manpage: Document probe provider compatibility

Fixes #502

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3
index 0b2de235a4f9d225b5d75d1a023a799c4486d2cf..27b32e9ff6bac1ee77f2ab221d1c80ff9f8e501c 100644 (file)
--- a/doc/man/lttng-ust.3
+++ b/doc/man/lttng-ust.3
@@ -371,10 +371,23 @@ startup time.
 lttng-gen-tp(1), lttng(1), babeltrace(1), lttng-ust-cyg-profile(3),
 lttng-sessiond(8)
 .PP
+
+.SH "COMPATIBILITY"
+
+.PP
+Older lttng-ust libraries reject more recent, and incompatible, probe
+providers. Newer lttng-ust librairies accept older probe providers, even
+though some newer features might not be available with those providers.
+.PP
+
 .SH "BUGS"
 
 .PP
-No known bugs at this point.
+LTTng-UST 2.0 and 2.1 lttng-ust libraries do not check for probe
+provider version compatibility. This can lead to out-of-bound accesses
+when using a more recent probe provider with an older lttng-ust library.
+These error only trigger when tracing is active. This issue has been
+fixed in LTTng-UST 2.2.
 
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