fix: workqueue: Fix type of cpu in trace event (v5.19)

See upstream commit :

  commit 873a400938b31a1e443c4d94b560b78300787540
  Author: Wonhyuk Yang <vvghjk1234@gmail.com>
  Date:   Wed May 4 11:32:03 2022 +0900

    workqueue: Fix type of cpu in trace event

    The trace event "workqueue_queue_work" use unsigned int type for
    req_cpu, cpu. This casue confusing cpu number like below log.

    $ cat /sys/kernel/debug/tracing/trace
    cat-317  [001] ...: workqueue_queue_work: ... req_cpu=8192 cpu=4294967295

    So, change unsigned type to signed type in the trace event. After
    applying this patch, cpu number will be printed as -1 instead of
    4294967295 as folllows.

    $ cat /sys/kernel/debug/tracing/trace
    cat-1338  [002] ...: workqueue_queue_work: ... req_cpu=8192 cpu=-1

Change-Id: I478083c350b6ec314d87e9159dc5b342b96daed7
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: fs: Remove flags parameter from aops->write_begin (v5.19)

See upstream commit :

  commit 9d6b0cd7579844761ed68926eb3073bab1dca87b
  Author: Matthew Wilcox (Oracle) <willy@infradead.org>
  Date:   Tue Feb 22 14:31:43 2022 -0500

    fs: Remove flags parameter from aops->write_begin

    There are no more aop flags left, so remove the parameter.

Change-Id: I82725b93e13d749f52a631b2ac60df81a5e839f8
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: mm/page_alloc: fix tracepoint mm_page_alloc_zone_locked() (v5.19)

See upstream commit :

  commit 10e0f7530205799e7e971aba699a7cb3a47456de
  Author: Wonhyuk Yang <vvghjk1234@gmail.com>
  Date:   Thu May 19 14:08:54 2022 -0700

    mm/page_alloc: fix tracepoint mm_page_alloc_zone_locked()

    Currently, trace point mm_page_alloc_zone_locked() doesn't show correct
    information.

    First, when alloc_flag has ALLOC_HARDER/ALLOC_CMA, page can be allocated
    from MIGRATE_HIGHATOMIC/MIGRATE_CMA.  Nevertheless, tracepoint use
    requested migration type not MIGRATE_HIGHATOMIC and MIGRATE_CMA.

    Second, after commit 44042b4498728 ("mm/page_alloc: allow high-order pages
    to be stored on the per-cpu lists") percpu-list can store high order
    pages.  But trace point determine whether it is a refiil of percpu-list by
    comparing requested order and 0.

    To handle these problems, make mm_page_alloc_zone_locked() only be called
    by __rmqueue_smallest with correct migration type.  With a new argument
    called percpu_refill, it can show roughly whether it is a refill of
    percpu-list.

Change-Id: I2e4a57393757f12b9c5a4566c4d1102ee2474a09
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Version 2.13.4

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I37d9d03bfc0bae7c271ce3956e71919c4e2fb6e7

Fix: event notifier: racy use of last subbuffer record

The lttng-modules event notifiers use the ring buffer internally. When
reading the payload of the last event in a sub-buffer with a multi-part
read (e.g. two read system calls), we should not "put" the sub-buffer
holding this data, else continuing reading the data in the following
read system call can observe corrupted data if it has been concurrently
overwritten by the producer.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Idb051e50ee8a25958cfd63a9b143f4943ca2e01a

Fix: bytecode interpreter context_get_index() leaves byte order uninitialized

Observed Issue
==============

When using the event notification capture feature to capture a context
field, e.g. '$ctx.cpu_id', the captured value is often observed in
reverse byte order.

Cause
=====

Within the bytecode interpreter, context_get_index() leaves the "rev_bo"
field uninitialized in the top of stack.

This only affects the event notification capture bytecode because the
BYTECODE_OP_GET_SYMBOL bytecode instruction (as of lttng-tools 2.13)
is only generated for capture bytecode in lttng-tools. Therefore, only
capture bytecode targeting contexts are affected by this issue. The
reason why lttng-tools uses the "legacy" bytecode instruction to get
context (BYTECODE_OP_GET_CONTEXT_REF) for the filter bytecode is to
preserve backward compatibility of filtering when interacting with
applications linked against LTTng-UST 2.12.

Solution
========

Initialize the rev_bo field based on the context field type
reserve_byte_order field.

Known drawbacks
===============

None.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I1483642b0b8f6bc28d5b68be170a04fb419fd9b3

fix: 'random' tracepoints removed in stable kernels

The upstream commit 14c174633f349cb41ea90c2c0aaddac157012f74 removing
the 'random' tracepoints is being backported to multiple stable kernel
branches, I don't see how that qualifies as a fix but here we are.

Use the presence of 'include/trace/events/random.h' in the kernel source
tree instead of the rather tortuous version check to determine if we
need to build 'lttng-probe-random.ko'.

