xref: /freebsd/lib/librtld_db/librtld_db.3 (revision a0b9e2e854027e6ff61fb075a1309dbc71c42b54)
1.\"-
2.\" Copyright (c) 2010 The FreeBSD Foundation
3.\" All rights reserved.
4.\"
5.\" This software was developed by Rui Paulo under sponsorship from
6.\" the FreeBSD Foundation.
7.\"
8.\" Redistribution and use in source and binary forms, with or without
9.\" modification, are permitted provided that the following conditions
10.\" are met:
11.\" 1. Redistributions of source code must retain the above copyright
12.\"    notice, this list of conditions and the following disclaimer.
13.\" 2. Redistributions in binary form must reproduce the above copyright
14.\"    notice, this list of conditions and the following disclaimer in the
15.\"    documentation and/or other materials provided with the distribution.
16.\"
17.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27.\" SUCH DAMAGE.
28.\"
29.\" $FreeBSD$
30.\"
31.Dd June 10, 2010
32.Dt LIBRTLD_DB 3
33.Os
34.Sh NAME
35.Nm librtld_db
36.Nd library for run-time linker debugging
37.Sh LIBRARY
38.Lb librtld_db
39.Sh SYNOPSIS
40.In rtld_db.h
41.Ft void
42.Fo rd_delete
43.Fa "rd_agent_t *rdap"
44.Fc
45.Ft char *
46.Fo rd_errstr
47.Fa "rd_err_e rderr"
48.Fc
49.Ft rd_err_e
50.Fo rd_event_addr
51.Fa "rd_agent_t *rdap, rd_event_e event, rd_notify_t *notify"
52.Fc
53.Ft rd_err_e
54.Fo rd_event_enable
55.Fa "rd_agent_t *rdap, int onoff"
56.Fc
57.Ft rd_err_e
58.Fo rd_event_getmsg
59.Fa "rd_agent_t *rdap, rd_event_msg_t *msg"
60.Fc
61.Ft rd_err_e
62.Fo rd_init
63.Fa "int version"
64.Fc
65.Ft typedef int
66.Fo rl_iter_f
67.Fa "const rd_loadobj_t *, void *"
68.Fc
69.Ft rd_err_e
70.Fo rd_loadobj_iter
71.Fa "rd_agent_t *rdap, rl_iter_f *cb, void *clnt_data"
72.Fc
73.Ft void
74.Fo rd_log
75.Fa "const int onoff"
76.Fc
77.Ft rd_agent_t *
78.Fo rd_new
79.Fa "struct proc_handle *php"
80.Fc
81.Ft rd_err_e
82.Fo rd_objpad_enable
83.Fa "rd_agent_t *rdap, size_t padsize"
84.Fc
85.Ft rd_err_e
86.Fo rd_plt_resolution
87.Fa "rd_agent_t *rdap, uintptr_t pc, struct proc *proc"
88.Fa "uintptr_t plt_base, rd_plt_info_t *rpi"
89.Fc
90.Ft rd_err_e
91.Fo rd_reset
92.Fa "rd_agent_t *rdap"
93.Fc
94.Sh DESCRIPTION
95The
96.Nm librtld_db
97library provides a debugging interface to the run-time linker (rtld).
98This library must be used along with
99.Xr libproc 3 .
100.Pp
101Most library functions take a
102.Ft rd_agent_t
103argument.
104This argument is an opaque structure containing information associated with
105the current status of the agent.
106.Pp
107Before you start using
108.Nm
109you should call
110.Fn rd_init
111with the
112.Ft RD_VERSION
113argument.
114This initializes the library to the correct version your program was compiled
115with and provides proper ABI stability.
116.Pp
117What follows is a description of what each function.
118.Pp
119.Fn rd_new
120creates a new
121.Nm
122agent.
123The
124.Ft php
125argument should be the
126.Ft proc_handle
127you received from
128.Xr libproc 3 .
129.Pp
130.Fn rd_reset
131resets your previously created agent.
132.Pp
133.Fn rd_delete
134deallocates the resources associated with the agent.
135.Pp
136.Fn rd_errstr
137returns an error string describing the error present in
138.Ft rderr .
139.Pp
140.Fn rd_event_enable
141enables reporting of events.
142This function always returns RD_OK.
143.Pp
144.Fn rd_event_addr
145returns the event address corresponding to the
146.Ft event
147parameter.
148At the moment we only report events of type RD_NOTIFY_BPT.
149.Pp
150.Fn rd_event_getmsg
151returns the message associated with the latest event.
152At the moment only RD_POSTINIT events are supported.
153.Pp
154.Fn rd_loadobj_iter
155allows you to iterate over the program's loaded objects.
156.Ft cb
157is a callback of type
158.Fn rl_iter_f .
159.Sh RETURN VALUES
160Most functions return an
161.Ft rd_err_e
162type error.
163The error codes are described in the header file for this library.
164You can get the error string using
165.Fn rd_errstr .
166.Sh SEE ALSO
167.Xr ld 1 ,
168.Xr ld-elf.so.1 1 ,
169.Xr ld.so 1 ,
170.Xr rtld 1 ,
171.Xr libproc 3
172.Sh HISTORY
173The
174.Nm librtld_db
175library first appeared in
176.Fx 9.0
177and was modeled after the same library present in the Solaris operating system.
178.Sh AUTHORS
179The
180.Nm librtld_db
181library and this manual page were written by
182.An Rui Paulo Aq Mt rpaulo@FreeBSD.org
183under sponsorship from the FreeBSD Foundation.
184.Sh CAVEATS
185The functions
186.Fn rd_event_enable ,
187.Fn rd_log ,
188.Fn rd_objpad_enable
189and
190.Fn rd_plt_resolution
191are not yet implemented.
192