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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH TNFCTL_PID_OPEN 3TNF "Mar 1, 2004" .SH NAME tnfctl_pid_open, tnfctl_exec_open, tnfctl_continue \- interfaces for direct probe and process control for another process .SH SYNOPSIS .LP .nf \fBcc\fR [ \fIflag\fR ... ] \fIfile\fR ... \fB-ltnfctl\fR [ \fIlibrary\fR ... ] #include \fBtnfctl_errcode_t\fR \fBtnfctl_pid_open\fR(\fBpid_t\fR \fIpid\fR, \fBtnfctl_handle_t **\fR\fIret_val\fR); .fi .LP .nf \fBtnfctl_errcode_t\fR \fBtnfctl_exec_open\fR(\fBconst char *\fR\fIpgm_name\fR, \fBchar * const *\fR\fIargv\fR, \fBchar * const *\fR\fIenvp\fR, \fBconst char *\fR\fIlibnfprobe_path\fR, \fBconst char *\fR\fIld_preload\fR, \fBtnfctl_handle_t **\fR\fIret_val\fR); .fi .LP .nf \fBtnfctl_errcode_t\fR \fBtnfctl_continue\fR(\fBtnfctl_handle_t *\fR\fIhndl\fR, \fBtnfctl_event_t *\fR\fIevt\fR, \fBtnfctl_handle_t **\fR\fIchild_hndl\fR); .fi .SH DESCRIPTION .sp .LP The \fBtnfctl_pid_open()\fR, \fBtnfctl_exec_open()\fR, and \fBtnfctl_continue()\fR functions create handles to control probes in another process (direct process probe control). Either \fBtnfctl_pid_open()\fR or \fBtnfctl_exec_open()\fR will return a handle in \fIret_val\fR that can be used for probe control. On return of these calls, the process is stopped. \fBtnfctl_continue()\fR allows the process specified by \fIhndl\fR to continue execution. .sp .LP The \fBtnfctl_pid_open()\fR function attaches to a running process with process id of \fIpid\fR. The process is stopped on return of this call. The \fBtnfctl_pid_open()\fR function returns an error message if \fIpid\fR is the same as the calling process. See \fBtnfctl_internal_open\fR(3TNF) for information on internal process probe control. A pointer to an opaque handle is returned in \fIret_val\fR, which can be used to control the process and the probes in the process. The target process must have \fBlibtnfprobe.so.1\fR (defined in <\fBtnf/tnfctl.h\fR> as macro \fBTNFCTL_LIBTNFPROBE)\fR linked in for probe control to work. .sp .LP The \fBtnfctl_exec_open()\fR function is used to \fBexec\fR(2) a program and obtain a probe control handle. For probe control to work, the process image to be \fBexec\fR'd must load \fBlibtnfprobe.so.1\fR. The \fBtnfctl_exec_open()\fR function makes it simple for the library to be loaded at process start up time. The \fIpgm_name\fR argument is the command to \fBexec\fR. If \fIpgm_name\fR is not an absolute path, then the \fB$PATH\fR environment variable is used to find the \fIpgm_name\fR. \fIargv\fR is a null-terminated argument pointer, that is, it is a null-terminated array of pointers to null-terminated strings. These strings constitute the argument list available to the new process image. The \fIargv\fR argument must have at least one member, and it should point to a string that is the same as \fIpgm_name\fR. See \fBexecve\fR(2). The \fIlibnfprobe_path\fR argument is an optional argument, and if set, it should be the path to the directory that contains \fBlibtnfprobe.so.1\fR. There is no need for a trailing "/" in this argument. This argument is useful if \fBlibtnfprobe.so.1\fR is not installed in \fB/usr/lib\fR. \fIld_preload\fR is a space-separated list of libraries to preload into the target program. This string should follow the syntax guidelines of the \fBLD_PRELOAD\fR environment variable. See \fBld.so.1\fR(1). The following illustrates how strings are concatenated to form the \fBLD_PRELOAD\fR environment variable in the new process image: .sp .in +2 .nf + + libtnfprobe_path + "/libtnfprobe.so.1" + + ld_preload .fi .in -2 .sp .LP This option is useful for preloading interposition libraries that have probes in them. .sp .LP \fIenvp\fR is an optional argument, and if set, it is used for the environment of the target program. It is a null-terminated array of pointers to null-terminated strings. These strings constitute the environment of the new process image. See \fBexecve\fR(2). If \fIenvp\fR is set, it overrides \fIld_preload\fR. In this case, it is the caller's responsibility to ensure that \fBlibtnfprobe.so.1\fR is loaded into the target program. If \fIenvp\fR is not set, the new process image inherits the environment of the calling process, except for \fBLD_PRELOAD\fR. .sp .LP The \fIret_val\fR argument is the handle that can be used to control the process and the probes within the process. Upon return, the process is stopped