Change-Id: I8f5f2f4c9e09c61127c49c7949b22dd3fab0460d
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: random: remove unused tracepoints (v5.10, v5.15)

The following kernel commit has been back ported to v5.10.119 and v5.15.44.

commit 14c174633f349cb41ea90c2c0aaddac157012f74
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date:   Thu Feb 10 16:40:44 2022 +0100

  random: remove unused tracepoints

  These explicit tracepoints aren't really used and show sign of aging.
  It's work to keep these up to date, and before I attempted to keep them
  up to date, they weren't up to date, which indicates that they're not
  really used. These days there are better ways of introspecting anyway.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I0b7eb8aa78b5bd2039e20ae3e1da4c5eb9018789

fix: sched/tracing: Append prev_state to tp args instead (v5.18)

See upstream commit :

  commit 9c2136be0878c88c53dea26943ce40bb03ad8d8d
  Author: Delyan Kratunov <delyank@fb.com>
  Date:   Wed May 11 18:28:36 2022 +0000

    sched/tracing: Append prev_state to tp args instead

    Commit fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting
    sched_switch event, 2022-01-20) added a new prev_state argument to the
    sched_switch tracepoint, before the prev task_struct pointer.

    This reordering of arguments broke BPF programs that use the raw
    tracepoint (e.g. tp_btf programs). The type of the second argument has
    changed and existing programs that assume a task_struct* argument
    (e.g. for bpf_task_storage access) will now fail to verify.

    If we instead append the new argument to the end, all existing programs
    would continue to work and can conditionally extract the prev_state
    argument on supported kernel versions.

Change-Id: Ife2ec88a8bea2743562590cbd357068d7773863f
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: mm: compaction: cleanup the compaction trace events (v5.18)

See upstream commit :

  commit abd4349ff9b8d242376b67711254221f64f447c7
  Author: Baolin Wang <baolin.wang@linux.alibaba.com>
  Date:   Tue Mar 22 14:45:56 2022 -0700

    mm: compaction: cleanup the compaction trace events

    As Steven suggested [1], we should access the pointers from the trace
    event to avoid dereferencing them to the tracepoint function when the
    tracepoint is disabled.

    [1] https://lkml.org/lkml/2021/11/3/409

Change-Id: I6c08250df8596e8dbc76780ae5d95c899c12e6fe
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: scsi: core: Remove <scsi/scsi_request.h> (v5.18)

See upstream commit :

  commit 26440303310591e29121964ede0048583cb3126d
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Thu Feb 24 18:55:52 2022 +0100

    scsi: core: Remove <scsi/scsi_request.h>

    This header is empty now except for an include of <linux/blk-mq.h>, so
    remove it.

Change-Id: Ic8ee3352f1e8bddfcd44c31be9b788db82f183aa
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: kprobes: Use rethook for kretprobe if possible (v5.18)

See upstream commit :

  commit 73f9b911faa74ac5107879de05c9489c419f41bb
  Author: Masami Hiramatsu <mhiramat@kernel.org>
  Date:   Sat Mar 26 11:27:05 2022 +0900

    kprobes: Use rethook for kretprobe if possible

    Use rethook for kretprobe function return hooking if the arch sets
    CONFIG_HAVE_RETHOOK=y. In this case, CONFIG_KRETPROBE_ON_RETHOOK is
    set to 'y' automatically, and the kretprobe internal data fields
    switches to use rethook. If not, it continues to use kretprobe
    specific function return hooks.

Change-Id: I2b7670dc04e4769c1e3c372582ad2f555f6d7a66
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: random: remove unused tracepoints (v5.18)

See upstream commit :

  commit 14c174633f349cb41ea90c2c0aaddac157012f74
  Author: Jason A. Donenfeld <Jason@zx2c4.com>
  Date:   Thu Feb 10 16:40:44 2022 +0100

    random: remove unused tracepoints

    These explicit tracepoints aren't really used and show sign of aging.
    It's work to keep these up to date, and before I attempted to keep them
    up to date, they weren't up to date, which indicates that they're not
    really used. These days there are better ways of introspecting anyway.

Change-Id: I3b8c3e2732e7efdd76ce63204ac53a48784d0df6
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: scsi: block: Remove REQ_OP_WRITE_SAME support (v5.18)

See upstream commit :

  commit 73bd66d9c834220579c881a3eb020fd8917075d8
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Wed Feb 9 09:28:28 2022 +0100

    scsi: block: Remove REQ_OP_WRITE_SAME support

    No more users of REQ_OP_WRITE_SAME or drivers implementing it are left,
    so remove the infrastructure.

Change-Id: Ifbff71f79f8b590436fc7cb79f82d90c6e033d84
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: block: remove genhd.h (v5.18)

See upstream commit :

  commit 322cbb50de711814c42fb088f6d31901502c711a
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Mon Jan 24 10:39:13 2022 +0100

    block: remove genhd.h

    There is no good reason to keep genhd.h separate from the main blkdev.h
    header that includes it.  So fold the contents of genhd.h into blkdev.h
    and remove genhd.h entirely.

Change-Id: I7cf2aaa3a4c133320b95f2edde49f790f9515dbd
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: sched/tracing: Don't re-read p->state when emitting sched_switch event (v5.18)

See upstream commit :

  commit fa2c3254d7cfff5f7a916ab928a562d1165f17bb
  Author: Valentin Schneider <valentin.schneider@arm.com>
  Date:   Thu Jan 20 16:25:19 2022 +0000

    sched/tracing: Don't re-read p->state when emitting sched_switch event

    As of commit

      c6e7bd7afaeb ("sched/core: Optimize ttwu() spinning on p->on_cpu")

    the following sequence becomes possible:

                          p->__state = TASK_INTERRUPTIBLE;
                          __schedule()
                            deactivate_task(p);
      ttwu()
        READ !p->on_rq
        p->__state=TASK_WAKING
                            trace_sched_switch()
                              __trace_sched_switch_state()
                                task_state_index()
                                  return 0;

    TASK_WAKING isn't in TASK_REPORT, so the task appears as TASK_RUNNING in
    the trace event.

