fix: block instrumentation: NULL pointer dereference

This backtrace appears with kernel 3.9.4:

[19311.313455] BUG: unable to handle kernel NULL pointer dereference at           (null)
[19311.316589] IP: [<ffffffffa076392b>] __event_probe__block_bio+0x8b/0x1a0 [lttng_probe_block]
[19311.316589] PGD 41808a067 PUD 4190a3067 PMD 0
[19311.316589] Oops: 0000 [#1] PREEMPT SMP
[19311.316589] Modules linked in: lttng_probe_writeback(O) lttng_probe_workqueue(O) lttng_probe_vmscan(O) lttng_probe_udp(O) lm
[19311.316589] CPU 4
[19311.316589] Pid: 1423, comm: kjournald Tainted: G           O 3.9.4-trace-test #143 Supermicro X7DAL/X7DAL
[19311.316589] RIP: 0010:[<ffffffffa076392b>]  [<ffffffffa076392b>] __event_probe__block_bio+0x8b/0x1a0 [lttng_probe_block]
[19311.316589] RSP: 0018:ffff88041c0d5aa8  EFLAGS: 00010246
[19311.316589] RAX: 0000000000000000 RBX: ffff88041a994c00 RCX: ffff88041b610800
[19311.316589] RDX: 0000000000000004 RSI: ffff88041c0d5b00 RDI: ffff88041c0d5ab0
[19311.316589] RBP: ffff88041c0d5b18 R08: fffffffffffc0000 R09: 0000000000000000
[19311.316589] R10: ffff88041a9947e8 R11: 0000000000000001 R12: ffff880419252c18
[19311.316589] R13: ffff88041c9e0a48 R14: ffff88041749bd10 R15: ffff88041749bd20
[19311.316589] FS:  0000000000000000(0000) GS:ffff88042fd00000(0000) knlGS:0000000000000000
[19311.316589] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[19311.316589] CR2: 0000000000000000 CR3: 0000000417a0a000 CR4: 00000000000007e0
[19311.316589] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[19311.316589] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[19311.316589] Process kjournald (pid: 1423, threadinfo ffff88041c0d4000, task ffff88041daa0000)
[19311.316589] Stack:
[19311.316589]  0000000000000000 ffff88041c3e4000 ffff880408987518 0000000000000024
[19311.316589]  0000000400000001 ffff88042fd19e30 000000000000002a 00000000000126c1
[19311.316589]  00000000000126bb 0000119043fa4efc ffff880400000000 0000000000000246
[19311.316589] Call Trace:
[19311.316589]  [<ffffffff812e79fb>] bio_attempt_back_merge+0xfb/0x1e0
[19311.316589]  [<ffffffff812ec96f>] blk_queue_bio+0x43f/0x570
[19311.316589]  [<ffffffff812ea68a>] generic_make_request+0xca/0x100
[19311.316589]  [<ffffffff81495bfe>] raid1_unplug+0x12e/0x170
[19311.316589]  [<ffffffff812ec36c>] blk_flush_plug_list+0x9c/0x210
[19311.316589]  [<ffffffff812ec4f8>] blk_finish_plug+0x18/0x50
[19311.316589]  [<ffffffff81243a48>] journal_commit_transaction+0x728/0x1f30
[19311.316589]  [<ffffffff8104e463>] ? try_to_del_timer_sync+0x53/0x70
[19311.316589]  [<ffffffff8104e485>] ? del_timer_sync+0x5/0xd0
[19311.316589]  [<ffffffff8124967d>] kjournald+0xed/0x290
[19311.316589]  [<ffffffff8106a270>] ? __init_waitqueue_head+0x60/0x60
[19311.316589]  [<ffffffff81249590>] ? commit_timeout+0x10/0x10
[19311.316589]  [<ffffffff810695fb>] kthread+0xdb/0xe0
[19311.316589]  [<ffffffff81672c60>] ? _raw_spin_unlock_irq+0x30/0x60
[19311.316589]  [<ffffffff81069520>] ? __init_kthread_worker+0x70/0x70
[19311.316589]  [<ffffffff8167af1c>] ret_from_fork+0x7c/0xb0
[19311.316589]  [<ffffffff81069520>] ? __init_kthread_worker+0x70/0x70

Fixes #559

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

Fix: 3.9.0 block layer instrumentation build

Linux upstream commit:

commit 0a82a8d132b26d438eb90b3ab35a7016e7227a1d
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu Apr 18 09:00:26 2013 -0700

    Revert "block: add missing block_bio_complete() tracepoint"

Requires us to revert in lttng-modules too.

