Fix: don't perform extra flush on metadata channel

The metadata channel requires that the LTTng client layer and the ring
buffer keep a notion of the amount of data produced in the channel.

This issue has been introduced recently by commit
"Fix: flush empty packets on snapshot channel".

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

Fix: flush empty packets on snapshot channel

Snapshot operation on a non-stopped stream should use a "final" flush to
ensure empty packets are flushed, so we gather timestamps at the moment
where the snapshot is taken. This is important for streams that have a
low amount of activity.

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

Fix: do not generate packet at destroy after stop

In the following scenario:
- create, enable events (kernel),
- start
- ...
- stop (await for data_pending to complete)
- destroy
- rm the trace directory

We would expect that the "rm" operation would not conflict with the
consumer daemon trying to output data into the trace files, since the
"stop" operation ensured that there was no data_pending.

However, the "destroy" operation currently generates an extra packet
after the data_pending check. This causes the consumer daemon to try to
perform trace file rotation concurrently with the trace directory
removal in the scenario above, which triggers errors. The main reason
why this empty packet is generated by "destroy" is to deal with trace
start/stop scenario which would otherwise generate a completely empty
stream.

Therefore, introduce the concept of a "quiescent stream". It is
initialized at false on stream creation (first packet is empty). When
tracing is started, it is set to false (for cases of start/stop/start).
When tracing is stopped, if the stream is not quiescent, perform a
"final" flush (which will generate an empty packet if the current packet
was empty), and set quiescent to true.  On "destroy" stream: if the
stream is not quiescent, perform a "final" flush, and set the quiescent
state to true.

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

Fix: compat ioctl for flush/get metadata version

Unlike the non-compat version, the compat ioctl lttng ABI code for the
ring buffer flush operation does not invoke
lttng_metadata_output_channel before calling the ring buffer operation.
This could lead to incomplete metadata on 64-bit kernels running with
32-bit lttng userland.

There is also a discrepancy between the non-compat and compat code: the
GET_METADATA_VERSION operation is performed before calling the ring
buffer code. Ensure both non-compat and compat code are alike.

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

Fix: __string() and tp_strcpy() should handle NULL pointers

The regmap instrumentation can send a NULL string (e.g. on ARM32).

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

Fix: add modules target to base Makefile

This way running 'make modules' will indeed build the modules
like in the upstream build system.

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

Fix: make clean does not include dot-config

Skip the CONFIG_TRACEPOINT test if dot-config has not been included.

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

Fix: trigger build error if CONFIG_TRACEPOINTS is not set

Fixes: #1015
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: x86 kvm mmutrace instrumentation for kernel < 3.6

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

Fix: Ubuntu kernel range for mm_page_alloc_extfrag

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

Fix: update sched instrumentation for kernel 4.4.0

Due to upstream Linux kernel commit:

commit c73464b1c8434ad4cbfd5369c3e724f3e8ffe5a4
Author: Peter Zijlstra <peterz@infradead.org>
Date:   Mon Sep 28 18:06:56 2015 +0200

    sched/core: Fix trace_sched_switch()

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

Fix: missing Tracepoint prototype checking due to bogus merge

Backport of the following commit:

commit 6633b022a8e6ef247af926919b493284308f7883
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date:   Fri Apr 17 16:35:35 2015 -0400

    Fix: check that class and instance prototype match

accidently disabled Tracepoint prototype checking by removing
the #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) required
to perform prototype checking between kernel and lttng-modules.
This issue was introduced in 2.6.1, only in the stable-2.6 branch.

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

Version 2.6.5

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

Fix: make writeback instrumentation build for 4.3 kernel

The backported patch "Fix: writeback instrumentation update for 4.3
Linux kernel" (ee33121c8ff05b44ab) used a newer definition of
LTTNG_TRACEPOINT_EVENT_CLASS which is not available in v2.6.

Note that, while this fixes the build, the global_dirty_limit symbol
used by some writeback events is no longer present since the 4.2 kernel,
and will result in runtime "lookup failed" warnings if those events are
used.  This is also the case on current master.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: make sched instrumentation build for 4.3 kernel

The backported patch "Fix: update sched wakeup instrumentation for 4.3
kernel" (c93180196ea8) used a newer definition of
LTTNG_TRACEPOINT_EVENT_CLASS which is not available in v2.6.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: header size larger than 256 bytes

When adding large context (e.g. callstack), headers larger than 256
bytes cause discrepancy between calculated size and size written into
the trace buffers. This generates a corrupted trace and triggers a
warning in ring buffer backend, which triggers a safety net disabling
tracing for the current channel.

