Fix c99 compatibility: tp_rcu_dereference_bp() should not use braced-groups within expressions

Allow tp_rcu_dereference_bp() to be used within programs compiled with
--std=c99 -pedantic -Werror. Fixes the following:

In file included from hello.c:34:0:
ust_tests_hello.h: In function ‘__tracepoint_cb_ust_tests_hello___tptest’:
ust_tests_hello.h:28:1: warning: ISO C forbids braced-groups within expressions [-pedantic]
ust_tests_hello.h:28:1: warning: ISO C forbids conversion of object pointer to function pointer type [-pedantic]

We can easily fix this one since tp_rcu_dereference_bp() really
evaluates only a single expression.

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

Fix: perform TLS fixup of nest count outside of UST mutex

Could otherwise lead to a deadlock between the dynamic linker, TLS
fixup, and the UST mutex due to reversed lock acquisition order.

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

Fix: liblttng-ust-fork deadlock

* Mathieu Desnoyers (mathieu.desnoyers@efficios.com) wrote:
> * Burton, Michael (mburton@ciena.com) wrote:
> > Mathieu,
> >
> > I think there is a deadlock scenario in UST, which has been causing my problem.
>
> Good catch !
>
> >
> > sessiond is started as root:
> >     - creates global sockets ONLY
> >     - DOES NOT CREATE shm in $HOME/lttng-ust-wait-<uid>
> >
> > application linked against ust is run as root:
> >   - in lttng_ust_init constructor
> >   - ust_listener_thread  (local_apps)
> >     - fails to connect to local_apps in $HOME/.lttng (as expected)
> >     - prev_connect_failed=1
> >     - ust_unlock()
> >     - restart
> >     - wait_for_sessiond()
> >  -->  - ust_lock()
> >  |      - get_map_shm()
> >  |        - get_wait_shm()
> > DEADLOCK    - shm_open() FAILS (not created by sessiond when run by root)
> >  |            - fork() (trying to create shared memory itself)
> >  |              - ust_before_fork()
> >  ------------>    - ust_lock()
> >
> >
> > You should be able to create this with an empty main, with no
> > tracepoints.  As long as sessiond is started as root so
> > $HOME/lttng-ust-wait-<uid> is not created.  You can also make the
> > lttng-ust constructor (lttng_ust_init) wait forever and then you'll be
> > able to see the deadlock in gdb without even leaving the
> > lttng_ust_init constructor.
>
> Ah, I see. This deadlock is caused by the interaction between
> [ liblttng-ust-fork ] and liblttng-ust (the fork override is
> performed by [ liblttng-ust-fork ]).

This can be reproduced easily with the in-tree tests: by removing the
lttng-ust-apps-wait* files belonging to the user in /dev/shm, running
the "tests/fork" test (with ./run) hangs. If we run "hello" first, and
then the fork test, it works fine.

Fixing this by keeping a nesting counter around the fork() call, so we
return immediately from the pre/post fork handlers if they are
overridden by liblttng-ust-fork.

Reported-by: Michael Burton <mburton@ciena.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: handle pthread errors

Show a descriptive error message if pthread calls fail.

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

Fix: local apps allowed should disable local (not global) tracing

Reported-by: Michael Burton <mburton@ciena.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix strict ISO-C compatibility for ust-tracepoint-event.h public header

../../include/lttng/ust-tracepoint-event.h:328:23: warning: ISO C does not permit named variadic macros [-Wvariadic-macros]

Use ... and __VA_ARGS__ instead of args... and args.

This enables ISO-C compability for the tracepoint headers for program
instrumentation. Note that the probes need to be built _without_ strict
C99 flags (they require gnu extensions).

