, stack3, stack4);
78
79			return (DTRACE_INVOP_NOP);
80		}
81	}
82
83	return (0);
84}
85#elif defined(__x86_64__)
86/*ARGSUSED*/
87int
88sdt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
89{
90#pragma unused(eax)
91	sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
92
93	for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
94		if ((uintptr_t)sdt->sdp_patchpoint == addr) {
95			x86_saved_state64_t *regs = (x86_saved_state64_t *)stack;
96
97			dtrace_probe(sdt->sdp_id, regs->rdi, regs->rsi, regs->rdx, regs->rcx, regs->r8);
98
99			return (DTRACE_INVOP_NOP);
100		}
101	}
102
103	return (0);
104}
105#else
106#error Unknown arch
107#endif
108
109
110struct frame {
111    struct frame *backchain;
112    uintptr_t retaddr;
113};
114
115/*ARGSUSED*/
116uint64_t
117sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
118{
119#pragma unused(arg, id, parg)
120	uint64_t val;
121	struct frame *fp = (struct frame *)__builtin_frame_address(0);
122	uintptr_t *stack;
123	uintptr_t pc;
124	int i;
125
126#if defined(__x86_64__)
127    /*
128     * A total of 6 arguments are passed via registers; any argument with
129     * index of 5 or lower is therefore in a register.
130     */
131    int inreg = 5;
132#endif
133
134	for (i = 1; i <= aframes; i++) {
135		fp = fp->backchain;
136		pc = fp->retaddr;
137
138		if (dtrace_invop_callsite_pre != NULL
139			&& pc  >  (uintptr_t)dtrace_invop_callsite_pre
140			&& pc  <= (uintptr_t)dtrace_invop_callsite_post) {
141#if defined(__i386__)
142			/*
143			 * If we pass through the invalid op handler, we will
144			 * use the pointer that it passed to the stack as the
145			 * second argument to dtrace_invop() as the pointer to
146			 * the frame we're hunting for.
147			 */
148
149			stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
150			fp = (struct frame *)stack[1]; /* Grab *second* argument */
151			stack = (uintptr_t *)&fp[0]; /* Find marshalled arguments */
152#elif defined(__x86_64__)
153			/*
154			 * In the case of x86_64, we will use the pointer to the
155			 * save area structure that was pushed when we took the
156			 * trap.  To get this structure, we must increment
157			 * beyond the frame structure. If the
158			 * argument that we're seeking is passed on the stack,
159			 * we'll pull the true stack pointer out of the saved
160			 * registers and decrement our argument by the number
161			 * of arguments passed in registers; if the argument
162			 * we're seeking is passed in regsiters, we can just
163			 * load it directly.
164			 */
165
166			/* fp points to frame of dtrace_invop() activation. */
167			fp = fp->backchain; /* to fbt_perfcallback() activation. */
168			fp = fp->backchain; /* to kernel_trap() activation. */
169			fp = fp->backchain; /* to trap_from_kernel() activation. */
170
171			x86_saved_state_t   *tagged_regs = (x86_saved_state_t *)&fp[1];
172			x86_saved_state64_t *saved_state = saved_state64(tagged_regs);
173
174			if (argno <= inreg) {
175				stack = (uintptr_t *)&saved_state->rdi;
176			} else {
177				fp = (struct frame *)(saved_state->isf.rsp);
178				stack = (uintptr_t *)&fp[0]; /* Find marshalled
179								arguments */
180				argno -= (inreg +1);
181			}
182#else
183#error Unknown arch
184#endif
185			goto load;
186		}
187	}
188
189	/*
190	 * We know that we did not come through a trap to get into
191	 * dtrace_probe() --  We arrive here when the provider has
192	 * called dtrace_probe() directly.
193	 * The probe ID is the first argument to dtrace_probe().
194	 * We must advance beyond that to get the argX.
195	 */
196	argno++; /* Advance past probeID */
197
198#if defined(__x86_64__)
199	if (argno <= inreg) {
200		/*
201		 * This shouldn't happen.  If the argument is passed in a
202		 * register then it should have been, well, passed in a
203		 * register...
204		 */
205		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
206		return (0);
207	}
208
209	argno -= (inreg + 1);
210#endif
211	stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
212
213load:
214	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
215	/* dtrace_probe arguments arg0 ... arg4 are 64bits wide */
216	val = (uint64_t)(*(((uintptr_t *)stack) + argno));
217	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
218
219	return (val);
220}
221
222