1 | /* Pointer Bounds Checker IPA passes. |
2 | Copyright (C) 2014-2017 Free Software Foundation, Inc. |
3 | Contributed by Ilya Enkovich (ilya.enkovich@intel.com) |
4 | |
5 | This file is part of GCC. |
6 | |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free |
9 | Software Foundation; either version 3, or (at your option) any later |
10 | version. |
11 | |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
15 | for more details. |
16 | |
17 | You should have received a copy of the GNU General Public License |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ |
20 | |
21 | #include "config.h" |
22 | #define INCLUDE_STRING |
23 | #include "system.h" |
24 | #include "coretypes.h" |
25 | #include "backend.h" |
26 | #include "tree.h" |
27 | #include "gimple.h" |
28 | #include "tree-pass.h" |
29 | #include "stringpool.h" |
30 | #include "lto-streamer.h" |
31 | #include "stor-layout.h" |
32 | #include "calls.h" |
33 | #include "cgraph.h" |
34 | #include "tree-chkp.h" |
35 | #include "tree-inline.h" |
36 | #include "ipa-chkp.h" |
37 | #include "stringpool.h" |
38 | #include "attribs.h" |
39 | |
40 | /* Pointer Bounds Checker has two IPA passes to support code instrumentation. |
41 | |
42 | In instrumented code each pointer is provided with bounds. For input |
43 | pointer parameters it means we also have bounds passed. For calls it |
44 | means we have additional bounds arguments for pointer arguments. |
45 | |
46 | To have all IPA optimizations working correctly we have to express |
47 | dataflow between passed and received bounds explicitly via additional |
48 | entries in function declaration arguments list and in function type. |
49 | Since we may have both instrumented and not instrumented code at the |
50 | same time, we cannot replace all original functions with their |
51 | instrumented variants. Therefore we create clones (versions) instead. |
52 | |
53 | Instrumentation clones creation is a separate IPA pass which is a part |
54 | of early local passes. Clones are created after SSA is built (because |
55 | instrumentation pass works on SSA) and before any transformations |
56 | which may change pointer flow and therefore lead to incorrect code |
57 | instrumentation (possibly causing false bounds check failures). |
58 | |
59 | Instrumentation clones have pointer bounds arguments added right after |
60 | pointer arguments. Clones have assembler name of the original |
61 | function with suffix added. New assembler name is in transparent |
62 | alias chain with the original name. Thus we expect all calls to the |
63 | original and instrumented functions look similar in assembler. |
64 | |
65 | During instrumentation versioning pass we create instrumented versions |
66 | of all function with body and also for all their aliases and thunks. |
67 | Clones for functions with no body are created on demand (usually |
68 | during call instrumentation). |
69 | |
70 | Original and instrumented function nodes are connected with IPA |
71 | reference IPA_REF_CHKP. It is mostly done to have reachability |
72 | analysis working correctly. We may have no references to the |
73 | instrumented function in the code but it still should be counted |
74 | as reachable if the original function is reachable. |
75 | |
76 | When original function bodies are not needed anymore we release |
77 | them and transform functions into a special kind of thunks. Each |
78 | thunk has a call edge to the instrumented version. These thunks |
79 | help to keep externally visible instrumented functions visible |
80 | when linker resolution files are used. Linker has no info about |
81 | connection between original and instrumented function and |
82 | therefore we may wrongly decide (due to difference in assembler |
