TRACEPOINT_EVENT: add floating point support

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

Fix context order

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

Update tracepoint header comments

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

Change tracepoint.h header

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

TRACEPOINT_EVENT API

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

ltt-context: document that pointers may change

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

context: document and check that only last context is removed

Merge from lttng-modules:

commit 4cae220c1be2cc73008603a21152fce7643cfc35
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date:   Sat Jul 23 12:37:54 2011 -0400

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

Fix git URL

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

Implement multi-session registry

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

implement ring buffer clients

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

Resync with kernel LTTng headers

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

Lib ring buffer: use TLS for nesting count

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

Ring buffer: use shmp (shared-memory pointers) for per-channel shm structures

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

Port ring buffer to userspace, part 1

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

Merge LTTng commit 360f38ea4fee91e2403c03cb43841ef6769aaac7

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

Merge LTTng commit 5c0552665e4d152e97edc995650711d4f6ac418d

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

Merge LTTng commit c6485006a92b1b86fbb48c2b277732d3405295c9

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

Merge LTTng commit e64957da15e3652322dcf6a5389beb01901de8e6

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

Build libringbuffer, remove kernel includes

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

Initial addition of lttng ring buffer clients

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

add ltt-probes.c

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

Add event and context files

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

Add alignment header

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

Add bug management header

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

Add bitfield header

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

lttng priority heap initial import

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

lib ring buffer initial import

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

More removal

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

Move away headers that will be deprecated

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

Move away files that will be deprecated

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

Fix compilation with uclibc

Reported-by: Khem Raj <raj.khem@gmail.com>
Reported-by: Dexuan Cui <dexuan.cui@intel.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Remove execinfo.h include

Not required, and breaks uclibc build.

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

Update changelog and version to UST 0.14

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

Update info page for 0.14 API

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

Disable exit fast test (known issue)

Disable this test before the release, as we are working on a solution
that involves redesign of the way libust is controlled (synchronization
with a lttng-tools session daemon). We don't want to flood testers with
known issues.

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

Update to urcu/ref.h and urcu/uatomic.h

liburcu 0.6 is changing the name of these two headers.

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

Update dependency to liburcu 0.6

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

Update liburcu version check

liburcu symbols have changed (_bp suffix added for the -bp flavor used
by UST), and we now depend on urcu 0.5.5 for struct rcu_head definition.
Therefore, check for synchronize_rcu_bp and call_rcu_bp.

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

Update following liburcu changes

Addition of call_rcu in liburcu deprecates the simple.h kcompat header.

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

Add a version.h header

It contains the major and minor version numbers

[ edit: coding style fixes by Mathieu Desnoyers ]

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

Add pkg-config file generation

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

Update note in buffer.c

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

Remove installed headers, cleanup header names

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

Fix make check includes

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

Cleanup leftover UST comments, add comments about current implementation limitations

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

TRACEPOINT_EVENT: standardize locking wrt tracepoints and markers

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

Tracepoints and markers: cleanup init, add missing mutex lock/unlock

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

Markers: sync from LTTng 0.249 marker code

- Add missing mutexes.
- Cleanup RCU usage.
- Remove unused code.

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

Privatize headers

Remove most installed headers, which should be internal. The header
kcompat (kernel-style compatibility header) only makes sense within the
UST package: this should never be exported, nor be included into
instrumented applications.

Move the type-serializer header back into libust/. It is so internal it
does not even belong to include/ust/.

Standardize all the installed headers on non-kcompat style: use uint64_t
instead of u64 for types, open-code likely/unlikely.

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

Add Maintainer and Mailing list contact information to README

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

Change libtap.so to a local static library which is not installed

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

Privatize part of marker.h, and type-serializer.h

The current interface we publish is ust_marker(), tracepoint() and
TRACEPOINT_EVENT() (and associated _NOARGS, CLASS, INSTANCE and
TRACEPOINT_CREATE_PROBES). Besides that, consider any lower-level API
showing the UST internals as, well, internal.

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

Tracepoint and TRACEPOINT_EVENT API cleanup

We want to move towards a TRACEPOINT_EVENT-based API only, so start
cleaning up right now.

