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implemented base support of DWARF lexical block and call site

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This commit is contained in:
nnosov
2020-01-17 09:44:59 +04:00
parent e215c6af76
commit dcfbcd0952
2 changed files with 154 additions and 77 deletions
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framework/sysutils.cpp
+152 -77
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@@ -37,7 +37,7 @@ typedef struct __reginfo {
regname[0] = 0;
regno = -1;
}
char regname[1024];
char regname[32];
int regno;
} reginfo;
@@ -57,7 +57,7 @@ bool handle_location(pst_context* ctx, Dwarf_Attribute* attr, dwarf_stack& stack
Dwarf_Addr offset = pc - ctx->base_addr;
if(dwarf_hasform(attr, DW_FORM_exprloc)) {
// Location expression (exprloc form of location in DWARF terms)
// Location expression (exprloc class of location in DWARF terms)
Dwarf_Op *expr;
size_t exprlen;
if(dwarf_getlocation(attr, &expr, &exprlen) == 0) {
@@ -67,7 +67,7 @@ bool handle_location(pst_context* ctx, Dwarf_Attribute* attr, dwarf_stack& stack
}
}
} else if(dwarf_hasform(attr, DW_FORM_sec_offset)) {
// Location list (loclist form of location in DWARF terms)
// Location list (loclist class of location in DWARF terms)
Dwarf_Addr base, start, end;
ptrdiff_t off = 0;
Dwarf_Op *expr;
@@ -77,7 +77,7 @@ bool handle_location(pst_context* ctx, Dwarf_Attribute* attr, dwarf_stack& stack
for(int i = 0; (off = dwarf_getlocations (attr, off, &base, &start, &end, &expr, &exprlen)) > 0; ++i) {
ctx->print_expr_block (expr, exprlen, str, strsize, attr);
if(offset >= start && offset <= end) {
// actual location, try to calculate Location expression and retrieve value of parameter
// actual location, try to calculate Location expression
if(stack.calc_expression(expr, exprlen, attr)) {
return true;
}
@@ -296,7 +296,6 @@ bool __pst_parameter::handle_dwarf(Dwarf_Die* result)
handle_type(attr);
}
dwarf_stack stack(ctx);
if(dwarf_hasattr(result, DW_AT_location)) {
// determine location of parameter in stack/heap or CPU registers
attr = dwarf_attr(result, DW_AT_location, &attr_mem);
@@ -304,7 +303,7 @@ bool __pst_parameter::handle_dwarf(Dwarf_Die* result)
unw_get_reg(&ctx->curr_frame, UNW_REG_IP, &pc);
dwarf_stack stack(ctx);
char str[1024];
char str[1024]; str[0] = 0;
if(handle_location(ctx, attr, stack, pc, str, sizeof(str))) {
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "Parameter Location: %s ==> 0x%lX", str, value);
@@ -450,6 +449,146 @@ bool __pst_function::print_dwarf()
return true;
}
bool __pst_function::handle_lexical_block(Dwarf_Die* result)
{
uint64_t lowpc = 0, highpc = 0; const char* origin_name = "";
dwarf_lowpc(result, &lowpc);
dwarf_highpc(result, &lowpc);
Dwarf_Attribute attr_mem;
Dwarf_Die origin;
if(dwarf_hasattr (result, DW_AT_abstract_origin) && dwarf_formref_die (dwarf_attr (result, DW_AT_abstract_origin, &attr_mem), &origin) != NULL) {
origin_name = dwarf_diename(&origin);
Dwarf_Die child;
if(dwarf_child (&origin, &child) == 0) {
do {
switch (dwarf_tag (&child))
{
case DW_TAG_variable:
case DW_TAG_formal_parameter:
ctx->log(SEVERITY_DEBUG, "Abstract origin: %s('%s')", dwarf_diename(&origin), dwarf_diename (&child));
break;
default:
break;
}
} while (dwarf_siblingof (&child, &child) == 0);
}
}
const char* die_name = "";
if(dwarf_diename(result)) {
die_name = dwarf_diename(result);
}
ctx->log(SEVERITY_DEBUG, "Lexical block with name '%s', tag 0x%X and origin '%s' found. lowpc = 0x%lX, highpc = 0x%lX", die_name, dwarf_tag (result), origin_name, lowpc, highpc);
Dwarf_Die child;
if(dwarf_child (result, &child) == 0) {
do {
switch (dwarf_tag (&child)) {
case DW_TAG_lexical_block:
handle_lexical_block(&child);
break;
case DW_TAG_variable: {
pst_parameter* param = add_param();
if(!param->handle_dwarf(&child)) {
del_param(param);
}
break;
}
case DW_TAG_GNU_call_site:
handle_call_site(&child);
break;
case DW_TAG_inlined_subroutine:
ctx->log(SEVERITY_DEBUG, "Skipping Lexical block tag 'DW_TAG_inlined_subroutine'");
break;
default:
ctx->log(SEVERITY_DEBUG, "Unknown Lexical block tag 0x%X", dwarf_tag(&child));
break;
}
}while (dwarf_siblingof (&child, &child) == 0);
}
return true;
}
// DW_AT_low_pc should point to the offset from process base address which is actually PC of current function, usually.