    Prevent this by pushing the value read from __schedule() down the trace
    event.

Change-Id: I46743cd006be4b4d573cae2d77df7d6d16744d04
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: KVM: x86: Unexport kvm_x86_ops (v5.18)

See upstream commit :

  commit dfc4e6ca041135217c07ebcd102b6694cea22856
  Author: Sean Christopherson <seanjc@google.com>
  Date:   Fri Jan 28 00:51:56 2022 +0000

    KVM: x86: Unexport kvm_x86_ops

    Drop the export of kvm_x86_ops now it is no longer referenced by SVM or
    VMX.  Disallowing access to kvm_x86_ops is very desirable as it prevents
    vendor code from incorrectly modifying hooks after they have been set by
    kvm_arch_hardware_setup(), and more importantly after each function's
    associated static_call key has been updated.

    No functional change intended.

Change-Id: Icee959a984570f95ab9b71354225b5aeecea7da0
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: do not warn on unknown counter ioctl

It is perfectly valid for a newer lttng-tools to try to use an unknown
ioctl and handle -ENOSYS.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ia9f6472ca1196f983eee1327805b0ad69d028a98

Fix: tracepoint event: allow same provider and event name

Using the same name for the provider (TRACE_SYSTEM) and event name
causes a compilation error because the same identifiers are emitted
twice.

Fix this by prefixing the provider identifier with
"__provider_event_desc___".

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I8cdf8f859e35b8bd5c19737860d12f1ed546dfc2

Fix: compaction migratepages event name

The commit "fix: mm: compaction: fix the migration stats in trace_mm_compaction_migratepages() (v5.17)"

Triggers this warning:

    LTTng: event provider mismatch: The event name needs to start with provider name + _ + one or more letter, provider: compaction, event name: mm_compaction_migratepages

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I01c7485af765084dafb33bf33ae392e60bfbf1e7

Version 2.13.3

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ief0169c89e54c719907186e654d314d65a527098

Document expected ISO8601 time formats in ABI header

Document the expected ISO8601 time formats in the ABI header to justify
the choice of string maximum length.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I4dedde83b5fb81c376245338773ea63677401a09

Fix: lttng ABI: lttng_counter_ioctl() tainted scalar

Found by Coverity:

>>>     CID 1476250:    (TAINTED_SCALAR)
>>>     Using tainted variable "local_counter_aggregate.index.number_dimensions" as a loop boundary.

>>>     CID 1476250:    (TAINTED_SCALAR)
>>>     Using tainted variable "local_counter_clear.index.number_dimensions" as a loop boundary.

>>>     CID 1476250:    (TAINTED_SCALAR)
>>>     Using tainted variable "local_counter_read.index.number_dimensions" as a loop boundary.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I7d35cf96781bb18837fe4564e4e8a34aa2ddc310

Fix: sample discarded events count before reserve

Sampling the discarded events count in the buffer_end callback is done
out of order, and may therefore include increments performed by following
events (in following packets) if the thread doing the end-of-packet
event write is interrupted for a long time.

Sampling the event discarded counts before reserving space for the last
event in a packet, and keeping this as part of the private ring buffer
context, should fix this race.

In lttng-modules, this scenario would only happen if an interrupt
handler produces many events, when nested over an event between its
reserve and commit. Note that if lttng-modules supports faultable
tracepoints in the future, this may become more easy to trigger due to
preemption.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I696a206b3926fc1abbee35caa9af65461ff56c68

Cleanup: comment alignment in ring buffer config.h

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I38fdfd786dfb60e1339634780be2645968351ed8

Version 2.13.2

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I8796907b413e09d417a1d087da5e4bdaf2a2bbf3

Fix: incorrect in/out direction for syscall exit

Syscall exit should fetch the "sc_out" parameters. This issue was
introduced by commit e42c4f49c15b ("Split syscall tracepoint generation in their own files").

Fixes: e42c4f49c15b ("Split syscall tracepoint generation in their own files")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ib34912005323ea34b6d11ca9acc5edf491649cdd

fix: net: socket: rename SKB_DROP_REASON_SOCKET_FILTER (v5.17)

No version check needed since this change is between two RCs, see
upstream commit :

  commit 364df53c081d93fcfd6b91085ff2650c7f17b3c7
  Author: Menglong Dong <imagedong@tencent.com>
  Date:   Thu Jan 27 17:13:01 2022 +0800

    net: socket: rename SKB_DROP_REASON_SOCKET_FILTER

    Rename SKB_DROP_REASON_SOCKET_FILTER, which is used
    as the reason of skb drop out of socket filter before
    it's part of a released kernel. It will be used for
    more protocols than just TCP in future series.

Link: https://lore.kernel.org/all/20220127091308.91401-2-imagedong@tencent.com/
Change-Id: I666461a5b541fe9e0bf53ad996ce33237af4bfbb
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: net: skb: introduce kfree_skb_reason() (v5.17)

See upstream commit :

  commit c504e5c2f9648a1e5c2be01e8c3f59d394192bd3
  Author: Menglong Dong <imagedong@tencent.com>
  Date:   Sun Jan 9 14:36:26 2022 +0800

    net: skb: introduce kfree_skb_reason()

    Introduce the interface kfree_skb_reason(), which is able to pass
    the reason why the skb is dropped to 'kfree_skb' tracepoint.