Fixes #512

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

block: update instrumentation to 3.9 rc kernel

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

Backport block-related changes from "Update kernel probes to more detailed match to kernel versions"

This commit:

commit 7c68b363332170e4db100327ecc9e09b8a79cf29
Author: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Date:   Mon Dec 10 11:12:14 2012 -0500

    Update kernel probes to more detailed match to kernel versions

    Some ifdef's are added to kernel probes instrumentation to make them
    more close to original tracepoints in different kernel versions.
    Supported kernel version are from 2.6.32 to 3.7.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Contains block-layer related changes needed to push compatibility fixes
for newer kernels.

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

Fix: warning kvm_trace_exit_reason redefined for 3.9 kernel

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

Fix 3.8 kernel support: namespace lttng_is_signed_type()

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

lttng-module: sched.h: Fix compilation on 3.9 kernel

With commit 8bd75c77b7c6a3954140dd2e20346aef3efe4a35
included in 3.9-rc1 kernel, rt specific bits in "linux/sched.h"
were moved into new header file "linux/sched/rt.h".

Fixes this compilation error:
 CC [M]  /home/majo/lttng/lttng-modules/probes/lttng-probe-sched.o
...
/home/majo/lttng/lttng-modules/probes/../instrumentation/events/lttng-module
/../../../probes/../instrumentation/events/lttng-module/sched.h:
In function '__event_probe__sched_switch':
/home/majo/lttng/lttng-modules/probes/../instrumentation/events/lttng-module
/../../../probes/../instrumentation/events/lttng-module/sched.h:164:1:
error: 'MAX_RT_PRIO' undeclared (first use in this function)
...

Signed-off-by: Maxin B. John <maxin.john@enea.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: don't flush-final for offset 0 if reader is on sub-buffer

Triggers rare sub-buffer corruption when a buffer is completely full and
a final flush is then performed.

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

Version 2.1.1

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

Fix: statedump: missing locking, use lttng_iterate_fd

- Take a spinlock around use of dentry->d_name.name.
- Use lttng_iterate_fd wrapper (and thus iterate_fd() from Linux kernels
  from v3.7 and onward).

Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Implement lttng_iterate_fd wrapper

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

Fix check in lttng_strlen_user_inatomic

__copy_from_user_inatomic returns the number of bytes that could not be
copied, not an error code. This fixes the test accordingly.

[ Edit by Mathieu Desnoyers: change "ret" type to unsigned long too. ]

Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: statedump hang/too early completion due to logic error

The previous "Fix: statedump hang due to incorrect wait/wakeup use" was
not actually fixing the real problem.

The issue is that we should pass the expected condition to wait_event()
rather than its contrary.

This bug has been sitting there for a while. I suspect that a recent
change in the Linux scheduler behavior for newly spawned worker threads
might have contributed to trigger the hang more reliably.

The effects of this bugs are:
- possible hang of the lttng-sessiond (within the kernel) at tracing
  start,
- the statedump end event is traced before all worker threads have
  actually completed, which can confuse LTTng viewer state systems.

Reported-by: Phil Wilshire <sysdcs@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: statedump hang due to incorrect wait/wakeup use

Reported-by: Phil Wilshire <sysdcs@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Version 2.1.0

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

put_ulong calls in lib_ring_buffer_compat_ioctl() should be compat

I was noticing the that some of the put_ulong calls in
lib_ring_buffer_compat_ioctl() were not compat_put_ulong.  I can't
imagine this is correct.

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

wrapper/perf.h: Fix kernel version condition

The pid_t parameter of function perf_event_create_kernel_counter
was changed to task_struct pointer starting from 2.6.37.x.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix possible kernel build errors with linux-patches

Kernel sources of version 2.6.32 - 2.6.34 with applied patches
from linux-patches may fail to compile if tracepoint samples
are configured to build. Some part of backported commits
are added to the kernel patches to avoid those errors.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Add missing MIT license text to 3 files under this license

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

Check if interrupt action name is not null in statedump

Protection against poorly written drivers who give a null name to their
irq handlers.

Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix exec instrumentation: only for kernels 3.4.0 and higher

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

Add TRACE_EVENT(sched_process_exec) to sched.h

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

lib/ringbuffer/frontend_api.h: Include linux/prefetch.h.

prefetch() is used in this file so make sure we include the appropriate
header before using it.

Signed-off-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix warning with 3.6.0 kernel

No actual runtime impact, but neater anyway.

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

ABI with support for compat 32/64 bits

The current ABI does not work for compat 32/64 bits.
This patch moves the current ABI as old-abi and provides a new ABI in
which all the structures exchanged between user and kernel-space are
packed. Also this new ABI moves the "int overwrite" member of the
struct lttng_kernel_channel to remove the alignment added by the
compiler.

A patch for lttng-tools has been developed in parallel to this one to
support the new ABI. These 2 patches have been tested in all
possible configurations (applied or not) on 64-bit and 32-bit kernels
(with CONFIG_COMPAT) and a user-space in 32 and 64-bit.

Here are the results of the tests :
k 64 compat     | u 32 compat     | OK
k 64 compat     | u 64 compat     | OK
k 64 compat     | u 32 non-compat | KO
k 64 compat     | u 64 non-compat | OK

k 64 non-compat | u 64 compat     | OK
k 64 non-compat | u 32 compat     | KO
k 64 non-compat | u 64 non-compat | OK
k 64 non-compat | u 32 non-compat | KO

k 32 compat     | u compat        | OK
k 32 compat     | u non-compat    | OK

k 32 non-compat | u compat        | OK
k 32 non-compat | u non-compat    | OK

The results are as expected :
- on 32-bit user-space and kernel, every configuration works.
- on 64-bit user-space and kernel, every configuration works.
- with 32-bit user-space on a 64-bit kernel the only configuration
  where it works is when the compat patch is applied everywhere.

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

Perform calculation on bit size in 64-bit

allow 32-bit architectures to have sub-buffers larger than 256MB.

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

Use uint64_t for packet header content size and packet size

Allow packets larger than 256MB (4GB / 8 bits per byte).

Fixes #354

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

Fix: compat layer only on supported architectures

The compat_ulong_t type is only defined on some architectures, so we
need to protect the compat defines with the ifdef CONFIG_COMPAT.

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

Fix ring buffer 32/64 bits compat

The type of fields exchanged between kernel and userspace must be
compat_ulong_t instead of unsigned long in case of compat where
userspace is 32 bits and kernel is 64 bits.

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

Fix cleanup: move lttng-tracer-core.h include to lib ringbuffer config.h

This is where it is used. Add a #ifdef check for the LTTNG_TRACER_CORE_H
define to ensure that the header it depends on is always included.

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

Fix ring_buffer_frontend.c: missing include lttng-tracer-core.h

In lib/ringbuffer/ring_buffer_frontend.c, RING_BUFFER_ALIGN is undefined,
leading to no alignment offset being recorded after the call to
config->cb.record_header_size() in lib_ring_buffer_try_reserve_slow().

However, lttng-ring-buffer-client.h does define RING_BUFFER_ALIGN, so
the alignment offset will be produced when the packet header is written
in lttng_write_event_header().

This discrepancy may be observed on architectures that don't set
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, such as ARM, with a babeltrace
error such as:

babeltrace: ../../include/babeltrace/ctf/types.h:206: ctf_pos_get_event:
Assertion `pos->offset <= pos->content_size' failed.
Aborted

indicating that the actual content size differs from the calculated one
due to the difference in alignment.  Including the appropriate header
file in ring_buffer_frontend.c solves the problem.

Signed-off-by: Wade Farnsworth <wade_farnsworth@mentor.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: statedump missing check for NULL namespace

Cause kernel OOPS. statedump PID namespace support is newly introduced
in lttng-modules 2.1. Happens when iterating on a zombie process.

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

Update version to 2.1.0-rc1

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

fix timestamps on architectures without CONFIG_KTIME_SCALAR

trace_clock_monotonic_wrapper() should return a u64 representing the
number of nanoseconds since system startup.
ktime_get() provides that value directly within its .tv64 field only
on those architectures defining CONFIG_KTIME_SCALAR, whereas in all
other cases (e.g. PowerPC) a ktime_to_ns() conversion (which
translates back to .tv64 when CONFIG_KTIME_SCALAR is defined)
becomes necessary.

Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Support for linux kernels 2.6.32 through 2.6.37

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

Document limitation of vppid and ppid context wrt eventual RCU instrumentation

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

Cleanup: no need to hold RCU read-side lock when reading current nsproxy

As documented in include/linux/nsproxy.h.

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

Add env hostname information

Approximation in case of hostname change or in case of
contextualisation, but it does the job for 95% of use-cases.

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

Fix: lttng_statedump_process_state for each PID NS has infinite loop

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

lttng_statedump_process_state for each PID NS

When a process is in a namespace, its pid, tid and ppid are relative to
the namespace. Since namespaces can be nested, we need to know the
representation of each process in each namespace.

This patch changes the lttng_enumerate_task_fd to iterate over each
PID namespace of a process if any, that way we generate, in the
statedump, an entry for each process in each namespace it belongs.
To know the nesting level, the field "level" is added to the
lttng_statedump_process_state event, 0 being the top-level.
For processes running on the top-level namespace, the statedump
behaviour is unchanged (except the added "level" field).

For example (no nesting, just one level of namespace) :
lttng_statedump_process_state: {
        tid = 32185, vtid = 1, pid = 32185,
        vpid = 1, ppid = 32173, vppid = 0,
        level = 1, name = "init" }
lttng_statedump_process_state: {
        tid = 32185, vtid = 32185, pid = 32185,
        vpid = 32185, ppid = 32173, vppid = 32173,
        level = 0, name = "init" }

Confirmed that the process 32173 in the top-level namespace is indeed
the lxc-start command that created the container and its namespace.

[ Edit by Mathieu Desnoyers: Minor cleanups ]

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

Support the hostname context

This is particularly useful when tracing a machine with containers
(lxc), that way we can easily distinguish events generated inside
a container.

[ Edit by Mathieu Desnoyers: various fix. ]

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

Fix: statedump namespaced pid, tid and ppid

Use the target process namespace to lookup the value (pid, tid or ppid),
not the current task.

[ Edit by Mathieu Desnoyers: removed extra p->nsproxy check. Already
  performed within rcu read-side critical section. ]

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

Fix: statedump: disable vm maps enumeration

We need the tasklist lock to correctly dump these, which is unavailable
to modules. Disable this feature for now.

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

Fix: ensure userspace accesses are done with _inatomic

Otherwise, triggers scheduling while atomic (might_sleep()) warnings,
since we call those from a tracepoint probe (with preemption disabled).

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

Fix: vppid context should test for current nsproxy

Triggers a NULL pointer exception with tracing scheduling events with
vppid context activated.

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

Add MIPS system call support

[ Edit by Mathieu: currently missing: update of arch-independent headers
  to include the MIPS headers to complete system call support. ]

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Change mode of lttng-syscalls-generate-headers.sh to 755

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

cleanup: fix typo in syscall instrumentation header

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Cleanup: remove trailing whitespace in README

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

trace event: introduce TP_MODULE_NOAUTOLOAD and TP_MODULE_NOINIT

In preparation for introducing uevent tracing. (user-space events)

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

LTTng: probe-statedump: add #include <linux/sched.h>

This fixes the following build error on ARM;

  CC [M]  drivers/staging/lttng/probes/lttng-probe-statedump.o
In file included from drivers/staging/lttng/probes/../instrumentation/events/lttng-module/../../../probes/lttng-events.h:221:0,
                 from drivers/staging/lttng/probes/../instrumentation/events/lttng-module/../../../probes/define_trace.h:117,
                 from drivers/staging/lttng/probes/../instrumentation/events/lttng-module/lttng-statedump.h:162,
                 from drivers/staging/lttng/probes/lttng-probe-statedump.c:41:
drivers/staging/lttng/probes/../instrumentation/events/lttng-module/../../../probes/../instrumentation/events/lttng-module/lttng-statedump.h:29:1: error: 'TASK_COMM_LEN' undeclared here (not in a function)

Signed-off-by: UCHINO Satoshi <satoshi.uchino@toshiba.co.jp>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: signal_generate event should print utf8 for comm field

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

Makes write operation a parameter for tp_memcpy macro

Memcpy source can be either user-space or kernel-space. To avoid code
duplication, this patch makes the operation a parameter to the macros.
Available macros are thus:

* tp_memcpy:               kernel-space array copy
* tp_memcpy_from_user:     user-space array copy
* tp_memcpy_dyn:           kernel-space sequence copy
* tp_memcpy_dyn_from_user: user-space sequence copy

Those are TP_fast_assign macros that can be used with __dynamic_array
macros in TP_STRUCT__entry in a TRACE_EVENT.

