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// Copyright (c) 2010 Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// basic_source_line_resolver.cc: BasicSourceLineResolver implementation.
//
// See basic_source_line_resolver.h and basic_source_line_resolver_types.h
// for documentation.
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits>
#include <map>
#include <utility>
#include <vector>
#include "google_breakpad/processor/basic_source_line_resolver.h"
#include "processor/basic_source_line_resolver_types.h"
#include "processor/module_factory.h"
#include "processor/tokenize.h"
using std::map;
using std::vector;
using std::make_pair;
namespace google_breakpad {
#ifdef _WIN32
#ifdef _MSC_VER
#define strtok_r strtok_s
#endif
#define strtoull _strtoui64
#endif
namespace {
// Utility function to tokenize given the presence of an optional initial
// field. In this case, optional_field is the expected string for the optional
// field, and max_tokens is the maximum number of tokens including the optional
// field. Refer to the documentation for Tokenize for descriptions of the other
// arguments.
bool TokenizeWithOptionalField(char *line,
const char *optional_field,
const char *separators,
int max_tokens,
vector<char*> *tokens) {
// First tokenize assuming the optional field is not present. If we then see
// the optional field, additionally tokenize the last token into two tokens.
if (!Tokenize(line, separators, max_tokens - 1, tokens)) {
return false;
}
if (strcmp(tokens->front(), optional_field) == 0) {
// The optional field is present. Split the last token in two to recover the
// field prior to the last.
vector<char*> last_tokens;
if (!Tokenize(tokens->back(), separators, 2, &last_tokens)) {
return false;
}
// Replace the previous last token with the two new tokens.
tokens->pop_back();
tokens->push_back(last_tokens[0]);
tokens->push_back(last_tokens[1]);
}
return true;
}
} // namespace
static const char *kWhitespace = " \r\n";
static const int kMaxErrorsPrinted = 5;
static const int kMaxErrorsBeforeBailing = 100;
BasicSourceLineResolver::BasicSourceLineResolver() :
SourceLineResolverBase(new BasicModuleFactory) { }
// static
void BasicSourceLineResolver::Module::LogParseError(
const string &message,
int line_number,
int *num_errors) {
if (++(*num_errors) <= kMaxErrorsPrinted) {
if (line_number > 0) {
BPLOG(ERROR) << "Line " << line_number << ": " << message;
} else {
BPLOG(ERROR) << message;
}
}
}
bool BasicSourceLineResolver::Module::LoadMapFromMemory(
char *memory_buffer,
size_t memory_buffer_size) {
linked_ptr<Function> cur_func;
int line_number = 0;
int num_errors = 0;
char *save_ptr;
// If the length is 0, we can still pretend we have a symbol file. This is
// for scenarios that want to test symbol lookup, but don't necessarily care
// if certain modules do not have any information, like system libraries.
if (memory_buffer_size == 0) {
return true;
}
// Make sure the last character is null terminator.
size_t last_null_terminator = memory_buffer_size - 1;
if (memory_buffer[last_null_terminator] != '\0') {
memory_buffer[last_null_terminator] = '\0';
}
// Skip any null terminators at the end of the memory buffer, and make sure
// there are no other null terminators in the middle of the memory buffer.
bool has_null_terminator_in_the_middle = false;
while (last_null_terminator > 0 &&
memory_buffer[last_null_terminator - 1] == '\0') {
last_null_terminator--;
}
for (size_t i = 0; i < last_null_terminator; i++) {
if (memory_buffer[i] == '\0') {
memory_buffer[i] = '_';
has_null_terminator_in_the_middle = true;
}
}
if (has_null_terminator_in_the_middle) {
LogParseError(
"Null terminator is not expected in the middle of the symbol data",
line_number,
&num_errors);
}
char *buffer;
buffer = strtok_r(memory_buffer, "\r\n", &save_ptr);
while (buffer != NULL) {
++line_number;
if (strncmp(buffer, "FILE ", 5) == 0) {
if (!ParseFile(buffer)) {
LogParseError("ParseFile on buffer failed", line_number, &num_errors);
}
} else if (strncmp(buffer, "STACK ", 6) == 0) {
if (!ParseStackInfo(buffer)) {
LogParseError("ParseStackInfo failed", line_number, &num_errors);
}
} else if (strncmp(buffer, "FUNC ", 5) == 0) {
cur_func.reset(ParseFunction(buffer));
if (!cur_func.get()) {
LogParseError("ParseFunction failed", line_number, &num_errors);
} else {
// StoreRange will fail if the function has an invalid address or size.
