1 /*-
2  * Copyright (c) 2010 Kai Wang
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include "_libdwarf.h"
28 
29 ELFTC_VCSID("$Id: dwarf_pro_expr.c 2074 2011-10-27 03:34:33Z jkoshy $");
30 
31 static struct _Dwarf_P_Expr_Entry *
_dwarf_add_expr(Dwarf_P_Expr expr,Dwarf_Small opcode,Dwarf_Unsigned val1,Dwarf_Unsigned val2,Dwarf_Error * error)32 _dwarf_add_expr(Dwarf_P_Expr expr, Dwarf_Small opcode, Dwarf_Unsigned val1,
33     Dwarf_Unsigned val2, Dwarf_Error *error)
34 {
35 	struct _Dwarf_P_Expr_Entry *ee;
36 	Dwarf_Debug dbg;
37 	int len;
38 
39 	dbg = expr->pe_dbg;
40 
41 	if (_dwarf_loc_expr_add_atom(dbg, NULL, NULL, opcode, val1, val2, &len,
42 	    error) != DW_DLE_NONE)
43 		return (NULL);
44 	assert(len > 0);
45 
46 	if ((ee = calloc(1, sizeof(*ee))) == NULL) {
47 		DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
48 		return (NULL);
49 	}
50 
51 	STAILQ_INSERT_TAIL(&expr->pe_eelist, ee, ee_next);
52 
53 	ee->ee_loc.lr_atom = opcode;
54 	ee->ee_loc.lr_number = val1;
55 	ee->ee_loc.lr_number2 = val2;
56 	ee->ee_loc.lr_offset = expr->pe_length;
57 	expr->pe_length += len;
58 	expr->pe_invalid = 1;
59 
60 	return (ee);
61 }
62 
63 int
_dwarf_expr_into_block(Dwarf_P_Expr expr,Dwarf_Error * error)64 _dwarf_expr_into_block(Dwarf_P_Expr expr, Dwarf_Error *error)
65 {
66 	struct _Dwarf_P_Expr_Entry *ee;
67 	Dwarf_Debug dbg;
68 	int len, pos, ret;
69 
70 	dbg = expr->pe_dbg;
71 
72 	if (expr->pe_block != NULL) {
73 		free(expr->pe_block);
74 		expr->pe_block = NULL;
75 	}
76 
77 	if (expr->pe_length <= 0) {
78 		DWARF_SET_ERROR(dbg, error, DW_DLE_EXPR_LENGTH_BAD);
79 		return (DW_DLE_EXPR_LENGTH_BAD);
80 	}
81 
82 
83 	if ((expr->pe_block = calloc((size_t) expr->pe_length, 1)) == NULL) {
84 		DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
85 		return (DW_DLE_MEMORY);
86 	}
87 
88 	pos = 0;
89 	STAILQ_FOREACH(ee, &expr->pe_eelist, ee_next) {
90 		assert((Dwarf_Unsigned) pos < expr->pe_length);
91 		ret = _dwarf_loc_expr_add_atom(dbg,
92 		    &expr->pe_block[pos], &expr->pe_block[expr->pe_length],
93 		    ee->ee_loc.lr_atom, ee->ee_loc.lr_number,
94 		    ee->ee_loc.lr_number2, &len, error);
95 		assert(ret == DW_DLE_NONE);
96 		assert(len > 0);
97 		pos += len;
98 	}
99 
100 	expr->pe_invalid = 0;
101 
102 	return (DW_DLE_NONE);
103 }
104 
105 void
_dwarf_expr_cleanup(Dwarf_P_Debug dbg)106 _dwarf_expr_cleanup(Dwarf_P_Debug dbg)
107 {
108 	Dwarf_P_Expr pe, tpe;
109 	struct _Dwarf_P_Expr_Entry *ee, *tee;
110 
111 	assert(dbg != NULL && dbg->dbg_mode == DW_DLC_WRITE);
112 
113 	STAILQ_FOREACH_SAFE(pe, &dbg->dbgp_pelist, pe_next, tpe) {
114 		STAILQ_REMOVE(&dbg->dbgp_pelist, pe, _Dwarf_P_Expr, pe_next);
115 		STAILQ_FOREACH_SAFE(ee, &pe->pe_eelist, ee_next, tee) {
116 			STAILQ_REMOVE(&pe->pe_eelist, ee, _Dwarf_P_Expr_Entry,
117 			    ee_next);
118 			free(ee);
119 		}
120 		if (pe->pe_block)
121 			free(pe->pe_block);
122 		free(pe);
123 	}
124 }
125 
126 Dwarf_P_Expr
dwarf_new_expr(Dwarf_P_Debug dbg,Dwarf_Error * error)127 dwarf_new_expr(Dwarf_P_Debug dbg, Dwarf_Error *error)
