lib/sanitizer_common/sanitizer_stacktrace.cc - platform/external/compiler-rt - Gitiles

 //===-- sanitizer_stacktrace.cc -------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is shared between AddressSanitizer and ThreadSanitizer
 // run-time libraries.
 //===----------------------------------------------------------------------===//

 #include "sanitizer_common.h"
 #include "sanitizer_procmaps.h"
 #include "sanitizer_stacktrace.h"
 #include "sanitizer_symbolizer.h"

 namespace __sanitizer {
 const char *StripPathPrefix(const char *filepath,
                             const char *strip_file_prefix) {
   if (filepath == 0) return 0;
   if (filepath == internal_strstr(filepath, strip_file_prefix))
     return filepath + internal_strlen(strip_file_prefix);
   return filepath;
 }

 // ----------------------- StackTrace ----------------------------- {{{1
 uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
 #ifdef __arm__
   // Cancel Thumb bit.
   pc = pc & (~1);
 #endif
 #if defined(__powerpc__) || defined(__powerpc64__)
   // PCs are always 4 byte aligned.
   return pc - 4;
 #elif defined(__sparc__)
   return pc - 8;
 #else
   return pc - 1;
 #endif
 }

 static void PrintStackFramePrefix(uptr frame_num, uptr pc) {
   Printf("    #%zu 0x%zx", frame_num, pc);
 }

 static void PrintSourceLocation(const char *file, int line, int column,
                                 const char *strip_file_prefix) {
   CHECK(file);
   Printf(" %s", StripPathPrefix(file, strip_file_prefix));
   if (line > 0) {
     Printf(":%d", line);
     if (column > 0)
       Printf(":%d", column);
   }
 }

 static void PrintModuleAndOffset(const char *module, uptr offset,
                                  const char *strip_file_prefix) {
   Printf(" (%s+0x%zx)", StripPathPrefix(module, strip_file_prefix), offset);
 }

 void StackTrace::PrintStack(const uptr *addr, uptr size,
                             bool symbolize, const char *strip_file_prefix,
                             SymbolizeCallback symbolize_callback ) {
   MemoryMappingLayout proc_maps;
   InternalScopedBuffer<char> buff(GetPageSizeCached() * 2);
   InternalScopedBuffer<AddressInfo> addr_frames(64);
   uptr frame_num = 0;
   for (uptr i = 0; i < size && addr[i]; i++) {
     // PCs in stack traces are actually the return addresses, that is,
     // addresses of the next instructions after the call.
     uptr pc = GetPreviousInstructionPc(addr[i]);
     uptr addr_frames_num = 0;  // The number of stack frames for current
                                // instruction address.
     if (symbolize_callback) {
       if (symbolize_callback((void*)pc, buff.data(), buff.size())) {
         addr_frames_num = 1;
         PrintStackFramePrefix(frame_num, pc);
         // We can't know anything about the string returned by external
         // symbolizer, but if it starts with filename, try to strip path prefix
         // from it.
         Printf(" %s\n", StripPathPrefix(buff.data(), strip_file_prefix));
         frame_num++;
       }
     }
     if (symbolize && addr_frames_num == 0) {
       // Use our own (online) symbolizer, if necessary.
       addr_frames_num = SymbolizeCode(pc, addr_frames.data(),
                                       addr_frames.size());
       for (uptr j = 0; j < addr_frames_num; j++) {
         AddressInfo &info = addr_frames[j];
         PrintStackFramePrefix(frame_num, pc);
         if (info.function) {
           Printf(" in %s", info.function);
         }
         if (info.file) {
           PrintSourceLocation(info.file, info.line, info.column,
                               strip_file_prefix);
         } else if (info.module) {
           PrintModuleAndOffset(info.module, info.module_offset,
                                strip_file_prefix);
         }
         Printf("\n");
         info.Clear();
         frame_num++;
       }
     }
     if (addr_frames_num == 0) {
       // If online symbolization failed, try to output at least module and
       // offset for instruction.
       PrintStackFramePrefix(frame_num, pc);
       uptr offset;
       if (proc_maps.GetObjectNameAndOffset(pc, &offset,
                                            buff.data(), buff.size(),
                                            /* protection */0)) {
         PrintModuleAndOffset(buff.data(), offset, strip_file_prefix);
       }
       Printf("\n");
       frame_num++;
     }
   }
 }

 uptr StackTrace::GetCurrentPc() {
   return GET_CALLER_PC();
 }

 void StackTrace::FastUnwindStack(uptr pc, uptr bp,
                                  uptr stack_top, uptr stack_bottom) {
   CHECK(size == 0 && trace[0] == pc);
   size = 1;
   uhwptr *frame = (uhwptr *)bp;
   uhwptr *prev_frame = frame - 1;
   // Avoid infinite loop when frame == frame[0] by using frame > prev_frame.
   while (frame > prev_frame &&
          frame < (uhwptr *)stack_top - 2 &&
          frame > (uhwptr *)stack_bottom &&
          size < max_size) {
     uhwptr pc1 = frame[1];
     if (pc1 != pc) {
       trace[size++] = (uptr) pc1;
     }
     prev_frame = frame;
     frame = (uhwptr *)frame[0];
   }
 }

 void StackTrace::PopStackFrames(uptr count) {
   CHECK(size >= count);
   size -= count;
   for (uptr i = 0; i < size; i++) {
     trace[i] = trace[i + count];
   }
 }