// further handle DW_AT_abstract_origin attribute of DW_TAG_GNU_call_site DIE to determine what DIE is referenced by it.
// probably by invoke by:
// Dwarf_Die *scopes;
// int n = dwarf_getscopes_die (funcdie, &scopes); // where 'n' is the number of scopes
// if (n <= 0) -> FAILURE
// see handle_function() in elfutils/tests/funcscopes.c -> handle_function() -> print_vars()
// DW_TAG_GNU_call_site_parameter is defined under child DIE of DW_TAG_GNU_call_site and defines value of subroutine before calling it
// relates to DW_OP_GNU_entry_value() handling in callee function to determine the value of an argument/variable of the callee
// get DIE of return type
bool __pst_function::handle_call_site(Dwarf_Die* result)
{
Dwarf_Die origin;
Dwarf_Attribute attr_mem;
Dwarf_Attribute* attr;
if(dwarf_hasattr (result, DW_AT_abstract_origin) && dwarf_formref_die (dwarf_attr (result, DW_AT_abstract_origin, &attr_mem), &origin) != NULL) {
Dwarf_Die child;
if(dwarf_child (&origin, &child) == 0) {
do {
switch (dwarf_tag (&child))
{
case DW_TAG_variable:
case DW_TAG_formal_parameter:
ctx->log(SEVERITY_DEBUG, "Abstract origin: %s('%s')", dwarf_diename(&origin), dwarf_diename (&child));
break;
default:
break;
}
} while (dwarf_siblingof (&child, &child) == 0);
}
}
Dwarf_Die child;
if(dwarf_child (result, &child) == 0) {
do {
switch (dwarf_tag (&child))
{
case DW_TAG_GNU_call_site_parameter: {
Dwarf_Addr pc;
unw_get_reg(&cursor, UNW_REG_IP, &pc);
dwarf_stack stack(ctx); char str[1024]; uint64_t value;
if(dwarf_hasattr(&child, DW_AT_location)) {
// handle location expression here
// determine location of parameter in stack/heap or CPU registers
attr = dwarf_attr(&child, DW_AT_location, &attr_mem);
if(handle_location(ctx, attr, stack, pc, str, sizeof(str))) {
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "DW_TAG_GNU_call_site_parameter Location: \"%s\" ==> 0x%lX", str, value);
} else {
ctx->log(SEVERITY_ERROR, "Failed to get value of calculated DW_AT_location expression: %s", str);
}
} else {
ctx->log(SEVERITY_ERROR, "Failed to calculate DW_AT_location expression: %s", str);
}
}
if(dwarf_hasattr(&child, DW_AT_GNU_call_site_value)) {
// handle value expression here
attr = dwarf_attr(&child, DW_AT_GNU_call_site_value, &attr_mem);
if(handle_location(ctx, attr, stack, pc, str, sizeof(str))) {
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "DW_AT_GNU_call_site_value Location:\"%s\" ==> 0x%lX", str, value);
} else {
ctx->log(SEVERITY_ERROR, "Failed to get value of calculated DW_AT_location expression: %s", str);
}
} else {
ctx->log(SEVERITY_ERROR, "Failed to calculate DW_AT_location expression: %s", str);
}
}
break;
}
default:
break;
}
} while (dwarf_siblingof (&child, &child) == 0);
}
return true;
}
bool __pst_function::handle_dwarf(Dwarf_Die* d)
{
die = d;
@@ -532,84 +671,19 @@ bool __pst_function::handle_dwarf(Dwarf_Die* d)
break;
}
case DW_TAG_GNU_call_site:
// DW_AT_low_pc should point to the offset from process base address which is actually PC of current function, usually.
