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 * $FreeBSD$
26 *
27 */
28
29/*
30 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
31 * Use is subject to license terms.
32 */
33
34#include <sys/cdefs.h>
35#include <sys/param.h>
36
37#include <sys/dtrace.h>
38#include <machine/stack.h>
39#include <machine/trap.h>
40
41#include "fbt.h"
42
43#define	FBT_PUSHM		0xe92d0000
44#define	FBT_POPM		0xe8bd0000
45#define	FBT_JUMP		0xea000000
46#define	FBT_SUBSP		0xe24dd000
47
48#define	FBT_ENTRY	"entry"
49#define	FBT_RETURN	"return"
50
51int
52fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval)
53{
54	solaris_cpu_t *cpu = &solaris_cpu[curcpu];
55	fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
56	register_t fifthparam;
57
58	for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
59		if ((uintptr_t)fbt->fbtp_patchpoint != addr)
60			continue;
61
62		cpu->cpu_dtrace_caller = addr;
63
64		if (fbt->fbtp_roffset == 0) {
65			/* Get 5th parameter from stack */
66			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
67			fifthparam = *(register_t *)frame->tf_svc_sp;
68			DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
69
70			dtrace_probe(fbt->fbtp_id, frame->tf_r0,
71			    frame->tf_r1, frame->tf_r2,
72			    frame->tf_r3, fifthparam);
73		} else {
74			dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval,
75			    0, 0, 0);
76		}
77
78		cpu->cpu_dtrace_caller = 0;
79		return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT));
80	}
81
82	return (0);
83}
84
85void
86fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val)
87{
88
89	*fbt->fbtp_patchpoint = val;
90	icache_sync((vm_offset_t)fbt->fbtp_patchpoint, sizeof(val));
91}
92
93int
94fbt_provide_module_function(linker_file_t lf, int symindx,
95    linker_symval_t *symval, void *opaque)
96{
97	char *modname = opaque;
98	const char *name = symval->name;
99	fbt_probe_t *fbt, *retfbt;
100	uint32_t *instr, *limit;
101	int popm;
102
103	if (fbt_excluded(name))
104		return (0);
105
106	instr = (uint32_t *)symval->value;
107	limit = (uint32_t *)(symval->value + symval->size);
108
109	/*
110	 * va_arg functions has first instruction of
111	 * sub sp, sp, #?
112	 */
113	if ((*instr & 0xfffff000) == FBT_SUBSP)
114		instr++;
115
116	/*
117	 * check if insn is a pushm with LR
118	 */
119	if ((*instr & 0xffff0000) != FBT_PUSHM ||
120	    (*instr & (1 << LR)) == 0)
121		return (0);
122
123	fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
124	fbt->fbtp_name = name;
125	fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
126	    name, FBT_ENTRY, 2, fbt);
127	fbt->fbtp_patchpoint = instr;
128	fbt->fbtp_ctl = lf;
129	fbt->fbtp_loadcnt = lf->loadcnt;
130	fbt->fbtp_savedval = *instr;
131	fbt->fbtp_patchval = FBT_BREAKPOINT;
132	fbt->fbtp_rval = DTRACE_INVOP_PUSHM;
133	fbt->fbtp_symindx = symindx;
134
135	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
136	fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
137
138	lf->fbt_nentries++;
139
140	popm = FBT_POPM | ((*instr) & 0x3FFF) | 0x8000;
141
142	retfbt = NULL;
143again:
144	for (; instr < limit; instr++) {
145		if (*instr == popm)
146			break;
147		else if ((*instr & 0xff000000) == FBT_JUMP) {
148			uint32_t *target, *start;
149			int offset;
150
151			offset = (*instr & 0xffffff);
152			offset <<= 8;
153			offset /= 64;
154			target = instr + (2 + offset);
155			start = (uint32_t *)symval->value;
156			if (target >= limit || target < start)
157				break;
158		}
159	}
160
161	if (instr >= limit)
162		return (0);
163
164	/*
165	 * We have a winner!
166	 */
167	fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
168	fbt->fbtp_name = name;
169	if (retfbt == NULL) {
170		fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
171		    name, FBT_RETURN, 2, fbt);
172	} else {
173		retfbt->fbtp_probenext = fbt;
174		fbt->fbtp_id = retfbt->fbtp_id;
175	}
176	retfbt = fbt;
177
178	fbt->fbtp_patchpoint = instr;
179	fbt->fbtp_ctl = lf;
180	fbt->fbtp_loadcnt = lf->loadcnt;
181	fbt->fbtp_symindx = symindx;
182	if ((*instr & 0xff000000) == FBT_JUMP)
183		fbt->fbtp_rval = DTRACE_INVOP_B;
184	else
185		fbt->fbtp_rval = DTRACE_INVOP_POPM;
186	fbt->fbtp_roffset = (uintptr_t)instr - (uintptr_t)symval->value;
187	fbt->fbtp_savedval = *instr;
188	fbt->fbtp_patchval = FBT_BREAKPOINT;
189	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
190	fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
191
192	lf->fbt_nentries++;
193
194	instr++;
195	goto again;
196}
197