 // On 32-bits we don't compress stack traces.
 // On 64-bits we compress stack traces: if a given pc differes slightly from
 // the previous one, we record a 31-bit offset instead of the full pc.
 SANITIZER_INTERFACE_ATTRIBUTE
 uptr StackTrace::CompressStack(StackTrace *stack, u32 *compressed, uptr size) {
 #if SANITIZER_WORDSIZE == 32
   // Don't compress, just copy.
   uptr res = 0;
   for (uptr i = 0; i < stack->size && i < size; i++) {
     compressed[i] = stack->trace[i];
     res++;
   }
   if (stack->size < size)
     compressed[stack->size] = 0;
 #else  // 64 bits, compress.
   uptr prev_pc = 0;
   const uptr kMaxOffset = (1ULL << 30) - 1;
   uptr c_index = 0;
   uptr res = 0;
   for (uptr i = 0, n = stack->size; i < n; i++) {
     uptr pc = stack->trace[i];
     if (!pc) break;
     if ((s64)pc < 0) break;
     // Printf("C pc[%zu] %zx\n", i, pc);
     if (prev_pc - pc < kMaxOffset || pc - prev_pc < kMaxOffset) {
       uptr offset = (s64)(pc - prev_pc);
       offset |= (1U << 31);
       if (c_index >= size) break;
       // Printf("C co[%zu] offset %zx\n", i, offset);
       compressed[c_index++] = offset;
     } else {
       uptr hi = pc >> 32;
       uptr lo = (pc << 32) >> 32;
       CHECK_EQ((hi & (1 << 31)), 0);
       if (c_index + 1 >= size) break;
       // Printf("C co[%zu] hi/lo: %zx %zx\n", c_index, hi, lo);
       compressed[c_index++] = hi;
       compressed[c_index++] = lo;
     }
     res++;
     prev_pc = pc;
   }
   if (c_index < size)
     compressed[c_index] = 0;
   if (c_index + 1 < size)
     compressed[c_index + 1] = 0;
 #endif  // SANITIZER_WORDSIZE

   // debug-only code
 #if 0
   StackTrace check_stack;
   UncompressStack(&check_stack, compressed, size);
   if (res < check_stack.size) {
     Printf("res %zu check_stack.size %zu; c_size %zu\n", res,
            check_stack.size, size);
   }
   // |res| may be greater than check_stack.size, because
   // UncompressStack(CompressStack(stack)) eliminates the 0x0 frames.
   CHECK(res >= check_stack.size);
   CHECK_EQ(0, REAL(memcmp)(check_stack.trace, stack->trace,
                           check_stack.size * sizeof(uptr)));
 #endif

   return res;
 }

 SANITIZER_INTERFACE_ATTRIBUTE
 void StackTrace::UncompressStack(StackTrace *stack,
                                  u32 *compressed, uptr size) {
 #if SANITIZER_WORDSIZE == 32
   // Don't uncompress, just copy.
   stack->size = 0;
   for (uptr i = 0; i < size && i < kStackTraceMax; i++) {
     if (!compressed[i]) break;
     stack->size++;
     stack->trace[i] = compressed[i];
   }
 #else  // 64 bits, uncompress
   uptr prev_pc = 0;
   stack->size = 0;
   for (uptr i = 0; i < size && stack->size < kStackTraceMax; i++) {
     u32 x = compressed[i];
     uptr pc = 0;
     if (x & (1U << 31)) {
       // Printf("U co[%zu] offset: %x\n", i, x);
       // this is an offset
       s32 offset = x;
       offset = (offset << 1) >> 1;  // remove the 31-byte and sign-extend.
       pc = prev_pc + offset;
       CHECK(pc);
     } else {
       // CHECK(i + 1 < size);
       if (i + 1 >= size) break;
       uptr hi = x;
       uptr lo = compressed[i+1];
       // Printf("U co[%zu] hi/lo: %zx %zx\n", i, hi, lo);
       i++;
       pc = (hi << 32) | lo;
       if (!pc) break;
     }
     // Printf("U pc[%zu] %zx\n", stack->size, pc);
     stack->trace[stack->size++] = pc;
     prev_pc = pc;
   }
 #endif  // SANITIZER_WORDSIZE
 }

