global refactoring: use libunwind to get stack frame, get rid on process

base address, better DWARF DW_OP_XXX handling, initial implementation of
parameter's values retrieval

Makefile

@@ -49,7 +49,7 @@ SRC 		= $(shell find . -name '*.cpp')
 #OBJ 		= $(patsubst %.cpp,%.o,$(addprefix $(BUILD_DIR)/,$(notdir $(SRC))))
 OBJ 		= $(BUILD_DIR)/main.o
 
-LIBS 		= -L./ -lpthread -lpq -lpqtypes -luuid -lrabbitmq -ljson-c -lcrypto -ldl -lcurl -ldw -lxml2 -lmicrohttpd -larchive -lmagic
+LIBS 		= -L./ -lpthread -lpq -lpqtypes -luuid -lrabbitmq -ljson-c -lcrypto -ldl -lcurl -ldw -lxml2 -lmicrohttpd -larchive -lmagic -lunwind -lunwind-x86_64
 ATR_LIBS	= ./build/libframework.a
 
 INCS		= -I./ \

framework/common.cpp

@@ -0,0 +1,105 @@
+/*
+ * common.cpp
+ *
+ *  Created on: Jan 8, 2020
+ *      Author: nnosov
+ */
+
+#include <inttypes.h>
+#include <stddef.h>
+
+#include "common.h"
+
+dwarf_op_map dw_op[] = {
+		{0x23, 0x0,  0, "DW_OP_plus_uconst"},
+		// Register location descriptions. From DWARF 5, section 2.6.1.1.3:
+		// Register location descriptions describe an object (or a piece of an object) that resides in a register.
+		// A register location description must stand alone as the entire description of an object or a piece of an object.
+		{0x50, 0x0,  "RAX", "DW_OP_reg0"},
+		{0x51, 0x1,  "RDX", "DW_OP_reg1"},
+		{0x52, 0x2,  "RCX", "DW_OP_reg2"},
+		{0x53, 0x3,  "RBX", "DW_OP_reg3"},
+		{0x54, 0x4,  "RSI", "DW_OP_reg4"},
+		{0x55, 0x5,  "RDI", "DW_OP_reg5"},
+		{0x56, 0x6,  "RBP", "DW_OP_reg6"},
+		{0x57, 0x7,  "RSP", "DW_OP_reg7"},
+		{0x58, 0x8,  "R8",  "DW_OP_reg8"},
+		{0x59, 0x9,  "R9",  "DW_OP_reg9"},
+		{0x5A, 0xA,  "R10", "DW_OP_reg10"},
+		{0x5B, 0xB,  "R11", "DW_OP_reg11"},
+		{0x5C, 0xC,  "R12", "DW_OP_reg12"},
+		{0x5D, 0xD,  "R13", "DW_OP_reg13"},
+		{0x5E, 0xE,  "R14", "DW_OP_reg14"},
+		{0x5F, 0xF,  "R15", "DW_OP_reg15"},
+		{0x60, 0x10, "RIP", "DW_OP_reg16"},
+
+		// Register values. DWARF5, section 2.5.1.2
+		// Register values are used to describe an object (or a piece of an object) that is located in memory at an address that is contained in
+		// a register (possibly offset by some constant)
+		{0x70, 0x0,  "RAX", "DW_OP_breg0"},
+		{0x71, 0x1,  "RDX", "DW_OP_breg1"},
+		{0x72, 0x2,  "RCX", "DW_OP_breg2"},
+		{0x73, 0x3,  "RBX", "DW_OP_breg3"},
+		{0x74, 0x4,  "RSI", "DW_OP_breg4"},
+		{0x75, 0x5,  "RDI", "DW_OP_breg5"},
+		{0x76, 0x6,  "RBP", "DW_OP_breg6"},
+		{0x77, 0x7,  "RSP", "DW_OP_breg7"},
+		{0x78, 0x8,  "R8",  "DW_OP_breg8"},
+		{0x79, 0x9,  "R9",  "DW_OP_breg9"},
+		{0x7A, 0xA,  "R10", "DW_OP_breg10"},
+		{0x7B, 0xB,  "R11", "DW_OP_breg11"},
+		{0x7C, 0xC,  "R12", "DW_OP_breg12"},
+		{0x7D, 0xD,  "R13", "DW_OP_breg13"},
+		{0x7E, 0xE,  "R14", "DW_OP_breg14"},
+		{0x7F, 0xF,  "R15", "DW_OP_breg15"},
+		{0x80, 0x10, "RIP", "DW_OP_breg16"},
+
+		// The DW_OP_fbreg operation provides a signed LEB128 offset from the address specified by the location description in the DW_AT_frame_base
+		// attribute of the current function. This is typically a stack pointer register plus or minus some offset
+		{0x91, -1,   "",     "DW_OP_fbreg"},
+		{0x92, -1,   "",     "DW_OP_bregx"},
+		{0x9C, -1,   "",     "DW_OP_call_frame_cfa"},
+		// DWARF5, Section 2.6.1.1.4:
+		// he DW_OP_stack_value operation specifies that the object does not exist in memory but its value is nonetheless known and is at the top of the DWARF
+		// expression stack. In this form of location description, the DWARF expression represents the actual value of the object, rather than its location.
+		// The DW_OP_stack_value operation terminates the expression.
+		{0x9F, -1,   "",     "DW_OP_stack_value"},
+		//
+		{0xF3, -1,   "",     "DW_OP_GNU_entry_value"},
+};
+
+const dwarf_op_map* find_op_map(int op)
+{
+	for(uint32_t i = 0; i < sizeof(dw_op) / sizeof(dwarf_op_map); ++i) {
+		if(dw_op[i].op_num == op) {
+			return &dw_op[i];
+		}
+	}
+
+	return NULL;
+}
+
+int32_t decode_sleb128(uint8_t *sleb128)
+{
+	int32_t num = 0, shift = 0, size = 0;
+	do {
+		num |= ((*sleb128 & 0x7f) << shift);
+		shift += 7;
+		size += 8;
+	} while(*sleb128++ & 0x80);
+	if((shift < size) && (*(--sleb128) & 0x40)) {
+		num |= - (1 << shift);
+	}
+	return num;
+}
+
+uint32_t decode_uleb128(uint8_t *uleb128)
+{
+	uint32_t num = 0, shift = 0;
+	do {
+		num |= ((*uleb128 & 0x7f) << shift);
+		shift += 7;
+	} while(*uleb128++ & 0x80);
+	return num;
+}
+

framework/common.h

@@ -0,0 +1,13 @@
+#pragma once
+
+
+typedef struct __dwarf_op_map {
+	int				op_num;		// DWARF Operation DW_OP_XXX
+	int				regno;		// platform-dependent register number if present
+	const char*		regname;	// register name if regno specified
+	const char* 	op_name;	// string representation of an operation
+} dwarf_op_map;
+
+const dwarf_op_map* find_op_map(int op);
+int32_t decode_sleb128(uint8_t *sleb128);
+uint32_t decode_uleb128(uint8_t *uleb128);

framework/sysutils.cpp

@@ -20,28 +20,51 @@
 
 extern SC_LogBase* logger;
 