83 | names) that instrumented function version is local and can be |
84 | removed. */ |
85 | |
86 | #define CHKP_BOUNDS_OF_SYMBOL_PREFIX "__chkp_bounds_of_" |
87 | #define CHKP_WRAPPER_SYMBOL_PREFIX "__mpx_wrapper_" |
88 | |
89 | /* Return 1 calls to FNDECL should be replaced with |
90 | a call to wrapper function. */ |
91 | bool |
92 | chkp_wrap_function (tree fndecl) |
93 | { |
94 | if (!flag_chkp_use_wrappers) |
95 | return false; |
96 | |
97 | if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) |
98 | { |
99 | switch (DECL_FUNCTION_CODE (fndecl)) |
100 | { |
101 | case BUILT_IN_STRLEN: |
102 | case BUILT_IN_STRCPY: |
103 | case BUILT_IN_STRNCPY: |
104 | case BUILT_IN_STPCPY: |
105 | case BUILT_IN_STPNCPY: |
106 | case BUILT_IN_STRCAT: |
107 | case BUILT_IN_STRNCAT: |
108 | case BUILT_IN_MEMCPY: |
109 | case BUILT_IN_MEMPCPY: |
110 | case BUILT_IN_MEMSET: |
111 | case BUILT_IN_MEMMOVE: |
112 | case BUILT_IN_BZERO: |
113 | case BUILT_IN_MALLOC: |
114 | case BUILT_IN_CALLOC: |
115 | case BUILT_IN_REALLOC: |
116 | return 1; |
117 | |
118 | default: |
119 | return 0; |
120 | } |
121 | } |
122 | |
123 | return false; |
124 | } |
125 | |
126 | static const char * |
127 | chkp_wrap_function_name (tree fndecl) |
128 | { |
129 | gcc_assert (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL); |
130 | |
131 | switch (DECL_FUNCTION_CODE (fndecl)) |
132 | { |
133 | case BUILT_IN_STRLEN: |
134 | return CHKP_WRAPPER_SYMBOL_PREFIX "strlen" ; |
135 | case BUILT_IN_STRCPY: |
136 | return CHKP_WRAPPER_SYMBOL_PREFIX "strcpy" ; |
137 | case BUILT_IN_STRNCPY: |
138 | return CHKP_WRAPPER_SYMBOL_PREFIX "strncpy" ; |
139 | case BUILT_IN_STPCPY: |
140 | return CHKP_WRAPPER_SYMBOL_PREFIX "stpcpy" ; |
141 | case BUILT_IN_STPNCPY: |
142 | return CHKP_WRAPPER_SYMBOL_PREFIX "stpncpy" ; |
143 | case BUILT_IN_STRCAT: |
144 | return CHKP_WRAPPER_SYMBOL_PREFIX "strcat" ; |
145 | case BUILT_IN_STRNCAT: |
146 | return CHKP_WRAPPER_SYMBOL_PREFIX "strncat" ; |
147 | case BUILT_IN_MEMCPY: |
148 | return CHKP_WRAPPER_SYMBOL_PREFIX "memcpy" ; |
149 | case BUILT_IN_MEMPCPY: |
150 | return CHKP_WRAPPER_SYMBOL_PREFIX "mempcpy" ; |
151 | case BUILT_IN_MEMSET: |
152 | return CHKP_WRAPPER_SYMBOL_PREFIX "memset" ; |
153 | case BUILT_IN_MEMMOVE: |
154 | return CHKP_WRAPPER_SYMBOL_PREFIX "memmove" ; |
155 | case BUILT_IN_BZERO: |
156 | return CHKP_WRAPPER_SYMBOL_PREFIX "bzero" ; |
157 | case BUILT_IN_MALLOC: |
158 | return CHKP_WRAPPER_SYMBOL_PREFIX "malloc" ; |
159 | case BUILT_IN_CALLOC: |
160 | return CHKP_WRAPPER_SYMBOL_PREFIX "calloc" ; |
161 | case BUILT_IN_REALLOC: |
162 | return CHKP_WRAPPER_SYMBOL_PREFIX "realloc" ; |
163 | |
164 | default: |
165 | gcc_unreachable (); |
166 | } |
167 | |
168 | return "" ; |
169 | } |
170 | |
171 | /* Build a clone of FNDECL with a modified name. */ |
172 | |
173 | static tree |
174 | chkp_build_instrumented_fndecl (tree fndecl) |
175 | { |
176 | tree new_decl = copy_node (fndecl); |
177 | tree new_name; |
178 | std::string s; |
179 | |
180 | /* called_as_built_in checks DECL_NAME to identify calls to |
181 | builtins. We want instrumented calls to builtins to be |
182 | recognized by called_as_built_in. Therefore use original |
183 | DECL_NAME for cloning with no prefixes. */ |
184 | s = IDENTIFIER_POINTER (DECL_NAME (fndecl)); |
185 | s += ".chkp" ; |
186 | DECL_NAME (new_decl) = get_identifier (s.c_str ()); |
187 | |
188 | /* References to the original and to the instrumented version |
189 | should look the same in the output assembly. And we cannot |
190 | use the same assembler name for the instrumented version |
191 | because it conflicts with decl merging algorithms in LTO. |
192 | Achieve the result by using transparent alias name for the |
193 | instrumented version. */ |
194 | if (chkp_wrap_function(fndecl)) |
195 | { |
