noble (2) utrace.2freebsd.gz

Provided by: freebsd-manpages_12.2-1_all bug

NAME
     utrace — insert user record in ktrace log


LIBRARY
     Standard C Library (libc, -lc)


SYNOPSIS
     #include <sys/param.h>
     #include <sys/time.h>
     #include <sys/uio.h>
     #include <sys/ktrace.h>

     int
     utrace(const void *addr, size_t len);


DESCRIPTION
     Adds a record to the process trace with information supplied by user.  The record contains len bytes from
     memory pointed to by addr.  This call only has an effect if the calling process is being traced.


RETURN VALUES
     Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global
     variable errno is set to indicate the error.


ERRORS
     [EINVAL]           Specified data length len was bigger than KTR_USER_MAXLEN.

     [ENOMEM]           Insufficient memory to honor the request.

     [ENOSYS]           Currently running kernel was compiled without ktrace(2) support (options KTRACE).


SEE ALSO
     kdump(1), ktrace(1), truss(1), ktrace(2), sysdecode_utrace(3)


HISTORY
     The utrace() system call first appeared in FreeBSD 2.2.