-char __stack_trace[8192];
+#define USEI_LIBUNWIND
 
+#ifdef USEI_LIBUNWIND
+#include <libunwind.h>
+#endif
 
-Dwarf_Frame* frame = 0;
+#include "common.h"
-Dwarf_Frame* prev_frame = 0;
+
-Dwfl_Module* module;
+bool __pst_context::print(const char* fmt, ...)
+{
+	bool nret = true;
+
+	va_list args;
+	va_start(args, fmt);
+	int size = sizeof(buff) - offset;
+	int ret = vsnprintf(buff + offset, size, fmt, args);
+	if(ret >= size || ret < 0) {
+		nret = false;
+	}
+	offset += ret;
+	va_end(args);
+
+	return nret;
+}
+
+void __pst_context::log(SC_LogSeverity severity, const char* fmt, ...)
+{
+	uint32_t    str_len = 0;
+	char        str[PATH_MAX]; str[0] = 0;
+	va_list args;
+	va_start(args, fmt);
+	str_len += vsnprintf(str + str_len, sizeof(str) - str_len, fmt, args);
+	va_end(args);
+
+	logger->Log(severity, "%s", str);
+}
 
 // dwfl_addrsegment() possibly can be used to check address validity
 // dwarf_getattrs() allows to enumerate all DIE attributes
 // dwarf_getfuncs() allows to enumerate functions within CU
 
-static void print_detail (int result, const Dwarf_Op *ops, size_t nops, Dwarf_Addr bias, const char* prefix);
-
 bool is_location_form(int form)
 {
-    if (form == DW_FORM_block1 ||
+    if (form == DW_FORM_block1 || form == DW_FORM_block2 || form == DW_FORM_block4 || form == DW_FORM_block ||
-        form == DW_FORM_block2 ||
+    	form == DW_FORM_data4  || form == DW_FORM_data8  || form == DW_FORM_sec_offset) {
-        form == DW_FORM_block4 ||
-        form == DW_FORM_block ||
-        form == DW_FORM_data4 ||
-        form == DW_FORM_data8 ||
-        form == DW_FORM_sec_offset) {
         return true;
     }
     return false;
@@ -83,6 +106,7 @@ int regname_callback (void *arg, int regno, const char *setname, const char *pre
 	return 0;
 }
 
+/*
 int reginfo_callback (void *arg, int regno, const char *setname, const char *prefix, const char *regname, int bits, int type)
 {
 	reginfo* info = (reginfo*)arg;
@@ -114,56 +138,9 @@ int reginfo_callback (void *arg, int regno, const char *setname, const char *pre
 
 	return 0;
 }
+*/
 
-void HandleType(Dwarf_Attribute* param, bool is_return = false)
+/*
-{
-	Dwarf_Attribute attr_mem;
-	Dwarf_Attribute* attr;
-
-	// get DIE of return type
-	Dwarf_Die ret_die;
-
-	if(dwarf_formref_die(param, &ret_die)) {
-		switch (dwarf_tag(&ret_die)) {
-			case DW_TAG_base_type: {
-				// get Size attribute and it's value
-				Dwarf_Word size = 0;
-				attr = dwarf_attr(&ret_die, DW_AT_byte_size, &attr_mem);
-				if(attr) {
-					dwarf_formudata(attr, &size);
-				}
-				logger->Log(SEVERITY_INFO, "base type '%s'(%lu)", dwarf_diename(&ret_die), size);
-				break;
-			}
-			case DW_TAG_array_type:
-				logger->Log(SEVERITY_INFO, "array type");
-				break;
-			case DW_TAG_pointer_type:
-				logger->Log(SEVERITY_INFO, "pointer type");
-				break;
-			case DW_TAG_enumeration_type:
-				logger->Log(SEVERITY_INFO, "enumeration type");
-				break;
-			case DW_TAG_const_type:
-				logger->Log(SEVERITY_INFO, "constant type");
-				break;
-			case DW_TAG_subroutine_type:
-				logger->Log(SEVERITY_INFO, "subroutine type");
-				break;
-			case DW_TAG_typedef:
-				logger->Log(SEVERITY_INFO, "typedef '%s' type", dwarf_diename(&ret_die));
-				break;
-			default:
-				logger->Log(SEVERITY_INFO, "Unknown 0x%X tag type", dwarf_tag(&ret_die));
-				break;
-		}
-		attr = dwarf_attr(&ret_die, DW_AT_type, &attr_mem);
-		if(attr) {
-			HandleType(attr);
-		}
-	}
-}
-
 void print_framereg(int regno)
 {
 	Dwarf_Op ops_mem[3];
@@ -187,31 +164,145 @@ void print_framereg(int regno)
 		logger->Log(SEVERITY_DEBUG, "\t[%d] operation: 0x%hhX, operand1: 0x%lX, operand2: 0x%lx, offset: 0x%lX", i, ops[i].atom, ops[i].number, ops[i].number2, ops[i].offset);
 	}
 }
+*/
 