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

Fix: support -std=c99 in tracepoint macros

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

Fix c99 compatibility: use __typeof__ instead of typeof in public headers

Reported-by: John Steele Scott <toojays@toojays.net>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

hello test: fail on old style definition

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

Fix: tracepoint.h should not generate old-style definitions

I've defined a tracepoint without arguments:

   TRACEPOINT_EVENT(

        qemu_tb_hash,

        flushall,

        TP_ARGS(void),

        TP_FIELDS()

   )

When I build (with -Werror=old-style-definition), I get this error:

   In file included from /home/hollisb/work/qemu.git/exec.c:59:0:

   /home/hollisb/work/qemu.git/tracepoints.h:24:2: error: function declaration isn’t a prototype [-Werror=strict-prototypes]

   /home/hollisb/work/qemu.git/tracepoints.h: In function ‘__tracepoint_cb_qemu_tb_hash___flushall’:

   /home/hollisb/work/qemu.git/tracepoints.h:24:2: error: old-style function definition [-Werror=old-style-definition]

   cc1: all warnings being treated as errors

The preprocessed code looks like so:

   extern struct

   # 129 "/usr/local/include/lttng/tracepoint.h" 3

                  tracepoint

   # 24 "/home/hollisb/work/qemu.git/tracepoints.h"

     __tracepoint_qemu_tb_hash___flushall

   # 19 "/home/hollisb/work/qemu.git/tracepoints.h"

     ; static __attribute__ (( always_inline )) __inline__ void

     __tracepoint_cb_qemu_tb_hash___flushall

   # 19 "/home/hollisb/work/qemu.git/tracepoints.h"

     () { struct tracepoint_probe *__tp_probe; if (!tracepoint_dlopen.rcu_read_lock_sym_bp) return; tracepoint_dlopen.rcu_read_lock_sym_bp(); __tp_probe = ({ typeof(__tracepoint_qemu_tb_hash___flushall.probes) _________p1 = ((typeof(__tracepoint_qemu_tb_hash___flushall.probes)) (tracepoint_dlopen.rcu_dereference_sym_bp(((void *) (__tracepoint_qemu_tb_hash___flushall.probes))))); (_________p1); }); if (__builtin_expect(!!(!__tp_probe), 0)) goto end; do { void *__tp_cb = __tp_probe->func; void *__tp_data = __tp_probe->data; ((void (*)(void *__tp_data)) (__tp_cb)) (__tp_data); } while ((++__tp_probe)->func); end: tracepoint_dlopen.rcu_read_unlock_sym_bp(); } static __attribute__ (( always_inline )) __inline__ void

I believe the problem comes from -Werror=old-style-definition not liking
that empty "()", i.e. tracepoint_cb_qemu_tb_hash___flushall() { ... }.

Reported-by: Hollis Blanchard <hollis_blanchard@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: don't define variables in headers

From Hollis Blanchard <hollis_blanchard@mentor.com>:
> Hi, I was adding an LTTng UST 2.0 tracepoint to an application that uses
> -warn-common (see http://www.math.utah.edu/docs/info/ld_2.html). I created
> a simple tracepoint, had lttng-gen-tp produce tracepoints.o, then linked
> that to the application, along with -llttng-ust. This results in some
> warnings:
>
> tracepoints.o: warning: common of `handle' overridden by definition
> /usr/local/lib/liblttng-ust.so: warning: defined here
> tracepoints.o: warning: common of `lttng_client_callbacks_overwrite' overridden
> +by definition
> /usr/local/lib/liblttng-ust.so: warning: defined here
> tracepoints.o: warning: common of `lttng_client_callbacks_discard' overridden by
> +definition
> /usr/local/lib/liblttng-ust.so: warning: defined here
> tracepoints.o: warning: common of `lttng_client_callbacks_metadata' overridden
> +by definition
> /usr/local/lib/liblttng-ust.so: warning: defined here
> /usr/local/lib/liblttng-ust-tracepoint.so.0: warning: multiple common of
> +`handle'
> tracepoints.o: warning: previous common is here
>
> This seems to be a valid warning. The LTTng UST headers contain
> definitions like this in include/lttng/ringbuffer-config.h:
> struct lttng_ust_shm_handle *handle;
>
> If two objects use that header, each will get a copy of "handle", right?

handle: This was meant to be a forward declaration of

  struct lttng_ust_shm_handle

so just removing the "*handle" part. This can be considered as a
cleanup (or a fix without actual runtime effect).

lttng_client_callbacks_*: if the cb values would have been used in the
consumer daemon, this would have caused an issue: these would be set to
NULL instead of the actual callback pointers. So in a way this is a fix,
but it does not have any runtime impact at this point.

