1 /*--------------------------------------------------------------------*/
2 /*--- Callgrind ---*/
3 /*--- bb.c ---*/
4 /*--------------------------------------------------------------------*/
5
6 /*
7 This file is part of Callgrind, a Valgrind tool for call tracing.
8
9 Copyright (C) 2002-2017, Josef Weidendorfer (Josef.Weidendorfer@gmx.de)
10
11 This program is free software; you can redistribute it and/or
12 modify it under the terms of the GNU General Public License as
13 published by the Free Software Foundation; either version 2 of the
14 License, or (at your option) any later version.
15
16 This program is distributed in the hope that it will be useful, but
17 WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24 02111-1307, USA.
25
26 The GNU General Public License is contained in the file COPYING.
27 */
28
29 #include "global.h"
30
31 /*------------------------------------------------------------*/
32 /*--- Basic block (BB) operations ---*/
33 /*------------------------------------------------------------*/
34
35 /* BB hash, resizable */
36 bb_hash bbs;
37
CLG_(init_bb_hash)38 void CLG_(init_bb_hash)()
39 {
40 Int i;
41
42 bbs.size = 8437;
43 bbs.entries = 0;
44 bbs.table = (BB**) CLG_MALLOC("cl.bb.ibh.1",
45 bbs.size * sizeof(BB*));
46
47 for (i = 0; i < bbs.size; i++) bbs.table[i] = NULL;
48 }
49
CLG_(get_bb_hash)50 bb_hash* CLG_(get_bb_hash)()
51 {
52 return &bbs;
53 }
54
55 /* The hash stores BBs according to
56 * - ELF object (is 0 for code in anonymous mapping)
57 * - BB base as object file offset
58 */
59 static __inline__
bb_hash_idx(obj_node * obj,PtrdiffT offset,UInt size)60 UInt bb_hash_idx(obj_node* obj, PtrdiffT offset, UInt size)
61 {
62 return (((Addr)obj) + offset) % size;
63 }
64
65 /* double size of bb table */
66 static
resize_bb_table(void)67 void resize_bb_table(void)
68 {
69 Int i, new_size, conflicts1 = 0, conflicts2 = 0;
70 BB **new_table, *curr, *next;
71 UInt new_idx;
72
73 new_size = 2* bbs.size +3;
74 new_table = (BB**) CLG_MALLOC("cl.bb.rbt.1",
75 new_size * sizeof(BB*));
76
77 for (i = 0; i < new_size; i++)
78 new_table[i] = NULL;
79
80 for (i = 0; i < bbs.size; i++) {
81 if (bbs.table[i] == NULL) continue;
82
83 curr = bbs.table[i];
84 while (NULL != curr) {
85 next = curr->next;
86
87 new_idx = bb_hash_idx(curr->obj, curr->offset, new_size);
88
89 curr->next = new_table[new_idx];
90 new_table[new_idx] = curr;
91 if (curr->next) {
92 conflicts1++;
93 if (curr->next->next)
94 conflicts2++;
95 }
96
97 curr = next;
98 }
99 }
100
101 VG_(free)(bbs.table);
102
103
104 CLG_DEBUG(0, "Resize BB Hash: %u => %d (entries %u, conflicts %d/%d)\n",
105 bbs.size, new_size,
106 bbs.entries, conflicts1, conflicts2);
107
108 bbs.size = new_size;
109 bbs.table = new_table;
110 CLG_(stat).bb_hash_resizes++;
111 }
112
113
114 /**
115 * Allocate new BB structure (including space for event type list)
116 * Not initialized:
117 * - instr_len, cost_count, instr[]
118 */
new_bb(obj_node * obj,PtrdiffT offset,UInt instr_count,UInt cjmp_count,Bool cjmp_inverted)119 static BB* new_bb(obj_node* obj, PtrdiffT offset,
120 UInt instr_count, UInt cjmp_count, Bool cjmp_inverted)
121 {
122 BB* bb;
123 UInt idx, size;
124
125 /* check fill degree of bb hash table and resize if needed (>80%) */
126 bbs.entries++;
127 if (10 * bbs.entries / bbs.size > 8)
128 resize_bb_table();