196 | new_name = get_identifier (chkp_wrap_function_name (fndecl)); |
197 | DECL_VISIBILITY (new_decl) = VISIBILITY_DEFAULT; |
198 | } |
199 | else |
200 | { |
201 | s = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl)); |
202 | s += ".chkp" ; |
203 | new_name = get_identifier (s.c_str ()); |
204 | IDENTIFIER_TRANSPARENT_ALIAS (new_name) = 1; |
205 | TREE_CHAIN (new_name) = DECL_ASSEMBLER_NAME (fndecl); |
206 | } |
207 | SET_DECL_ASSEMBLER_NAME (new_decl, new_name); |
208 | |
209 | /* For functions with body versioning will make a copy of arguments. |
210 | For functions with no body we need to do it here. */ |
211 | if (!gimple_has_body_p (fndecl)) |
212 | { |
213 | tree arg; |
214 | |
215 | DECL_ARGUMENTS (new_decl) = copy_list (DECL_ARGUMENTS (fndecl)); |
216 | for (arg = DECL_ARGUMENTS (new_decl); arg; arg = DECL_CHAIN (arg)) |
217 | DECL_CONTEXT (arg) = new_decl; |
218 | } |
219 | |
220 | /* We are going to modify attributes list and therefore should |
221 | make own copy. */ |
222 | DECL_ATTRIBUTES (new_decl) = copy_list (DECL_ATTRIBUTES (fndecl)); |
223 | |
224 | /* Change builtin function code. */ |
225 | if (DECL_BUILT_IN (new_decl)) |
226 | { |
227 | gcc_assert (DECL_BUILT_IN_CLASS (new_decl) == BUILT_IN_NORMAL); |
228 | gcc_assert (DECL_FUNCTION_CODE (new_decl) < BEGIN_CHKP_BUILTINS); |
229 | DECL_FUNCTION_CODE (new_decl) |
230 | = (enum built_in_function)(DECL_FUNCTION_CODE (new_decl) |
231 | + BEGIN_CHKP_BUILTINS + 1); |
232 | } |
233 | |
234 | return new_decl; |
235 | } |
236 | |
237 | |
238 | /* Fix operands of attribute from ATTRS list named ATTR_NAME. |
239 | Integer operands are replaced with values according to |
240 | INDEXES map having LEN elements. For operands out of len |
241 | we just add DELTA. */ |
242 | |
243 | static void |
244 | chkp_map_attr_arg_indexes (tree attrs, const char *attr_name, |
245 | unsigned *indexes, int len, int delta) |
246 | { |
247 | tree attr = lookup_attribute (attr_name, attrs); |
248 | tree op; |
249 | |
250 | if (!attr) |
251 | return; |
252 | |
253 | TREE_VALUE (attr) = copy_list (TREE_VALUE (attr)); |
254 | for (op = TREE_VALUE (attr); op; op = TREE_CHAIN (op)) |
255 | { |
256 | int idx; |
257 | |
258 | if (TREE_CODE (TREE_VALUE (op)) != INTEGER_CST) |
259 | continue; |
260 | |
261 | idx = TREE_INT_CST_LOW (TREE_VALUE (op)); |
262 | |
263 | /* If idx exceeds indexes length then we just |
264 | keep it at the same distance from the last |
265 | known arg. */ |
266 | if (idx > len) |
267 | idx += delta; |
268 | else |
269 | idx = indexes[idx - 1] + 1; |
270 | TREE_VALUE (op) = build_int_cst (TREE_TYPE (TREE_VALUE (op)), idx); |
271 | } |
272 | } |
273 | |
274 | /* Make a copy of function type ORIG_TYPE adding pointer |
275 | bounds as additional arguments. */ |
276 | |
277 | tree |
278 | chkp_copy_function_type_adding_bounds (tree orig_type) |
279 | { |
280 | tree type; |
281 | tree arg_type, attrs; |
282 | unsigned len = list_length (TYPE_ARG_TYPES (orig_type)); |
283 | unsigned *indexes = XALLOCAVEC (unsigned, len); |
284 | unsigned idx = 0, new_idx = 0; |
285 | |
286 | for (arg_type = TYPE_ARG_TYPES (orig_type); |
287 | arg_type; |
288 | arg_type = TREE_CHAIN (arg_type)) |
289 | if (TREE_VALUE (arg_type) == void_type_node) |
290 | continue; |
291 | else if (BOUNDED_TYPE_P (TREE_VALUE (arg_type)) |
292 | || pass_by_reference (NULL, TYPE_MODE (TREE_VALUE (arg_type)), |
293 | TREE_VALUE (arg_type), true) |
294 | || chkp_type_has_pointer (TREE_VALUE (arg_type))) |
295 | break; |
296 | |
297 | /* We may use original type if there are no bounds passed. */ |
298 | if (!arg_type) |
299 | return orig_type; |
300 | |
301 | type = build_distinct_type_copy (orig_type); |
302 | TYPE_ARG_TYPES (type) = copy_list (TYPE_ARG_TYPES (type)); |
303 | |
304 | for (arg_type = TYPE_ARG_TYPES (type); |