// We'll silently ignore this, the function and any corresponding lines
// will be destroyed when cur_func is released.
functions_.StoreRange(cur_func->address, cur_func->size, cur_func);
}
} else if (strncmp(buffer, "PUBLIC ", 7) == 0) {
// Clear cur_func: public symbols don't contain line number information.
cur_func.reset();
if (!ParsePublicSymbol(buffer)) {
LogParseError("ParsePublicSymbol failed", line_number, &num_errors);
}
} else if (strncmp(buffer, "MODULE ", 7) == 0) {
// Ignore these. They're not of any use to BasicSourceLineResolver,
// which is fed modules by a SymbolSupplier. These lines are present to
// aid other tools in properly placing symbol files so that they can
// be accessed by a SymbolSupplier.
//
// MODULE <guid> <age> <filename>
} else if (strncmp(buffer, "INFO ", 5) == 0) {
// Ignore these as well, they're similarly just for housekeeping.
//
// INFO CODE_ID <code id> <filename>
} else {
if (!cur_func.get()) {
LogParseError("Found source line data without a function",
line_number, &num_errors);
} else {
Line *line = ParseLine(buffer);
if (!line) {
LogParseError("ParseLine failed", line_number, &num_errors);
} else {
cur_func->lines.StoreRange(line->address, line->size,
linked_ptr<Line>(line));
}
}
}
if (num_errors > kMaxErrorsBeforeBailing) {
break;
}
buffer = strtok_r(NULL, "\r\n", &save_ptr);
}
is_corrupt_ = num_errors > 0;
return true;
}
void BasicSourceLineResolver::Module::LookupAddress(StackFrame *frame) const {
MemAddr address = frame->instruction - frame->module->base_address();
// First, look for a FUNC record that covers address. Use
// RetrieveNearestRange instead of RetrieveRange so that, if there
// is no such function, we can use the next function to bound the
// extent of the PUBLIC symbol we find, below. This does mean we
// need to check that address indeed falls within the function we
// find; do the range comparison in an overflow-friendly way.
linked_ptr<Function> func;
linked_ptr<PublicSymbol> public_symbol;
MemAddr function_base;
MemAddr function_size;
MemAddr public_address;
if (functions_.RetrieveNearestRange(address, &func, &function_base,
NULL /* delta */, &function_size) &&
address >= function_base && address - function_base < function_size) {
frame->function_name = func->name;
frame->function_base = frame->module->base_address() + function_base;
linked_ptr<Line> line;
MemAddr line_base;
if (func->lines.RetrieveRange(address, &line, &line_base, NULL /* delta */,
NULL /* size */)) {
FileMap::const_iterator it = files_.find(line->source_file_id);
if (it != files_.end()) {
frame->source_file_name = files_.find(line->source_file_id)->second;
}
frame->source_line = line->line;
frame->source_line_base = frame->module->base_address() + line_base;
}
} else if (public_symbols_.Retrieve(address,
&public_symbol, &public_address) &&
(!func.get() || public_address > function_base)) {
frame->function_name = public_symbol->name;
frame->function_base = frame->module->base_address() + public_address;
}
}
WindowsFrameInfo *BasicSourceLineResolver::Module::FindWindowsFrameInfo(
const StackFrame *frame) const {
MemAddr address = frame->instruction - frame->module->base_address();
scoped_ptr<WindowsFrameInfo> result(new WindowsFrameInfo());
// We only know about WindowsFrameInfo::STACK_INFO_FRAME_DATA and
// WindowsFrameInfo::STACK_INFO_FPO. Prefer them in this order.
// WindowsFrameInfo::STACK_INFO_FRAME_DATA is the newer type that
// includes its own program string.