Reported-by: Hollis Blanchard <hollis_blanchard@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

test "hello": add boolean test

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

Fix: perform macro expansion on tracepoint signatures

The problem can be seen by patching the demo test from lttng-ust as
follows:

--- a/tests/demo/ust_tests_demo3.h
+++ b/tests/demo/ust_tests_demo3.h
@@ -22,12 +22,14 @@ extern "C" {
  * all copies or substantial portions of the Software.
  */

+#include <stdbool.h>
+
 #include <lttng/tracepoint.h>

 TRACEPOINT_EVENT(ust_tests_demo3, done,
-       TP_ARGS(int, value),
+       TP_ARGS(bool, value),
        TP_FIELDS(
-               ctf_integer(int, value, value)
+               ctf_integer(bool, value, value)
        )
 )

Then when the demo is run with LTTNG_UST_DEBUG=1, a warning is shown,
like:

liblttng_ust_tracepoint[3315/3315]: Warning: Tracepoint signature mismatch, not
enabling one or more tracepoints. Ensure that the tracepoint probes prototypes
match the application. (in set_tracepoint() at tracepoint.c:310)
liblttng_ust_tracepoint[3315/3315]: Warning: Tracepoint "ust_tests_demo3:done"
signatures: call: "_Bool, value" vs probe: "bool, value". (in set_tracepoint()
at tracepoint.c:312)

It seems that TP_ARGS does not perform preprocessor expansion on the
"bool" type spec, while something underneath TP_FIELDS does. And since
(at least on this Centos 6.2 box) stdbool.h uses a #define rather than a
typedef to make bool equivalent to _Bool, liblttng detects a mismatch.

Reported-by: John Steele Scott <toojays@toojays.net>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

UST check pointer/de-reference order

I stumbled across some code where pointers are de-referenced and then
checked for NULL.

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

Fix list field: handle error

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

Implement event fields listing

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

Implement field listing command

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

Fix: Block all signals in listener thread

The listener thread does not block signals and receives signals that are
intended for the application. As this can cause applications to fail,
the listener thread should block all signals. The attached patch is
derived from an old commit and fixes the issue.

Fixes #241

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

Add CodingStyle document to tarball

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

Add coding style document

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

endian.h: support cygwin

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

align.h: support cygwin page size

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

Add cygwin support to libringbuffer getcpu.h

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

Add "2x int" and "2x long" types to the Java interface

Since we have to statically define all the available event types,
offer types for two integers and two longs, which are relatively
common use cases.

Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Add Integer and Long tracepoint types to the Java interface

Also added Javadoc comments to the .java file.

Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: don't SIGBUS when filesystem is full

Write zeroes into the buffer after its allocation to ensure that writes
to the shm will not trigger SIGBUS upon full filesystem situations.

This scenario can occur if /dev/shm is filled, e.g. by specifying too
large buffers with --enable-channel.

When the write() fails, the buffer creation for this channel fails.

Fixes #230

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

tracepoint: include stdio.h for NULL definition

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

manpage update: document that probes need gcc

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

Fix: remove # in front on extern "C" {

Fails to compile with g++.

Reported-by: Francis Giraldeau <francis.giraldeau@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Cleanup: don't use GNU old-style field designator extension

ustfork.c:112:38: warning: use of GNU old-style field designator extension
      [-Wgnu-designator]
                struct ustfork_clone_info info = { fn: fn, arg: arg };
                                                   ^~~
                                                   .fn =
ustfork.c:112:46: warning: use of GNU old-style field designator extension
      [-Wgnu-designator]
                struct ustfork_clone_info info = { fn: fn, arg: arg };
                                                           ^~~~
                                                           .arg =

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

Fix: remove padding field after variable sized array

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

Use unsigned long type for events discarded counter

Overflows at 64-bit on 64-bit systems.