305 | arg_type; |
306 | arg_type = TREE_CHAIN (arg_type)) |
307 | { |
308 | indexes[idx++] = new_idx++; |
309 | |
310 | /* pass_by_reference returns 1 for void type, |
311 | so check for it first. */ |
312 | if (TREE_VALUE (arg_type) == void_type_node) |
313 | continue; |
314 | else if (BOUNDED_TYPE_P (TREE_VALUE (arg_type)) |
315 | || pass_by_reference (NULL, TYPE_MODE (TREE_VALUE (arg_type)), |
316 | TREE_VALUE (arg_type), true)) |
317 | { |
318 | tree new_type = build_tree_list (NULL_TREE, |
319 | pointer_bounds_type_node); |
320 | TREE_CHAIN (new_type) = TREE_CHAIN (arg_type); |
321 | TREE_CHAIN (arg_type) = new_type; |
322 | |
323 | arg_type = TREE_CHAIN (arg_type); |
324 | new_idx++; |
325 | } |
326 | else if (chkp_type_has_pointer (TREE_VALUE (arg_type))) |
327 | { |
328 | bitmap slots = BITMAP_ALLOC (NULL); |
329 | bitmap_iterator bi; |
330 | unsigned bnd_no; |
331 | |
332 | chkp_find_bound_slots (TREE_VALUE (arg_type), slots); |
333 | |
334 | EXECUTE_IF_SET_IN_BITMAP (slots, 0, bnd_no, bi) |
335 | { |
336 | tree new_type = build_tree_list (NULL_TREE, |
337 | pointer_bounds_type_node); |
338 | TREE_CHAIN (new_type) = TREE_CHAIN (arg_type); |
339 | TREE_CHAIN (arg_type) = new_type; |
340 | |
341 | arg_type = TREE_CHAIN (arg_type); |
342 | new_idx++; |
343 | } |
344 | BITMAP_FREE (slots); |
345 | } |
346 | } |
347 | |
348 | /* If function type has attribute with arg indexes then |
349 | we have to copy it fixing attribute ops. Map for |
350 | fixing is in indexes array. */ |
351 | attrs = TYPE_ATTRIBUTES (type); |
352 | if (lookup_attribute ("nonnull" , attrs) |
353 | || lookup_attribute ("format" , attrs) |
354 | || lookup_attribute ("format_arg" , attrs)) |
355 | { |
356 | int delta = new_idx - len; |
357 | attrs = copy_list (TYPE_ATTRIBUTES (type)); |
358 | chkp_map_attr_arg_indexes (attrs, "nonnull" , indexes, len, delta); |
359 | chkp_map_attr_arg_indexes (attrs, "format" , indexes, len, delta); |
360 | chkp_map_attr_arg_indexes (attrs, "format_arg" , indexes, len, delta); |
361 | TYPE_ATTRIBUTES (type) = attrs; |
362 | } |
363 | |
364 | return type; |
365 | } |
366 | |
367 | /* For given function FNDECL add bounds arguments to arguments |
368 | list. */ |
369 | |
370 | static void |
371 | chkp_add_bounds_params_to_function (tree fndecl) |
372 | { |
373 | tree arg; |
374 | |
375 | for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg)) |
376 | if (BOUNDED_P (arg)) |
377 | { |
378 | std::string new_name = CHKP_BOUNDS_OF_SYMBOL_PREFIX; |
379 | tree new_arg; |
380 | |
381 | if (DECL_NAME (arg)) |
382 | new_name += IDENTIFIER_POINTER (DECL_NAME (arg)); |
383 | else |
384 | { |
385 | char uid[25]; |
386 | snprintf (uid, 25, "D.%u" , DECL_UID (arg)); |
387 | new_name += uid; |
388 | } |
389 | |
390 | new_arg = build_decl (DECL_SOURCE_LOCATION (arg), PARM_DECL, |
391 | get_identifier (new_name.c_str ()), |
392 | pointer_bounds_type_node); |
393 | DECL_ARG_TYPE (new_arg) = pointer_bounds_type_node; |
394 | DECL_CONTEXT (new_arg) = DECL_CONTEXT (arg); |
395 | DECL_ARTIFICIAL (new_arg) = 1; |
396 | DECL_CHAIN (new_arg) = DECL_CHAIN (arg); |
397 | DECL_CHAIN (arg) = new_arg; |
398 | |
399 | arg = DECL_CHAIN (arg); |
400 | |
401 | } |
402 | else if (chkp_type_has_pointer (TREE_TYPE (arg))) |
403 | { |
404 | tree orig_arg = arg; |
405 | bitmap slots = BITMAP_ALLOC (NULL); |
406 | bitmap_iterator bi; |
407 | unsigned bnd_no; |
408 | |
409 | chkp_find_bound_slots (TREE_TYPE (arg), slots); |
410 | |
411 | EXECUTE_IF_SET_IN_BITMAP (slots, 0, bnd_no, bi) |
412 | { |
413 | std::string new_name = CHKP_BOUNDS_OF_SYMBOL_PREFIX; |
414 | tree new_arg; |
415 | char offs[25]; |
416 | |
417 | if (DECL_NAME (orig_arg)) |
418 | new_name += IDENTIFIER_POINTER (DECL_NAME (orig_arg)); |
419 | else |
420 | { |