Prefix with _ or __ all members that are internal to UST. Move all the
non-exported API members (that don't need to be around in program
inclusion) to tracepoint-internal.h (which is not meant to be installed
on the system).

Unit tests can still use the internal API members for now, but should
gradually move to use TRACEPOINT_EVENT as we start implementing the
FIELDS() declaration.

TRACEPOINT_EVENT is changed from the kernel incarnation (TRACE_EVENT):
we take only 3 arguments: proto, args and fields. The "fields" describe
the event layout _and_ targets the data source.

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

Mark old trace_mark API deprecated (gcc attribute)

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

version update to 0.13

ChangeLog updates for 0.13 v2

add missing usterr_signal_safe.h to makefile

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

New fast-exit test-case

A fast-exit test-case that just writes one marker and exits,
tests that the consumer daemon maps the buffers before the
program exits. Exiting is tested both by normal return
and by commiting suicide (SIGKILL to self).

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Make libustctl list only online pids v3

Changes since v2:
Botox.

Changes since v1:
Cosmetic surgery at a european cost

Previously libustctl would list all pids. This patch changes this
so only online pids are listed. This is done by appending on each
socket name the mtime from the proc/<pid> directory. This way a
socket can be checked to see if the appended mtime matches the
mtime of the proc dir for the current pid, thus allowing us to
distinguish between old and new socket files.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

change runtests GPL version

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

armv5 archs require write alignment

Reads and writes to unsigned int 32 bit numbers must be address
aligned or the l2 cache can return junk in the high order 16 bits on
reads.

This patch activates the original work done for alignment in ltt for
the UST code.  The config.ac changes will isolate the use of alignment
to the known arch type with the problem.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Only ignore the top config.h.in

Only he top config.h.in is autogenerated the include/ust/config.h.in
is a source controled file.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

add mips support

The recent changes to UST make it trivial to add MIPS support.

The trick for MIPS is that there are many different library formats
and the gcc 4.x compiler will correctly choose the default one so long
as the libust.ldscript.in does not not make a reference to the library
format.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

support busybox for manual trace tests

The busybox version of find does not support using -L, and it does not
appear to be needed in order to pass the test.  In the interest of
being able to run internal UST tests on a busybox based rootfs,
appropriately detect if -L is available as an argument to find and use
it when it is available.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

ust-consumerd: fix exit race log corruption

In the following scenario on an SMP system the ust-consumerd can end
up not properly closing out file handles which leads to log
corruption:
  * usttrace -m -l small_quick_app_lots_of_malloc_and_free
  * The app completes and usttrace sees and sends the SIGTERM to ust-consumerd
  * The ust-consumerd main thread will exit and the _exit() handlers
    kills off the remaining pthreads without everything getting closed out

The solution to the problem is to introduce an active_thread count for
the private ustconsumer_instance.  This counter will be zeroed out
when it is safe to completely shutdown the main thread, which will
subsequently run the _exit() handlers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

ust-consumerd: fix exit race crashes

The ust-consumerd gets shutdown by the SIGTERM signal and a number of
places in the ust-consumerd did not properly deal with the case where
a system call returns EINTR in errno as a result of a signal to the
process.  The failure to handle EINTR properly was leading to some
data corruption in the buffer code and causing some random "victim"
crashes in lowlevel.c

The way all the offending functions were tracked down was to
temporarily add an abort() in the SIGTERM signal handler.  Then it was
a matter of looking at what threads were blocked on system calls at
the time outside of the thread that received the signal.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Markers: temporarily remove GDB support

Remove GDB support temporarily, awaiting a better implementation that
does not require so much asm trickery. Imported the kernel LTTng code
back into UST to use C declarations for the marker structures.

The plan is to move to a SDT-based implementation (using variable
number of arguments).

This patch is required to make the MIPS port work. Tested by Jason
Wessel.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tested-by: Jason Wessel <jason.wessel@windriver.com>

Tracepoint: make tracepoint ptrs section rw

The pointer section needs to be rw so that the linker can update the
pointers at link-time, thus allowing the code to be compiled with -fPIC.

The previous behavior would cause section flag mismatch, because
TRACEPOINT_LIB declared the ptr with "= NULL", which is not a void *
const, but rather a void *, which forces the element it is assigned to
to become non-const.