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

Fix: lttng trace-clock needs to disable preemption

We use a per-cpu data structure, and some contexts (e.g. buffer create)
call this function with preemption enabled. This is the case also for
buffer flush operation.

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

Version 2.6.4

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

Fix: writeback instrumentation update for 4.3 Linux kernel

Linux upstream commit:

commit 5634cc2aa9aebc77bc862992e7805469dcf83dac
Author: Tejun Heo <tj@kernel.org>
Date:   Tue Aug 18 14:54:56 2015 -0700

    writeback: update writeback tracepoints to report cgroup

Updated the tracepoint signatures for writeback probes. Follow this
change. Don't add extra data (cgroup information) yet.

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

Fix: update sched wakeup instrumentation for 4.3 kernel

Change introduced in upstream Linux:

commit fbd705a0c6184580d0e2fbcbd47a37b6e5822511
Author: Peter Zijlstra <peterz@infradead.org>
Date:   Tue Jun 9 11:13:36 2015 +0200

    sched: Introduce the 'trace_sched_waking' tracepoint

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

Version 2.6.3

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

Fix: use after free in channel release

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

Fix: build failure on 2.6.36

Fixes build failure on the 2.6.36 kernel branch which misses the
vzalloc() function.

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

Fix: writeback instrumentation for 4.2 kernels

Bandwidth related fields were moved by this commit:

commit a88a341a73be4ef035ca26170c849f002797da27
Author: Tejun Heo <tj@kernel.org>
Date:   Fri, 22 May 2015 17:13:28 -0400

    writeback: move bandwidth related fields from backing_dev_info into
    bdi_writeback

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

Fix: mm_page_alloc_extfrag instrumentation for kernel 3.18.10

The following commit has been backported from kernel 3.19.2 into
3.18.10, introducing a change to mm_page_alloc_extfrag and therefore
provoking a build failure on a 3.18.10 kernel:

commit a4f3f96f850db69890f47984c60606a2362bee89
Author: Vlastimil Babka <vbabka@suse.cz>
Date:   Wed Feb 11 15:28:15 2015 -0800

    mm: when stealing freepages, also take pages created by splitting buddy page

    commit 99592d598eca62bdbbf62b59941c189176dfc614 upstream.

This patch adds the proper version check to allow building on 3.18.y.

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

Fix: kmem probe with Ubuntu 3.13 kernels

Fixes an undefined reference to get_pageblock_flags_mask.

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

Fix: disable kvm probe if lapic.h isn't found

In a typical distribution if just linux-headers is installed, lapic.h
will not be installed. We should check if that file exists and not build
the module.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: timer instrumentation for 4.2 kernels

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

Fix: ext4 instrumentation for 4.2 kernels

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

Fix: kvm instrumentation for 4.2 kernels

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

Fix: allow LTTng to be built within kernel tree

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

Fix: Building the event list fails on fragmented memory

On a small arm imx6 solo with 256MB RAM it often happens that memory
becomes fragmented rather quickly, so that kmalloc will not be able to
get enough consecutive pages (enocuntered for example if you enable all
kernel events: lttng enable-event -k syscall --all).

This patch switches the allocation to vmalloc. Tested for x86 on Ubuntu
12.04 Lts and on imx6 solo 256MB RAM

If this patch is not applied, you can identify low and/or fragmented
memory failures by looking at the kernel ring buffer (please ignore DMA,
it is due to some memory setup misconfiguration, should read Normal):

...
[  321.993820] lttng-sessiond: page allocation failure: order:4, mode:0x1040d0
...
[  321.994711] lowmem_reserve[]: 0 0 0
[  321.994727] DMA: 801*4kB (UEMC) 424*8kB (EMC) 355*16kB (UEMC) 344*32kB (MC) 340*64kB (C) 8*128kB (C) 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB 0*32768kB = 46068kB

[ Edit by Mathieu: use vzalloc() rather than vmalloc() + memset 0. ]