 
-void
+uint32_t __pst_context::print_expr_block (Dwarf_Op *exprs, int len, char* buff, uint32_t buff_size, Dwarf_Attribute* attr)
-print_expr_block (Dwarf_Op *exprs, int len, char* buff, uint32_t buff_size)
 {
 	uint32_t offset = 0;
 	for (int i = 0; i < len; i++) {
 		//printf ("%s", (i + 1 < len ? ", " : ""));
-		offset += snprintf(buff + offset, buff_size - offset, "0x%hhX(0x%lX, 0x%lx) ", exprs[i].atom, exprs[i].number, exprs[i].number2);
+		const dwarf_op_map* map = find_op_map(exprs[i].atom);
-		if(exprs[i].atom >= DW_OP_reg0 && exprs[i].atom <= DW_OP_bregx) {
+		if(map) {
-			print_framereg(exprs[i].atom);
+			if(map->op_num >= DW_OP_breg0 && map->op_num <= DW_OP_breg16) {
+				int32_t off = decode_sleb128((unsigned char*)&exprs[i].number);
+
+				unw_word_t ptr = 0;
+				unw_get_reg(&cursor, map->regno, &ptr);
+				//ptr += off;
+
+				offset += snprintf(buff + offset, buff_size - offset, "%s(*%s%s%d) reg_value: 0x%lX ", map->op_name, map->regname, off >=0 ? "+" : "", off, ptr);
+			} else if(map->op_num >= DW_OP_reg0 && map->op_num <= DW_OP_reg16) {
+				unw_word_t value = 0;
+				unw_get_reg(&cursor, map->regno, &value);
+				offset += snprintf(buff + offset, buff_size - offset, "%s(*%s) value: 0x%lX", map->op_name, map->regname, value);
+			} else if(map->op_num == DW_OP_GNU_entry_value) {
+				uint32_t value = decode_uleb128((unsigned char*)&exprs[i].number);
+				offset += snprintf(buff + offset, buff_size - offset, "%s(%u, ", map->op_name, value);
+				Dwarf_Attribute attr_mem;
+				if(!dwarf_getlocation_attr(attr, exprs, &attr_mem)) {
+					Dwarf_Op *expr;
+					size_t exprlen;
+					if (dwarf_getlocation(&attr_mem, &expr, &exprlen) == 0) {
+						offset += print_expr_block (expr, exprlen, buff + offset, buff_size - offset, attr);
+						offset += snprintf(buff + offset, buff_size - offset, ") ");
+					} else {
+						log(SEVERITY_ERROR, "Failed to get DW_OP_GNU_entry_value attr location");
+					}
+				} else {
+					log(SEVERITY_ERROR, "Failed to get DW_OP_GNU_entry_value attr expression");
+				}
+			} else if(map->op_num == DW_OP_stack_value) {
+				offset += snprintf(buff + offset, buff_size - offset, "%s", map->op_name);
+			} else if(map->op_num == DW_OP_plus_uconst) {
+				uint32_t value = decode_uleb128((unsigned char*)&exprs[i].number);
+				offset += snprintf(buff + offset, buff_size - offset, "%s(+%u) ", map->op_name, value);
+			} else if(map->op_num == DW_OP_bregx) {
+				uint32_t regno = decode_uleb128((unsigned char*)&exprs[i].number);
+				int32_t off = decode_sleb128((unsigned char*)&exprs[i].number2);
+
+				unw_word_t ptr = 0;
+				unw_get_reg(&cursor, map->regno, &ptr);
+				//ptr += off;
+
+				offset += snprintf(buff + offset, buff_size - offset, "%s(%s%s%d) reg_value = 0x%lX", map->op_name, unw_regname(regno), off >= 0 ? "+" : "", off, ptr);
+			} else {
+				offset += snprintf(buff + offset, buff_size - offset, "%s(0x%lX, 0x%lx) ", map->op_name, exprs[i].number, exprs[i].number2);
+			}
+		} else {
+			offset += snprintf(buff + offset, buff_size - offset, "0x%hhX(0x%lX, 0x%lx) ", exprs[i].atom, exprs[i].number, exprs[i].number2);
 		}
+//		if(exprs[i].atom >= DW_OP_reg0 && exprs[i].atom <= DW_OP_bregx) {
+//			print_framereg(exprs[i].atom);
+//		}
 	}
 
+	return offset;
 }
-void HandleParameter(Dwarf_Die* result)
+
+bool __pst_parameter::handle_type(Dwarf_Attribute* param, bool is_return)
 {
 	Dwarf_Attribute attr_mem;
 	Dwarf_Attribute* attr;
 
+	// get DIE of return type
+	Dwarf_Die ret_die;
+
+	if(!dwarf_formref_die(param, &ret_die)) {
+		function->ctx->log(SEVERITY_ERROR, "Failed to get parameter DIE");
+		return false;
+	}
+
+	switch (dwarf_tag(&ret_die)) {
+		case DW_TAG_base_type: {
+			// get Size attribute and it's value
+			Dwarf_Word size = 0;
+			attr = dwarf_attr(&ret_die, DW_AT_byte_size, &attr_mem);
+			if(attr) {
+				dwarf_formudata(attr, &size);
+			}
+			function->ctx->log(SEVERITY_INFO, "base type '%s'(%lu)", dwarf_diename(&ret_die), size);
+			types.push_back(dwarf_diename(&ret_die));
+			break;
+		}
+		case DW_TAG_array_type:
+			logger->Log(SEVERITY_INFO, "array type");
+			types.push_back("[]");
+			break;
+		case DW_TAG_pointer_type:
+			logger->Log(SEVERITY_INFO, "pointer type");
+			types.push_back("*");
+			break;
+		case DW_TAG_enumeration_type:
+			logger->Log(SEVERITY_INFO, "enumeration type");
+			types.push_back("enum");
+			break;
+		case DW_TAG_const_type:
+			logger->Log(SEVERITY_INFO, "constant type");
+			types.push_back("const");
+			break;
+		case DW_TAG_subroutine_type:
+			logger->Log(SEVERITY_INFO, "subroutine type");
+			break;
+		case DW_TAG_typedef:
+			logger->Log(SEVERITY_INFO, "typedef '%s' type", dwarf_diename(&ret_die));
+			types.push_back(dwarf_diename(&ret_die));
+			break;
+		default:
+			logger->Log(SEVERITY_INFO, "Unknown 0x%X tag type", dwarf_tag(&ret_die));
+			break;
+	}
+
+	attr = dwarf_attr(&ret_die, DW_AT_type, &attr_mem);
+	if(attr) {
+		return handle_type(attr);
+	}
+
+	return true;
+}
+
+bool __pst_parameter::handle_dwarf(Dwarf_Die* result)
+{
+	die = result;
+
+	Dwarf_Attribute attr_mem;
+	Dwarf_Attribute* attr;
+
 	// Get reference to attribute type of the parameter/variable
 	attr = dwarf_attr(result, DW_AT_type, &attr_mem);
-	logger->Log(SEVERITY_INFO, "Handle '%s' %s", dwarf_diename(result), dwarf_tag(result) == DW_TAG_formal_parameter ? "parameter" : "variable");
+	function->ctx->log(SEVERITY_INFO, "Handle '%s' %s", dwarf_diename(result), dwarf_tag(result) == DW_TAG_formal_parameter ? "parameter" : "variable");
 	if(attr) {
-		HandleType(attr);
+		handle_type(attr);
 	}
 