    Add the 'reason' field to 'trace_kfree_skb', therefor user can get
    more detail information about abnormal skb with 'drop_monitor' or
    eBPF.

    All drop reasons are defined in the enum 'skb_drop_reason', and
    they will be print as string in 'kfree_skb' tracepoint in format
    of 'reason: XXX'.

    ( Maybe the reasons should be defined in a uapi header file, so that
    user space can use them? )

Change-Id: I6766678a288da959498a4736fc3f95bf239c3e94
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: random: rather than entropy_store abstraction, use global (v5.17)

See upstream commit :

  commit 90ed1e67e896cc8040a523f8428fc02f9b164394
  Author: Jason A. Donenfeld <Jason@zx2c4.com>
  Date:   Wed Jan 12 17:18:08 2022 +0100

    random: rather than entropy_store abstraction, use global

    Originally, the RNG used several pools, so having things abstracted out
    over a generic entropy_store object made sense. These days, there's only
    one input pool, and then an uneven mix of usage via the abstraction and
    usage via &input_pool. Rather than this uneasy mixture, just get rid of
    the abstraction entirely and have things always use the global. This
    simplifies the code and makes reading it a bit easier.

Change-Id: I1a2a14d7b6e69a047804e1e91e00fe002f757431
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: btrfs: pass fs_info to trace_btrfs_transaction_commit (v5.17)

See upstream commit :

  commit 2e4e97abac4c95f8b87b2912ea013f7836a6f10b
  Author: Josef Bacik <josef@toxicpanda.com>
  Date:   Fri Nov 5 16:45:29 2021 -0400

    btrfs: pass fs_info to trace_btrfs_transaction_commit

    The root on the trans->root can be anything, and generally we're
    committing from the transaction kthread so it's usually the tree_root.
    Change this to just take an fs_info, and to maintain compatibility
    simply put the ROOT_TREE_OBJECTID as the root objectid for the
    tracepoint.  This will allow use to remove trans->root.

Change-Id: Ie5a4804330edabffac0714fcb9c25b8c8599e424
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: mm: compaction: fix the migration stats in trace_mm_compaction_migratepages() (v5.17)

See upstream commit :

  commit 84b328aa81216e08804d8875d63f26bda1298788
  Author: Baolin Wang <baolin.wang@linux.alibaba.com>
  Date:   Fri Jan 14 14:08:40 2022 -0800

    mm: compaction: fix the migration stats in trace_mm_compaction_migratepages()

    Now the migrate_pages() has changed to return the number of {normal
    page, THP, hugetlb} instead, thus we should not use the return value to
    calculate the number of pages migrated successfully.  Instead we can
    just use the 'nr_succeeded' which indicates the number of normal pages
    migrated successfully to calculate the non-migrated pages in
    trace_mm_compaction_migratepages().

Link: https://lkml.kernel.org/r/b4225251c4bec068dcd90d275ab7de88a39e2bd7.1636275127.git.baolin.wang@linux.alibaba.com
Change-Id: Ib8e8f2a16a273f16cd73fe63afbbfc25c0a2540c
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: block: remove the ->rq_disk field in struct request (v5.17)

See upstream commit :

  commit f3fa33acca9f0058157214800f68b10d8e71ab7a
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Fri Nov 26 13:18:00 2021 +0100

    block: remove the ->rq_disk field in struct request

    Just use the disk attached to the request_queue instead.

Link: https://lore.kernel.org/r/20211126121802.2090656-4-hch@lst.de
Change-Id: I24263be519d1b51f4b00bd95f14a9aeb8457889a
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: block: remove GENHD_FL_SUPPRESS_PARTITION_INFO (v5.17)

See upstream commit :

  commit 3b5149ac50970669ee0ddb9629ec77ffd5c0622d
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Mon Nov 22 14:06:21 2021 +0100

    block: remove GENHD_FL_SUPPRESS_PARTITION_INFO

    This flag is not set directly anywhere and only inherited from
    GENHD_FL_HIDDEN.  Just check for GENHD_FL_HIDDEN instead.

Link: https://lore.kernel.org/r/20211122130625.1136848-11-hch@lst.de
Change-Id: Ide92bdaaff7d16e96be23aaf00cebeaa601235b7
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Copyright ownership transfer

Apply copyright ownership transfer from Julien Desfossez to EfficiOS Inc.

Link: https://lists.lttng.org/pipermail/lttng-dev/2022-January/030092.html
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Julien Desfossez <ju@klipix.org>
Signed-off-by: Julien Desfossez <ju@klipix.org>
Change-Id: Ida168b1fbe6589cb371a549ef14d9b4b28b221b3

Version 2.13.1

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I96afc0704a05f50e8478eca11977d7435c8db533

fix: mm: move kvmalloc-related functions to slab.h (v5.16)

See upstream commit :

  commit 8587ca6f34152ea650bad4b2db68456601159024
  Author: Matthew Wilcox (Oracle) <willy@infradead.org>
  Date:   Fri Nov 5 13:35:07 2021 -0700

    mm: move kvmalloc-related functions to slab.h

    Not all files in the kernel should include mm.h.  Migrating callers from
    kmalloc to kvmalloc is easier if the kvmalloc functions are in slab.h.