129
130 size = sizeof(BB) + instr_count * sizeof(InstrInfo)
131 + (cjmp_count+1) * sizeof(CJmpInfo);
132 bb = (BB*) CLG_MALLOC("cl.bb.nb.1", size);
133 VG_(memset)(bb, 0, size);
134
135 bb->obj = obj;
136 bb->offset = offset;
137
138 bb->instr_count = instr_count;
139 bb->cjmp_count = cjmp_count;
140 bb->cjmp_inverted = cjmp_inverted;
141 bb->jmp = (CJmpInfo*) &(bb->instr[instr_count]);
142 bb->instr_len = 0;
143 bb->cost_count = 0;
144 bb->sect_kind = VG_(DebugInfo_sect_kind)(NULL, offset + obj->offset);
145 bb->fn = 0;
146 bb->line = 0;
147 bb->is_entry = 0;
148 bb->bbcc_list = 0;
149 bb->last_bbcc = 0;
150
151 /* insert into BB hash table */
152 idx = bb_hash_idx(obj, offset, bbs.size);
153 bb->next = bbs.table[idx];
154 bbs.table[idx] = bb;
155
156 CLG_(stat).distinct_bbs++;
157
158 #if CLG_ENABLE_DEBUG
159 CLG_DEBUGIF(3) {
160 VG_(printf)(" new_bb (instr %u, jmps %u, inv %s) [now %d]: ",
161 instr_count, cjmp_count,
162 cjmp_inverted ? "yes":"no",
163 CLG_(stat).distinct_bbs);
164 CLG_(print_bb)(0, bb);
165 VG_(printf)("\n");
166 }
167 #endif
168
169 CLG_(get_fn_node)(bb);
170
171 return bb;
172 }
173
174
175 /* get the BB structure for a BB start address */
176 static __inline__
lookup_bb(obj_node * obj,PtrdiffT offset)177 BB* lookup_bb(obj_node* obj, PtrdiffT offset)
178 {
179 BB* bb;
180 Int idx;
181
182 idx = bb_hash_idx(obj, offset, bbs.size);
183 bb = bbs.table[idx];
184
185 while(bb) {
186 if ((bb->obj == obj) && (bb->offset == offset)) break;
187 bb = bb->next;
188 }
189
190 CLG_DEBUG(5, " lookup_bb (Obj %s, off %#lx): %p\n",
191 obj->name, (UWord)offset, bb);
192 return bb;
193 }
194
195 static __inline__
obj_of_address(Addr addr)196 obj_node* obj_of_address(Addr addr)
197 {
198 obj_node* obj;
199 DebugInfo* di;
200 PtrdiffT offset;
201
202 di = VG_(find_DebugInfo)(addr);
203 obj = CLG_(get_obj_node)( di );
204
205 /* Update symbol offset in object if remapped */
206 /* FIXME (or at least check this) 2008 Feb 19: 'offset' is
207 only correct for text symbols, not for data symbols */
208 offset = di ? VG_(DebugInfo_get_text_bias)(di):0;
209 if (obj->offset != offset) {
210 Addr start = di ? VG_(DebugInfo_get_text_avma)(di) : 0;
211
212 CLG_DEBUG(0, "Mapping changed for '%s': %#lx -> %#lx\n",
213 obj->name, obj->start, start);
214
215 /* Size should be the same, and offset diff == start diff */
216 CLG_ASSERT( obj->size == (di ? VG_(DebugInfo_get_text_size)(di) : 0) );
217 CLG_ASSERT( obj->start - start == obj->offset - offset );
218 obj->offset = offset;
219 obj->start = start;
220 }
221
222 return obj;
223 }
224
225 /* Get the BB structure for a BB start address.
226 * If the BB has to be created, the IRBB is needed to
227 * compute the event type list for costs, and seen_before is
228 * set to False. Otherwise, seen_before is set to True.
229 *
230 * BBs are never discarded. There are 2 cases where this function
231 * is called from CLG_(instrument)() and a BB already exists:
232 * - The instrumented version was removed from Valgrinds TT cache
233 * - The ELF object of the BB was unmapped and mapped again.
234 * This involves a possibly different address, but is handled by
235 * looking up a BB keyed by (obj_node, file offset).
236 *
237 * bbIn==0 is possible for artificial BB without real code.
238 * Such a BB is created when returning to an unknown function.
