xref: /freebsd/sys/cddl/dev/fbt/aarch64/fbt_isa.c (revision d66820f2c8c6cdc3d0359abf1004dac0a466a01d)
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  * Portions Copyright 2015 Ruslan Bukin <br@bsdpad.com>
25  *
26  * $FreeBSD$
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 
39 #include "fbt.h"
40 
41 #define	AARCH64_BRK		0xd4200000
42 #define	AARCH64_BRK_IMM16_SHIFT	5
43 #define	AARCH64_BRK_IMM16_VAL	(0x40d << AARCH64_BRK_IMM16_SHIFT)
44 #define	FBT_PATCHVAL		(AARCH64_BRK | AARCH64_BRK_IMM16_VAL)
45 #define	FBT_ENTRY	"entry"
46 #define	FBT_RETURN	"return"
47 
48 int
49 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval)
50 {
51 	solaris_cpu_t *cpu;
52 	fbt_probe_t *fbt;
53 
54 	cpu = &solaris_cpu[curcpu];
55 	fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
56 
57 	for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
58 		if ((uintptr_t)fbt->fbtp_patchpoint == addr) {
59 			cpu->cpu_dtrace_caller = addr;
60 
61 			dtrace_probe(fbt->fbtp_id, frame->tf_x[0],
62 			    frame->tf_x[1], frame->tf_x[2],
63 			    frame->tf_x[3], frame->tf_x[4]);
64 
65 			cpu->cpu_dtrace_caller = 0;
66 			return (fbt->fbtp_savedval);
67 		}
68 	}
69 
70 	return (0);
71 }
72 
73 void
74 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val)
75 {
76 
77 	*fbt->fbtp_patchpoint = val;
78 	cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4);
79 }
80 
81 int
82 fbt_provide_module_function(linker_file_t lf, int symindx,
83     linker_symval_t *symval, void *opaque)
84 {
85 	fbt_probe_t *fbt, *retfbt;
86 	uint32_t *target, *start;
87 	uint32_t *instr, *limit;
88 	const char *name;
89 	char *modname;
90 	int offs;
91 
92 	modname = opaque;
93 	name = symval->name;
94 
95 	/* Check if function is excluded from instrumentation */
96 	if (fbt_excluded(name))
97 		return (0);
98 
99 	instr = (uint32_t *)(symval->value);
100 	limit = (uint32_t *)(symval->value + symval->size);
101 
102 	/* Look for stp (pre-indexed) operation */
103 	for (; instr < limit; instr++) {
104 		if ((*instr & LDP_STP_MASK) == STP_64)
105 			break;
106 	}
107 
108 	if (instr >= limit)
109 		return (0);
110 
111 	fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
112 	fbt->fbtp_name = name;
113 	fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
114 	    name, FBT_ENTRY, 3, fbt);
115 	fbt->fbtp_patchpoint = instr;
116 	fbt->fbtp_ctl = lf;
117 	fbt->fbtp_loadcnt = lf->loadcnt;
118 	fbt->fbtp_savedval = *instr;
119 	fbt->fbtp_patchval = FBT_PATCHVAL;
120 	fbt->fbtp_rval = DTRACE_INVOP_PUSHM;
121 	fbt->fbtp_symindx = symindx;
122 
123 	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
124 	fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
125 
126 	lf->fbt_nentries++;
127 
128 	retfbt = NULL;
129 again:
130 	for (; instr < limit; instr++) {
131 		if (*instr == RET_INSTR)
132 			break;
133 		else if ((*instr & B_MASK) == B_INSTR) {
134 			offs = (*instr & B_DATA_MASK);
135 			offs *= 4;
136 			target = (instr + offs);
137 			start = (uint32_t *)symval->value;
138 			if (target >= limit || target < start)
139 				break;
140 		}
141 	}
142 
143 	if (instr >= limit)
144 		return (0);
145 
146 	/*
147 	 * We have a winner!
148 	 */
149 	fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
150 	fbt->fbtp_name = name;
151 	if (retfbt == NULL) {
152 		fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
153 		    name, FBT_RETURN, 3, fbt);
154 	} else {
155 		retfbt->fbtp_probenext = fbt;
156 		fbt->fbtp_id = retfbt->fbtp_id;
157 	}
158 	retfbt = fbt;
159 
160 	fbt->fbtp_patchpoint = instr;
161 	fbt->fbtp_ctl = lf;
162 	fbt->fbtp_loadcnt = lf->loadcnt;
163 	fbt->fbtp_symindx = symindx;
164 	if ((*instr & B_MASK) == B_INSTR)
165 		fbt->fbtp_rval = DTRACE_INVOP_B;
166 	else
167 		fbt->fbtp_rval = DTRACE_INVOP_RET;
168 	fbt->fbtp_savedval = *instr;
169 	fbt->fbtp_patchval = FBT_PATCHVAL;
170 	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
171 	fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
172 
173 	lf->fbt_nentries++;
174 
175 	instr++;
176 	goto again;
177 }
178