 	// determine location of parameter in stack/heap or CPU registers
@@ -222,209 +313,265 @@ void HandleParameter(Dwarf_Die* result)
 			size_t exprlen;
 			if (dwarf_getlocation(attr, &expr, &exprlen) == 0) {
 				char str[1024]; str[0] = 0;
-				print_expr_block (expr, exprlen, str, sizeof(str));
+				function->ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
-				logger->Log(SEVERITY_DEBUG, "Found DW_AT_location expression: %s", str);
+				function->ctx->log(SEVERITY_DEBUG, "Found DW_AT_location expression: %s", str);
-				if(expr[0].atom >= DW_OP_reg0 && expr[0].atom <= DW_OP_bregx) {
+//				if(expr[0].atom >= DW_OP_reg0 && expr[0].atom <= DW_OP_bregx) {
-					print_framereg(expr[0].atom);
+//					print_framereg(expr[0].atom);
-				}
+//				}
 			}
 		} else if(dwarf_hasform(attr, DW_FORM_sec_offset)) {
 			Dwarf_Addr base, start, end;
 			ptrdiff_t off = 0;
 			Dwarf_Op *expr;
 			size_t exprlen;
-			Dwarf_Word value;
+
-			int ret = dwarf_formudata(attr, &value);
-			if(ret < 0) {
-				logger->Log(SEVERITY_ERROR, "Cannot get DW_AT_location offset");
-			}
 			for(int i = 0; (off = dwarf_getlocations (attr, off, &base, &start, &end, &expr, &exprlen)) > 0; ++i) {
 				char str[1024]; str[0] = 0;
-				print_expr_block (expr, exprlen, str, sizeof(str));
+				function->ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
-				logger->Log(SEVERITY_DEBUG, "[%d] low_offset: %" PRIx64 ", high_offset: %" PRIx64 ", .debug_locations section offset: 0x%lX ==> %s", i, start, end, value, str);
+				function->ctx->log(SEVERITY_DEBUG, "[%d] low_offset: 0x%" PRIx64 ", high_offset: 0x%" PRIx64 " ==> %s", i, start, end, str);
 			}
 
 		} else {
-			logger->Log(SEVERITY_WARNING, "Unknown attribute form = 0x%X, code = 0x%X, ", attr->form, attr->code);
+			function->ctx->log(SEVERITY_WARNING, "Unknown attribute form = 0x%X, code = 0x%X, ", attr->form, attr->code);
 		}
-
 	}
+
+	return true;
 }
 
-void HandleFunction(Dwarf_Die* func, const char* fname)
+bool __pst_function::handle_dwarf(Dwarf_Die* d)
 {
-	if(!strcmp(fname, dwarf_diename(func))) {
+	die = d;
-		logger->Log(SEVERITY_INFO, "Found function in debug info. DWARF tag: 0x%X, name = %s(...)", dwarf_tag(func), dwarf_diename(func));
 
-		Dwarf_Attribute attr_mem;
+	Dwarf_Attribute attr_mem;
-		Dwarf_Attribute* attr;
+	Dwarf_Attribute* attr;
 
-		// determine function's stack frame base
+	// get offset to function in memory against base address where process executed
-		attr = dwarf_attr(func, DW_AT_frame_base, &attr_mem);
+	dwarf_lowpc(d, &lowpc);
-		if(attr) {
+    Dwarf_Addr highpc;
-			if(dwarf_hasform(attr, DW_FORM_exprloc)) {
+    dwarf_highpc(d, &highpc);
-				Dwarf_Op *expr;
+
-				size_t exprlen;
+    unw_proc_info_t info;
-				if (dwarf_getlocation (attr, &expr, &exprlen) == 0) {
+    unw_get_proc_info(&ctx->cursor, &info);
-					char str[1024]; str[0] = 0;
+
-					print_expr_block (expr, exprlen, str, sizeof(str));
+    logger->Log(SEVERITY_INFO, "Found function in debug info. name = %s(...), PC = 0x%lX, LOW_PC = 0x%lX, HIGH_PC = 0x%lX, offset from base address: 0x%lX, info start = 0x%lX, offset from info start: 0x%lX",
-					logger->Log(SEVERITY_DEBUG, "Found DW_AT_framebase expression: %s", str);
+    		dwarf_diename(d), pc, lowpc, highpc, pc - ctx->base_addr, info.start_ip, info.start_ip - ctx->base_addr);
-					//print_detail(0, expr, exprlen, 0, "\tLocation ");
+
-				} else {
+	// determine function's stack frame base
-					logger->Log(SEVERITY_WARNING, "Unknown attribute form = 0x%X, code = 0x%X", attr->form, attr->code);
+	attr = dwarf_attr(die, DW_AT_frame_base, &attr_mem);
-				}
+	if(attr) {
+		if(dwarf_hasform(attr, DW_FORM_exprloc)) {
+			Dwarf_Op *expr;
+			size_t exprlen;
+			if (dwarf_getlocation (attr, &expr, &exprlen) == 0) {
+				char str[1024]; str[0] = 0;
+				ctx->print_expr_block (expr, exprlen, str, sizeof(str), attr);
+				ctx->log(SEVERITY_DEBUG, "Found DW_AT_framebase expression: %s", str);
+			} else {
+				ctx->log(SEVERITY_WARNING, "Unknown attribute form = 0x%X, code = 0x%X", attr->form, attr->code);
 			}
 		}
-
-		// Get reference to return attribute type of the function
-		// may be to use dwfl_module_return_value_location() instead
-		attr = dwarf_attr(func, DW_AT_type, &attr_mem);
-		if(attr) {
-			logger->Log(SEVERITY_INFO, "Handle return parameter");
-			HandleType(attr, true);
-		} else {
-			logger->Log(SEVERITY_DEBUG, "return attr name = 'void(0)'");
-		}
-
-		Dwarf_Die result;
-		if (dwarf_child(func, &result) != 0)
-		    return;
-
-		// went through parameters and local variables of the function
-		do {
-			switch (dwarf_tag(&result)) {
-				case DW_TAG_formal_parameter:
-				case DW_TAG_variable:
-					HandleParameter(&result);
-					break;
-//				case DW_TAG_inlined_subroutine:
-//					/* Recurse further down */
-//					HandleFunction(&result, dwarf_diename(&result));
-//					break;
-				default:
-					break;
-			}
-		} while(dwarf_siblingof(&result, &result) == 0);
 	}
-	return;
-}
 