128 {
129 	Dwarf_P_Expr pe;
130 
131 	if (dbg == NULL) {
132 		DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
133 		return (DW_DLV_BADADDR);
134 	}
135 
136 	if ((pe = calloc(1, sizeof(struct _Dwarf_P_Expr))) == NULL) {
137 		DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
138 		return (DW_DLV_BADADDR);
139 	}
140 	STAILQ_INIT(&pe->pe_eelist);
141 
142 	STAILQ_INSERT_TAIL(&dbg->dbgp_pelist, pe, pe_next);
143 	pe->pe_dbg = dbg;
144 
145 	return (pe);
146 }
147 
148 Dwarf_Unsigned
dwarf_add_expr_gen(Dwarf_P_Expr expr,Dwarf_Small opcode,Dwarf_Unsigned val1,Dwarf_Unsigned val2,Dwarf_Error * error)149 dwarf_add_expr_gen(Dwarf_P_Expr expr, Dwarf_Small opcode, Dwarf_Unsigned val1,
150     Dwarf_Unsigned val2, Dwarf_Error *error)
151 {
152 
153 	if (expr == NULL) {
154 		DWARF_SET_ERROR(NULL, error, DW_DLE_ARGUMENT);
155 		return (DW_DLV_NOCOUNT);
156 	}
157 
158 	if (_dwarf_add_expr(expr, opcode, val1, val2, error) == NULL)
159 		return (DW_DLV_NOCOUNT);
160 
161 	return (expr->pe_length);
162 }
163 
164 Dwarf_Unsigned
dwarf_add_expr_addr(Dwarf_P_Expr expr,Dwarf_Unsigned address,Dwarf_Signed sym_index,Dwarf_Error * error)165 dwarf_add_expr_addr(Dwarf_P_Expr expr, Dwarf_Unsigned address,
166     Dwarf_Signed sym_index, Dwarf_Error *error)
167 {
168 
169 	return (dwarf_add_expr_addr_b(expr, address, sym_index, error));
170 }
171 
172 Dwarf_Unsigned
dwarf_add_expr_addr_b(Dwarf_P_Expr expr,Dwarf_Unsigned address,Dwarf_Unsigned sym_index,Dwarf_Error * error)173 dwarf_add_expr_addr_b(Dwarf_P_Expr expr, Dwarf_Unsigned address,
174     Dwarf_Unsigned sym_index, Dwarf_Error *error)
175 {
176 	struct _Dwarf_P_Expr_Entry *ee;
177 
178 	if (expr == NULL) {
179 		DWARF_SET_ERROR(NULL, error, DW_DLE_ARGUMENT);
180 		return (DW_DLV_NOCOUNT);
181 	}
182 
183 	if ((ee = _dwarf_add_expr(expr, DW_OP_addr, address, 0, error)) == NULL)
184 		return (DW_DLV_NOCOUNT);
185 
186 	ee->ee_sym = sym_index;
187 
188 	return (expr->pe_length);
189 }
190 
191 Dwarf_Unsigned
dwarf_expr_current_offset(Dwarf_P_Expr expr,Dwarf_Error * error)192 dwarf_expr_current_offset(Dwarf_P_Expr expr, Dwarf_Error *error)
193 {
194 
195 	if (expr == NULL) {
196 		DWARF_SET_ERROR(NULL, error, DW_DLE_ARGUMENT);
197 		return (DW_DLV_NOCOUNT);
198 	}
199 
200 	return (expr->pe_length);
201 }
202 
203 Dwarf_Addr
dwarf_expr_into_block(Dwarf_P_Expr expr,Dwarf_Unsigned * length,Dwarf_Error * error)204 dwarf_expr_into_block(Dwarf_P_Expr expr, Dwarf_Unsigned *length,
205     Dwarf_Error *error)
206 {
207 	Dwarf_Debug dbg;
208 
209 	dbg = expr != NULL ? expr->pe_dbg : NULL;
210 
211 	if (expr == NULL || length == NULL) {
212 		DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
213 		return ((Dwarf_Addr) (uintptr_t) DW_DLV_BADADDR);
214 	}
215 
216 	if (expr->pe_block == NULL || expr->pe_invalid)
217 		if (_dwarf_expr_into_block(expr, error) != DW_DLE_NONE)
218 			return ((Dwarf_Addr) (uintptr_t) DW_DLV_BADADDR);
219 
220 	*length = expr->pe_length;
221 
222 	return ((Dwarf_Addr) (uintptr_t) expr->pe_block);
223 }
224