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

Add missing string.h include in libustctl_function_tests

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

Markers: ust_marker_[A-Z] -> UST_MARKER_[A-Z] cleanup

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

Markers: Add MARKER_LIB backward compatibility

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

Markers: trace_mark should not pass "ust" to ust_mark

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

Markers: fix compatility trace_mark

When providing no args, we need to paste args with ## args.

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

Add MARK_NOARGS compatibility API, marked for deprecation.

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

Add "trace_mark()" compatibility API (progressive deprecation)

Add back the trace_mark() API for backward compability, tagging it as
being slowly being deprecated.

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

Update manual

Update info manual to reflect the latest instrumentation API changes for
both tracepoints and markers.

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

Tracepoints: Introduce DEFINE/DECLARE_TRACEPOINT, TRACEPOINT_EVENT...

* Instrumentation API change *

Introduce the upcoming "TRACEPOINT_EVENT" API:

TRACEPOINT_EVENT
TRACEPOINT_CREATE_PROBES
TRACEPOINT_EVENT_LIB

And move the current tracepoint declaration/definition to a more
standard name (these will become internal API when we switch to
TRACEPOINT_EVENT):

DEFINE_TRACEPOINT
DECLARE_TRACEPOINT

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

Remove #define _LGPL_SOURCE from public headers

this header can be included by non-LGPL applications. Ensure that
use it.

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

Markers: make __ust_marker_ptrs PIC

> As I prepared the 0.12 release for Debian, I noticed that libust.so was
> not PIC:
>
>     $ readelf -d libust/.libs/libust.so.0.0.0 | grep TEXTREL
>     0x0000000000000016 (TEXTREL)            0x0
>
> Since all of the objects in libust are built with -fPIC, I thought
> perhaps there was some assembly added between 0.11 and 0.12 that
> contained text relocations. I bisected the two tags down to the
> offending commit:
>
>     eb5d20c68aaf73661ffc02ba8fea3683c0358702
>
> Within that commit, it seems to be a problem in include/ust/marker.h
> with these lines:
>
> @@ -129,7 +124,12 @@ struct marker {
> [...]
> +                       /*".section __markers_ptrs\n\t"*/ \
> +                       ".section __markers_ptrs,\"a\",@progbits\n\t"                           \
>
> If I make the __markers_ptrs section writable, with:
>
>                         ".section __markers_ptrs,\"aw\"\n\t
>
> TEXTREL goes away and everything seems okay, tests pass. Is this
> a correct solution? I don't understand why the section must be writable
> to avoid relocations, can anyone explain?

Oh.. I think I see. __markers_ptrs contains pointers to another section
that must be populated by the dynamic linker (thus at runtime). If the
section is read-only, the linker cannot update them at load time, so a
relocation table is probably needed.

Reported-by: Jon Bernard <jbernard@debian.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

LGPLv2.1 relicensing agreements

Steven just stated clearly that he only accepts relicencing to
LGPLv2.1 (not later). So I think we might have been interpreting his
previous acceptance a little too broadly when specifying "LGPLV2.1+".
Change the licensing text to reflect this.

If some of the contributors specifically said they were OK with "or
later", we could add this back upon rechecking their original acceptance
email. The pointers to the original public emails should have been
present in the relicensing file to make our current job easier, but this
is unfortunately not the case.

Also updated the stringify.h, tracepoint.c, marker.c and trace_event.c
files.

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

Tracepoints: namespace cleanups

All internal symbols, no API change. Enforce "tracepoint_" or "tp_"
prefixes to local symbols, as well as rename struct probes to struct
tracepoint_probes.

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

Remove "struct module" from tracepoint.h (unused)

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

Remove immediate values code (non-effective anyway)

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

Markers: Namespace cleanup, with API change.

** API change: MARK_NOARGS becomes UST_MARKER_NOARGS **

Cleanup the "marker" namespace by using "ust_marker/UST_MARKER".