    [akpm@linux-foundation.org: move the new kvrealloc() also]
    [akpm@linux-foundation.org: drivers/hwmon/occ/p9_sbe.c needs slab.h]

Link: https://lkml.kernel.org/r/20210622215757.3525604-1-willy@infradead.org
Change-Id: I84e885ffbd1e2ff551a4738950e0c9462551b853
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: block: don't call blk_status_to_errno in blk_update_request (v5.16)

See upstream commit :

  commit 8a7d267b4a2c71a5ff5dd9046abea7117c7d0ac2
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Mon Oct 18 10:45:18 2021 +0200

    block: don't call blk_status_to_errno in blk_update_request

    We only need to call it to resolve the blk_status_t -> errno mapping for
    tracing, so move the conversion into the tracepoints that are not called
    at all when tracing isn't enabled.

Change-Id: Ic556cee1d82e44a93a1467f55d45b6e17a48d387
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: KVM: MMU: change tracepoints arguments to kvm_page_fault (v5.16)

See upstream commit :

  commit f0066d94c92dc5cf7f1a272a1bd324b0fc575292
  Author: Paolo Bonzini <pbonzini@redhat.com>
  Date:   Fri Aug 6 04:35:50 2021 -0400

    KVM: MMU: change tracepoints arguments to kvm_page_fault

    Pass struct kvm_page_fault to tracepoints instead of extracting the
    arguments from the struct.  This also lets the kvm_mmu_spte_requested
    tracepoint pick the gfn directly from fault->gfn, instead of using
    the address.

Change-Id: I5ee3f344a8d1cd0ed185cdeecb3a3121183c9b43
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info (v5.16)

See upstream commit :

  commit 0a62a0319abb92c89a4f91c2dbfcaee4e47f37ca
  Author: David Edmondson <david.edmondson@oracle.com>
  Date:   Mon Sep 20 11:37:35 2021 +0100

    KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info

    Extend the get_exit_info static call to provide the reason for the VM
    exit. Modify relevant trace points to use this rather than extracting
    the reason in the caller.

Change-Id: I28903e658eb7cbfc6666e35ba4cffba5e49d1445
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: isystem: delete global -isystem compile option (v5.16)

See upstream commit :

  commit 04e85bbf71c9072dcf0ad9a7150495d72461105c
  Author: Alexey Dobriyan <adobriyan@gmail.com>
  Date:   Mon Aug 2 23:43:15 2021 +0300

    isystem: delete global -isystem compile option

    Further isolate kernel from userspace, prevent accidental inclusion of
    undesireable headers, mainly float.h and stdatomic.h.

    nds32 keeps -isystem globally due to intrinsics used in entrenched header.

    -isystem is selectively reenabled for some files, again, for intrinsics.

Change-Id: I5bea29687dc2bc15e96eeb13008aefe1acc97b8a
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: block: move block-related definitions out of fs.h (v5.16)

See upstream commit :

  commit 3f1266f1f82d7b8c72472a8921e80aa3e611fb62
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Sat Jun 20 09:16:41 2020 +0200

    block: move block-related definitions out of fs.h

    Move most of the block related definition out of fs.h into more suitable
    headers.

Change-Id: I8d072406a04f549d1ddb0f2ac392deaabbb26a92
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Fix: syscall tracing: missing trigger actions

Observed issue
==============

There is an issue when associating multiple actions to a single system
call, where the first action is effectively added, but the following
actions are silently ignored.

Cause
=====

The is caused by event creation of the 2nd event to be skipped because
lttng_syscall_filter_enable returns "-EBUSY", because the bit is already
set in the bitmap.

Solution
========

Fixing this double-add-trigger scenario requires changes to how the
lttng_syscall_filter_enable -EBUSY errors are dealt with on event
creation, but the problem runs deeper.

Given that many events may be responsible for requiring a bit to be set
in the bitmap of the syscall filter, we cannot simply clear the bit
whenever one event is disabled

Otherwise, this will cause situations where all events for a given
system call are disabled (due to the syscall filter bit being cleared)
whenever one single event for that system call is disabled (e.g. 2
triggers on the same system call, but with different actions).

We need to keep track of all events associated with this bit in the
bitmap, and only clear the bit when the reference count reaches 0.
This fixes the double-add-trigger issue by enturing that no -EBUSY
is returned when creating the second event, and fixes the
double-add-trigger-then-remove-trigger scenario as well.

Known drawbacks
===============

None.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3c1e966e9720a2e8f4438ae2c98d83ffe318e424

Warn on event registration/unregistration failure

Warn whenever event registration/unregistration fails, including when
synchonizing the event list.

Silently ignoring errors makes identification of those failures tricky.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I764455c8535ddb906325942e70aa689ca21c04bb

fix: implicit-int error in EXPORT_SYMBOL_GPL

Add module header to fix error:
error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL'
[-Werror=implicit-int]

Log:
/workdir/build/workspace/sources/lttng-modules/src/wrapper/random.c:54:1:
warning: data definition has no type or storage class
   54 EXPORT_SYMBOL_GPL(wrapper_get_bootid);
      ^~~~~~~~~~~~~~~~~
/workdir/build/workspace/sources/lttng-modules/src/wrapper/random.c:54:1:
error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL'
[-Werror=implicit-int]
/workdir/build/workspace/sources/lttng-modules/src/wrapper/random.c:54:1:
warning: parameter names (without types) in function declaration
cc1: some warnings being treated as errors
make[3]: ***
[/workdir/build/tmp/work-shared/qt5222/kernel-source/scripts/Makefile.build:271:
/workdir/build/workspace/sources/lttng-modules/src/wrapper/random.o]

Signed-off-by: Daniel Gomez <daniel@qtec.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: If1b96f6fcc19988b94dc09b12d071f2c61491b83

fix: Revert "Makefile: Enable -Wimplicit-fallthrough for Clang" (v5.15)

Starting with v5.15, "-Wimplicit-fallthrough=5" was added to the build
flags which requires the use of "__attribute__((__fallthrough__))" to
annotate fallthrough case statements.

