Fix: liblttng-ust-ctl: keep using lttng-ust-sock-8 and lttng-ust-wait-8 filenames

commit 6a359b8a4006 ("Bump LTTNG_UST_ABI version from 8.1 to 9.0")
attempted to ensure that a session daemon linked against an old
lttng-ust-ctl (2.12) would not attempt to interact with newer
applications.

This was done by increasing the major ABI version number, but
introducing LTTNG_UST_ABI_MAJOR_VERSION_OLDEST_COMPATIBLE (set to 8) as
a mean to allow session daemon to accept both major versions 8 and 9.

Unfortunately, changing LTTNG_UST_ABI_MAJOR_VERSION means the filenames
used for communication changed as well, meaning that applications linked
against older lttng-ust 2.12 cannot interact with lttng sessiond linked
against lttng-ust-ctl 2.13, which is unintended.

Therefore, go back to using the previous filenames: lttng-ust-sock-8,
and lttng-ust-wait-8 for communication.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ieeabc23c1d7c58eb1b6d4387c1e2b0f35b171bf3

diff --git a/include/lttng/ust-ctl.h b/include/lttng/ust-ctl.h
index d7ab7afd1594effb4ca4d045493bc0ef9ad4ce58..6e99bff5ff9e5c3dcbe255b62098eb33815c4e06 100644 (file)
--- a/include/lttng/ust-ctl.h
+++ b/include/lttng/ust-ctl.h
@@ -25,7 +25,7 @@
 /* Default unix socket path */
 #define LTTNG_UST_SOCK_FILENAME                                        \
        "lttng-ust-sock-"                                       \
-       lttng_ust_stringify(LTTNG_UST_ABI_MAJOR_VERSION)
+       lttng_ust_stringify(LTTNG_UST_ABI_MAJOR_VERSION_OLDEST_COMPATIBLE)
 
 /*
  * Shared memory files path are automatically related to shm root, e.g.
@@ -33,7 +33,7 @@
  */
 #define LTTNG_UST_WAIT_FILENAME                                        \
        "lttng-ust-wait-"                                       \
-       lttng_ust_stringify(LTTNG_UST_ABI_MAJOR_VERSION)
+       lttng_ust_stringify(LTTNG_UST_ABI_MAJOR_VERSION_OLDEST_COMPATIBLE)
 
 struct lttng_ust_ctl_consumer_channel_attr {
        enum lttng_ust_abi_chan_type type;