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

Add coding style document

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

Update instrumentation/events README file

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

Add makefile target for preprocessor

By specifying .i target, it runs gcc preprocessor for that file.
Example:

  make myfile.i

will read myfile.c and output preprocessor to myfile.i

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

Fix: free_event_id check should compare unsigned int with -1U

Otherwise, on 32-bit:

lttng-modules/lttng-events.c:295: warning: comparison is always false due
to limited range of data type

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: update signal instrumentation for 3.4 kernel

Fix #226

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

LTTng Modules ARM syscall instrumentation

This patch adds detailed instrumentation for ARM system calls, based on
a 2.6.38 kernel.

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

Fix: generate header missing echo -e for escape chars

"why is the -e needed ? What was the experienced oddness ?"

   The \n wasn't getting evaluated to a newline and was being inserted
into the header file as '\n'

   From man echo(1):

       If -e is in effect, the following sequences are recognized:

       \\     backslash

       \a     alert (BEL)

       \b     backspace

       \c     produce no further output

       \e     escape

       \f     form feed

       \n     new line

       \r     carriage return

       \t     horizontal tab

       \v     vertical tab

Suggested-by: Ryan Kyser <Ryan.Kyser@jci.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: add missing uaccess.h include (for ARM)

"What required uaccess.h ?"

   I was getting the following error:
   syscalls_pointers_override.h:6:1: error: implicit declaration of function ?strlen_user?

   I found that strlen_user was defined in asm/uaccess.h, which is
included by linux/uaccess.h.

Suggested-by: Ryan Kyser <Ryan.Kyser@jci.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

README: Document that CONFIG_MODULES is required

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

Fix: README typo

Reported-by: Ryan Kyser <Ryan.Kyser@jci.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: document required and optional kernel config options in README

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

Update version to 2.0.1

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

Fix: is_compat_task !CONFIG_COMPAT compile error on kernels >= 3.3

The Linux kernel already defines a is_compat_task()   (0) when
!CONFIG_COMPAT since kernel 3.3, so if we see it is already defined,
don't redefine it.

Closes #195

Reported-by: David Goulet <dgoulet@efficios.com>
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>

Update version to 2.0.0-rc4

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

Update README and add version name place-holder

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 clock offset 32-bit multiplication overflow

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

Fix : wrong assign of fd in state dump

lttng_statedump_file_descriptor was using the tgid instead of the fd for
the fd field.

Reported-by: Mathieu Bain <mathieu.bain@polymtl.ca>
Signed-off-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

License cleanup, ifdef namespace cleanup

- Spell out the LGPL license completely in each file.
- Change LINUX_* ifdefs for LIB_* in lib/ringbuffer header.

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

Fix: ensure power of 2 check handles 64-bit size_t entirely

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>

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 dmesg console.

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

Fix: use transport name as channel name

Clarify dmesg printout.

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

Fix: Return -EINVAL instead of print warning if non power of 2 size/num_subbuf

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

Update Version to 2.0.0-rc1

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

Standardize version across toolchain

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

statedump: Use old macro name for kernel 2.6.38

Signed-off-by: Juha Niskanen <juniskane@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Update ChangeLog to 2.0-pre15

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

Add timer instrumentation

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

fix: need to undef mainline define

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

fix: Include signal.h instead of irq.h for prototype match check

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

Add signal instrumentation

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

Update ChangeLog to 2.0-pre14

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

syscall tracing: sys_getcpu

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

Add sys_clone x86 instrumentation

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

statedump: fix include circular dep

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

Implement state dump

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

Update Changelog to 2.0-pre13

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

Update README

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

environment: write sysname, release, version, domain to metadata

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

Allow open /proc/lttng for read & write

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

Update Changelog to 2.0-pre12

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

Add x86 32/64 execve syscall instrumentation override

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

Remove unused defines

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

Add padding to ABI

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