// WindowsFrameInfo::STACK_INFO_FPO is the older type
// corresponding to the FPO_DATA struct. See stackwalker_x86.cc.
linked_ptr<WindowsFrameInfo> frame_info;
if ((windows_frame_info_[WindowsFrameInfo::STACK_INFO_FRAME_DATA]
.RetrieveRange(address, &frame_info))
|| (windows_frame_info_[WindowsFrameInfo::STACK_INFO_FPO]
.RetrieveRange(address, &frame_info))) {
result->CopyFrom(*frame_info.get());
return result.release();
}
// Even without a relevant STACK line, many functions contain
// information about how much space their parameters consume on the
// stack. Use RetrieveNearestRange instead of RetrieveRange, so that
// we can use the function to bound the extent of the PUBLIC symbol,
// below. However, this does mean we need to check that ADDRESS
// falls within the retrieved function's range; do the range
// comparison in an overflow-friendly way.
linked_ptr<Function> function;
MemAddr function_base, function_size;
if (functions_.RetrieveNearestRange(address, &function, &function_base,
NULL /* delta */, &function_size) &&
address >= function_base && address - function_base < function_size) {
result->parameter_size = function->parameter_size;
result->valid |= WindowsFrameInfo::VALID_PARAMETER_SIZE;
return result.release();
}
// PUBLIC symbols might have a parameter size. Use the function we
// found above to limit the range the public symbol covers.
linked_ptr<PublicSymbol> public_symbol;
MemAddr public_address;
if (public_symbols_.Retrieve(address, &public_symbol, &public_address) &&
(!function.get() || public_address > function_base)) {
result->parameter_size = public_symbol->parameter_size;
}
return NULL;
}
CFIFrameInfo *BasicSourceLineResolver::Module::FindCFIFrameInfo(
const StackFrame *frame) const {
MemAddr address = frame->instruction - frame->module->base_address();
MemAddr initial_base, initial_size;
string initial_rules;
// Find the initial rule whose range covers this address. That
// provides an initial set of register recovery rules. Then, walk
// forward from the initial rule's starting address to frame's
// instruction address, applying delta rules.
if (!cfi_initial_rules_.RetrieveRange(address, &initial_rules, &initial_base,
NULL /* delta */, &initial_size)) {
return NULL;
}
// Create a frame info structure, and populate it with the rules from
// the STACK CFI INIT record.
scoped_ptr<CFIFrameInfo> rules(new CFIFrameInfo());
if (!ParseCFIRuleSet(initial_rules, rules.get()))
return NULL;
// Find the first delta rule that falls within the initial rule's range.
map<MemAddr, string>::const_iterator delta =
cfi_delta_rules_.lower_bound(initial_base);
// Apply delta rules up to and including the frame's address.
while (delta != cfi_delta_rules_.end() && delta->first <= address) {
ParseCFIRuleSet(delta->second, rules.get());
delta++;
}
return rules.release();
}
bool BasicSourceLineResolver::Module::ParseFile(char *file_line) {
long index;
char *filename;
if (SymbolParseHelper::ParseFile(file_line, &index, &filename)) {
files_.insert(make_pair(index, string(filename)));
return true;
}
return false;
}
BasicSourceLineResolver::Function*
BasicSourceLineResolver::Module::ParseFunction(char *function_line) {
bool is_multiple;
uint64_t address;
uint64_t size;
long stack_param_size;
char *name;
if (SymbolParseHelper::ParseFunction(function_line, &is_multiple, &address,
&size, &stack_param_size, &name)) {
return new Function(name, address, size, stack_param_size, is_multiple);
}
return NULL;
}
BasicSourceLineResolver::Line* BasicSourceLineResolver::Module::ParseLine(
char *line_line) {
uint64_t address;
uint64_t size;
long line_number;
long source_file;
if (SymbolParseHelper::ParseLine(line_line, &address, &size, &line_number,
&source_file)) {
return new Line(address, size, source_file, line_number);
}
return NULL;
}
bool BasicSourceLineResolver::Module::ParsePublicSymbol(char *public_line) {
bool is_multiple;
uint64_t address;
long stack_param_size;
char *name;
if (SymbolParseHelper::ParsePublicSymbol(public_line, &is_multiple, &address,
&stack_param_size, &name)) {
// A few public symbols show up with an address of 0. This has been seen
// in the dumped output of ntdll.pdb for symbols such as _CIlog, _CIpow,
// RtlDescribeChunkLZNT1, and RtlReserveChunkLZNT1. They would conflict
// with one another if they were allowed into the public_symbols_ map,
// but since the address is obviously invalid, gracefully accept them
// as input without putting them into the map.
