linux/arch/x86/kernel/sigframe.h

#ifdef CONFIG_X86_32
struct sigframe {
	char __user *pretcode;
	int sig;
	struct sigcontext sc;
	struct _fpstate fpstate;
	unsigned long extramask[_NSIG_WORDS-1];
	char retcode[8];
};

struct rt_sigframe {
	char __user *pretcode;
	int sig;
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
	struct _fpstate fpstate;
	char retcode[8];
};
#else
struct rt_sigframe {
	char __user *pretcode;
	struct ucontext uc;
	struct siginfo info;
};
#endif