1 /* Copyright (c) 2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
11 #include <elfutils/libdw.h>
13 #include "mc_private.h"
15 static int mc_dwarf_push_value(mc_expression_state_t state, Dwarf_Off value) {
16 if(state->stack_size>=MC_EXPRESSION_STACK_SIZE)
17 return MC_EXPRESSION_E_STACK_OVERFLOW;
19 state->stack[state->stack_size++] = value;
23 static int mc_dwarf_register_to_libunwind(int dwarf_register) {
24 #if defined(UNW_TARGET_X86_64)
25 // It seems for this arch, DWARF and libunwind agree in the numbering:
26 return dwarf_register;
27 #elif defined(UNW_TARGET_X86)
28 // Could't find the authoritative source of information for this.
29 // This is inspired from http://source.winehq.org/source/dlls/dbghelp/cpu_i386.c#L517.
30 switch(dwarf_register) {
31 case 0: return UNW_X86_EAX;
32 case 1: return UNW_X86_ECX;
33 case 2: return UNW_X86_EDX;
34 case 3: return UNW_X86_EBX;
35 case 4: return UNW_X86_ESP;
36 case 5: return UNW_X86_EBP;
37 case 6: return UNW_X86_ESI;
38 case 7: return UNW_X86_EDI;
39 case 8: return UNW_X86_EIP;
40 case 9: return UNW_X86_EFLAGS;
41 case 10: return UNW_X86_CS;
42 case 11: return UNW_X86_SS;
43 case 12: return UNW_X86_DS;
44 case 13: return UNW_X86_ES;
45 case 14: return UNW_X86_FS;
46 case 15: return UNW_X86_GS;
47 case 16: return UNW_X86_ST0;
48 case 17: return UNW_X86_ST1;
49 case 18: return UNW_X86_ST2;
50 case 19: return UNW_X86_ST3;
51 case 20: return UNW_X86_ST4;
52 case 21: return UNW_X86_ST5;
53 case 22: return UNW_X86_ST6;
54 case 23: return UNW_X86_ST7;
55 default: xbt_die("Bad/unknown register number.");
58 #error This architecture is not supported yet.
62 int mc_dwarf_execute_expression(
63 size_t n, const Dwarf_Op* ops, mc_expression_state_t state) {
64 for(int i=0; i!=n; ++i) {
66 const Dwarf_Op* op = ops + i;
67 uint8_t atom = op->atom;
73 case DW_OP_breg0: case DW_OP_breg1: case DW_OP_breg2: case DW_OP_breg3:
74 case DW_OP_breg4: case DW_OP_breg5: case DW_OP_breg6: case DW_OP_breg7:
75 case DW_OP_breg8: case DW_OP_breg9: case DW_OP_breg10: case DW_OP_breg11:
76 case DW_OP_breg12: case DW_OP_breg13: case DW_OP_breg14: case DW_OP_breg15:
77 case DW_OP_breg16: case DW_OP_breg17: case DW_OP_breg18: case DW_OP_breg19:
78 case DW_OP_breg20: case DW_OP_breg21: case DW_OP_breg22: case DW_OP_breg23:
79 case DW_OP_breg24: case DW_OP_breg25: case DW_OP_breg26: case DW_OP_breg27:
80 case DW_OP_breg28: case DW_OP_breg29: case DW_OP_breg30: case DW_OP_breg31:{
81 int register_id = mc_dwarf_register_to_libunwind(op->atom - DW_OP_breg0);
84 return MC_EXPRESSION_E_MISSING_STACK_CONTEXT;
85 unw_get_reg(state->cursor, register_id, &res);
86 error = mc_dwarf_push_value(state, res + op->number);
90 // Push the CFA (Canonical Frame Addresse):
91 case DW_OP_call_frame_cfa:
93 // UNW_X86_64_CFA does not return the CFA DWARF expects
94 // (it is a synonym for UNW_X86_64_RSP) so copy the cursor,
95 // unwind it once in order to find the parent SP:
98 return MC_EXPRESSION_E_MISSING_STACK_CONTEXT;
101 unw_cursor_t cursor = *(state->cursor);
105 unw_get_reg(&cursor, UNW_TDEP_SP, &res);
106 error = mc_dwarf_push_value(state, res);
114 if(!state->frame_base)
115 return MC_EXPRESSION_E_MISSING_FRAME_BASE;
116 error = mc_dwarf_push_value(state, ((uintptr_t)state->frame_base) + op->number);
123 case DW_OP_lit0: case DW_OP_lit1: case DW_OP_lit2: case DW_OP_lit3:
124 case DW_OP_lit4: case DW_OP_lit5: case DW_OP_lit6: case DW_OP_lit7:
125 case DW_OP_lit8: case DW_OP_lit9: case DW_OP_lit10: case DW_OP_lit11:
126 case DW_OP_lit12: case DW_OP_lit13: case DW_OP_lit14: case DW_OP_lit15:
127 case DW_OP_lit16: case DW_OP_lit17: case DW_OP_lit18: case DW_OP_lit19:
128 case DW_OP_lit20: case DW_OP_lit21: case DW_OP_lit22: case DW_OP_lit23:
129 case DW_OP_lit24: case DW_OP_lit25: case DW_OP_lit26: case DW_OP_lit27:
130 case DW_OP_lit28: case DW_OP_lit29: case DW_OP_lit30: case DW_OP_lit31:
131 error = mc_dwarf_push_value(state, atom - DW_OP_lit0);
135 if(!state->object_info)
136 return MC_EXPRESSION_E_NO_BASE_ADDRESS;
137 if(state->stack_size==MC_EXPRESSION_STACK_SIZE)
138 return MC_EXPRESSION_E_STACK_OVERFLOW;
139 error = mc_dwarf_push_value(state,
140 (Dwarf_Off)(uintptr_t)MC_object_base_address(state->object_info) + op->number);
153 if(state->stack_size==MC_EXPRESSION_STACK_SIZE)
154 return MC_EXPRESSION_E_STACK_OVERFLOW;
155 error = mc_dwarf_push_value(state, op->number);
158 // Stack manipulation:
160 // Push the value at the top of the stack:
162 if(state->stack_size==0)
163 return MC_EXPRESSION_E_STACK_UNDERFLOW;
165 error = mc_dwarf_push_value(state, state->stack[state->stack_size-1]);
169 if(state->stack_size==0)
170 return MC_EXPRESSION_E_STACK_UNDERFLOW;
176 if(state->stack_size<2)
177 return MC_EXPRESSION_E_STACK_UNDERFLOW;
179 uintptr_t temp = state->stack[state->stack_size-2];
180 state->stack[state->stack_size-2] = state->stack[state->stack_size-1];
181 state->stack[state->stack_size-1] = temp;
186 if(state->stack_size<2)
187 return MC_EXPRESSION_E_STACK_UNDERFLOW;
188 error = mc_dwarf_push_value(state, state->stack[state->stack_size-2]);
194 if(state->stack_size<2)
195 return MC_EXPRESSION_E_STACK_UNDERFLOW;
197 uintptr_t result = state->stack[state->stack_size-2] + state->stack[state->stack_size-1];
198 state->stack[state->stack_size-2] = result;
204 if(state->stack_size<2)
205 return MC_EXPRESSION_E_STACK_UNDERFLOW;
207 uintptr_t result = state->stack[state->stack_size-2] - state->stack[state->stack_size-1];
208 state->stack[state->stack_size-2] = result;
213 case DW_OP_plus_uconst:
214 if(state->stack_size==0)
215 return MC_EXPRESSION_E_STACK_UNDERFLOW;
216 state->stack[state->stack_size-1] += op->number;
220 if(state->stack_size==0)
221 return MC_EXPRESSION_E_STACK_UNDERFLOW;
222 state->stack[state->stack_size-1] = ~state->stack[state->stack_size-1];
226 if(state->stack_size==0)
227 return MC_EXPRESSION_E_STACK_UNDERFLOW;
229 intptr_t value = state->stack[state->stack_size-1];
230 if(value<0) value = -value;
231 state->stack[state->stack_size-1] = value;
236 if(state->stack_size<2)
237 return MC_EXPRESSION_E_STACK_UNDERFLOW;
239 uintptr_t result = state->stack[state->stack_size-2] - state->stack[state->stack_size-1];
240 state->stack[state->stack_size-2] = result;
246 if(state->stack_size<2)
247 return MC_EXPRESSION_E_STACK_UNDERFLOW;
249 uintptr_t result = state->stack[state->stack_size-2] & state->stack[state->stack_size-1];
250 state->stack[state->stack_size-2] = result;
256 if(state->stack_size<2)
257 return MC_EXPRESSION_E_STACK_UNDERFLOW;
259 uintptr_t result = state->stack[state->stack_size-2] | state->stack[state->stack_size-1];
260 state->stack[state->stack_size-2] = result;
266 if(state->stack_size<2)
267 return MC_EXPRESSION_E_STACK_UNDERFLOW;
269 uintptr_t result = state->stack[state->stack_size-2] ^ state->stack[state->stack_size-1];
270 state->stack[state->stack_size-2] = result;
279 case DW_OP_deref_size:
280 return MC_EXPRESSION_E_UNSUPPORTED_OPERATION;
283 if(state->stack_size==0)
284 return MC_EXPRESSION_E_STACK_UNDERFLOW;
287 uintptr_t address = (uintptr_t) state->stack[state->stack_size-1];
288 uintptr_t* p = (uintptr_t*)mc_translate_address(address, state->snapshot);
289 state->stack[state->stack_size-1] = *p;
295 return MC_EXPRESSION_E_UNSUPPORTED_OPERATION;