if (address == 0) {
return true;
}
linked_ptr<PublicSymbol> symbol(new PublicSymbol(name, address,
stack_param_size,
is_multiple));
return public_symbols_.Store(address, symbol);
}
return false;
}
bool BasicSourceLineResolver::Module::ParseStackInfo(char *stack_info_line) {
// Skip "STACK " prefix.
stack_info_line += 6;
// Find the token indicating what sort of stack frame walking
// information this is.
while (*stack_info_line == ' ')
stack_info_line++;
const char *platform = stack_info_line;
while (!strchr(kWhitespace, *stack_info_line))
stack_info_line++;
*stack_info_line++ = '\0';
// MSVC stack frame info.
if (strcmp(platform, "WIN") == 0) {
int type = 0;
uint64_t rva, code_size;
linked_ptr<WindowsFrameInfo>
stack_frame_info(WindowsFrameInfo::ParseFromString(stack_info_line,
type,
rva,
code_size));
if (stack_frame_info == NULL)
return false;
// TODO(mmentovai): I wanted to use StoreRange's return value as this
// method's return value, but MSVC infrequently outputs stack info that
// violates the containment rules. This happens with a section of code
// in strncpy_s in test_app.cc (testdata/minidump2). There, problem looks
// like this:
// STACK WIN 4 4242 1a a 0 ... (STACK WIN 4 base size prolog 0 ...)
// STACK WIN 4 4243 2e 9 0 ...
// ContainedRangeMap treats these two blocks as conflicting. In reality,
// when the prolog lengths are taken into account, the actual code of
// these blocks doesn't conflict. However, we can't take the prolog lengths
// into account directly here because we'd wind up with a different set
// of range conflicts when MSVC outputs stack info like this:
// STACK WIN 4 1040 73 33 0 ...
// STACK WIN 4 105a 59 19 0 ...
// because in both of these entries, the beginning of the code after the
// prolog is at 0x1073, and the last byte of contained code is at 0x10b2.
// Perhaps we could get away with storing ranges by rva + prolog_size
// if ContainedRangeMap were modified to allow replacement of
// already-stored values.
windows_frame_info_[type].StoreRange(rva, code_size, stack_frame_info);
return true;
} else if (strcmp(platform, "CFI") == 0) {
// DWARF CFI stack frame info
return ParseCFIFrameInfo(stack_info_line);
} else {
// Something unrecognized.
return false;
}
}
bool BasicSourceLineResolver::Module::ParseCFIFrameInfo(
char *stack_info_line) {
char *cursor;
// Is this an INIT record or a delta record?
char *init_or_address = strtok_r(stack_info_line, " \r\n", &cursor);
if (!init_or_address)
return false;
if (strcmp(init_or_address, "INIT") == 0) {
// This record has the form "STACK INIT <address> <size> <rules...>".
char *address_field = strtok_r(NULL, " \r\n", &cursor);
if (!address_field) return false;
char *size_field = strtok_r(NULL, " \r\n", &cursor);
if (!size_field) return false;
char *initial_rules = strtok_r(NULL, "\r\n", &cursor);
if (!initial_rules) return false;
MemAddr address = strtoul(address_field, NULL, 16);
MemAddr size = strtoul(size_field, NULL, 16);
cfi_initial_rules_.StoreRange(address, size, initial_rules);
return true;
}
// This record has the form "STACK <address> <rules...>".