See upstream commit by the man himself:

  commit d936eb23874433caa3e3d841cfa16f5434b85dcf
  Author: Linus Torvalds <torvalds@linux-foundation.org>
  Date:   Thu Jul 15 18:05:31 2021 -0700

    Revert "Makefile: Enable -Wimplicit-fallthrough for Clang"

    This reverts commit b7eb335e26a9c7f258c96b3962c283c379d3ede0.

    It turns out that the problem with the clang -Wimplicit-fallthrough
    warning is not about the kernel source code, but about clang itself, and
    that the warning is unusable until clang fixes its broken ways.

    In particular, when you enable this warning for clang, you not only get
    warnings about implicit fallthroughs.  You also get this:

       warning: fallthrough annotation in unreachable code [-Wimplicit-fallthrough]

    which is completely broken becasue it

     (a) doesn't even tell you where the problem is (seriously: no line
         numbers, no filename, no nothing).

     (b) is fundamentally broken anyway, because there are perfectly valid
         reasons to have a fallthrough statement even if it turns out that
         it can perhaps not be reached.

    In the kernel, an example of that second case is code in the scheduler:

                    switch (state) {
                    case cpuset:
                            if (IS_ENABLED(CONFIG_CPUSETS)) {
                                    cpuset_cpus_allowed_fallback(p);
                                    state = possible;
                                    break;
                            }
                            fallthrough;
                    case possible:

    where if CONFIG_CPUSETS is enabled you actually never hit the
    fallthrough case at all.  But that in no way makes the fallthrough
    wrong.

    So the warning is completely broken, and enabling it for clang is a very
    bad idea.

    In the meantime, we can keep the gcc option enabled, and make the gcc
    build use

        -Wimplicit-fallthrough=5

    which means that we will at least continue to require a proper
    fallthrough statement, and that gcc won't silently accept the magic
    comment versions. Because gcc does this all correctly, and while the odd
    "=5" part is kind of obscure, it's documented in [1]:

      "-Wimplicit-fallthrough=5 doesn’t recognize any comments as
       fallthrough comments, only attributes disable the warning"

    so if clang ever fixes its bad behavior we can try enabling it there again.

Change-Id: Iea69849592fb69ac04fb9bb28efcd6b8dce8ba88
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: cpu/hotplug: Remove deprecated CPU-hotplug functions. (v5.15)

The CPU-hotplug functions get|put_online_cpus() were deprecated in v4.13
and removed in v5.15.

See upstream commits :

commit 8c854303ce0e38e5bbedd725ff39da7e235865d8
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Tue Aug 3 16:16:21 2021 +0200

    cpu/hotplug: Remove deprecated CPU-hotplug functions.

    No users in tree use the deprecated CPU-hotplug functions anymore.

    Remove them.

Introduced in v4.13 :

  commit 8f553c498e1772cccb39a114da4a498d22992758
  Author: Thomas Gleixner <tglx@linutronix.de>
  Date:   Wed May 24 10:15:12 2017 +0200

    cpu/hotplug: Provide cpus_read|write_[un]lock()

    The counting 'rwsem' hackery of get|put_online_cpus() is going to be
    replaced by percpu rwsem.

    Rename the functions to make it clear that it's locking and not some
    refcount style interface. These new functions will be used for the
    preparatory patches which make the code ready for the percpu rwsem
    conversion.

    Rename all instances in the cpu hotplug code while at it.

Change-Id: I5a37cf5afc075a402b7347989fac637dfa60a1ed
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Version 2.13.0

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I24bced435d30a8660489e76f94370a19160fe9d1

Version 2.13.0-rc3

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I6d21580daba07be92428c5dab4227eae8aaace0a

fix: sched: Change task_struct::state (v5.14)

See upstream commit:

  commit 2f064a59a11ff9bc22e52e9678bc601404c7cb34
  Author: Peter Zijlstra <peterz@infradead.org>
  Date:   Fri Jun 11 10:28:17 2021 +0200

    sched: Change task_struct::state

    Change the type and name of task_struct::state. Drop the volatile and
    shrink it to an 'unsigned int'. Rename it in order to find all uses
    such that we can use READ_ONCE/WRITE_ONCE as appropriate.

Change-Id: I3a379192d6b977753fe58d4f67833a78dd7a0a47
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: btrfs: pass btrfs_inode to btrfs_writepage_endio_finish_ordered() (v5.14)

See upstream commit:

  commit 38a39ac77e089515acbe85c6c70c3df1e728357d
  Author: Qu Wenruo <wqu@suse.com>
  Date:   Thu Apr 8 20:32:27 2021 +0800

    btrfs: pass btrfs_inode to btrfs_writepage_endio_finish_ordered()

    There is a pretty bad abuse of btrfs_writepage_endio_finish_ordered() in
    end_compressed_bio_write().

    It passes compressed pages to btrfs_writepage_endio_finish_ordered(),
    which is only supposed to accept inode pages.