-static void print_detail (int result, const Dwarf_Op *ops, size_t nops, Dwarf_Addr bias, const char* prefix)
+	// Get reference to return attribute type of the function
-{
+	// may be to use dwfl_module_return_value_location() instead
-	printf("\t%s ", prefix);
+	pst_parameter ret_p(this); ret_p.is_return = true;
-	if (result < 0) {
+	attr = dwarf_attr(die, DW_AT_type, &attr_mem);
-		printf("indeterminate (%s)\n", dwarf_errmsg (-1));
+	if(attr) {
-	} else if (nops == 0) {
+		ctx->log(SEVERITY_INFO, "Handle return parameter");
-		printf("%s\n", ops == NULL ? "same_value" : "undefined");
+		if(ret_p.handle_type(attr, true)) {
+			params.push_back(ret_p);
+		}
 	} else {
-		printf("%s expression:", result == 0 ? "location" : "value");
+		ret_p.types.push_back("void");
-		for (size_t i = 0; i < nops; ++i) {
+		params.push_back(ret_p);
-			printf (" 0x%X (offset: 0x%lX)", ops[i].atom, ops[i].offset);
+		ctx->log(SEVERITY_DEBUG, "return attr name = 'void(0)'");
-			if (ops[i].number2 == 0) {
-				if (ops[i].atom == DW_OP_addr) {
-					printf ("(%#" PRIx64 ")", ops[i].number + bias);
-				} else if (ops[i].number != 0) {
-					printf ("(%" PRIx64 ")", ops[i].number);
-				}
-			}
-			else {
-				printf ("(%" PRIx64 ",%" PRIx64 ")", ops[i].number, ops[i].number2);
-			}
-		}
-		puts("");
 	}
+
+	Dwarf_Die result;
+	if(dwarf_child(die, &result) != 0)
+		return false;
+
+	// went through parameters and local variables of the function
+	do {
+		pst_parameter param(this);
+
+		switch (dwarf_tag(&result)) {
+		case DW_TAG_formal_parameter:
+		case DW_TAG_variable:
+			if(param.handle_dwarf(&result)) {
+				params.push_back(param);
+			}
+			break;
+			//				case DW_TAG_inlined_subroutine:
+			//					/* Recurse further down */
+			//					HandleFunction(&result, dwarf_diename(&result));
+			//					break;
+		default:
+			break;
+		}
+	} while(dwarf_siblingof(&result, &result) == 0);
+
+	return true;
 }
 
-void HandleCompilationUnit(Dwfl_Module* module, Dwarf_Addr addr, const char* fname)
+bool __pst_function::unwind(Dwfl* dwfl, Dwfl_Module* module, Dwarf_Addr addr)
 {
-    Dwarf_Addr mod_cu = 0;
+	pc = addr;
-    // get CU(Compilation Unit) debug definition
-    Dwarf_Die* cdie = dwfl_module_addrdie(module, addr, &mod_cu);
-    logger->Log(SEVERITY_DEBUG, "Function bias in module is 0x%lX", mod_cu);
-    //Dwarf_Die* cdie = dwfl_addrdie(dwfl, addr, &mod_bias);
-    if(!cdie) {
-    	logger->Log(SEVERITY_INFO, "Failed to find DWARF DIE for address %X", addr);
-    	return;
-    }
 
+	Dwfl_Line *line = dwfl_getsrc(dwfl, addr);
+	if(line != NULL) {
+		int nline;
+		Dwarf_Addr addr;
+		const char* filename = dwfl_lineinfo (line, &addr, &nline, NULL, NULL, NULL);
+		if(filename) {
+			const char* str = strrchr(filename, '/');
+			if(str && *str != 0) {
+				str++;
+			} else {
+				str = filename;
+			}
+			ctx->print("%s:%d", str, nline);
+		} else {
+			ctx->print("%p", (void*)addr);
+		}
+	} else {
+		ctx->print("%p", (void*)addr);
+	}
+
+	const char* addrname = dwfl_module_addrname(module, addr);
+	char* demangle_name = NULL;
+	if(addrname) {
+		int status;
+		demangle_name = abi::__cxa_demangle(addrname, NULL, NULL, &status);
+		char* function_name = NULL;
+		if(asprintf(&function_name, "%s%s", demangle_name ? demangle_name : addrname, demangle_name ? "" : "()") == -1) {
+			ctx->log(SEVERITY_ERROR, "Failed to allocate memory");
+			return false;
+		}
+		ctx->print(" --> %s", function_name);
+
+		char* str = strchr(function_name, '(');
+		if(str) {
+			*str = 0;
+		}
+		name = function_name;
+		free(function_name);
+	}
+
+	if(demangle_name) {
+		free(demangle_name);
+	}
+
+	return true;
+}
+
+
+bool __pst_context::get_frame()
+{
     // get CFI (Call Frame Information) for current module
     // from handle_cfi()
     Dwarf_Addr mod_bias = 0;
     Dwarf_CFI* cfi = dwfl_module_eh_cfi(module, &mod_bias);
     //Dwarf_CFI* cfi = dwfl_module_dwarf_cfi(module, &mod_bias);
-    if(cfi) {
+    if(!cfi) {
-    	// get frame of CFI for address
+    	log(SEVERITY_INFO, "Cannot find CFI for module");
-    	logger->Log(SEVERITY_INFO, "Found CFI for module %s", dwarf_diename(cdie));
+    	return false;
-    	if(frame) {
+    }
-    		prev_frame = frame;
-    	}
-    	int result = dwarf_cfi_addrframe (cfi, addr - mod_bias, &frame);
-    	if (result == 0) {
-    		// get frame information
-        	logger->Log(SEVERITY_INFO, "Found CFI frame for module %s", dwarf_diename(cdie));
-        	Dwarf_Addr start = addr;
-        	Dwarf_Addr end = addr;
-        	bool signalp;
-        	int ra_regno = dwarf_frame_info (frame, &start, &end, &signalp);
-        	if(ra_regno >= 0) {
-        		start += mod_bias;
-        		end += mod_bias;
-        	}
-        	logger->Log(SEVERITY_DEBUG, "Per '.eh_frame' info has %#" PRIx64 " => [%#" PRIx64 ", %#" PRIx64 "] in_signal = %s", addr, start, end, signalp ? "true" : "false");
-        	  if (ra_regno < 0)
-        	    logger->Log(SEVERITY_DEBUG, "return address register unavailable (%s)", dwarf_errmsg (0));
-        	  else {
-        		  reginfo info; info.regno = ra_regno;
-        		  dwfl_module_register_names(module, regname_callback, &info);
-        		  logger->Log(SEVERITY_DEBUG, "return address in reg%u%s ==> %s", ra_regno, signalp ? " (signal frame)" : "", info.regname);
-        	  }
 
