44   stack_t ss;  in SetUpAlternateSignalStack()  local
45   ss.ss_sp = new uint8_t[kHostAltSigStackSize];  in SetUpAlternateSignalStack()
46   ss.ss_size = kHostAltSigStackSize;  in SetUpAlternateSignalStack()
47   ss.ss_flags = 0;  in SetUpAlternateSignalStack()
48   CHECK(ss.ss_sp != nullptr);  in SetUpAlternateSignalStack()
49   SigAltStack(&ss, nullptr);  in SetUpAlternateSignalStack()
52   ss.ss_sp = nullptr;  in SetUpAlternateSignalStack()
53   SigAltStack(nullptr, &ss);  in SetUpAlternateSignalStack()
54   VLOG(threads) << "Alternate signal stack is " << PrettySize(ss.ss_size) << " at " << ss.ss_sp;  in SetUpAlternateSignalStack()
59   stack_t ss;  in TearDownAlternateSignalStack()  local
60   SigAltStack(nullptr, &ss);  in TearDownAlternateSignalStack()
61   uint8_t* allocated_signal_stack = reinterpret_cast<uint8_t*>(ss.ss_sp);  in TearDownAlternateSignalStack()
64   ss.ss_sp = nullptr;  in TearDownAlternateSignalStack()
65   ss.ss_flags = SS_DISABLE;  in TearDownAlternateSignalStack()
66   ss.ss_size = kHostAltSigStackSize;  // Avoid ENOMEM failure with Mac OS' buggy libc.  in TearDownAlternateSignalStack()
67   SigAltStack(&ss, nullptr);  in TearDownAlternateSignalStack()