421 | snprintf (offs, 25, "D.%u" , DECL_UID (arg)); |
422 | new_name += offs; |
423 | } |
424 | snprintf (offs, 25, "__%u" , bnd_no * POINTER_SIZE / BITS_PER_UNIT); |
425 | |
426 | new_arg = build_decl (DECL_SOURCE_LOCATION (orig_arg), |
427 | PARM_DECL, |
428 | get_identifier (new_name.c_str ()), |
429 | pointer_bounds_type_node); |
430 | DECL_ARG_TYPE (new_arg) = pointer_bounds_type_node; |
431 | DECL_CONTEXT (new_arg) = DECL_CONTEXT (orig_arg); |
432 | DECL_ARTIFICIAL (new_arg) = 1; |
433 | DECL_CHAIN (new_arg) = DECL_CHAIN (arg); |
434 | DECL_CHAIN (arg) = new_arg; |
435 | |
436 | arg = DECL_CHAIN (arg); |
437 | } |
438 | BITMAP_FREE (slots); |
439 | } |
440 | |
441 | TREE_TYPE (fndecl) = |
442 | chkp_copy_function_type_adding_bounds (TREE_TYPE (fndecl)); |
443 | } |
444 | |
445 | /* Return an instrumentation clone for builtin function |
446 | FNDECL. Create one if needed. */ |
447 | |
448 | tree |
449 | chkp_maybe_clone_builtin_fndecl (tree fndecl) |
450 | { |
451 | tree clone; |
452 | enum built_in_function fcode = DECL_FUNCTION_CODE (fndecl); |
453 | |
454 | gcc_assert (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL |
455 | && fcode < BEGIN_CHKP_BUILTINS); |
456 | |
457 | fcode = (enum built_in_function) (fcode + BEGIN_CHKP_BUILTINS + 1); |
458 | clone = builtin_decl_explicit (fcode); |
459 | if (clone) |
460 | return clone; |
461 | |
462 | clone = chkp_build_instrumented_fndecl (fndecl); |
463 | chkp_add_bounds_params_to_function (clone); |
464 | |
465 | gcc_assert (DECL_FUNCTION_CODE (clone) == fcode); |
466 | |
467 | set_builtin_decl (fcode, clone, false); |
468 | |
469 | return clone; |
470 | } |
471 | |
472 | /* Return 1 if function FNDECL should be instrumented. */ |
473 | |
474 | bool |
475 | chkp_instrumentable_p (tree fndecl) |
476 | { |
477 | struct function *fn = DECL_STRUCT_FUNCTION (fndecl); |
478 | return (!lookup_attribute ("bnd_legacy" , DECL_ATTRIBUTES (fndecl)) |
479 | && (!flag_chkp_instrument_marked_only |
480 | || lookup_attribute ("bnd_instrument" , DECL_ATTRIBUTES (fndecl))) |
481 | && (!fn || !copy_forbidden (fn))); |
482 | } |
483 | |
484 | /* Return clone created for instrumentation of NODE or NULL. */ |
485 | |
486 | cgraph_node * |
487 | chkp_maybe_create_clone (tree fndecl) |
488 | { |
489 | cgraph_node *node = cgraph_node::get_create (fndecl); |
490 | cgraph_node *clone = node->instrumented_version; |
491 | |
492 | gcc_assert (!node->instrumentation_clone); |
493 | |
494 | if (DECL_BUILT_IN (fndecl) |
495 | && (DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL |
496 | || DECL_FUNCTION_CODE (fndecl) >= BEGIN_CHKP_BUILTINS)) |
497 | return NULL; |
498 | |
499 | clone = node->instrumented_version; |
500 | |
501 | /* Some instrumented builtin function calls may be optimized and |
502 | cgraph nodes may be removed as unreachable. Later optimizations |
503 | may generate new calls to removed functions and in this case |
504 | we have to recreate cgraph node. FUNCTION_DECL for instrumented |
505 | builtin still exists and should be reused in such case. */ |
506 | if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL |
507 | && fndecl == builtin_decl_explicit (DECL_FUNCTION_CODE (fndecl)) |
508 | && !clone) |
509 | { |
510 | enum built_in_function fncode = DECL_FUNCTION_CODE (fndecl); |
511 | tree new_decl; |
512 | |
513 | fncode = (enum built_in_function) (fncode + BEGIN_CHKP_BUILTINS + 1); |
514 | new_decl = builtin_decl_explicit (fncode); |
515 | |
516 | /* We've actually already created an instrumented clone once. |
517 | Restore it. */ |
518 | if (new_decl) |
519 | { |
520 | clone = cgraph_node::get (new_decl); |
521 | |
522 | if (!clone) |
523 | { |
524 | gcc_assert (!gimple_has_body_p (fndecl)); |
525 | clone = cgraph_node::get_create (new_decl); |
526 | clone->externally_visible = node->externally_visible; |
