NAME
ktrgenio,
ktrnamei, ktrpsig,
ktrsyscall, ktrsysret,
KTRPOINT —
process tracing kernel
interface
SYNOPSIS
#include
<sys/param.h>
#include <sys/proc.h>
#include <sys/ktrace.h>
KTRPOINT(struct
proc *p, int
type);
void
ktrgenio(struct
proc *p, int fd,
enum uio_rw rw,
struct iovec *iov,
int len,
int error);
void
ktrnamei(struct
proc *p, char
*path);
void
ktrpsig(struct
proc *p, int sig,
sig_t action,
int mask,
int code,
siginfo_t *si);
void
ktrsyscall(struct
proc *p, register_t
code, size_t
argsize, register_t
args[]);
void
ktrsysret(struct
proc *p, register_t
code, int error,
register_t retval);
DESCRIPTION
This interface is meant for kernel subsystems and machine
dependent code to inform the user about the events occurring to the process
should tracing of such be enabled using the
ktrace(2) system call. Each of the functions (except for
KTRPOINT) is meant for a particular type of event
and is described below.
The
KTRPOINT()
macro should be used before calling any of the other tracing functions to
verify that tracing for that particular type of events has been enabled.
type must be a KTR_ value corresponding to a KTRFAC_
value described in
ktrace(2).
ktrgenio()
should be called for each generic input/output transaction that is described
by the fd file descriptor, rw
transaction type (consult sys/sys/uio.h for the
enum uio_rw definition), iov
input/output data vector, len size of the
iov vector, and, lastly, error
status of the transaction.
ktrnamei()
should be called every time a
namei(9) operation is performed over the path
name.
ktrpsig()
should be called for each signal sig posted for the
traced process. The action taken is one of
SIG_DFL, SIG_IGN, or
SIG_ERR as described in the
sigaction(2) document. mask is the current
traced process' signal mask. Signal-specific code and
siginfo_t
structure as described in
<sys/siginfo.h> are given in
the code and si arguments
respectively.
ktrsyscall()
should be called for each system call number code
executed with arguments in args of total count of
argsize.
ktrsysret()
should be called for a return from each system call number
code and error number of error
as described in errno(2) and a return value in retval
that is syscall dependent.
CODE REFERENCES
The process tracing facility is implemented in sys/kern/kern_ktrace.c.
SEE ALSO
HISTORY
The process tracing facility first appeared in 4.4BSD.
The ktrace section manual page appeared in
OpenBSD 3.4.