char *address_field = init_or_address;
char *delta_rules = strtok_r(NULL, "\r\n", &cursor);
if (!delta_rules) return false;
MemAddr address = strtoul(address_field, NULL, 16);
cfi_delta_rules_[address] = delta_rules;
return true;
}
// static
bool SymbolParseHelper::ParseFile(char *file_line, long *index,
char **filename) {
// FILE <id> <filename>
assert(strncmp(file_line, "FILE ", 5) == 0);
file_line += 5; // skip prefix
vector<char*> tokens;
if (!Tokenize(file_line, kWhitespace, 2, &tokens)) {
return false;
}
char *after_number;
*index = strtol(tokens[0], &after_number, 10);
if (!IsValidAfterNumber(after_number) || *index < 0 ||
*index == std::numeric_limits<long>::max()) {
return false;
}
*filename = tokens[1];
if (!*filename) {
return false;
}
return true;
}
// static
bool SymbolParseHelper::ParseFunction(char *function_line, bool *is_multiple,
uint64_t *address, uint64_t *size,
long *stack_param_size, char **name) {
// FUNC [<multiple>] <address> <size> <stack_param_size> <name>
assert(strncmp(function_line, "FUNC ", 5) == 0);
function_line += 5; // skip prefix
vector<char*> tokens;
if (!TokenizeWithOptionalField(function_line, "m", kWhitespace, 5, &tokens)) {
return false;
}
*is_multiple = strcmp(tokens[0], "m") == 0;
int next_token = *is_multiple ? 1 : 0;
char *after_number;
*address = strtoull(tokens[next_token++], &after_number, 16);
if (!IsValidAfterNumber(after_number) ||
*address == std::numeric_limits<unsigned long long>::max()) {
return false;
}
*size = strtoull(tokens[next_token++], &after_number, 16);
if (!IsValidAfterNumber(after_number) ||
*size == std::numeric_limits<unsigned long long>::max()) {
return false;
}
*stack_param_size = strtol(tokens[next_token++], &after_number, 16);
if (!IsValidAfterNumber(after_number) ||
*stack_param_size == std::numeric_limits<long>::max() ||
*stack_param_size < 0) {
return false;
}
*name = tokens[next_token++];
return true;
}
// static
bool SymbolParseHelper::ParseLine(char *line_line, uint64_t *address,
uint64_t *size, long *line_number,
long *source_file) {
// <address> <size> <line number> <source file id>
vector<char*> tokens;
if (!Tokenize(line_line, kWhitespace, 4, &tokens)) {
return false;
}
char *after_number;
*address = strtoull(tokens[0], &after_number, 16);
if (!IsValidAfterNumber(after_number) ||
*address == std::numeric_limits<unsigned long long>::max()) {
return false;
}
*size = strtoull(tokens[1], &after_number, 16);
if (!IsValidAfterNumber(after_number) ||
*size == std::numeric_limits<unsigned long long>::max()) {
return false;
}
*line_number = strtol(tokens[2], &after_number, 10);
if (!IsValidAfterNumber(after_number) ||
*line_number == std::numeric_limits<long>::max()) {
return false;
}
*source_file = strtol(tokens[3], &after_number, 10);
if (!IsValidAfterNumber(after_number) || *source_file < 0 ||
*source_file == std::numeric_limits<long>::max()) {
return false;
}
// Valid line numbers normally start from 1, however there are functions that
// are associated with a source file but not associated with any line number
// (block helper function) and for such functions the symbol file contains 0
// for the line numbers. Hence, 0 should be treated as a valid line number.
// For more information on block helper functions, please, take a look at:
if (*line_number < 0) {
return false;
}
return true;
}
// static
bool SymbolParseHelper::ParsePublicSymbol(char *public_line, bool *is_multiple,
uint64_t *address,
long *stack_param_size,
char **name) {
// PUBLIC [<multiple>] <address> <stack_param_size> <name>
assert(strncmp(public_line, "PUBLIC ", 7) == 0);
public_line += 7; // skip prefix
vector<char*> tokens;
if (!TokenizeWithOptionalField(public_line, "m", kWhitespace, 4, &tokens)) {
return false;
}
*is_multiple = strcmp(tokens[0], "m") == 0;
int next_token = *is_multiple ? 1 : 0;
char *after_number;
*address = strtoull(tokens[next_token++], &after_number, 16);
if (!IsValidAfterNumber(after_number) ||
*address == std::numeric_limits<unsigned long long>::max()) {
return false;
}
*stack_param_size = strtol(tokens[next_token++], &after_number, 16);
if (!IsValidAfterNumber(after_number) ||
*stack_param_size == std::numeric_limits<long>::max() ||
*stack_param_size < 0) {
return false;
}
*name = tokens[next_token++];
return true;
}
// static
bool SymbolParseHelper::IsValidAfterNumber(char *after_number) {
if (after_number != NULL && strchr(kWhitespace, *after_number) != NULL) {
return true;
}
return false;
}
} // namespace google_breakpad