lttng-ust-dl(3)

1LTTNG-UST-DL(3)                  LTTng Manual                  LTTNG-UST-DL(3)
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NAME

6       lttng-ust-dl - Dynamic linker tracing (LTTng-UST helper)
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SYNOPSIS

9       Launch your application by preloading liblttng-ust-dl.so:
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11       LD_PRELOAD=liblttng-ust-dl.so my-app
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DESCRIPTION

14       When the liblttng-ust-dl.so library is preloaded before a given
15       application starts, it causes all calls to dlopen(3) and dlclose(3) in
16       said application to be traced with LTTng-UST (see lttng-ust(3)).
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18       See lttng(1) to learn more about how to control LTTng tracing sessions.
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20       The following LTTng-UST events are available when using this library:
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22       lttng_ust_dl:dlopen
23           Emitted when dlopen(3) is called.
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25           Fields:
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27           ┌───────────┬───────────────────────────┐
28           │Field name │ Description               │
29           ├───────────┼───────────────────────────┤
30           │baddr      │ Base address of loaded    │
31           │           │ library                   │
32           ├───────────┼───────────────────────────┤
33           │memsz      │ Size of loaded library in │
34           │           │ memory                    │
35           ├───────────┼───────────────────────────┤
36           │path       │ Path to loaded library    │
37           │           │ file                      │
38           └───────────┴───────────────────────────┘
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40       lttng_ust_dl:dlclose
41           Emitted when dlclose(3) is called.
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43           Fields:
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45           ┌───────────┬────────────────────────┐
46           │Field name │ Description            │
47           ├───────────┼────────────────────────┤
48           │baddr      │ Base address of loaded │
49           │           │ library                │
50           └───────────┴────────────────────────┘
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52       lttng_ust_dl:debug_link
53           Emitted when debug link information is found when loading a library
54           with dlopen(3). See Debugging Information in Separate Files
55           <https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-
56           Files.html> for more information about debug links.
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58           Fields:
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60           ┌───────────┬────────────────────────┐
61           │Field name │ Description            │
62           ├───────────┼────────────────────────┤
63           │baddr      │ Base address of loaded │
64           │           │ library                │
65           ├───────────┼────────────────────────┤
66           │filename   │ Debug link file name   │
67           ├───────────┼────────────────────────┤
68           │crc        │ Debug link file’s CRC  │
69           └───────────┴────────────────────────┘
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71       lttng_ust_dl:build_id
72           Emitted when a build ID is found when loading a library with
73           dlopen(3). See Debugging Information in Separate Files
74           <https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-
75           Files.html> for more information about build IDs.
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77           Fields:
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79           ┌───────────┬────────────────────────┐
80           │Field name │ Description            │
81           ├───────────┼────────────────────────┤
82           │baddr      │ Base address of loaded │
83           │           │ library                │
84           ├───────────┼────────────────────────┤
85           │build_id   │ Build ID               │
86           └───────────┴────────────────────────┘
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BUGS

89       If you encounter any issue or usability problem, please report it on
90       the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-ust>.
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RESOURCES

93       ·   LTTng project website <http://lttng.org>
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95       ·   LTTng documentation <http://lttng.org/docs>
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97       ·   Git repositories <http://git.lttng.org>
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99       ·   GitHub organization <http://github.com/lttng>
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101       ·   Continuous integration <http://ci.lttng.org/>
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103       ·   Mailing list <http://lists.lttng.org> for support and development:
104           lttng-dev@lists.lttng.org
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106       ·   IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
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COPYRIGHTS

109       This library is part of the LTTng-UST project.
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111       This library is distributed under the GNU Lesser General Public
112       License, version 2.1 <http://www.gnu.org/licenses/old-
113       licenses/lgpl-2.1.en.html>. See the COPYING
114       <https://github.com/lttng/lttng-ust/blob/master/COPYING> file for more
115       details.
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THANKS

118       Thanks to Ericsson for funding this work, providing real-life use
119       cases, and testing.
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121       Special thanks to Michel Dagenais and the DORSAL laboratory
122       <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for
123       the LTTng journey.
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AUTHORS

126       LTTng-UST was originally written by Mathieu Desnoyers, with additional
127       contributions from various other people. It is currently maintained by
128       Mathieu Desnoyers <mailto:mathieu.desnoyers@efficios.com>.
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