50   stack_t ss;  in SetUpAlternateSignalStack()  local
51   ss.ss_sp = new uint8_t[kHostAltSigStackSize];  in SetUpAlternateSignalStack()
52   ss.ss_size = kHostAltSigStackSize;  in SetUpAlternateSignalStack()
53   ss.ss_flags = 0;  in SetUpAlternateSignalStack()
54   CHECK(ss.ss_sp != nullptr);  in SetUpAlternateSignalStack()
55   SigAltStack(&ss, nullptr);  in SetUpAlternateSignalStack()
58   ss.ss_sp = nullptr;  in SetUpAlternateSignalStack()
59   SigAltStack(nullptr, &ss);  in SetUpAlternateSignalStack()
60   VLOG(threads) << "Alternate signal stack is " << PrettySize(ss.ss_size) << " at " << ss.ss_sp;  in SetUpAlternateSignalStack()
65   stack_t ss;  in TearDownAlternateSignalStack()  local
66   SigAltStack(nullptr, &ss);  in TearDownAlternateSignalStack()
67   uint8_t* allocated_signal_stack = reinterpret_cast<uint8_t*>(ss.ss_sp);  in TearDownAlternateSignalStack()
70   ss.ss_sp = nullptr;  in TearDownAlternateSignalStack()
71   ss.ss_flags = SS_DISABLE;  in TearDownAlternateSignalStack()
72   ss.ss_size = kHostAltSigStackSize;  // Avoid ENOMEM failure with Mac OS' buggy libc.  in TearDownAlternateSignalStack()
73   SigAltStack(&ss, nullptr);  in TearDownAlternateSignalStack()