Signed-off-by: Martin Leisener <martin@leisener.de>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: use after free on metadata cache reallocation

When the metadata cache is expanded (reallocated) by
lttng_metadata_printf(), the metadata cache reader
(lttng_metadata_output_channel()) may use freed memory, because the
metadata cache is not protected from concurrent read accesses. The
metadata cache updates are protected from each other by the sessions
mutex, but metadata cache reads do not hold the sessions mutex.
Actually, the comment on top of lttng_metadata_output_channel() stating
"We have exclusive access to our metadata buffer (protected by the
sessions_mutex)" is simply wrong, because this mutex is never held when
calling lttng_metadata_output_channel().

Promote the per-stream lock to the metadata cache used by each of those
metadata streams, thus ensuring mutual exclusion between metadata cache
reallocation and readers.

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

Version 2.6.2

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

Fix: version checks for kernel 4.0

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

Fix: Incorrect Ubuntu kernel patchlevel

The kernel version used should be the one in Makefile and generated
version.h, not the one tweaked by Ubuntu as "0" in the built package.

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

Fix: Update kmem event for Ubuntu's 3.16 kernel

The upstream patch in question in commit 72906e1 was cherry-picked into
Ubuntu's 3.16 kernel backport branch (called lts-utopic). The version
check should also include this branch.

The other backport branch, lts-vivid, and all following ones will be
covered by the standard

  LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,2)

check, so should not require other workarounds.

References #889.

Signed-off-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: RHEL 7.1 block instrumentation

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

Fix: add RHEL version macros

RHEL 7.1 has backported upstream patches that change the kvm.h
tracepoint prototype. Add version check specific to RHEL to handle this
case.

RHEL 7.x has the required fixes backported that allow removing the 3.10
blacklist check for them, so take this into account.

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

Fix: add missing parenthesis in ubuntu version check

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

Fix: remove regmap instrumentation for kernels < 4.1

Modifications to regmap.h instrumentation in mainline Linux kernel has
been no less than erratic. First, the public instrumentation header
regmap.h include a private driver header in Linux 4.0. Then, regmap.h
is moved to the private driver directory in Linux 4.1. To make things
worse, the 4.0 commit has been picked into stable branches of the Linux
kernel.

Since this does not appear to be an instrumentation of utmost
importance, only build this instrumentation probe if the private header
is found in the driver directory (need full kernel sources).

This removes regmap instrumentation for older kernels.

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

Fix: Update kmem event for recent Ubuntu kernel

Ubuntu backported a patch into their 3.13 (Trusty) branch which
changes kmem event definition.

Upstream commit
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=99592d598eca62bdbbf62b59941c189176dfc614
first appears in 4.0 (and was later backported to 3.19.2).
We already have the proper check for this.

This corresponds to Ubuntu commit
http://kernel.ubuntu.com/git/ubuntu/ubuntu-trusty.git/commit/?id=d938e4bff1089a1f4757ed94a5cace803c6a363b
which was first released with 3.13.0-50.82.
This required adding a new check specifically for the
Ubuntu version.

Signed-off-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: missing statedump end event when block device listing available

Incorrect handling of lttng_enumerate_block_devices() return value of 0
(which means "ok"), causing do_lttng_statedump() to return early.

To causes missing "lttng_statedump_end" in traces where block device
enumeration is available (CONFIG_KALLSYMS=y).

Reported-by: Antoine Busque <abusque@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: don't generate incorrect macros for debian/ubuntu version check

When the debian/ubuntu macros are unset, we end up generating macros
that have no right hand operand to "+", which seems to break compilation
on some compilers, even though it will always be optimized away.

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

Revert "Fix: build against Ubuntu kernels"

This reverts commit a748963b76f353d459a3faf85eecc96f52811eee.

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

Fix: build against Ubuntu kernels

Recent Ubuntu kernels appear to define DEBIAN_API_VERSION, but they are
not really a Debian kernel per-se: the abi-debian-version.sh cannot find
the expected Debian kernel version string layout.

Therefore, change the conditional check to use directly the
LTTNG_DEBIAN_VERSION_CODE define, which is defined only when the
abi-debian-version.sh script figures out it builds against a Debian
kernel.

