Psysentry,
Psysexit —
set system call entry and exit actions
Process Control Library (libproc, -lproc)
#include
<libproc.h>
int
Psysentry(
struct
ps_prochandle *P,
int which,
int stop);
int
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 objects.
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.
Uncommitted
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)