ref: a65f71ddd0bb0fae2868884002807ac166b32909
dir: /src/libc/arch/linux/_sigaction.c/
#include <string.h>
#include <arch/sigaction.h>
#include <sys.h>
extern void _sigreturn(void);
int _sigaction(int sig, struct sigaction *sa, struct sigaction *old)
{
	struct sigaction ksa, *p = NULL;
	if (sa) {
		ksa.sa_handler = sa->sa_handler;
		ksa.sa_flags = sa->sa_flags | SA_RESTORER;
		ksa.sa_restorer = _sigreturn;
		memcpy(&ksa.sa_mask, &sa->sa_mask, sizeof(ksa.sa_mask));
		p = &ksa;
	}
	if (__sigaction(sig, p, old, sizeof(ksa.sa_mask)) < 0)
		return -1;
	return 0;
}