utrace(2) [debian man page]

UTRACE(2)						      BSD System Calls Manual							 UTRACE(2)

NAME

     utrace -- insert user record in ktrace log

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/types.h>
     #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), ktrace(2)

HISTORY

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

BSD
								 December 28, 2000							       BSD

KTRACE(2)						      BSD System Calls Manual							 KTRACE(2)

NAME

     ktrace -- process tracing

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

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

     int
     ktrace(const char *tracefile, int ops, int trpoints, int pid);

DESCRIPTION

     The ktrace() function enables or disables tracing of one or more processes.  Users may only trace their own processes.  Only the super-user
     can trace setuid or setgid programs.

     The tracefile gives the pathname of the file to be used for tracing.  The file must exist and be a regular file writable by the calling
     process.  All trace records are always appended to the file, so the file must be truncated to zero length to discard previous trace data.	If
     tracing points are being disabled (see KTROP_CLEAR below), tracefile may be NULL.

     The ops parameter specifies the requested ktrace operation.  The defined operations are:

	   KTROP_SET		 Enable trace points specified in trpoints.
	   KTROP_CLEAR		 Disable trace points specified in trpoints.
	   KTROP_CLEARFILE	 Stop all tracing.
	   KTRFLAG_DESCEND	 The tracing change should apply to the specified process and all its current children.

     The trpoints parameter specifies the trace points of interest.  The defined trace points are:

	   KTRFAC_SYSCALL	Trace system calls.
	   KTRFAC_SYSRET	Trace return values from system calls.
	   KTRFAC_NAMEI 	Trace name lookup operations.
	   KTRFAC_GENIO 	Trace all I/O (note that this option can generate much output).
	   KTRFAC_PSIG		Trace posted signals.
	   KTRFAC_CSW		Trace context switch points.
	   KTRFAC_INHERIT	Inherit tracing to future children.

     Each tracing event outputs a record composed of a generic header followed by a trace point specific structure.  The generic header is:

     struct ktr_header {
	     int     ktr_len;		     /* length of buf */
	     short   ktr_type;		     /* trace record type */
	     pid_t   ktr_pid;		     /* process id */
	     char    ktr_comm[MAXCOMLEN+1];  /* command name */
	     struct  timeval ktr_time;	     /* timestamp */
	     caddr_t ktr_buf;
     };

     The ktr_len field specifies the length of the ktr_type data that follows this header.  The ktr_pid and ktr_comm fields specify the process
     and command generating the record.  The ktr_time field gives the time (with microsecond resolution) that the record was generated.  The
     ktr_buf is an internal kernel pointer and is not useful.

     The generic header is followed by ktr_len bytes of a ktr_type record.  The type specific records are defined in the <sys/ktrace.h> include
     file.

RETURN VALUES

     The ktrace() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate
     the error.

ERRORS

     Ktrace() will fail if:

     [ENOTDIR]		A component of the path prefix is not a directory.

     [ENAMETOOLONG]	A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.

     [ENOENT]		The named tracefile does not exist.

     [EACCES]		Search permission is denied for a component of the path prefix.

     [ELOOP]		Too many symbolic links were encountered in translating the pathname.

     [EIO]		An I/O error occurred while reading from or writing to the file system.

     [ENOSYS]		The kernel was not compiled with ktrace support.

SEE ALSO

     kdump(1), ktrace(1)

HISTORY

     A ktrace() function call first appeared in 4.4BSD.

BSD
								   June 4, 1993 							       BSD