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

Version 2.6.1

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

Fix: regmap build against kernel 4.0 kernel headers

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

Fix: mmutrace warnings about redefined macros

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

Fix: add missing x86 mmutrace kernel header include

Needed to ensure the compiler checks prototypes of lttng-modules probe
against the kernel prototypes.

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

Fix: x86 mmutrace event extra field for kernels >= 3.11

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

Fix: remove execute flag from kvm.h file

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

Fix: build x86 kvm probes on kernels >= 4.1-rc1

iodev.h has moved to include/kvm/.

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

Fix: compilation warnings on 4.1-rc1 kernel

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

Fix: compilation on 4.1-rc1 kernel, remove unused WB_WORK_REASON

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

Fix: 4.1-rc1 Linux build and regmap instrumentation

regmap header has been privatized.

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

Fix: don't clash with older Debian kernel versions

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

Fix: update get_pfnblock_flags_mask wrapper for debian kernels

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

Fix: discover Debian API

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

Fix: Update README.md to match reality: kernels >= 2.6.36 are supported

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

Fix: add struct file_handle forward declaration

For older kernels (e.g. 2.6.38).

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

Fix: atomic.h wrapper for kernels < 2.6.37

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

Fix: disable x86 kvm instrumentation for kernels < 2.6.38

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

Fix: check that class and instance prototype match

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

Fix: lttng-events.h check function takes void

The kernel nerver really emit this, but our function prototype should
not take the void *data parameter, so we are similar to the the "with
argument" prototype, which does not have the private data pointer.

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

Update regmap instrumentation for Linux 3.19.4 and 4.0

This is necessary after commit c6b570d97c0e77f570bb6b2ed30d372b2b1e9aae
in the kernel.

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

Fix: kernels >= 2.6.33 put utsrelease.h in generated/

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

Fix: Include utsrelease.h in lttng-kernel-version.h

Including module.h includes other headers, which is an issue for the
get_pfnblock_flags_mask wrapper.

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

Fix: old kernels need module.h included before vermagic.h

This is at least true for 3.2.

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

Fix: version condition in makefile

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

Implement wrapper around get_pfnblock_flags_mask

This is used by kmem instrumentation, and changed in 4.0.0. This change
has been backported to 3.19.2 stable kernel.

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

Fix: Support 4.x kernel versions in Makefile

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

Fix: mm_page_alloc_extfrag instrumentation for kernel 3.14.36

The following commit has been backported from kernel 3.19.2 into
3.14.36, introducing a change to mm_page_alloc_extfrag and therefore
provoking a build failure on a 3.14.36 kernel:

commit a4f3f96f850db69890f47984c60606a2362bee89
Author: Vlastimil Babka <vbabka@suse.cz>
Date:   Wed Feb 11 15:28:15 2015 -0800

    mm: when stealing freepages, also take pages created by splitting buddy page

    commit 99592d598eca62bdbbf62b59941c189176dfc614 upstream.

This patch adds the proper version check to allow building on 3.14.y.

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

Fix: update writeback instrumentation for kernel 4.0+

Introduced by Linux kernel commit:

commit 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8
Author: Theodore Ts'o <tytso@mit.edu>
Date:   Mon Feb 2 00:37:00 2015 -0500

    vfs: add support for a lazytime mount option

And:

commit de1414a654e66b81b5348dbc5259ecf2fb61655e
Author: Christoph Hellwig <hch@lst.de>
Date:   Wed Jan 14 10:42:36 2015 +0100

    fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info

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

Fix: compaction mm_compaction_isolate_template update for Linux 4.0+

Updated by Linux commit:

commit b7aba6984dc048503b69c2a885098cdd430832bf
Author: Mel Gorman <mel@csn.ul.ie>
Date:   Thu Jan 13 15:45:54 2011 -0800

    mm: compaction: add trace events for memory compaction activity

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

Fix: kmem instrumentation update for mm_page_alloc_extfrag kernel 3.19.2+

This commit introduces an API change for mm_page_alloc_extfrag
instrumentation:

commit cdf476685b5c9dcd20f0305791bd60212cace25d
Author: Vlastimil Babka <vbabka@suse.cz>
Date:   Wed Feb 11 15:28:15 2015 -0800

    mm: when stealing freepages, also take pages created by splitting buddy page

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

Fix: kmem instrumentation: mm_page_alloc extfrag change_ownership field

Linux kernel 3.12.30 and onward changes the parameter received by this
callback. It's the same type, but the meaning differs. This is why it
did compile fine, but the data gathered did not really represent
change_ownership.

