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//===-- sanitizer_stacktrace_libcdep.cpp ----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
//===----------------------------------------------------------------------===//
#include "sanitizer_common.h"
#include "sanitizer_placement_new.h"
#include "sanitizer_stacktrace.h"
#include "sanitizer_stacktrace_printer.h"
#include "sanitizer_symbolizer.h"
namespace __sanitizer {
namespace {
class StackTraceTextPrinter {
public:
StackTraceTextPrinter(const char *stack_trace_fmt, char frame_delimiter,
InternalScopedString *output,
InternalScopedString *dedup_token)
: stack_trace_fmt_(stack_trace_fmt),
frame_delimiter_(frame_delimiter),
output_(output),
dedup_token_(dedup_token),
symbolize_(RenderNeedsSymbolization(stack_trace_fmt)) {}
bool ProcessAddressFrames(uptr pc) {
SymbolizedStack *frames = symbolize_
? Symbolizer::GetOrInit()->SymbolizePC(pc)
: SymbolizedStack::New(pc);
if (!frames)
return false;
for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
uptr prev_len = output_->length();
RenderFrame(output_, stack_trace_fmt_, frame_num_++, cur->info.address,
symbolize_ ? &cur->info : nullptr,
common_flags()->symbolize_vs_style,
common_flags()->strip_path_prefix);
if (prev_len != output_->length())
output_->append("%c", frame_delimiter_);
ExtendDedupToken(cur);
}
frames->ClearAll();
return true;
}
private:
// Extend the dedup token by appending a new frame.
void ExtendDedupToken(SymbolizedStack *stack) {
if (!dedup_token_)
return;
if (dedup_frames_-- > 0) {
if (dedup_token_->length())
dedup_token_->append("--");
if (stack->info.function != nullptr)
dedup_token_->append("%s", stack->info.function);
}
}
const char *stack_trace_fmt_;
const char frame_delimiter_;
int dedup_frames_ = common_flags()->dedup_token_length;
uptr frame_num_ = 0;
InternalScopedString *output_;
InternalScopedString *dedup_token_;
const bool symbolize_ = false;
};
static void CopyStringToBuffer(const InternalScopedString &str, char *out_buf,
uptr out_buf_size) {
if (!out_buf_size)
return;
CHECK_GT(out_buf_size, 0);
uptr copy_size = Min(str.length(), out_buf_size - 1);
internal_memcpy(out_buf, str.data(), copy_size);
out_buf[copy_size] = '\0';
}
} // namespace
void StackTrace::PrintTo(InternalScopedString *output) const {
CHECK(output);
InternalScopedString dedup_token;
StackTraceTextPrinter printer(common_flags()->stack_trace_format, '\n',
output, &dedup_token);
if (trace == nullptr || size == 0) {
output->append(" <empty stack>\n\n");
return;
}
for (uptr i = 0; i < size && trace[i]; i++) {
// PCs in stack traces are actually the return addresses, that is,
// addresses of the next instructions after the call.
uptr pc = GetPreviousInstructionPc(trace[i]);
CHECK(printer.ProcessAddressFrames(pc));
}
// Always add a trailing empty line after stack trace.
output->append("\n");
// Append deduplication token, if non-empty.
if (dedup_token.length())
output->append("DEDUP_TOKEN: %s\n", dedup_token.data());
}
uptr StackTrace::PrintTo(char *out_buf, uptr out_buf_size) const {
CHECK(out_buf);
InternalScopedString output;
PrintTo(&output);
CopyStringToBuffer(output, out_buf, out_buf_size);
return output.length();
}
void StackTrace::Print() const {
InternalScopedString output;
PrintTo(&output);
Printf("%s", output.data());
}
void BufferedStackTrace::Unwind(u32 max_depth, uptr pc, uptr bp, void *context,
uptr stack_top, uptr stack_bottom,
bool request_fast_unwind) {
// Ensures all call sites get what they requested.
CHECK_EQ(request_fast_unwind, WillUseFastUnwind(request_fast_unwind));
top_frame_bp = (max_depth > 0) ? bp : 0;
// Avoid doing any work for small max_depth.
if (max_depth == 0) {
size = 0;
return;
}
if (max_depth == 1) {
size = 1;
trace_buffer[0] = pc;
return;
}
if (!WillUseFastUnwind(request_fast_unwind)) {
#if SANITIZER_CAN_SLOW_UNWIND
if (context)
UnwindSlow(pc, context, max_depth);
else
UnwindSlow(pc, max_depth);
// If there are too few frames, the program may be built with
// -fno-asynchronous-unwind-tables. Fall back to fast unwinder below.
if (size > 2 || size >= max_depth)
return;
#else
UNREACHABLE("slow unwind requested but not available");
#endif
}
UnwindFast(pc, bp, stack_top, stack_bottom, max_depth);
}
static int GetModuleAndOffsetForPc(uptr pc, char *module_name,
uptr module_name_len, uptr *pc_offset) {
const char *found_module_name = nullptr;
bool ok = Symbolizer::GetOrInit()->GetModuleNameAndOffsetForPC(
pc, &found_module_name, pc_offset);
if (!ok) return false;
if (module_name && module_name_len) {
internal_strncpy(module_name, found_module_name, module_name_len);
module_name[module_name_len - 1] = '\x00';
}
return true;
}
} // namespace __sanitizer
using namespace __sanitizer;
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE
void __sanitizer_symbolize_pc(uptr pc, const char *fmt, char *out_buf,
uptr out_buf_size) {
if (!out_buf_size)
return;
pc = StackTrace::GetPreviousInstructionPc(pc);
InternalScopedString output;
StackTraceTextPrinter printer(fmt, '\0', &output, nullptr);
if (!printer.ProcessAddressFrames(pc)) {
output.clear();
output.append("<can't symbolize>");
}
CopyStringToBuffer(output, out_buf, out_buf_size);
}
SANITIZER_INTERFACE_ATTRIBUTE
void __sanitizer_symbolize_global(uptr data_addr, const char *fmt,
char *out_buf, uptr out_buf_size) {
if (!out_buf_size) return;
out_buf[0] = 0;
DataInfo DI;
if (!Symbolizer::GetOrInit()->SymbolizeData(data_addr, &DI)) return;
InternalScopedString data_desc;
RenderData(&data_desc, fmt, &DI, common_flags()->strip_path_prefix);
internal_strncpy(out_buf, data_desc.data(), out_buf_size);
out_buf[out_buf_size - 1] = 0;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __sanitizer_get_module_and_offset_for_pc(uptr pc, char *module_name,
uptr module_name_len,
uptr *pc_offset) {
return __sanitizer::GetModuleAndOffsetForPc(pc, module_name, module_name_len,
pc_offset);
}
} // extern "C"
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