-        	  // finally get CFA (Canonical Frame Address)
+    // get frame of CFI for address
-        	  // Point cfa_ops to dummy to match print_detail expectations.
+    int result = dwarf_cfi_addrframe (cfi, addr - mod_bias, &frame);
-        	  // (nops == 0 && cfa_ops != NULL => "undefined")
+    if (result == 0) {
-        	  Dwarf_Op dummy;
+    	// get frame information
-        	  Dwarf_Op *cfa_ops = &dummy;
+    	log(SEVERITY_INFO, "Found CFI frame for module");
-        	  size_t cfa_nops;
+    	Dwarf_Addr start = addr;
-        	  result = dwarf_frame_cfa(frame, &cfa_ops, &cfa_nops);
+    	Dwarf_Addr end = addr;
-        	  char str[1024]; str[0] = 0;
+    	bool signalp;
-        	  print_expr_block (cfa_ops, cfa_nops, str, sizeof(str));
+    	int ra_regno = dwarf_frame_info (frame, &start, &end, &signalp);
-        	  logger->Log(SEVERITY_INFO, "Found CFA expression: %s", str);
+    	if(ra_regno >= 0) {
-        	  //print_detail (result, cfa_ops, cfa_nops, mod_bias, "\tCFA ");
+    		start += mod_bias;
+    		end += mod_bias;
+    	}
+    	log(SEVERITY_DEBUG, "Per '.eh_frame' info has %#" PRIx64 " => [%#" PRIx64 ", %#" PRIx64 "] in_signal = %s", addr, start, end, signalp ? "true" : "false");
+    	if (ra_regno < 0)
+    		log(SEVERITY_DEBUG, "return address register unavailable (%s)", dwarf_errmsg(0));
+    	else {
+    		reginfo info; info.regno = ra_regno;
+    		dwfl_module_register_names(module, regname_callback, &info);
+    		log(SEVERITY_DEBUG, "return address in reg%u%s ==> %s", ra_regno, signalp ? " (signal frame)" : "", info.regname);
     	}
 
+    	// finally get CFA (Canonical Frame Address)
+    	// Point cfa_ops to dummy to match print_detail expectations.
+    	// (nops == 0 && cfa_ops != NULL => "undefined")
+    	Dwarf_Op dummy;
+    	Dwarf_Op *cfa_ops = &dummy;
+    	size_t cfa_nops;
+    	result = dwarf_frame_cfa(frame, &cfa_ops, &cfa_nops);
+    	char str[1024]; str[0] = 0;
+    	print_expr_block (cfa_ops, cfa_nops, str, sizeof(str));
+    	log(SEVERITY_INFO, "Found CFA expression: %s", str);
+    	//print_detail (result, cfa_ops, cfa_nops, mod_bias, "\tCFA ");
+    }
+
+    return true;
+}
+
+bool __pst_context::get_dwarf_function(pst_function& fun)
+{
+    Dwarf_Addr mod_cu = 0;
+    // get CU(Compilation Unit) debug definition
+    Dwarf_Die* cdie = dwfl_module_addrdie(module, addr, &mod_cu);
+    //Dwarf_Die* cdie = dwfl_addrdie(dwfl, addr, &mod_bias);
+    if(!cdie) {
+    	logger->Log(SEVERITY_INFO, "Failed to find DWARF DIE for address %X", addr);
+    	return false;
     }
 
     if(dwarf_tag(cdie) != DW_TAG_compile_unit) {
     	logger->Log(SEVERITY_DEBUG, "Skipping non-cu die. DWARF tag: 0x%X, name = %s", dwarf_tag(cdie), dwarf_diename(cdie));
-    	return;
+    	return false;
     }
 
-	logger->Log(SEVERITY_DEBUG, "Enumerating Compilation Unit '%s' to lookup for function %s()", dwarf_diename(cdie), fname);
+    Dwarf_Die result;
-	Dwarf_Die result;
 	if(dwarf_child(cdie, &result)) {
-		logger->Log(SEVERITY_INFO, "No child DIE found for CU");
+		logger->Log(SEVERITY_ERROR, "No child DIE found for CU %s", dwarf_diename(cdie));
-		return;
+		return false;
 	}
 
+	bool nret = false;
+
 	do {
-		switch (dwarf_tag(&result)) {
+		int tag = dwarf_tag(&result);
-			case DW_TAG_subprogram:
+		if(tag == DW_TAG_subprogram || tag == DW_TAG_entry_point || tag == DW_TAG_inlined_subroutine) {
-			case DW_TAG_entry_point:
+			if(!strcmp(fun.name.c_str(), dwarf_diename(&result))) {
-			case DW_TAG_inlined_subroutine:
+				return fun.handle_dwarf(&result);
-				HandleFunction(&result, fname);
+			}
-				break;
-			default:
-				//logger->Log(SEVERITY_INFO, "Unknown tag 0x%X for die '%s'", dwarf_tag(&result), dwarf_diename(&result));
-				break;
 		}
 	} while(dwarf_siblingof(&result, &result) == 0);
+
+	return nret;
 }
 
