llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cc

87 lines
2.4 KiB
C++

//===-- 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_flags.h"
#include "sanitizer_stacktrace.h"
namespace __sanitizer {
uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
#if defined(__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
}
uptr StackTrace::GetCurrentPc() {
return GET_CALLER_PC();
}
void StackTrace::FastUnwindStack(uptr pc, uptr bp,
uptr stack_top, uptr stack_bottom,
uptr max_depth) {
CHECK_GE(max_depth, 2);
trace[0] = pc;
size = 1;
uhwptr *frame = (uhwptr *)bp;
uhwptr *prev_frame = frame - 1;
if (stack_top < 4096) return; // Sanity check for stack top.
// 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 &&
IsAligned((uptr)frame, sizeof(*frame)) &&
size < max_depth) {
uhwptr pc1 = frame[1];
if (pc1 != pc) {
trace[size++] = (uptr) pc1;
}
prev_frame = frame;
frame = (uhwptr *)frame[0];
}
}
static bool MatchPc(uptr cur_pc, uptr trace_pc, uptr threshold) {
return cur_pc - trace_pc <= threshold || trace_pc - cur_pc <= threshold;
}
void StackTrace::PopStackFrames(uptr count) {
CHECK_LT(count, size);
size -= count;
for (uptr i = 0; i < size; ++i) {
trace[i] = trace[i + count];
}
}
uptr StackTrace::LocatePcInTrace(uptr pc) {
// Use threshold to find PC in stack trace, as PC we want to unwind from may
// slightly differ from return address in the actual unwinded stack trace.
const int kPcThreshold = 288;
for (uptr i = 0; i < size; ++i) {
if (MatchPc(pc, trace[i], kPcThreshold))
return i;
}
return 0;
}
} // namespace __sanitizer