    Thankfully the important info here is the inode, so let's pass
    btrfs_inode directly into btrfs_writepage_endio_finish_ordered(), and
    make @page parameter optional.

    By this, end_compressed_bio_write() can happily pass page=NULL while
    still getting everything done properly.

    Also, to cooperate with such modification, replace @page parameter for
    trace_btrfs_writepage_end_io_hook() with btrfs_inode.
    Although this removes page_index info, the existing start/len should be
    enough for most usage.

Change-Id: If96e99c2d9533d96d9d1aa6460bb7fd3ac9ed7ab
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

fix: adjust ranges for RHEL 8.4

Change-Id: I9ac44467cca4850fb4051252937542d5a054ccc4
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Version 2.13.0-rc2

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I1e09e6683a3aad482fb7cc8b44eb3b603132c9b8

fix: adjust ranges for RHEL 8.2 and 8.3

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I0863ac030f9fdfeb0173b843e75396acda21f3b6

Disable x86 error code bitwise enum in default build

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

commit 8c7f2a9f2732b11f5cc9798cecb621420cc0e972
Author: Francis Deslauriers <francis.deslauriers@efficios.com>
Date:   Fri Jun 5 18:42:54 2020 -0400

    x86: add error code enum to pagefault tracepoints

Change-Id: I7901fad216b4774a9bbf3665568f357321805871
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Disable mmap bitwise enum in default build

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

Original commit:

  commit 3cf55950d0f6aa43eb5ad119bad1dbda69f75a54
  Author: Francis Deslauriers <francis.deslauriers@efficios.com>
  Date:   Fri Jun 5 11:38:14 2020 -0400

    syscalls: Make mmap()'s fields `prot` and `flags` enums

Change-Id: I033f42855c2967356b1e90cd89450eb5100a0f0b
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Disable block rwbs bitwise enum in default build

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

Original commit:

  commit 23634515e7271c8c8594ad87a6685232d4eff297
  Author: Geneviève Bastien <gbastien@versatic.net>
  Date:   Tue Feb 11 11:20:27 2020 -0500

    block: Make the rwbs field as a bit field enum

Change-Id: I6c285d1cbfbd88e151d4b0abb52ad9a650764ea2
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Disable sched_switch bitwise enum in default build

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

Original commit:

  commit 721caea47b6506f7ad9086c3e9801dc9dfe06b6a
  Author: Geneviève Bastien <gbastien@versatic.net>
  Date:   Wed Feb 12 16:58:25 2020 -0500

    sched: Make the sched_switch task state an enum

Change-Id: Ib19d06365fbed7daa9440d5dfff283c4f89db6ee
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Disable open[at] bitwise enum in default build

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

Original commit:

  commit c8dfb72431505d5f01a6f090f3f7427d9ca6fe94
  Author: Geneviève Bastien <gbastien@versatic.net>
  Date:   Wed Mar 11 12:33:04 2020 -0400

    syscalls: Make the flags and mode fields of open[at] enumerations

Use the non-override system call tracing implementation when the enum is
not used.

Change-Id: I2dbebe56eaba6186843dab20264d3378962c7d30
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Disable fcntl bitwise enum in default build

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

Original commit:

  commit c1c07d681a68ba37da066d6f0456129957073169
  Author: Geneviève Bastien <gbastien+lttng@versatic.net>
  Date:   Wed Mar 11 12:38:51 2020 -0400

    syscalls: Make the cmd field of fcntl an enum

Use the non-override system call tracing implementation when the enum is
not used.

Change-Id: I4c650d40a14b1c56ada0ed9aae1877364d0c4580
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Disable clone bitwise enum in default build

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

Original commit:

  commit d775625e2ba4825b73b5897e7701ad6e2bdba115
  Author: Geneviève Bastien <gbastien@versatic.net>
  Date:   Wed Apr 1 14:31:49 2020 -0400

    syscalls: Make clone()'s `flags` field a 2 enum struct.

Change-Id: Ia67b5fc93b932b8b76330b4965753a43401c1514
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Add experimental bitwise enum config option

Only generate the bitwise enumerations when
CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM is enabled, so the default build
does not generate traces which lead to warnings when viewed with
babeltrace 1.x and babeltrace 2 with default options.

Change-Id: Id45c7a78b280a7f35bbeafb80f2f6f5aa1ebbdc9
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Add defaults to Kconfig options

Add defaults to the Kconfig options used when building in-tree that
match the default configuration when built out-of-tree.

Change-Id: I436251f1fb4c3e238a013d18d67932565b92ef45
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Cleanup: remove unused EXTCFLAGS from Makefile

Change-Id: I36c4f6f403b03a1aa158863f393049efdc70af04
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Sync `show_inode_state()` macro with upstream stable kernels

The following commit was backported to multiple stable branches:

  commit 5fcd57505c002efc5823a7355e21f48dd02d5a51
  Author: Jan Kara <jack@suse.cz>
  Date:   Fri May 29 16:24:43 2020 +0200

    writeback: Drop I_DIRTY_TIME_EXPIRE

    The only use of I_DIRTY_TIME_EXPIRE is to detect in
    __writeback_single_inode() that inode got there because flush worker
    decided it's time to writeback the dirty inode time stamps (either
    because we are syncing or because of age). However we can detect this
    directly in __writeback_single_inode() and there's no need for the
    strange propagation with I_DIRTY_TIME_EXPIRE flag.