239 */
CLG_(get_bb)240 BB* CLG_(get_bb)(Addr addr, IRSB* bbIn, /*OUT*/ Bool *seen_before)
241 {
242 BB* bb;
243 obj_node* obj;
244 UInt n_instrs, n_jmps;
245 Bool cjmp_inverted = False;
246
247 CLG_DEBUG(5, "+ get_bb(BB %#lx)\n", addr);
248
249 obj = obj_of_address(addr);
250 bb = lookup_bb(obj, addr - obj->offset);
251
252 n_instrs = 0;
253 n_jmps = 0;
254 CLG_(collectBlockInfo)(bbIn, &n_instrs, &n_jmps, &cjmp_inverted);
255
256 *seen_before = bb ? True : False;
257 if (*seen_before) {
258 if (bb->instr_count != n_instrs) {
259 VG_(message)(Vg_DebugMsg,
260 "ERROR: BB Retranslation Mismatch at BB %#lx\n", addr);
261 VG_(message)(Vg_DebugMsg,
262 " new: Obj %s, Off %#lx, BBOff %#lx, Instrs %u\n",
263 obj->name, (UWord)obj->offset,
264 addr - obj->offset, n_instrs);
265 VG_(message)(Vg_DebugMsg,
266 " old: Obj %s, Off %#lx, BBOff %#lx, Instrs %u\n",
267 bb->obj->name, (UWord)bb->obj->offset,
268 (UWord)bb->offset, bb->instr_count);
269 CLG_ASSERT(bb->instr_count == n_instrs );
270 }
271 CLG_ASSERT(bb->cjmp_count == n_jmps );
272 CLG_(stat).bb_retranslations++;
273
274 CLG_DEBUG(5, "- get_bb(BB %#lx): seen before.\n", addr);
275 return bb;
276 }
277
278 bb = new_bb(obj, addr - obj->offset, n_instrs, n_jmps, cjmp_inverted);
279
280 CLG_DEBUG(5, "- get_bb(BB %#lx)\n", addr);
281
282 return bb;
283 }
284
285 /* Delete the BB info for the bb with unredirected entry-point
286 address 'addr'. */
CLG_(delete_bb)287 void CLG_(delete_bb)(Addr addr)
288 {
289 BB *bb, *bp;
290 Int idx, size;
291
292 obj_node* obj = obj_of_address(addr);
293 PtrdiffT offset = addr - obj->offset;
294
295 idx = bb_hash_idx(obj, offset, bbs.size);
296 bb = bbs.table[idx];
297
298 /* bb points at the current bb under consideration, and bp is the
299 one before. */
300 bp = NULL;
301 while(bb) {
302 if ((bb->obj == obj) && (bb->offset == offset)) break;
303 bp = bb;
304 bb = bb->next;
305 }
306
307 if (bb == NULL) {
308 CLG_DEBUG(3, " delete_bb (Obj %s, off %#lx): NOT FOUND\n",
309 obj->name, (UWord)offset);
310
311 /* we didn't find it.
312 * this happens when callgrinds instrumentation mode
313 * was off at BB translation time, ie. no BB was created.
314 */
315 return;
316 }
317
318 /* unlink it from hash table */
319
320 if (bp == NULL) {
321 /* we found the first one in the list. */
322 tl_assert(bb == bbs.table[idx]);
323 bbs.table[idx] = bb->next;
324 } else {
325 tl_assert(bb != bbs.table[idx]);
326 bp->next = bb->next;
327 }
328
329 CLG_DEBUG(3, " delete_bb (Obj %s, off %#lx): %p, BBCC head: %p\n",
330 obj->name, (UWord)offset, bb, bb->bbcc_list);
331
332 if (bb->bbcc_list == 0) {
333 /* can be safely deleted */
334
335 /* Fill the block up with junk and then free it, so we will
336 hopefully get a segfault if it is used again by mistake. */
337 size = sizeof(BB)
338 + bb->instr_count * sizeof(InstrInfo)
339 + (bb->cjmp_count+1) * sizeof(CJmpInfo);
340 VG_(memset)( bb, 0xAA, size );
341 CLG_FREE(bb);
342 return;
343 }
344 CLG_DEBUG(3, " delete_bb: BB in use, can not free!\n");
345 }
346