298 if(error) return error;
305 /** \brief Resolve a location expression
306 * \deprecated Use mc_dwarf_resolve_expression
308 uintptr_t mc_dwarf_resolve_location(mc_expression_t expression, mc_object_info_t object_info, unw_cursor_t* c, void* frame_pointer_address, mc_snapshot_t snapshot) {
309 s_mc_expression_state_t state;
310 memset(&state, 0, sizeof(s_mc_expression_state_t));
311 state.frame_base = frame_pointer_address;
313 state.snapshot = snapshot;
314 state.object_info = object_info;
316 if(mc_dwarf_execute_expression(expression->size, expression->ops, &state))
317 xbt_die("Error evaluating DWARF expression");
318 if(state.stack_size==0)
319 xbt_die("No value on the stack");
321 return state.stack[state.stack_size-1];
324 uintptr_t mc_dwarf_resolve_locations(mc_location_list_t locations, mc_object_info_t object_info, unw_cursor_t* c, void* frame_pointer_address, mc_snapshot_t snapshot) {
328 if(unw_get_reg(c, UNW_REG_IP, &ip))
329 xbt_die("Could not resolve IP");
332 for(size_t i=0; i!=locations->size; ++i) {
333 mc_expression_t expression = locations->locations + i;
334 if( (expression->lowpc==NULL && expression->highpc==NULL)
335 || (c && ip >= (unw_word_t) expression->lowpc && ip < (unw_word_t) expression->highpc)) {
336 return mc_dwarf_resolve_location(expression, object_info, c, frame_pointer_address, snapshot);
339 xbt_die("Could not resolve location");
342 /** \brief Find the frame base of a given frame
347 void* mc_find_frame_base(dw_frame_t frame, mc_object_info_t object_info, unw_cursor_t* unw_cursor) {
348 return (void*) mc_dwarf_resolve_locations(&frame->frame_base, object_info, unw_cursor, NULL, NULL);
351 void mc_dwarf_expression_clear(mc_expression_t expression) {
352 free(expression->ops);
353 expression->ops = NULL;
354 expression->size = 0;
355 expression->lowpc = NULL;
356 expression->highpc = NULL;
359 void mc_dwarf_location_list_clear(mc_location_list_t list) {
360 for(size_t i=0; i!=list->size; ++i) {
361 mc_dwarf_expression_clear(list->locations + i);
363 free(list->locations);
364 list->locations = NULL;
368 void mc_dwarf_expression_init(mc_expression_t expression, size_t len, Dwarf_Op* ops) {
369 if(expression->ops) {
370 free(expression->ops);
372 expression->lowpc = NULL;
373 expression->highpc = NULL;
374 expression->size = len;
375 expression->ops = xbt_malloc(len*sizeof(Dwarf_Op));
376 memcpy(expression->ops, ops, len*sizeof(Dwarf_Op));
379 void mc_dwarf_location_list_init_from_expression(mc_location_list_t target, size_t len, Dwarf_Op* ops) {
380 if(target->locations) {
381 mc_dwarf_location_list_clear(target);
384 target->locations = (mc_expression_t) xbt_malloc(sizeof(s_mc_expression_t));
385 mc_dwarf_expression_init(target->locations, len, ops);
388 void mc_dwarf_location_list_init(mc_location_list_t list, mc_object_info_t info, Dwarf_Die* die, Dwarf_Attribute* attr) {
389 if(list->locations) {
390 mc_dwarf_location_list_clear(list);
394 ptrdiff_t offset = 0;
395 Dwarf_Addr base, start, end;
401 offset = dwarf_getlocations(attr, offset, &base, &start, &end, &ops, &len);
405 xbt_die("Error while loading location list");
409 list->locations = (mc_expression_t) realloc(list->locations, list->size*sizeof(s_mc_expression_t));
410 mc_expression_t expression = list->locations + i;
411 expression->ops = NULL;
412 mc_dwarf_expression_init(expression, len, ops);
414 void* base = info->flags & MC_OBJECT_INFO_EXECUTABLE ? 0 : MC_object_base_address(info);
415 // If start == 0, this is not a location list:
416 expression->lowpc = start == 0 ? NULL : (char*) base + start;
417 expression->highpc = start == 0 ? NULL : (char*) base + end;