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

Fix: getcpu build with modern uClibc versions

uClibc has sched_getcpu since 0.9.33, so the compat workaround should
only be used for older uClibc versions.

Fixes #225

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: lttng-ust.pc needs to specify -ldl

Fixes #224

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

Fix: examples Makefiles should pass $(LIBS) at last

Fixes #210

Description

Since Ubuntu 11.10, the "--as-needed" option is given by default to ld
(linker). This option breaks the makefiles given with the userspace
tracing examples. Therefore the libraries against which the program
should be linked should be passed at last:
$(CC) -o $@ $^ $(LIBS)

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

Build a jar for the Java side of the JNI interface

Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: ustctl need to send the second fd upon error of 1st fd

Otherwise cause protocol discrepancy between ust and sessiond upon send
error. The sessiond will wait for an fd that never arrives.

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

Fix: Add missing fork test program dependency library

Only seem to affect some setups (e.g. older gcc ?) with the BSD
compatibility.

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

Fix: Make the JNI interface actually work

Now a user can import LTTngUst.java (which is now in a proper
package) and then define tracepoints in his application with:

LTTngUst.tracepointString(name, args);

We could eventually ship it in a .jar when the JNI interface is
enabled. It's still very basic, only string payloads are
implemented, and there is no mechanism to enable/disable trace
points call sites at runtime (they are always enabled). The event under
which these events appear is "lttng_ust_java:string".

Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Merge branch 'dev'

Fix: stringify version description

Note: config.h is unused in lttng 2.0, so no need to backport this fix.

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

Update version to 2.0.1

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

Use bsd-compatible fcntl for close-on-exec on socket

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

Fix multi-session wildcard support

Incorrectly unset loglevel information upon creation of wildcard_entry
was causing a second session with wildcard enabled to not record its
events.

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

Fix event lost count when buffer is full

The tracing channels should count lost events due to buffer full, and
the metadata channel should not (see comment), but not the opposite.
This was a mixup between the two.

Reported-by: David Goulet <dgoulet@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Remove inappropriate \n from easy-ust sample

Although \n is permitted in strings, it adds newlines in the trace
pretty-printer output, which is not that nice.

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

Update version to 2.0.0 stable

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

make dist: Generate bzip2 instead of gzip

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

Update version to 2.0.0-rc4

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

Fix out-of-bound write in ltt-events.c

Valgrind complains that the size allocated is too small for the memcpy,
rightly so (off by one).

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

Document LTTNG_UST_DEBUG_VALGRIND compilation flag

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

Update COPYING

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

Add exception handling to lttng-gen-tp io operations

(closes: 54)

Signed-off-by: Yannick Brosseau <yannick.brosseau@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Update version to 2.0.0-rc3

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

Fix: sendmsg should retry on EINTR, and use MSG_NOSIGNAL

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

fix: ustcomm_close_unix_sock should close, not shutdown

.. and ensure that we actually use the API rather than doing the close()
directly in the caller.

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

Fix: do not print EPIPE perror, as it is an expected error

It is perfectly valid for the other end to close its socket, so do not
report broken pipe errors as perror.

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

Ensure that multiplication of clock offset is done on 64-bit

This is not a bug in UST per se, because we happen to force
multiplication by a ULL number, but force cast to uint64_t anyway to
ensure we don't trigger this overflow if the constant ever happen to
change.

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

Add 2 missing licenses in deprecated tests

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

Remove unbuild and unused (deprecated) make_shared_lib test

Was for UST 0.x.

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

License text standardization, add missing licenses

- Use MIT/X11 text for BSD-style license.
- Fix FSF address.
- Use appropriate LTTNG_ prefix for ifndef (rather than LINUX).

