xref: /freebsd/sys/cddl/dev/fbt/arm/fbt_isa.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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  */
26 
27 /*
28  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
29  * Use is subject to license terms.
30  */
31 
32 #include <sys/param.h>
33 
34 #include <sys/dtrace.h>
35 #include <machine/stack.h>
36 #include <machine/trap.h>
37 
38 #include "fbt.h"
39 
40 #define	FBT_PUSHM		0xe92d0000
41 #define	FBT_POPM		0xe8bd0000
42 #define	FBT_JUMP		0xea000000
43 #define	FBT_SUBSP		0xe24dd000
44 
45 int
46 fbt_invop(uintptr_t addr, struct trapframe *frame, uintptr_t rval)
47 {
48 	solaris_cpu_t *cpu = &solaris_cpu[curcpu];
49 	fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
50 	register_t fifthparam;
51 
52 	for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
53 		if ((uintptr_t)fbt->fbtp_patchpoint != addr)
54 			continue;
55 
56 		cpu->cpu_dtrace_caller = addr;
57 
58 		if (fbt->fbtp_roffset == 0) {
59 			/* Get 5th parameter from stack */
60 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
61 			fifthparam = *(register_t *)frame->tf_svc_sp;
62 			DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
63 
64 			dtrace_probe(fbt->fbtp_id, frame->tf_r0,
65 			    frame->tf_r1, frame->tf_r2,
66 			    frame->tf_r3, fifthparam);
67 		} else {
68 			dtrace_probe(fbt->fbtp_id, fbt->fbtp_roffset, rval,
69 			    0, 0, 0);
70 		}
71 
72 		cpu->cpu_dtrace_caller = 0;
73 		return (fbt->fbtp_rval | (fbt->fbtp_savedval << DTRACE_INVOP_SHIFT));
74 	}
75 
76 	return (0);
77 }
78 
79 void
80 fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val)
81 {
82 
83 	*fbt->fbtp_patchpoint = val;
84 	icache_sync((vm_offset_t)fbt->fbtp_patchpoint, sizeof(val));
85 }
86 
87 int
88 fbt_provide_module_function(linker_file_t lf, int symindx,
89     linker_symval_t *symval, void *opaque)
90 {
91 	char *modname = opaque;
92 	const char *name = symval->name;
93 	fbt_probe_t *fbt, *retfbt;
94 	uint32_t *instr, *limit;
95 	int popm;
96 
97 	if (fbt_excluded(name))
98 		return (0);
99 
100 	instr = (uint32_t *)symval->value;
101 	limit = (uint32_t *)(symval->value + symval->size);
102 
103 	/*
104 	 * va_arg functions has first instruction of
105 	 * sub sp, sp, #?
106 	 */
107 	if ((*instr & 0xfffff000) == FBT_SUBSP)
108 		instr++;
109 
110 	/*
111 	 * check if insn is a pushm with LR
112 	 */
113 	if ((*instr & 0xffff0000) != FBT_PUSHM ||
114 	    (*instr & (1 << LR)) == 0)
115 		return (0);
116 
117 	fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
118 	fbt->fbtp_name = name;
119 	fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
120 	    name, FBT_ENTRY, 2, fbt);
121 	fbt->fbtp_patchpoint = instr;
122 	fbt->fbtp_ctl = lf;
123 	fbt->fbtp_loadcnt = lf->loadcnt;
124 	fbt->fbtp_savedval = *instr;
125 	fbt->fbtp_patchval = FBT_BREAKPOINT;
126 	fbt->fbtp_rval = DTRACE_INVOP_PUSHM;
127 	fbt->fbtp_symindx = symindx;
128 
129 	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
130 	fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
131 
132 	lf->fbt_nentries++;
133 
134 	popm = FBT_POPM | ((*instr) & 0x3FFF) | 0x8000;
135 
136 	retfbt = NULL;
137 again:
138 	for (; instr < limit; instr++) {
139 		if (*instr == popm)
140 			break;
141 		else if ((*instr & 0xff000000) == FBT_JUMP) {
142 			uint32_t *target, *start;
143 			int offset;
144 
145 			offset = (*instr & 0xffffff);
146 			offset <<= 8;
147 			offset /= 64;
148 			target = instr + (2 + offset);
149 			start = (uint32_t *)symval->value;
150 			if (target >= limit || target < start)
151 				break;
152 		}
153 	}
154 
155 	if (instr >= limit)
156 		return (0);
157 
158 	/*
159 	 * We have a winner!
160 	 */
161 	fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
162 	fbt->fbtp_name = name;
163 	if (retfbt == NULL) {
164 		fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
165 		    name, FBT_RETURN, 2, fbt);
166 	} else {
167 		retfbt->fbtp_probenext = fbt;
168 		fbt->fbtp_id = retfbt->fbtp_id;
169 	}
170 	retfbt = fbt;
171 
172 	fbt->fbtp_patchpoint = instr;
173 	fbt->fbtp_ctl = lf;
174 	fbt->fbtp_loadcnt = lf->loadcnt;
175 	fbt->fbtp_symindx = symindx;
176 	if ((*instr & 0xff000000) == FBT_JUMP)
177 		fbt->fbtp_rval = DTRACE_INVOP_B;
178 	else
179 		fbt->fbtp_rval = DTRACE_INVOP_POPM;
180 	fbt->fbtp_roffset = (uintptr_t)instr - (uintptr_t)symval->value;
181 	fbt->fbtp_savedval = *instr;
182 	fbt->fbtp_patchval = FBT_BREAKPOINT;
183 	fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
184 	fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;
185 
186 	lf->fbt_nentries++;
187 
188 	instr++;
189 	goto again;
190 }
191