// This is invoked from a signal handler but in a sideline thread doing nothing
// else so it is a little less fragile than a typical signal handler.
static void takeSample(void *Arg) {
u32 BitIdx = CurWorkingSetBitIdx;
u32 Freq = 1;
++SnapshotNum; // Simpler to skip 0 whose mod matches everything.
while (BitIdx <= MaxAccumBitIdx && (SnapshotNum % Freq) == 0) {
u32 NumLines = computeWorkingSizeAndReset(BitIdx);
VReport(1, "%s: snapshot #%5d bit %d freq %4d: %8u\n", SanitizerToolName,
SnapshotNum, BitIdx, Freq, NumLines);
SizePerFreq[BitIdx].push_back(NumLines);
Freq = Freq << getFlags()->snapshot_step;
BitIdx++;
}
}
void verifyAddressSpace() {
#if SANITIZER_LINUX && defined(__x86_64__)
// The kernel determines its mmap base from the stack size limit.
// Our Linux 64-bit shadow mapping assumes the stack limit is less than a
// terabyte, which keeps the mmap region above 0x7e00'.
uptr StackLimit = GetStackSizeLimitInBytes();
if (StackSizeIsUnlimited() || StackLimit > MaxStackSize) {
VReport(1, "The stack size limit is beyond the maximum supported.\n"
"Re-execing with a stack size below 1TB.\n");
SetStackSizeLimitInBytes(MaxStackSize);
ReExec();
}
#endif
}