xref: /freebsd/sys/cddl/dev/fbt/arm/fbt_isa.c (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
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 
51 int
52 fbt_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 
85 void
86 fbt_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 
93 int
94 fbt_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;
143 again:
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