// further handle DW_AT_abstract_origin attribute of DW_TAG_GNU_call_site DIE to determine what DIE is referenced by it.
// probably by invoke by:
// Dwarf_Die *scopes;
// int n = dwarf_getscopes_die (funcdie, &scopes); // where 'n' is the number of scopes
// if (n <= 0) -> FAILURE
// see handle_function() in elfutils/tests/funcscopes.c -> handle_function() -> print_vars()
// DW_TAG_GNU_call_site_parameter is defined under child DIE of DW_TAG_GNU_call_site and defines value of subroutine before calling it
// relates to DW_OP_GNU_entry_value() handling in callee function to determine the value of an argument/variable of the callee
// get DIE of return type
Dwarf_Die origin;
if(dwarf_hasattr (&result, DW_AT_abstract_origin) && dwarf_formref_die (dwarf_attr (&result, DW_AT_abstract_origin, &attr_mem), &origin) != NULL) {
Dwarf_Die child;
if(dwarf_child (&origin, &child) == 0) {
do {
switch (dwarf_tag (&child))
{
case DW_TAG_variable:
case DW_TAG_formal_parameter:
ctx->log(SEVERITY_DEBUG, "Abstract origin: %s('%s')", dwarf_diename(&origin), dwarf_diename (&child));
break;
default:
break;
}
} while (dwarf_siblingof (&child, &child) == 0);
}
}
Dwarf_Die child;
if(dwarf_child (&result, &child) == 0) {
do {
switch (dwarf_tag (&child))
{
case DW_TAG_GNU_call_site_parameter: {
Dwarf_Addr pc;
unw_get_reg(&cursor, UNW_REG_IP, &pc);
dwarf_stack stack(ctx); char str[1024]; uint64_t value;
if(dwarf_hasattr(&child, DW_AT_location)) {
// handle location expression here
// determine location of parameter in stack/heap or CPU registers
attr = dwarf_attr(&child, DW_AT_location, &attr_mem);
if(handle_location(ctx, attr, stack, pc, str, sizeof(str))) {
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "DW_TAG_GNU_call_site_parameter Location: \"%s\" ==> 0x%lX", str, value);
} else {
ctx->log(SEVERITY_ERROR, "Failed to get value of calculated DW_AT_location expression: %s", str);
}
} else {
ctx->log(SEVERITY_ERROR, "Failed to calculate DW_AT_location expression: %s", str);
}
}
if(dwarf_hasattr(&child, DW_AT_GNU_call_site_value)) {
// handle value expression here
attr = dwarf_attr(&child, DW_AT_GNU_call_site_value, &attr_mem);
if(handle_location(ctx, attr, stack, pc, str, sizeof(str))) {
if(stack.get_value(value)) {
ctx->log(SEVERITY_DEBUG, "DW_AT_GNU_call_site_value Location:\"%s\" ==> 0x%lX", str, value);
} else {
ctx->log(SEVERITY_ERROR, "Failed to get value of calculated DW_AT_location expression: %s", str);
}
} else {
ctx->log(SEVERITY_ERROR, "Failed to calculate DW_AT_location expression: %s", str);
}
}
break;
}
default:
break;
}
} while (dwarf_siblingof (&child, &child) == 0);
}
handle_call_site(&result);
break;
// case DW_TAG_inlined_subroutine:
// /* Recurse further down */
// HandleFunction(&result);
// break;
case DW_TAG_lexical_block: {
handle_lexical_block(&result);
break;
}
default:
ctx->log(SEVERITY_DEBUG, "Unknown TAG of function: 0x%X", dwarf_tag(&result));
break;
}
} while(dwarf_siblingof(&result, &result) == 0);
@@ -798,6 +872,7 @@ bool __pst_handler::handle_dwarf()
for(pst_function* fun = next_function(NULL); fun; fun = next_function(fun)) {
dladdr((void*)(fun->pc), &info);
ctx.base_addr = (uint64_t)info.dli_fbase;
ctx.log(SEVERITY_DEBUG, "Function %s(...): module name: %s, base address: %p", fun->name.c_str(), info.dli_fname, info.dli_fbase);
ctx.curr_frame = fun->cursor;
if(fun->parent) {