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

Cleanup: remove duplicate check for 0 num_subbuf and subbuf_size

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

Fix: power of 2 size check should apply to size_t type, not uint32_t

Fix this by using the much simpler x & (x - 1) check (rather than
hweight(x) == 1).

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

Merge branch 'master' into dev

Fix: recvmsg should handle EINTR

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

Merge branch 'master' into dev

Make lttng-gen-tp work on python 2.6

(refs #114)

Signed-off-by: Yannick Brosseau <yannick.brosseau@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Make lttng-gen-tp executable

Signed-off-by: Yannick Brosseau <yannick.brosseau@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

usterr: do not include unused sys/syscall.h

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

Update version to 2.0.0-rc2

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

Manpage fixes

Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: dmesg printout should not print metadata warnings

Metadata channel retry when an event is dropped by the underlying
buffer. We should not print a message showing that the event has been
dropped to the user on debug console.

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

Fix: use transport name as channel name

Clarify lost event printout.

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

Merge branch 'master' into dev

Conflicts:
liblttng-ust/ltt-events.c
liblttng-ust/lttng-context-vtid.c
liblttng-ust/lttng-ust-comm.c
libringbuffer/ring_buffer_frontend.c

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

Fix: Add signature check in tracepoint activation

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

Fix: add tracepoint signature at tracepoint definition site

Will enable type-checking between call site and handler.

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

Fix: keep event probe signature, for use by event probe signature check

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

Fix ABI: add padding to structures shared between UST and consumer

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

Fix ABI: add padding to tracepoint and ring buffer config public structures

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

Fix ABI: Adding missing padding in tracepoint event structures

Add padding for future extensions.

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

Fix: Add include/lttng/ust-config.h to git ignore

(fixes #95)

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

Fix effect: update README about dlopen()

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

Fix: fixup vtid TLS

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

liblttng-ust/lttng-context-vtid.c

Fix: fixup ringbuffer tls at constructor by forcing read

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

liblttng-ust/lttng-ust-comm.c
libringbuffer/ring_buffer_frontend.c

Fix: fix deadlock with dlopen() lttng-ust

Pre-"fault" the libuuid TLS outside of the ust lock to ensure that we
never deadlock with the linker mutex in libc. This mutex is held both
for TLS fixup of dlopen'd libs, and across execution of all
constructors. We therefore have a reverse use of this mutex wrt ust
lock, that we fix by forcing the TLS fixup to happen very early in the
lttng-ust constructor.

[fixed merge from dev branch]

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

Fix effect: update README about dlopen()

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

Fix: fixup vtid TLS

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

Fix: fixup ringbuffer tls at constructor by forcing read

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

Fix: fix deadlock with dlopen() lttng-ust

Pre-"fault" the libuuid TLS outside of the ust lock to ensure that we
never deadlock with the linker mutex in libc. This mutex is held both
for TLS fixup of dlopen'd libs, and across execution of all
constructors. We therefore have a reverse use of this mutex wrt ust
lock, that we fix by forcing the TLS fixup to happen very early in the
lttng-ust constructor.

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

Merge branch 'master' into dev

Fix: only print event errors every 1048576 hits

Never spam the console, even in debug mode, since it would make debug
information very much useless.

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

Fix: add missing debug printout to identify the cause of lost events

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

Merge branch 'master' into dev

fix: liblttng-ust-ctl should check for incorrect parameters

Acked-by: David Goulet <dgoulet@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: ust comm error handling segfault

On comm errors, UST should not try to populate fields from NULL
pointers.

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

fix: ust comm error handling segfault

On comm errors, UST should not try to populate fields from NULL
pointers.

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

freebsd port: use a leading / prefix for shm tmp name

FreeBSD complains if the leading / is missing.

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

ust-endian.h: update warning message

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

Remove gettid warning

Not so important, hides really useful warnings.

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

Add configure amd64 support (for FreeBSD)

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