This change has been introduced in the Linux kernel by this commit:

commit 52c8f6a5aeb0bdd396849ecaa72d96f8175528f5
Author: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date:   Tue Nov 12 15:08:19 2013 -0800

    mm: get rid of unnecessary overhead of trace_mm_page_alloc_extfrag()

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

Version 2.6.0

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

Fix: missing parenthesis in offset_align_floor

Is currently unused. Triggers a compile error when used.

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

Fix: implement time.h wrapper for FD_ISSET

Kernels v3.4.0 to v3.4.7 still define FD_ISSET, but __FD_ISSET has been
removed. Therefore, we cannot use the FD_ISSET define to find out of we
need to use the new close_on_exec(). Implement a wrapper based on kernel
version detection instead.

Fixes #872

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

Fix: update sched instrumentation for 3.19+ kernels

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

Fix: update rcu instrumentation for 3.19+ kernels

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

Fix: update scsi instrumentation for 3.19+ kernels

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

Fix: update module instrumentation for 3.19+ kernels

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

Fix: Add f_dentry wrapper for 3.19+ kernels

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

Fix: introduce lttng_get_unused_fd() wrapper for 3.19 kernels

get_unused_fd disappears in 3.19 kernel, where get_unused_fd_flags(0)
should be used instead.

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

Fix: lttng_this_cpu_ptr wrapper for kernel 3.19+

Starting from kernel 3.19-rc1, __get_cpu_var() disappears, replaced by
this_cpu_ptr(). Introduce a wrapper using either depending on the kernel
version. Older kernels did not expose a this_cpu_ptr(), so keep on using
__get_cpu_var() on old kernels.

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

Fix: Update btrfs instrumentation for 3.18 Linux kernel

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

Fix compile error on kernel 3.0.101 with CONFIG_PERF_EVENTS

The context parameter of perf_event_create_kernel_counter() was introduced
with kernel 3.1.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Conditional compilation introduced by lttng-modules commit

  0007344741ef65259bc52dea72259173dfbf96c0

needs to be applied for kernels 3.12.30 and up in the 3.12.x branch.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Version 2.6.0-rc2

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

Fix: compaction instrumentation update for 3.14.x stable kernels

Conditional compilation introduced by lttng-modules commit

  0007344741ef65259bc52dea72259173dfbf96c0

needs to be applied to kernels 3.14.25 and up in the 3.14.x branch.

Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
Reported-by: Bjørn Forsman <bjorn.forsman@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: context alignment not properly handled

This issue affects only architectures without efficient unaligned
accesses, only when a context field with larger alignment follows a
context field with smaller alignment. It generates unreadable traces
when such context fields are enabled in this configuration.

Fixes #858

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

Fix compilation on Linux kernel >= 3.18.0

Since kernel commit 8a9522d2fe compilation fails as kvm_age_page
tracepoint had its signature changed, so update it accordingly.

Tested pointing to kernels:
    git reset --hard v3.17; make init/version.o
    git reset --hard v3.18-rc1; make init/version.o

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: build for architectures without HAVE_SYSCALL_TRACEPOINTS

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

Version 2.6.0-rc1

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

Expose lttng-modules ABI version ioctl

Check compatibility between lttng-modules and tools using a version
numbering specifically for the ABI, rather than relying on the major
version of lttng-modules per se. This takes into account that we
sometimes depend on lock-step updates of the toolchain, including tools
and modules.

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

Fix: syscall list ioctl number conflict

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

lttng-modules: fix build for non-x86

Since commit 644d6e9c2807041db2b4fd9c3350d4fa243060b1 "Remove sys_
prefix from syscall names" the build has been broken for non-x86
architectures.

Remove the sys_ prefix from syscall names and related macros as has
already been done for x86.

Correct "OVVERRIDE" typo in arm and powerpc headers while we're at it.

Successfully built against v3.17 for 32- and 64-bit mips and powerpc;
runtime tested on arm, verifying that mmap2, execve, and clone syscall
events are captured.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: syscall listing of session

Fixes syscall listing of sessions when no syscall has been enabled.

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