ABI: refuse non-matching ABI minor version on event registration
In scenarios where a lttng-tools 2.8 (lttng-ust 2.8) stack is running
and an application linked against a lttng-ust 2.7, event registration
will fail on fields size validation [1]. This is not expected based on
the ABI versioning exposed by lttng-ust 2.7 (6.0) and lttng-ust 2.8
(6.1).
The same happen if the scenario is reversed.
This is the result of a change in _ustctl_basic_type.
2.8 introduced enumeration to _ustctl_basic_type. The defined padding is
of 296 while the new union member is 312 (310 of real data + 2 for
alignment) pushing the structure size to 312 instead of the previous
296. This should have been an major ABI break but until now the problem
did not surface.
To prevent this, refuse non matching minor version. No need to check for
particular major,minor version since only 6.0 (ust 2.7) and 6.1 (ust
2.8) exist until a major ABI break.
cf0393e...
by
Michael Jeanson <email address hidden>
Fix: Don't override user variables within the build system
Instead use the appropriatly prefixed AM_* variables as to not interfere
when a user variable is passed to a make command. The proper use of flag
variables is documented at :
Fix: race between lttng-ust getenv() and application setenv()
The LTTng-UST listener threads invoke getenv(), which can cause issues
if the application issues setenv() concurrently. This is a legitimate
use by the application because it may have a single thread and not be
aware that it runs with liblttng-ust.
Fix this by keeping our own environment variable table for the variables
we care about. Initialize this table within the lttng-ust library
constructor, when we don't race with the application.
doc/man: add typical `$` and `#` prompts to command lines
It is more instinctive for the typical reader to immediately recognize
command lines when they start with the classic prompts.
On the online version of the man pages, those prompts are treated
specially to make them non-selectable. This makes it possible to copy
multiple command lines at once (without copying the prompts) and to
paste them to your shell.
