sanitizer_stacktrace.cc [plain text]
#include "sanitizer_common.h"
#include "sanitizer_flags.h"
#include "sanitizer_stacktrace.h"
namespace __sanitizer {
uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
#ifdef __arm__
pc = pc & (~1);
#endif
#if 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) {
if (max_depth == 0) {
size = 0;
return;
}
trace[0] = pc;
size = 1;
uptr *frame = (uptr *)bp;
uptr *prev_frame = frame - 1;
if (stack_top < 4096) return; while (frame > prev_frame &&
frame < (uptr *)stack_top - 2 &&
frame > (uptr *)stack_bottom &&
IsAligned((uptr)frame, sizeof(*frame)) &&
size < max_depth) {
uptr pc1 = frame[1];
if (pc1 != pc) {
trace[size++] = pc1;
}
prev_frame = frame;
frame = (uptr*)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) {
const int kPcThreshold = 192;
for (uptr i = 0; i < size; ++i) {
if (MatchPc(pc, trace[i], kPcThreshold))
return i;
}
return 0;
}
}