asmlinkage int sys_sigsuspend(old_sigset_t mask);
asmlinkage int sys_sigaction(int sig, const struct old_sigaction __user *act,
struct old_sigaction __user *oact);
-asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
- unsigned long r6, unsigned long r7,
- struct pt_regs __regs);
asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs __regs);