break;
}
+ // Push the CFA (Canonical Frame Addresse):
+ case DW_OP_call_frame_cfa:
+ {
+ // UNW_X86_64_CFA does not return the CFA DWARF expects
+ // (it is a synonym for UNW_X86_64_RSP) so copy the cursor,
+ // unwind it once in order to find the parent SP:
+
+ if(!state->cursor)
+ return MC_EXPRESSION_E_MISSING_STACK_CONTEXT;
+
+ // Get frame:
+ unw_cursor_t cursor = *(state->cursor);
+ unw_step(&cursor);
+
+ unw_word_t res;
+ unw_get_reg(&cursor, UNW_TDEP_SP, &res);
+ error = mc_dwarf_push_value(state, res);
+ break;
+ }
+
// Frame base:
case DW_OP_fbreg:
break;
}
+
// Constants:
case DW_OP_lit0: case DW_OP_lit1: case DW_OP_lit2: case DW_OP_lit3:
break;
case DW_OP_addr:
+ if(!state->object_info)
+ return MC_EXPRESSION_E_NO_BASE_ADDRESS;
+ if(state->stack_size==MC_EXPRESSION_STACK_SIZE)
+ return MC_EXPRESSION_E_STACK_OVERFLOW;
+ error = mc_dwarf_push_value(state, (Dwarf_Off)MC_object_base_address(state->object_info) + op->number);
+ break;
+
case DW_OP_const1u:
case DW_OP_const2u:
case DW_OP_const4u:
// Dereference:
case DW_OP_deref_size:
- case DW_OP_deref:
return MC_EXPRESSION_E_UNSUPPORTED_OPERATION;
+ case DW_OP_deref:
+ if(state->stack_size==0)
+ return MC_EXPRESSION_E_STACK_UNDERFLOW;
+ {
+ // Computed address:
+ uintptr_t address = (uintptr_t) state->stack[state->stack_size-1];
+ uintptr_t* p = (uintptr_t*)mc_translate_address(address, state->snapshot);
+ state->stack[state->stack_size-1] = *p;
+ }
+ break;
+
// Not handled:
default:
return MC_EXPRESSION_E_UNSUPPORTED_OPERATION;
/** \brief Resolve a location expression
* \deprecated Use mc_dwarf_resolve_expression
*/
-Dwarf_Off mc_dwarf_resolve_location(mc_expression_t expression, unw_cursor_t* c, void* frame_pointer_address) {
+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) {
s_mc_expression_state_t state;
memset(&state, 0, sizeof(s_mc_expression_state_t));
state.frame_base = frame_pointer_address;
state.cursor = c;
+ state.snapshot = snapshot;
+ state.object_info = object_info;
if(mc_dwarf_execute_expression(expression->size, expression->ops, &state))
xbt_die("Error evaluating DWARF expression");
if(state.stack_size==0)
xbt_die("No value on the stack");
else
- return (Dwarf_Off) state.stack[state.stack_size-1];
+ return state.stack[state.stack_size-1];
+}
+
+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) {
+
+ unw_word_t ip;
+ if(c) {
+ if(unw_get_reg(c, UNW_REG_IP, &ip))
+ xbt_die("Could not resolve IP");
+ }
+
+ for(size_t i=0; i!=locations->size; ++i) {
+ mc_expression_t expression = locations->locations + i;
+ if( (expression->lowpc==NULL && expression->highpc==NULL)
+ || (c && ip >= (unw_word_t) expression->lowpc && ip < (unw_word_t) expression->highpc)) {
+ return mc_dwarf_resolve_location(expression, object_info, c, frame_pointer_address, snapshot);
+ }
+ }
+ xbt_die("Could not resolve location");
}
+/** \brief Find the frame base of a given frame
+ *
+ * \param frame
+ * \param unw_cursor
+ */
+void* mc_find_frame_base(dw_frame_t frame, mc_object_info_t object_info, unw_cursor_t* unw_cursor) {
+ return (void*) mc_dwarf_resolve_locations(&frame->frame_base, object_info, unw_cursor, NULL, NULL);
+}
+
+void mc_dwarf_expression_clear(mc_expression_t expression) {
+ free(expression->ops);
+ expression->ops = NULL;
+ expression->size = 0;
+ expression->lowpc = NULL;
+ expression->highpc = NULL;
+}
+
+void mc_dwarf_location_list_clear(mc_location_list_t list) {
+ for(size_t i=0; i!=list->size; ++i) {
+ mc_dwarf_expression_clear(list->locations + i);
+ }
+ free(list->locations);
+ list->locations = NULL;
+ list->size = 0;
+}
+
+void mc_dwarf_expression_init(mc_expression_t expression, size_t len, Dwarf_Op* ops) {
+ if(expression->ops) {
+ free(expression->ops);
+ }
+ expression->lowpc = NULL;
+ expression->highpc = NULL;
+ expression->size = len;
+ expression->ops = xbt_malloc(len*sizeof(Dwarf_Op));
+ memcpy(expression->ops, ops, len*sizeof(Dwarf_Op));
+}
+
+void mc_dwarf_location_list_init_from_expression(mc_location_list_t target, size_t len, Dwarf_Op* ops) {
+ if(target->locations) {
+ mc_dwarf_location_list_clear(target);
+ }
+ target->size = 1;
+ target->locations = (mc_expression_t) xbt_malloc(sizeof(s_mc_expression_t));
+ mc_dwarf_expression_init(target->locations, len, ops);
+}
+
+void mc_dwarf_location_list_init(mc_location_list_t list, mc_object_info_t info, Dwarf_Die* die, Dwarf_Attribute* attr) {
+ if(list->locations) {
+ mc_dwarf_location_list_clear(list);
+ }
+ list->size = 0;
+
+ ptrdiff_t offset = 0;
+ Dwarf_Addr base, start, end;
+ Dwarf_Op *ops;
+ size_t len;
+
+ while (1) {
+
+ offset = dwarf_getlocations(attr, offset, &base, &start, &end, &ops, &len);
+ if (offset==0)
+ return;
+ else if (offset==-1)
+ xbt_die("Error while loading location list");
+
+ int i = list->size;
+ list->size++;
+ list->locations = (mc_expression_t) realloc(list->locations, list->size*sizeof(s_mc_expression_t));
+ mc_expression_t expression = list->locations + i;
+
+ void* base = info->flags & MC_OBJECT_INFO_EXECUTABLE ? 0 : MC_object_base_address(info);
+ mc_dwarf_expression_init(expression, len, ops);
+
+ // If start == 0, this is not a location list:
+ expression->lowpc = start == 0 ? NULL : (char*) base + start;
+ expression->highpc = start == 0 ? NULL : (char*) base + end;
+ }
+
+}
