static void register_handler(void) __attribute__ ((constructor (200)));

static void register_handler() {
	struct sigaction sa;
	memset(&sa, 0, sizeof(sa));
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = SA_SIGINFO;
	sa.sa_sigaction = check_params;

	if (sigaction(SIGUSR1, &sa, NULL) != 0) {
		perror("failed to register SIGUSR1 handler");
		exit(EXIT_FAILURE);
	}
}
*/
import "C"

import "syscall"

func init() {

// that it is installed before the Go code starts.

static void init(void) __attribute__ ((constructor (200)));

static void init() {
	struct sigaction sa;

	memset(&sa, 0, sizeof sa);
	sa.sa_sigaction = ioHandler;
	if (sigemptyset(&sa.sa_mask) < 0) {
		die("sigemptyset");
	}
	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
	if (sigaction(SIGIO, &sa, NULL) < 0) {
		die("sigaction");
	}
}

	int i;
	struct timespec ts;

	verbose = argc > 2;
	setvbuf(stdout, NULL, _IONBF, 0);

	if (verbose) {
		fprintf(stderr, "calling sigaction\n");
	}

	memset(&sa, 0, sizeof sa);
	sa.sa_sigaction = ioHandler;
	if (sigemptyset(&sa.sa_mask) < 0) {
		die("sigemptyset");
	}
	sa.sa_flags = SA_SIGINFO;
	if (sigaction(SIGIO, &sa, NULL) < 0) {
		die("sigaction");
	}

	if (verbose) {

		archauxv(tag, val)
	}
	return i / 2
}

// sysSigaction calls the sigaction system call.
//
//go:nosplit
func sysSigaction(sig uint32, new, old *sigactiont) {
	// Use system stack to avoid split stack overflow on amd64
	if asmSigaction(uintptr(sig), new, old) != 0 {
		systemstack(func() {
			throw("sigaction failed")
		})
	}
}

// asmSigaction is implemented in assembly.
//
//go:noescape

	MOV	$1000000000, T2
	MUL	T2, T0
	ADD	T1, T0

	MOV	T0, ret+0(FP)
	RET

// func asmSigaction(sig uintptr, new, old *sigactiont) int32
TEXT runtime·asmSigaction(SB),NOSPLIT|NOFRAME,$0
	MOV	sig+0(FP), A0		// arg 1 sig
	MOV	new+8(FP), A1		// arg 2 act
	MOV	old+16(FP), A2		// arg 3 oact
	MOV	$SYS_sigaction, T0
	ECALL
	BEQ	T0, ZERO, ok
	MOV	$-1, A0
ok:
	MOVW	A0, ret+24(FP)
	RET

	MOVD	$1000000000, R3
	MUL	R3, R0
	ADD	R2, R0

	MOVD	R0, ret+0(FP)
	RET

// func asmSigaction(sig uintptr, new, old *sigactiont) int32
TEXT runtime·asmSigaction(SB),NOSPLIT|NOFRAME,$0
	MOVD	sig+0(FP), R0		// arg 1 sig
	MOVD	new+8(FP), R1		// arg 2 act
	MOVD	old+16(FP), R2		// arg 3 oact
	MOVD	$SYS_sigaction, R8
	SVC
	BCC	ok
	MOVW	$-1, R0
ok:
	MOVW	R0, ret+24(FP)
	RET

	*(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp
}

//go:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}

// sysSigaction calls the rt_sigaction system call.
//
//go:nosplit
func sysSigaction(sig uint32, new, old *sigactiont) {
	if rt_sigaction(uintptr(sig), new, old, unsafe.Sizeof(sigactiont{}.sa_mask)) != 0 {
		// Workaround for bugs in QEMU user mode emulation.
		//

// This version is used on Linux and FreeBSD systems on which we don't
// use cgo to call the C version of sigaction.

//go:nosplit
//go:nowritebarrierrec
func sigaction(sig uint32, new, old *sigactiont) {
	sysSigaction(sig, new, old)

		msanwrite(unsafe.Pointer(new), unsafe.Sizeof(*new))
	}
	if asanenabled && new != nil {
		asanwrite(unsafe.Pointer(new), unsafe.Sizeof(*new))
	}
	if _cgo_sigaction == nil || inForkedChild {
		sysSigaction(sig, new, old)
	} else {
		// We need to call _cgo_sigaction, which means we need a big enough stack
		// for C.  To complicate matters, we may be in libpreinit (before the

#include <asm-generic/errno.h>
#include <asm-generic/fcntl.h>
#include <asm-generic/poll.h>
#include <linux/eventpoll.h>

// This is the sigaction structure from the Linux 2.1.68 kernel which
//   is used with the rt_sigaction system call. For 386 this is not
//   defined in any public header file.

struct kernel_sigaction {
	__sighandler_t k_sa_handler;
	unsigned long sa_flags;
	void (*sa_restorer) (void);
	unsigned long long sa_mask;