527 | clone->local = node->local; |
528 | clone->address_taken = node->address_taken; |
529 | clone->thunk = node->thunk; |
530 | clone->alias = node->alias; |
531 | clone->weakref = node->weakref; |
532 | clone->cpp_implicit_alias = node->cpp_implicit_alias; |
533 | clone->orig_decl = fndecl; |
534 | clone->instrumentation_clone = true; |
535 | } |
536 | |
537 | clone->instrumented_version = node; |
538 | node->instrumented_version = clone; |
539 | } |
540 | } |
541 | |
542 | if (!clone) |
543 | { |
544 | tree new_decl = chkp_build_instrumented_fndecl (fndecl); |
545 | struct cgraph_edge *e; |
546 | struct ipa_ref *ref; |
547 | int i; |
548 | |
549 | clone = node->create_version_clone (new_decl, vNULL, NULL); |
550 | clone->externally_visible = node->externally_visible; |
551 | clone->local = node->local; |
552 | clone->address_taken = node->address_taken; |
553 | clone->thunk = node->thunk; |
554 | clone->alias = node->alias; |
555 | clone->weakref = node->weakref; |
556 | clone->cpp_implicit_alias = node->cpp_implicit_alias; |
557 | clone->instrumented_version = node; |
558 | clone->orig_decl = fndecl; |
559 | clone->instrumentation_clone = true; |
560 | node->instrumented_version = clone; |
561 | |
562 | if (gimple_has_body_p (fndecl)) |
563 | { |
564 | gcc_assert (chkp_instrumentable_p (fndecl)); |
565 | tree_function_versioning (fndecl, new_decl, NULL, false, |
566 | NULL, false, NULL, NULL); |
567 | clone->lowered = true; |
568 | } |
569 | |
570 | /* New params are inserted after versioning because it |
571 | actually copies args list from the original decl. */ |
572 | chkp_add_bounds_params_to_function (new_decl); |
573 | |
574 | /* Remember builtin fndecl. */ |
575 | if (DECL_BUILT_IN_CLASS (clone->decl) == BUILT_IN_NORMAL |
576 | && fndecl == builtin_decl_explicit (DECL_FUNCTION_CODE (fndecl))) |
577 | { |
578 | gcc_assert (!builtin_decl_explicit (DECL_FUNCTION_CODE (clone->decl))); |
579 | set_builtin_decl (DECL_FUNCTION_CODE (clone->decl), |
580 | clone->decl, false); |
581 | } |
582 | |
583 | /* Clones have the same comdat group as originals. */ |
584 | if (node->same_comdat_group |
585 | || (DECL_ONE_ONLY (node->decl) |
586 | && !DECL_EXTERNAL (node->decl))) |
587 | clone->add_to_same_comdat_group (node); |
588 | |
589 | if (gimple_has_body_p (fndecl)) |
590 | symtab->call_cgraph_insertion_hooks (clone); |
591 | |
592 | /* Clone all aliases. */ |
593 | for (i = 0; node->iterate_direct_aliases (i, ref); i++) |
594 | chkp_maybe_create_clone (ref->referring->decl); |
595 | |
596 | /* Clone all thunks. */ |
597 | for (e = node->callers; e; e = e->next_caller) |
598 | if (e->caller->thunk.thunk_p |
599 | && !e->caller->thunk.add_pointer_bounds_args |
600 | && !e->caller->instrumentation_clone) |
601 | { |
602 | struct cgraph_node *thunk |
603 | = chkp_maybe_create_clone (e->caller->decl); |
604 | /* Redirect thunk clone edge to the node clone. */ |
605 | thunk->callees->redirect_callee (clone); |
606 | } |
607 | |
608 | /* For aliases and thunks we should make sure target is cloned |
609 | to have proper references and edges. */ |
610 | if (node->thunk.thunk_p) |
611 | chkp_maybe_create_clone (node->callees->callee->decl); |
612 | else if (node->alias) |
613 | { |
614 | struct cgraph_node *target; |
615 | |
616 | ref = node->ref_list.first_reference (); |
617 | if (ref) |
618 | { |
619 | target = chkp_maybe_create_clone (ref->referred->decl); |
620 | clone->create_reference (target, IPA_REF_ALIAS); |
621 | } |
622 | |
623 | if (node->alias_target) |
624 | { |
625 | if (TREE_CODE (node->alias_target) == FUNCTION_DECL) |
626 | { |
627 | target = chkp_maybe_create_clone (node->alias_target); |
628 | clone->alias_target = target->decl; |
629 | } |
630 | else |
631 | clone->alias_target = node->alias_target; |
