stack_t
int sigaltstack(const stack_t* stack, stack_t* oldStack);
stack_t uc_stack;
void signal_get_user_stack(addr_t address, stack_t* stack);
status_t _user_set_signal_stack(const stack_t *newUserStack,
stack_t *oldUserStack);
extern status_t _kern_set_signal_stack(const stack_t *newStack,
stack_t *oldStack);
signal_get_user_stack(addr_t address, stack_t* stack)
_user_set_signal_stack(const stack_t* newUserStack, stack_t* oldUserStack)
struct stack_t newStack, oldStack;
|| user_memcpy(&newStack, newUserStack, sizeof(stack_t)) < B_OK))
|| user_memcpy(&oldStack, oldUserStack, sizeof(stack_t)) < B_OK)))
&& user_memcpy(oldUserStack, &oldStack, sizeof(stack_t)) < B_OK)
stack_t alternateStack;
sigaltstack(const stack_t *alternateStack, stack_t *oldAlternateStack)
stack_t signalStack;
stack_t newStack;