Bug #538: No events are recorded when a UST tracepoint provider is dynamically linked to the application by using dlopen() - LTTng-UST - LTTng bugs repository

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Bug #538

closed

No events are recorded when a UST tracepoint provider is dynamically linked to the application by using dlopen()

Added by Anonymous almost 11 years ago. Updated almost 11 years ago.

Status:

Resolved

Priority:

Normal

Assignee:

Target version:

Start date:

05/21/2013

Due date:

% Done:

100%

Estimated time:

Description

When a UST tracepoint provider is dynamically linked to the application by using dlopen(), no events are recorded (but no errors are emitted either). When using LD_PRELOAD or when statically linking the tracepoint provider, the events are recorded successfully.

The test application at: http://people.canonical.com/~afrantzis/lttng-tests.tar.gz exhibits the problem. It provides both a statically linked version of the server/client and a dynamically linked (to the TP provider) version served/clientd. To check the dlopen() variant do (and check the README file for more):

$ cd lttng-tests && make
$ mkfifo /tmp/myfifo
$ LD_LIBRARY_PATH=. ./clientd &
$ LD_LIBRARY_PATH=. ./serverd

The problem is seen in both 2.1.1 and the latest 2.2 daily.