632 | } |
633 | } |
634 | |
635 | /* Add IPA reference. It's main role is to keep instrumented |
636 | version reachable while original node is reachable. */ |
637 | ref = node->create_reference (clone, IPA_REF_CHKP, NULL); |
638 | } |
639 | |
640 | return clone; |
641 | } |
642 | |
643 | /* Create clone for all functions to be instrumented. */ |
644 | |
645 | static unsigned int |
646 | chkp_versioning (void) |
647 | { |
648 | struct cgraph_node *node; |
649 | const char *reason; |
650 | |
651 | bitmap_obstack_initialize (NULL); |
652 | |
653 | FOR_EACH_DEFINED_FUNCTION (node) |
654 | { |
655 | tree decl = node->decl; |
656 | if (!node->instrumentation_clone |
657 | && !node->instrumented_version |
658 | && !node->alias |
659 | && !node->thunk.thunk_p |
660 | && (!DECL_BUILT_IN (decl) |
661 | || (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL |
662 | && DECL_FUNCTION_CODE (decl) < BEGIN_CHKP_BUILTINS))) |
663 | { |
664 | if (chkp_instrumentable_p (decl)) |
665 | chkp_maybe_create_clone (decl); |
666 | else if ((reason = copy_forbidden (DECL_STRUCT_FUNCTION (decl)))) |
667 | { |
668 | if (warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wchkp, |
669 | "function cannot be instrumented" )) |
670 | inform (DECL_SOURCE_LOCATION (decl), reason, decl); |
671 | } |
672 | } |
673 | } |
674 | |
675 | /* Mark all aliases and thunks of functions with no instrumented |
676 | version as legacy function. */ |
677 | FOR_EACH_DEFINED_FUNCTION (node) |
678 | { |
679 | if (!node->instrumentation_clone |
680 | && !node->instrumented_version |
681 | && (node->alias || node->thunk.thunk_p) |
682 | && !lookup_attribute ("bnd_legacy" , DECL_ATTRIBUTES (node->decl))) |
683 | DECL_ATTRIBUTES (node->decl) |
684 | = tree_cons (get_identifier ("bnd_legacy" ), NULL, |
685 | DECL_ATTRIBUTES (node->decl)); |
686 | } |
687 | |
688 | bitmap_obstack_release (NULL); |
689 | |
690 | return 0; |
691 | } |
692 | |
693 | /* In this pass we remove bodies of functions having |
694 | instrumented version. Functions with removed bodies |
695 | become a special kind of thunks to provide a connection |
696 | between calls to the original version and instrumented |
697 | function. */ |
698 | |
699 | static unsigned int |
700 | chkp_produce_thunks (bool early) |
701 | { |
702 | struct cgraph_node *node; |
703 | |
704 | FOR_EACH_DEFINED_FUNCTION (node) |
705 | { |
706 | if (!node->instrumentation_clone |
707 | && node->instrumented_version |
708 | && gimple_has_body_p (node->decl) |
709 | && gimple_has_body_p (node->instrumented_version->decl) |
710 | && (!lookup_attribute ("always_inline" , DECL_ATTRIBUTES (node->decl)) |
711 | || !early)) |
712 | { |
713 | node->release_body (); |
714 | node->remove_callees (); |
715 | node->remove_all_references (); |
716 | |
717 | node->thunk.thunk_p = true; |
718 | node->thunk.add_pointer_bounds_args = true; |
719 | node->create_edge (node->instrumented_version, NULL, |
720 | node->count); |
721 | node->create_reference (node->instrumented_version, |
722 | IPA_REF_CHKP, NULL); |
723 | /* Thunk shouldn't be a cdtor. */ |
724 | DECL_STATIC_CONSTRUCTOR (node->decl) = 0; |
725 | DECL_STATIC_DESTRUCTOR (node->decl) = 0; |
726 | } |
727 | } |
728 | |
729 | /* Mark instrumentation clones created for aliases and thunks |
730 | as insttrumented so they could be removed as unreachable |
731 | now. */ |
732 | if (!early) |
733 | { |
734 | FOR_EACH_DEFINED_FUNCTION (node) |
735 | { |
736 | if (node->instrumentation_clone |
737 | && (node->alias || node->thunk.thunk_p) |
738 | && !chkp_function_instrumented_p (node->decl)) |
739 | chkp_function_mark_instrumented (node->decl); |
740 | } |
741 | } |
742 | |
743 | return TODO_remove_functions; |
744 | } |
745 | |
746 | const pass_data pass_data_ipa_chkp_versioning = |