 }  // namespace __sanitizer
	//===-- sanitizer_stacktrace.cc -------------------------------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file is shared between AddressSanitizer and ThreadSanitizer
	// run-time libraries.
	//===----------------------------------------------------------------------===//

	#include "sanitizer_common.h"
	#include "sanitizer_procmaps.h"
	#include "sanitizer_stacktrace.h"
	#include "sanitizer_symbolizer.h"

	namespace __sanitizer {
	const char StripPathPrefix(const char filepath,
	const char *strip_file_prefix) {
	if (filepath == 0) return 0;
	if (filepath == internal_strstr(filepath, strip_file_prefix))
	return filepath + internal_strlen(strip_file_prefix);
	return filepath;
	}

	// ----------------------- StackTrace ----------------------------- {{{1
	uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
	#ifdef __arm__
	// Cancel Thumb bit.
	pc = pc & (~1);
	#endif
	#if defined(__powerpc__) \|\| defined(__powerpc64__)
	// PCs are always 4 byte aligned.
	return pc - 4;
	#elif defined(__sparc__)
	return pc - 8;
	#else
	return pc - 1;
	#endif
	}

	static void PrintStackFramePrefix(uptr frame_num, uptr pc) {
	Printf(" #%zu 0x%zx", frame_num, pc);
	}

	static void PrintSourceLocation(const char *file, int line, int column,
	const char *strip_file_prefix) {
	CHECK(file);
	Printf(" %s", StripPathPrefix(file, strip_file_prefix));
	if (line > 0) {
	Printf(":%d", line);
	if (column > 0)
	Printf(":%d", column);
	}
	}

	static void PrintModuleAndOffset(const char *module, uptr offset,
	const char *strip_file_prefix) {
	Printf(" (%s+0x%zx)", StripPathPrefix(module, strip_file_prefix), offset);
	}

	void StackTrace::PrintStack(const uptr *addr, uptr size,
	bool symbolize, const char *strip_file_prefix,
	SymbolizeCallback symbolize_callback ) {
	MemoryMappingLayout proc_maps;
	InternalScopedBuffer<char> buff(GetPageSizeCached() * 2);
	InternalScopedBuffer<AddressInfo> addr_frames(64);
	uptr frame_num = 0;
	for (uptr i = 0; i < size && addr[i]; i++) {
	// PCs in stack traces are actually the return addresses, that is,
	// addresses of the next instructions after the call.
	uptr pc = GetPreviousInstructionPc(addr[i]);
	uptr addr_frames_num = 0; // The number of stack frames for current
	// instruction address.
	if (symbolize_callback) {
	if (symbolize_callback((void*)pc, buff.data(), buff.size())) {
	addr_frames_num = 1;
	PrintStackFramePrefix(frame_num, pc);
	// We can't know anything about the string returned by external
	// symbolizer, but if it starts with filename, try to strip path prefix
	// from it.
	Printf(" %s\n", StripPathPrefix(buff.data(), strip_file_prefix));
	frame_num++;
	}
	}
	if (symbolize && addr_frames_num == 0) {
	// Use our own (online) symbolizer, if necessary.
	addr_frames_num = SymbolizeCode(pc, addr_frames.data(),
	addr_frames.size());
	for (uptr j = 0; j < addr_frames_num; j++) {
	AddressInfo &info = addr_frames[j];
	PrintStackFramePrefix(frame_num, pc);
	if (info.function) {
	Printf(" in %s", info.function);
	}
	if (info.file) {
	PrintSourceLocation(info.file, info.line, info.column,
	strip_file_prefix);
	} else if (info.module) {
	PrintModuleAndOffset(info.module, info.module_offset,
	strip_file_prefix);
	}
	Printf("\n");
	info.Clear();
	frame_num++;
	}
	}
	if (addr_frames_num == 0) {
	// If online symbolization failed, try to output at least module and
	// offset for instruction.
	PrintStackFramePrefix(frame_num, pc);
	uptr offset;
	if (proc_maps.GetObjectNameAndOffset(pc, &offset,
	buff.data(), buff.size(),
	/* protection */0)) {
	PrintModuleAndOffset(buff.data(), offset, strip_file_prefix);
	}
	Printf("\n");
	frame_num++;
	}
	}
	}

	uptr StackTrace::GetCurrentPc() {
	return GET_CALLER_PC();
	}

	void StackTrace::FastUnwindStack(uptr pc, uptr bp,
	uptr stack_top, uptr stack_bottom) {
	CHECK(size == 0 && trace[0] == pc);
	size = 1;
	uhwptr frame = (uhwptr )bp;
	uhwptr *prev_frame = frame - 1;
	// Avoid infinite loop when frame == frame[0] by using frame > prev_frame.
	while (frame > prev_frame &&
	frame < (uhwptr *)stack_top - 2 &&
	frame > (uhwptr *)stack_bottom &&
	size < max_size) {
	uhwptr pc1 = frame[1];
	if (pc1 != pc) {
	trace[size++] = (uptr) pc1;
	}
	prev_frame = frame;
	frame = (uhwptr *)frame[0];
	}
	}

	void StackTrace::PopStackFrames(uptr count) {
	CHECK(size >= count);
	size -= count;
	for (uptr i = 0; i < size; i++) {
	trace[i] = trace[i + count];
	}
	}