before any user code, including \fB\&.init\fR sections, has been executed. .sp .LP The \fBtnfctl_continue()\fR function is a blocking call and lets the target process referenced by \fIhndl\fR continue running. It can only be used on handles returned by \fBtnfctl_pid_open()\fR and \fBtnfctl_exec_open()\fR (direct process probe control). It returns when the target stops; the reason that the process stopped is returned in \fIevt\fR. This call is interruptible by signals. If it is interrupted, the process is stopped, and \fBTNFCTL_EVENT_EINTR\fR is returned in \fIevt\fR. The client of this library will have to decide which signal implies a stop to the target and catch that signal. Since a signal interrupts \fBtnfctl_continue()\fR, it will return, and the caller can decide whether or not to call \fBtnfctl_continue()\fR again. .sp .LP \fBtnfctl_continue()\fR returns with an event of \fBTNFCTL_EVENT_DLOPEN\fR, \fBTNFCTL_EVENT_DLCLOSE\fR, \fBTNFCTL_EVENT_EXEC\fR, \fBTNFCTL_EVENT_FORK\fR, \fBTNFCTL_EVENT_EXIT\fR, or \fBTNFCTL_EVENT_TARGGONE\fR, respectively, when the target program calls \fBdlopen\fR(3C), \fBdlclose\fR(3C), any flavor of \fBexec\fR(2), \fBfork\fR(2) (or \fBfork1\fR(2)), \fBexit\fR(2), or terminates unexpectedly. If the target program called \fBexec\fR(2), the client then needs to call \fBtnfctl_close\fR(3TNF) on the current handle leaving the target resumed, suspended, or killed (second argument to \fBtnfctl_close\fR(3TNF)). No other \fBlibtnfctl\fR interface call can be used on the existing handle. If the client wants to control the \fBexec\fR'ed image, it should leave the old handle suspended, and use \fBtnfctl_pid_open()\fR to reattach to the same process. This new handle can then be used to control the \fBexec\fR'ed image. See \fBEXAMPLES\fR below for sample code. If the target process did a \fBfork\fR(2) or \fBfork1\fR(2), and if control of the child process is not needed, then \fIchild_hndl\fR should be \fINULL\fR. If control of the child process is needed, then \fIchild_hndl\fR should be set. If it is set, a pointer to a handle that can be used to control the child process is returned in \fIchild_hndl\fR. The child process is stopped at the end of the \fBfork()\fR system call. See \fBEXAMPLES\fR for an example of this event. .SH RETURN VALUES .sp .LP The \fBtnfctl_pid_open()\fR, \fBtnfctl_exec_open()\fR, and \fBtnfctl_continue()\fR functions return \fBTNFCTL_ERR_NONE\fR upon success. .SH ERRORS .sp .LP The following error codes apply to \fBtnfctl_pid_open()\fR: .sp .ne 2 .na \fB\fBTNFCTL_ERR_BADARG\fR\fR .ad .RS 28n The \fIpid\fR specified is the same process. Use \fBtnfctl_internal_open\fR(3TNF) instead. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_ACCES\fR\fR .ad .RS 28n Permission denied. No privilege to connect to a setuid process. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_ALLOCFAIL\fR\fR .ad .RS 28n A memory allocation failure occurred. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_BUSY\fR\fR .ad .RS 28n Another client is already using \fB/proc\fR to control this process or internal tracing is being used. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_NOTDYNAMIC\fR\fR .ad .RS 28n The process is not a dynamic executable. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_NOPROCESS\fR\fR .ad .RS 28n No such target process exists. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_NOLIBTNFPROBE\fR\fR .ad .RS 28n \fBlibtnfprobe.so.1\fR is not linked in the target process. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_INTERNAL\fR\fR .ad .RS 28n An internal error occurred. .RE .sp .LP The following error codes apply to \fBtnfctl_exec_open()\fR: .sp .ne 2 .na \fB\fBTNFCTL_ERR_ACCES\fR\fR .ad .RS 28n Permission denied. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_ALLOCFAIL\fR\fR .ad .RS 28n A memory allocation failure occurred. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_NOTDYNAMIC\fR\fR .ad .RS 28n The target is not a dynamic executable. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_NOLIBTNFPROBE\fR\fR .ad .RS 28n \fBlibtnfprobe.so.1\fR is not linked in the target process. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_FILENOTFOUND\fR\fR .ad .RS 28n The program is not found. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_INTERNAL\fR\fR .ad .RS 28n An internal error occurred. .RE .sp .LP The following error codes apply to \fBtnfctl_continue()\fR: .sp .ne 2 .na \fB\fBTNFCTL_ERR_BADARG\fR\fR .ad .RS 24n Bad input argument. \fIhndl\fR is not a direct process probe control handle. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_INTERNAL\fR\fR .ad .RS 24n An internal error occurred. .RE .sp .ne 2 .na \fB\fBTNFCTL_ERR_NOPROCESS\fR\fR .ad .RS 24n No such target process exists. .RE .SH EXAMPLES .LP \fBExample 1 \fRUsing \fBtnfctl_pid_open()\fR .sp .LP These examples do not include any error-handling code. Only the initial example includes the declaration of the variables that are used in all of the examples. .sp .LP The following example shows how to preload \fBlibtnfprobe.so.1\fR from the normal location and inherit the parent's environment. .sp .in +2 .nf const char *pgm; char * const *argv; tnfctl_handle_t *hndl, *new_hndl, *child_hndl; tnfctl_errcode_t err; char * const *envptr; extern char **environ; tnfctl_event_t evt; int pid; /* assuming argv has been allocated */ argv[0] = pgm; /* set up rest of argument vector here */ err = tnfctl_exec_open(pgm, argv, NULL, NULL, NULL, &hndl); .fi .in -2 .sp .LP This example shows how to preload two user-supplied libraries \fBlibc_probe.so.1\fR and \fBlibthread_probe.so.1\fR. They interpose on the corresponding \fBlibc.so\fR and \fBlibthread.so\fR interfaces and have probes for function entry and exit. \fBlibtnfprobe.so.1\fR is preloaded from the normal location and the parent's environment is inherited. .sp .in +2 .nf /* assuming argv has been allocated */ argv[0] = pgm; /* set up rest of argument vector here */ err = tnfctl_exec_open(pgm, argv, NULL, NULL, "libc_probe.so.1 libthread_probe.so.1", &hndl); .fi .in -2 .sp .LP This example preloads an interposition library \fBlibc_probe.so.1\fR, and specifies a different location from which to preload \fBlibtnfprobe.so.1\fR. .sp .in +2 .nf /* assuming argv has been allocated */ argv[0] = pgm; /* set up rest of argument vector here */ err = tnfctl_exec_open(pgm, argv, NULL, "/opt/SUNWXXX/lib", "libc_probe.so.1", &hndl); .fi .in -2 .sp .LP To set up the environment explicitly for probe control to work, the target process must link \fBlibtnfprobe.so.1\fR. If using \fIenvp\fR, it is the caller's responsibility to do so. .sp .in +2 .nf /* assuming argv has been allocated */ argv[0] = pgm; /* set up rest of argument vector here */ /* envptr set up to caller's needs */ err = tnfctl_exec_open(pgm, argv, envptr, NULL, NULL, &hndl); .fi .in -2 .sp .LP Use this example to resume a process that does an \fBexec\fR(2) without controlling it. .sp .in +2 .nf err = tnfctl_continue(hndl, &evt, NULL); switch (evt) { case TNFCTL_EVENT_EXEC: /* let target process continue without control */ err = tnfctl_close(hndl, TNFCTL_TARG_RESUME); ... break; } .fi .in -2 .sp .LP Alternatively, use the next example to control a process that does an \fBexec\fR(2). .sp .in +2 .nf /* * assume the pid variable has been set by calling * tnfctl_trace_attrs_get() */ err = tnfctl_continue(hndl, &evt, NULL); switch (evt) { case TNFCTL_EVENT_EXEC: /* suspend the target process */ err = tnfctl_close(hndl, TNFCTL_TARG_SUSPEND); /* re-open the exec'ed image */ err = tnfctl_pid_open(pid, &new_hndl); /* new_hndl now controls the exec'ed image */ ... break; } .fi .in -2 .sp .LP To let \fBfork\fR'ed children continue without control, use \fINULL\fR as the last argument to \fBtnfctl_continue(\|).\fR .sp .in +2 .nf err = tnfctl_continue(hndl, &evt, NULL); .fi .in -2 .sp .LP The next example is how to control child processes that \fBfork\fR(2) or \fBfork1\fR(2) create. .sp .in +2 .nf err = tnfctl_continue(hndl, &evt, &child_hndl); switch (evt) { case TNFCTL_EVENT_FORK: /* spawn a new thread or process to control child_hndl */ ... break; } .fi .in -2 .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS box; c | c l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE _ MT Level MT-Safe .TE .SH SEE ALSO .sp .LP \fBld\fR(1), \fBprex\fR(1), \fBproc\fR(1), \fBexec\fR(2), \fBexecve\fR(2), \fBexit\fR(2), \fBfork\fR(2), \fBTNF_PROBE\fR(3TNF), \fBdlclose\fR(3C), \fBdlopen\fR(3C), \fBlibtnfctl\fR(3TNF), \fBtnfctl_close\fR(3TNF), \fBtnfctl_internal_open\fR(3TNF), \fBtracing\fR(3TNF) \fBattributes\fR(5) .sp .LP \fILinker and Libraries Guide\fR .SH NOTES .sp .LP After a call to \fBtnfctl_continue()\fR returns, a client should use \fBtnfctl_trace_attrs_get\fR(3TNF) to check the \fBtrace_buf_state\fR member of the trace attributes and make sure that there is no internal error in the target.