PSYSENTRY(3PROC) Process Control Library Functions PSYSENTRY(3PROC)


Psysentry, Psysexit - set system call entry and exit actions


Process Control Library (libproc, -lproc)


#include <libproc.h>

Psysentry(struct ps_prochandle *P, int which, int stop);

Psysexit(struct ps_prochandle *P, int which, int stop);


The Psysentry() and Psysexit() functions controls what actions the process
handle P should take upon executing a system call.

The system allows a process to be stopped on both entry and exit of a
system call. For information on the state of the process when it is
stopped due to system call tracing, see the PCSENTRY and PCSEXIT sections
of proc(4).

The value of the stop parameter controls whether or not the system call
listed in which causes the process to stop. A value of non-zero indicates
the process should stop; a value of 0 indicates it should not.

The value of which indicates which system call the change applies to. A
value of 0 applies to all system calls. Note, the system does not supply a
stable mapping from system call names to identifiers.

These functions only apply to actively running processes. They do not
function on handles that refer to core files, zombie processes, or ELF


Upon successful completion, the Psysentry() and Psysexit() functions return
the previous disposition of the system call -- 0 if it was not set to stop
and 1 if it was -- and the system call state is updated. Otherwise, -1 is
returned, errno is updated with the error that occurred, and the system
call state is not updated.


The Psysentry() and Psysexit() functions will fail if:

EINVAL The value of which is invalid, e.g. it is less than zero
or greater than the largest defined system call.

ENOENT The handle P refers to a process that is a zombie, a
core file, or an ELF object.



Note, while the Psysentry() and Psysexit() functions are uncommitted, the
mapping of system calls to system call numbers is Not-an-Interface and may
change at any time.

See LOCKING in libproc(3LIB).


libproc(3LIB), proc(4), attributes(5)

illumos May 11, 2016 illumos