-const char* LibdwTraceCallStack(ucontext_t* uctx)
+void __pst_context::dwarf_print()
+{
+
+}
+
+char *debuginfo_path = NULL;
+Dwfl_Callbacks callbacks = {
+        .find_elf           = dwfl_linux_proc_find_elf,
+        .find_debuginfo     = dwfl_standard_find_debuginfo,
+        .section_address    = dwfl_offline_section_address,
+        .debuginfo_path     = &debuginfo_path,
+};
+
+#include <dlfcn.h>
+
+bool __pst_context::unwind()
 {
-    void * caller_address = 0;
 #ifdef REG_RIP // x86_64
-    caller_address = (void *) uctx->uc_mcontext.gregs[REG_RIP];
+    caller = (void *) hcontext->uc_mcontext.gregs[REG_RIP];
 #elif defined(REG_EIP) // x86_32
     caller_address = (void *) uctx->uc_mcontext.gregs[REG_EIP]);
 #elif defined(__arm__)
@@ -440,84 +587,76 @@ const char* LibdwTraceCallStack(ucontext_t* uctx)
 #else
 #   error "unknown architecture!"
 #endif
-    void * array[50];
+
-    int size = backtrace(array, 50);
+    handle = dlopen(NULL, RTLD_NOW);
+	Dl_info info;
+	dladdr(caller, &info);
+	base_addr = (uint64_t)info.dli_fbase;
+	logger->Log(SEVERITY_INFO, "Process address information: dlopen handle: %p, base address: %p, object name: %s, symbol name: %s", handle, info.dli_fbase, info.dli_fname, info.dli_sname);
+
     int skipped = 0;
+#ifndef USEI_LIBUNWIND
+    int size = 0;
+    void * array[50];
+    size = backtrace(array, 50);
     for(int i = 0; i < size && array[i] != caller_address; ++i, ++skipped);
-    __stack_trace[0] = 0; uint32_t offset = 0;
+    print("Stack trace(caller = %p. Total stack frames: %d, skipped: %d):\n", caller_address, size, skipped);
-    offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "Stack trace(caller = %p. Total stack frames: %d, skipped: %d):\n",
+#else
-            caller_address, size, skipped);
+    unw_word_t  	pc;
 
-    char *debuginfo_path = NULL;
+    unw_getcontext(&context);
-    Dwfl_Callbacks callbacks = {
+    unw_init_local(&cursor, &context);
-            .find_elf           = dwfl_linux_proc_find_elf,
+    while (unw_step(&cursor) > 0) {
-            .find_debuginfo     = dwfl_standard_find_debuginfo,
+    	unw_get_reg(&cursor, UNW_REG_IP,  &pc);
-            .section_address    = dwfl_offline_section_address,
+    	if(pc == (uint64_t)caller) {
-            .debuginfo_path     = &debuginfo_path,
+    		break;
-    };
+    	} else {
+    		++skipped;
+    	}
+    }
+    print("Stack trace(caller = %p. Skipped stack frames: %d):\n", caller, skipped);
+#endif
 
-    Dwfl* dwfl = dwfl_begin(&callbacks);
+    dwfl = dwfl_begin(&callbacks);
     if(dwfl == NULL) {
-        offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "Failed to initialize libdw session for parse stack frames");
+        print("Failed to initialize libdw session for parse stack frames");
-        return __stack_trace;
+        return false;
     }
 
     if(dwfl_linux_proc_report(dwfl, getpid()) != 0 || dwfl_report_end(dwfl, NULL, NULL) !=0) {
-        offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "Failed to parse debug section of executable");
+    	print("Failed to parse debug section of executable");
-        return __stack_trace;
+    	return false;
     }
 
+#ifndef USEI_LIBUNWIND
     for (int i = skipped, idx = 0; i < size ; ++i, ++idx) {
-        offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "[%-2d] ", idx);
+    	print("[%-2d] ", idx);
+    	Dwarf_Addr addr = (uintptr_t)array[i];
+#else
+   for (int i = skipped, idx = 0; true ; ++i, ++idx) {
+   		unw_get_reg(&cursor, UNW_REG_IP,  &pc);
+   		addr = pc;
+   		print("[%-2d] ", idx);
+#endif
+   		module = dwfl_addrmodule(dwfl, addr);
+   		get_frame();
+   		pst_function fun(this);
+   		if(fun.unwind(dwfl, module, pc)) {
+   			if(get_dwarf_function(fun)) {
+   				functions.push_back(fun);
+   			}
+   		}
+   		print("\n");
+#ifdef USEI_LIBUNWIND
+   		if(unw_step(&cursor) <= 0) {
+   			break;
+   		}
+#endif
+   }
 
-        Dwarf_Addr addr = (uintptr_t)array[i];
+//   for(int op = DW_OP_breg0; op <= DW_OP_breg16; op++ ) {
-        Dwfl_Line *line = dwfl_getsrc(dwfl, addr);
+//	   printf("{0x%X, 0x%X, \"%s\"},\n", op, op - DW_OP_breg0, unw_regname(op - DW_OP_breg0));
-        if(line != NULL) {
+//   }
-            int nline;
-            Dwarf_Addr addr;
-            const char* filename = dwfl_lineinfo (line, &addr, &nline, NULL, NULL, NULL);
-            if(filename) {
-                const char* str = strrchr(filename, '/');
-                if(str && *str != 0) {
-                    str++;
-                } else {
-                    str = filename;
-                }
-                offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "%s:%d", str, nline);
-            } else {
-                offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "%p", array[i]);
-            }
-        } else {
-            offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "%p", array[i]);
-        }
 