	// On 32-bits we don't compress stack traces.
	// On 64-bits we compress stack traces: if a given pc differes slightly from
	// the previous one, we record a 31-bit offset instead of the full pc.
	SANITIZER_INTERFACE_ATTRIBUTE
	uptr StackTrace::CompressStack(StackTrace stack, u32 compressed, uptr size) {
	#if SANITIZER_WORDSIZE == 32
	// Don't compress, just copy.
	uptr res = 0;
	for (uptr i = 0; i < stack->size && i < size; i++) {
	compressed[i] = stack->trace[i];
	res++;
	}
	if (stack->size < size)
	compressed[stack->size] = 0;
	#else // 64 bits, compress.
	uptr prev_pc = 0;
	const uptr kMaxOffset = (1ULL << 30) - 1;
	uptr c_index = 0;
	uptr res = 0;
	for (uptr i = 0, n = stack->size; i < n; i++) {
	uptr pc = stack->trace[i];
	if (!pc) break;
	if ((s64)pc < 0) break;
	// Printf("C pc[%zu] %zx\n", i, pc);
	if (prev_pc - pc < kMaxOffset \|\| pc - prev_pc < kMaxOffset) {
	uptr offset = (s64)(pc - prev_pc);
	offset \|= (1U << 31);
	if (c_index >= size) break;
	// Printf("C co[%zu] offset %zx\n", i, offset);
	compressed[c_index++] = offset;
	} else {
	uptr hi = pc >> 32;
	uptr lo = (pc << 32) >> 32;
	CHECK_EQ((hi & (1 << 31)), 0);
	if (c_index + 1 >= size) break;
	// Printf("C co[%zu] hi/lo: %zx %zx\n", c_index, hi, lo);
	compressed[c_index++] = hi;
	compressed[c_index++] = lo;
	}
	res++;
	prev_pc = pc;
	}
	if (c_index < size)
	compressed[c_index] = 0;
	if (c_index + 1 < size)
	compressed[c_index + 1] = 0;
	#endif // SANITIZER_WORDSIZE

	// debug-only code
	#if 0
	StackTrace check_stack;
	UncompressStack(&check_stack, compressed, size);
	if (res < check_stack.size) {
	Printf("res %zu check_stack.size %zu; c_size %zu\n", res,
	check_stack.size, size);
	}
	// \|res\| may be greater than check_stack.size, because
	// UncompressStack(CompressStack(stack)) eliminates the 0x0 frames.
	CHECK(res >= check_stack.size);
	CHECK_EQ(0, REAL(memcmp)(check_stack.trace, stack->trace,
	check_stack.size * sizeof(uptr)));
	#endif

	return res;
	}

	SANITIZER_INTERFACE_ATTRIBUTE
	void StackTrace::UncompressStack(StackTrace *stack,
	u32 *compressed, uptr size) {
	#if SANITIZER_WORDSIZE == 32
	// Don't uncompress, just copy.
	stack->size = 0;
	for (uptr i = 0; i < size && i < kStackTraceMax; i++) {
	if (!compressed[i]) break;
	stack->size++;
	stack->trace[i] = compressed[i];
	}
	#else // 64 bits, uncompress
	uptr prev_pc = 0;
	stack->size = 0;
	for (uptr i = 0; i < size && stack->size < kStackTraceMax; i++) {
	u32 x = compressed[i];
	uptr pc = 0;
	if (x & (1U << 31)) {
	// Printf("U co[%zu] offset: %x\n", i, x);
	// this is an offset
	s32 offset = x;
	offset = (offset << 1) >> 1; // remove the 31-byte and sign-extend.
	pc = prev_pc + offset;
	CHECK(pc);
	} else {
	// CHECK(i + 1 < size);
	if (i + 1 >= size) break;
	uptr hi = x;
	uptr lo = compressed[i+1];
	// Printf("U co[%zu] hi/lo: %zx %zx\n", i, hi, lo);
	i++;
	pc = (hi << 32) \| lo;
	if (!pc) break;
	}
	// Printf("U pc[%zu] %zx\n", stack->size, pc);
	stack->trace[stack->size++] = pc;
	prev_pc = pc;
	}
	#endif // SANITIZER_WORDSIZE
	}

	} // namespace __sanitizer