lttng-ust-dl(3)

===============

:object-type: library

NAME

----

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

SYNOPSIS

--------

Launch your application by preloading `liblttng-ust-dl.so`:

[role="term"]

[verse]

*LD_PRELOAD=liblttng-ust-dl.so* my-app

DESCRIPTION

-----------

When the `liblttng-ust-dl.so` library is preloaded before a given

application starts, it causes all calls to man:dlopen(3) and

man:dlclose(3) in said application to be traced with LTTng-UST (see

man:lttng-ust(3)).

See man:lttng(1) to learn more about how to control LTTng tracing

sessions.

The following LTTng-UST events are available when using this library:

`lttng_ust_dl:dlopen`::

    Emitted when man:dlopen(3) is called.

+

Fields:

+

[options="header"]

|==============================================================

| Field name                 | Description

| `baddr`                    | Base address of loaded library

| `memsz`                    | Size of loaded library in memory

| `path`                     | Path to loaded library file

|==============================================================

`lttng_ust_dl:dlclose`::

    Emitted when man:dlclose(3) is called.

+

Fields:

+

[options="header"]

|==============================================================

| Field name                 | Description

| `baddr`                    | Base address of loaded library

|==============================================================

`lttng_ust_dl:debug_link`::

    Emitted when debug link information is found when loading a library

    with man:dlopen(3). See

    https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html[Debugging Information in Separate Files]

    for more information about debug links.

+

Fields:

+

[options="header"]

|==============================================================

| Field name                 | Description

| `baddr`                    | Base address of loaded library

| `filename`                 | Debug link file name

| `crc`                      | Debug link file's CRC

|==============================================================

`lttng_ust_dl:build_id`::

    Emitted when a build ID is found when loading a library

    with man:dlopen(3). See

    https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html[Debugging Information in Separate Files]

    for more information about build IDs.

+

Fields:

+

[options="header"]

|==============================================================

| Field name                 | Description

| `baddr`                    | Base address of loaded library

| `build_id`                 | Build ID

|==============================================================

include::common-footer.txt[]

include::common-copyrights.txt[]

include::common-authors.txt[]

SEE ALSO

--------

man:lttng-ust(3),

man:dlopen(3),

man:lttng(1)