-        module = dwfl_addrmodule(dwfl, addr);
+   return true;
-        const char* addrname = dwfl_module_addrname(module, addr);
-        char* demangle_name = NULL;
-        if(addrname) {
-            int status;
-            demangle_name = abi::__cxa_demangle(addrname, NULL, NULL, &status);
-            char* function_name = NULL;
-            if(asprintf(&function_name, "%s%s", demangle_name ? demangle_name : addrname, demangle_name ? "" : "()") == -1) {
-            	logger->Log(SEVERITY_ERROR, "Failed to allocate memory");
-            	return __stack_trace;
-            }
-            offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, " --> %s", function_name);
-
-            char* str = strchr(function_name, '(');
-            if(str) {
-            	*str = 0;
-            }
-            HandleCompilationUnit(module, addr, function_name);
-            free(function_name);
-        }
-
-        if(demangle_name) {
-            free(demangle_name);
-        }
-
-        offset += snprintf(__stack_trace + offset, sizeof(__stack_trace) - offset, "\n");
-    }
-
-    return __stack_trace;
 }

framework/sysutils.h

@@ -14,17 +14,110 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <vector>
 #include <string.h>
 #include <ucontext.h>
-
+#include <libunwind.h>
-using std::string;
+#include <elfutils/libdwfl.h>
-
+#include <dlfcn.h>
-// stack trace string buffer
-extern char __stack_trace[8192];
-
-// libdw-based trace call stack implementation
-const char* LibdwTraceCallStack(ucontext_t* uctx);
 
 char* GetExecutableName(char* path, uint32_t size);
 
+typedef struct __pst_function pst_function;
+
+typedef struct __pst_parameter {
+	__pst_parameter(pst_function* fun) : function(fun)
+	{
+		die = NULL;
+		size = 0;
+		type = 0;
+		loc = NULL;
+		is_return = false;
+	}
+
+	bool handle_dwarf(Dwarf_Die* d);
+	bool handle_type(Dwarf_Attribute* param, bool is_return = false);
+
+	Dwarf_Die*					die; 	// DWARF DIE containing parameter's definition
+	std::string					name;	// parameter's name
+	Dwarf_Word					size;	// size of parameter in bytes
+	int							type;	// base type of parameter in DW_TAG_XXX types enumeration
+	std::vector<std::string>	types;	// list of parameters definitions i.e. 'typedef', 'uint32_t'
+	void*						loc;	// pointer to location of parameter's value
+	bool						is_return; // whether this parameter is return value of the function
+	pst_function*				function;
+} pst_parameter;
+
+typedef struct __pst_context pst_context;
+
+typedef struct __pst_function {
+	__pst_function(pst_context* ctx) : ctx(ctx)
+	{
+		pc = 0;
+		line = -1;
+		die = NULL;
+		lowpc = 0;
+	}
+
+	bool unwind(Dwfl* dwfl, Dwfl_Module* module, Dwarf_Addr addr);
+	bool handle_dwarf(Dwarf_Die* d);
+
+	Dwarf_Addr					lowpc;
+	Dwarf_Die*					die; 	// DWARF DIE containing definition of the function
+	std::string					name;	// function's name
+	std::vector<pst_parameter>	params;	// array of function's parameters
+	unw_word_t  				pc;		// pointer to the start of the function
+	int							line;	// line in code where function is defined
+	std::string					file;	// file name (DWARF Compilation Unit) where is function defined
+	pst_context*				ctx;
+} pst_function;
+
+typedef struct __pst_context {
+	__pst_context(ucontext_t* hctx) : hcontext(hctx)
+	{
+		caller = NULL;
+		module = NULL;
+		dwfl = NULL;
+		offset = 0;
+		buff[0] = 0;
+		frame = NULL;
+		addr = 0;
+		base_addr = 0;
+		handle = 0;
+	}
+
+	~__pst_context()
+	{
+		if(handle) {
+			dlclose(handle);
+		}
+	}
+
+
+	bool print(const char* fmt, ...);
+	void dwarf_print();
+	uint32_t print_expr_block(Dwarf_Op *exprs, int len, char* buff, uint32_t buff_size, Dwarf_Attribute* attr = 0);
+	void log(SC_LogSeverity severity, const char*fmt, ...);
+	bool unwind();
+	bool get_frame();
+	bool get_dwarf_function(pst_function& fun);
+
+	ucontext_t*					hcontext;// context of signal handler
+	unw_context_t				context;// context of stack trace
+	unw_cursor_t				cursor;	// currently examined frame of context
+	void*						handle;	// process handle
+	Dwarf_Addr 					addr;	// address of currently processed function
+	Dwarf_Addr					base_addr;// base address where process loaded
+	Dwfl* 						dwfl;	// DWARF context
+	Dwfl_Module* 				module;	// currently processed CU
+	Dwarf_Frame* 				frame;	// currently processed stack frame
+	void*						caller;	// pointer to the function which requested to unwind stack
+	std::vector<pst_function>	functions;// array of functions in stack frame
+	char						buff[8192]; // stack trace buffer
+	uint32_t					offset;	// offset in the 'buff'
+} pst_context;
+
+// libdw-based trace call stack implementation
+bool LibdwTraceCallStack(pst_context& ctx);
+
 #endif /* SC_SYSUTILS_H_ */

main.cpp

@@ -63,14 +63,15 @@ void FatalSignalHandler(int sig, siginfo_t* info, void* context)
     fatal_error_in_progress = 1;
 
     logger->Log(SEVERITY_ERROR, "%s signal handled", strsignal(sig));
-    const char* trace = 0;
+    bool trace = false;
+    pst_context ctx((ucontext_t*)context);
 	if((context != 0) && (sig == SIGSEGV || sig == SIGABRT || sig == SIGBUS || sig == SIGFPE))
 	{
-	    trace = LibdwTraceCallStack((ucontext_t*)context);
+	    trace = ctx.unwind();
     }
 
 	if(trace) {
-	    logger->Log(SEVERITY_DEBUG, "%s", trace);
+	    logger->Log(SEVERITY_DEBUG, "%s", ctx.buff);
 	} else {
 	    logger->Log(SEVERITY_ERROR, "No stack trace obtained");
 	}
@@ -193,7 +194,7 @@ int main(int argc, char* argv[])
 
     SetSignalHandler(SigusrHandler);
 
-    Fun1(1, DEF_2, 3);
+    Fun1(1, DEF_2, 5);
 
     return 0;
 }