github.com/afumu/libc@v0.0.6/musl/src/internal/syscall_ret.c (about)

     1  #include <errno.h>
     2  #include "syscall.h"
     3  
     4  long __syscall_ret(unsigned long r)
     5  {
     6  	if (r > -4096UL) {
     7  		errno = -r;
     8  		return -1;
     9  	}
    10  	return r;
    11  }