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

Test empty argument tracepoint

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Nils Carlson <nils.carlson@ericsson.com>

Tracepoints: add noargs support

Add support for tracepoints receiving no argument as parameters. Copied
from Linux kernel:

commit 38516ab59fbc5b3bb278cf5e1fe2867c70cff32e
Author: Steven Rostedt <srostedt@redhat.com>
Date:   Tue Apr 20 17:04:50 2010 -0400

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Nils Carlson <nils.carlson@ericsson.com>
CC: Steven Rostedt <rostedt@goodmis.org>

Tracepoints: add wrapper tracepoint() macro

** Instrumentation API change **

Moving tracepoints from

trace_name(args)
register_trace_name(...)
unregister_trace_name(...)

to

tracepoint(name, args)
register_tracepoint(name, ...)
unregister_tracepoint(name, ...)

This will allow doing macro tricks at the "tracepoint()" macro expansion
site. This will be useful for integration with SystemTAP probes, which
needs to expand an inline assembly with constraints on the arguments.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Nils Carlson <nils.carlson@ericsson.com>
CC: Steven Rostedt <srostedt@redhat.com>
CC: Josh Stone <jistone@redhat.com>

Markers: API change: rename trace_mark() to ust_marker()

Given that the markers will stay as debug-only "quick and dirty"
tracing interface, make them UST-specific. Make it clear by turning the
API to ust_marker().

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

Merge branch 'master' of ssh://git.lttng.org/home/git/ust

Fix up all use of /dev/stderr for portability to busybox /bin/sh

The typical shell on a small embedded target using busybox does
not have support for /dev/stderr.  A more portable way to send
output to stderr with echo is to redirect stdout to stderr with
1>&2.

In the usttrace script it did something that was effectively
a NOP.  The result of echo "" 2>/dev/stderr is not actually
going to send anything to stderr because the echo is going
to write to stdout.  This case was also fixed.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Markers: remove channel name from trace_mark()

*** This is an instrumentation API change ***

Given that UST will gradually move to a scheme where channels are
dynamically associated with markers on a per tracing session basis (and
thus associated dynamically rather than fixed statically), it does not
make sense to specify the "channel name" in addition to the marker name
in the trace_mark() arguments.

API touched:

GET_MARKER()
DEFINE_MARKER()
DEFINE_MARKER_TP()
trace_mark()
_trace_mark()

I'm introducing this API change without changing the underlying
implementation, trying to minimize the impact of API changes by doing
them sooner than later.

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

Make only libust and libustconsumer use a signal safe usterr.h

Copy usterr.h to usterr_signal_safe.h and rewrite those parts of
usterr.h that depended on libustsnprintf. This removes the dependency
on libustsnprintf from all parts of ust except libust.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

libustctl: cleanup ustctl_get_online_pids functions

Cleanup the ustctl_get_online_pids functions, checking more errors
and making the allocation strategy sane.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Make root able to connect to any traceable app

Make root able to connect to any traceable app, checking
(geteuid == 0).

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Make root see all available pids v2

Changes since v1:
* Fix a whitespace
* Make functions that should be static static

Allow root (geteuid() == 0) to see all pids. This way the super-user
can connect to any program. A step on the way of carefully outlining
what UST does and doesn't.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Add list-pids command to ustctl v2

Changes since v1:
* Case pid_t to long

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Restructure the ustctl_get_online_pids command v2

Changes since v1:
* Use list length, not the size in bytes
* Fix a possible bug for pid_t in a sscanf
* Use list length in the dir scanning function

Restructure the command to separate the pid gathering.
This will allow a root user to gather pid from multiple user
directories.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Add mode setting to socket directory creation

Set the mode when creating the personal socket directory,
this way all app sockets are private.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Make app socket directories per-user v2

Changes since v1:
* Document memory allocation

Make a separate app socket directories for each user, providing
some basic security and also the possibility of consistent cleanup.

Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>

Rename local variables "m" and "regs" to less conflicting names

Rename "m" local macro variable to "__marker_counter_ptr".
Rename "regs" local macro variable to "__marker_regs".

Initial report:

The following trivial piece of code will result in corrupt events:

void dump_ackerman_current( int m, int n )
{
    trace_mark( ackerman, current, "m %d n %d", m, n );
}

This is because in ust/marker.h line 173 the definition of the
__trace_mark_counter macro uses a temporary named m (which shadows the
original m). It might be a good idea to use underscore variable names
inside these macros to make naming conflicts less likely.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Paul Wögerer <paul_woegerer@mentor.com>