747 | { |
748 | SIMPLE_IPA_PASS, /* type */ |
749 | "chkp_versioning" , /* name */ |
750 | OPTGROUP_NONE, /* optinfo_flags */ |
751 | TV_NONE, /* tv_id */ |
752 | 0, /* properties_required */ |
753 | 0, /* properties_provided */ |
754 | 0, /* properties_destroyed */ |
755 | 0, /* todo_flags_start */ |
756 | 0 /* todo_flags_finish */ |
757 | }; |
758 | |
759 | const pass_data pass_data_ipa_chkp_early_produce_thunks = |
760 | { |
761 | SIMPLE_IPA_PASS, /* type */ |
762 | "chkp_ecleanup" , /* name */ |
763 | OPTGROUP_NONE, /* optinfo_flags */ |
764 | TV_NONE, /* tv_id */ |
765 | 0, /* properties_required */ |
766 | 0, /* properties_provided */ |
767 | 0, /* properties_destroyed */ |
768 | 0, /* todo_flags_start */ |
769 | 0 /* todo_flags_finish */ |
770 | }; |
771 | |
772 | const pass_data pass_data_ipa_chkp_produce_thunks = |
773 | { |
774 | SIMPLE_IPA_PASS, /* type */ |
775 | "chkp_cleanup" , /* name */ |
776 | OPTGROUP_NONE, /* optinfo_flags */ |
777 | TV_NONE, /* tv_id */ |
778 | 0, /* properties_required */ |
779 | 0, /* properties_provided */ |
780 | 0, /* properties_destroyed */ |
781 | 0, /* todo_flags_start */ |
782 | 0 /* todo_flags_finish */ |
783 | }; |
784 | |
785 | class pass_ipa_chkp_versioning : public simple_ipa_opt_pass |
786 | { |
787 | public: |
788 | pass_ipa_chkp_versioning (gcc::context *ctxt) |
789 | : simple_ipa_opt_pass (pass_data_ipa_chkp_versioning, ctxt) |
790 | {} |
791 | |
792 | /* opt_pass methods: */ |
793 | virtual opt_pass * clone () |
794 | { |
795 | return new pass_ipa_chkp_versioning (m_ctxt); |
796 | } |
797 | |
798 | virtual bool gate (function *) |
799 | { |
800 | return flag_check_pointer_bounds; |
801 | } |
802 | |
803 | virtual unsigned int execute (function *) |
804 | { |
805 | return chkp_versioning (); |
806 | } |
807 | |
808 | }; // class pass_ipa_chkp_versioning |
809 | |
810 | class pass_ipa_chkp_early_produce_thunks : public simple_ipa_opt_pass |
811 | { |
812 | public: |
813 | pass_ipa_chkp_early_produce_thunks (gcc::context *ctxt) |
814 | : simple_ipa_opt_pass (pass_data_ipa_chkp_early_produce_thunks, ctxt) |
815 | {} |
816 | |
817 | /* opt_pass methods: */ |
818 | virtual opt_pass * clone () |
819 | { |
820 | return new pass_ipa_chkp_early_produce_thunks (m_ctxt); |
821 | } |
822 | |
823 | virtual bool gate (function *) |
824 | { |
825 | return flag_check_pointer_bounds; |
826 | } |
827 | |
828 | virtual unsigned int execute (function *) |
829 | { |
830 | return chkp_produce_thunks (true); |
831 | } |
832 | |
833 | }; // class pass_chkp_produce_thunks |
834 | |
835 | class pass_ipa_chkp_produce_thunks : public simple_ipa_opt_pass |
836 | { |
837 | public: |
838 | pass_ipa_chkp_produce_thunks (gcc::context *ctxt) |
839 | : simple_ipa_opt_pass (pass_data_ipa_chkp_produce_thunks, ctxt) |
840 | {} |
841 | |
842 | /* opt_pass methods: */ |
843 | virtual opt_pass * clone () |
844 | { |
845 | return new pass_ipa_chkp_produce_thunks (m_ctxt); |
846 | } |
847 | |
848 | virtual bool gate (function *) |
849 | { |
850 | return flag_check_pointer_bounds; |
851 | } |
852 | |
853 | virtual unsigned int execute (function *) |
854 | { |
855 | return chkp_produce_thunks (false); |
856 | } |
857 | |
858 | }; // class pass_chkp_produce_thunks |
859 | |
860 | simple_ipa_opt_pass * |
861 | make_pass_ipa_chkp_versioning (gcc::context *ctxt) |
862 | { |
863 | return new pass_ipa_chkp_versioning (ctxt); |
864 | } |
865 | |
866 | simple_ipa_opt_pass * |
867 | make_pass_ipa_chkp_early_produce_thunks (gcc::context *ctxt) |
868 | { |
869 | return new pass_ipa_chkp_early_produce_thunks (ctxt); |
870 | } |
871 | |
872 | simple_ipa_opt_pass * |
873 | make_pass_ipa_chkp_produce_thunks (gcc::context *ctxt) |
874 | { |
875 | return new pass_ipa_chkp_produce_thunks (ctxt); |
876 | } |
877 | |