Change-Id: I6e7c0ced13acd4fcd88bcd572d0ba1f9b254c58c
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Update .gitreview for stable-2.13

Change-Id: I169739a9e4f43be052cb815feefb21610e7cf742
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Sync `show_inode_state()` macro with Ubuntu 4.15 kernel

The following commit changed the `show_inode_state()` macro which
triggered a warning on our CI build:
  commit 63388062bea96e5cd8b8d7abf7b7142f8666ca1f
  Author: Jan Kara <jack@suse.cz>
  Date:   Mon Jan 25 12:37:43 2021 -0800

      writeback: Drop I_DIRTY_TIME_EXPIRE

Also, this commit adds a comment to clarify why we keep these
`#if/#elif` even though we don't use it the macro.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I2dd53a1a286ab8a431977bda6cde01f700f0c7d9

fix: block: remove disk_part_iter (v5.12)

In v5.12 a refactoring of the genhd code was started and the symbols
related to 'disk_part_iter' were unexported. In v5.13 they were
completely removed.

This patch replaces the short lived compat code that is specific to
v5.12 and replaces it with a generic internal implementation that
iterates directly on the 'disk->part_tbl' xarray which will be used
on v5.12 and up.

This seems like a better option than keeping the compat code that will
only work on v5.12 and make maintenance more complicated. The compat was
backported to the stable branches but isn't yet part of a point release
so can be safely replaced.

See the upstream commits:

  commit 3212135a718b06be38811f2d9a320ae842e76409
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Tue Apr 6 08:23:02 2021 +0200

    block: remove disk_part_iter

    Just open code the xa_for_each in the remaining user.

  commit a33df75c6328bf40078b35f2040d8e54d574c357
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Sun Jan 24 11:02:41 2021 +0100

    block: use an xarray for disk->part_tbl

    Now that no fast path lookups in the partition table are left, there is
    no point in micro-optimizing the data structure for it.  Just use a bog
    standard xarray.

Change-Id: If3497e087fadaa285e135f57aab7e6df157b06c6
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Cleanup: lib ring buffer: rename pagecpy local variable

Rename pagecpy local variable to bytes_left_in_page, which has a clearer
semantic. Also remove the unused pagecpy parameter from slow paths which
was always 0.

Also add a missing __user annotation on @src of
the _lib_ring_buffer_copy_from_user_inatomic prototype.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I22a85cb8e94a65aaa80ca49951479243477ac600

Cleanup: clarify strcpy/strcpy_from_user local variables

The variable name "bytes_left_in_page" is clearer than "pagecpy". Also
the only caller of slow paths always has a 0 pagecpy parameter, so
remove that parameter. Also use a "bool" for src_terminated (no
functional change).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I38520b8cab54c31dbbb7b9296200b432afb3cee9

Implement ring buffer Pascal string copy

Introduce a new lib_ring_buffer_pstrcpy() to handle copying into a ring
buffer Pascal String, use them for array and sequence of text.

Cover strings copied from both kernel and user-space.

This ensures that when copying from a string input to a ring buffer
utf8/ascii-encoded array or sequence, the source is not read beyond its
null terminating character.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I74996c8c8db6eec39b189693739aa2f980e29816

Move alignment into event write callback

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I7563cdd07163fc22e2269627879a83e871c4eb01

Cleanup: disable page fault after access_ok

The page faults don't need to be disabled for access_ok. Simplify the
fill buffer error paths.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I2e31d308d45efdfede04e2159c37c066749871ae

Fix: increment buffer offset when failing to copy from user-space

Upon failure to copy from user-space due to failing access ok check, the
ring buffer offset is not incremented, which could generate unreadable
traces because we don't account for the padding we write into the ring
buffer.

Note that this typically won't affect a common use-case of copying
strings from user-space, because unless mprotect is invoked within a
narrow race window (between user strlen and user strcpy), the strlen
will fail on access ok when calculating the space to reserve, which will
match what happens on strcpy.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic4d9487dd8870a526bae3023bb80f5e6301cec50

Fix: add missing #include for 3.8 kernel

Add the `linux/compat.h` include to fix the following error while
building the modules against a 3.8 kernel for x86-64 kernel:
  error: ‘F_GETLK64’ undeclared here (not in a function)
     ctf_enum_value("F_GETLK64", F_GETLK64)

Also, move the #include directives from the instrumentation headers to
the `lttng-syscalls.h` file.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I334a14d0b40ec77e0ca0aa3b762197de2050a1ae

Fix: builtin script referring to old directories

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I30fb8abb1a69d6695552947e30cf2b43d3db36b3

events.h API const-ness

Ensure events.h definitions, fields, and arguments referring to const
arrays of pointers are const.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Id1f9a736de72220f7576d9780b82ab7879eac300

Rename struct lib_ring_buffer* to struct lttng_kernel_ring_buffer*

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I61b5a78c6485422ae4a2e2e45e32465db82b3d97

Rename struct channel to struct lttng_kernel_ring_buffer_channel

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ifb737dfa71c9fdd08b62680f7782328b50a70d61

Refactoring: struct lttng_channel

Split lttng_channel into public/private structures, and introduce
inheritance for common fields which will be shared between the channel
buffer and upcoming channel counter.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I932231c4af9ed1066d010b5be4f75f34842e8484

Fix: missing #include for 3.8 kernel

Change-Id: If13a6615c2bed93d887047b6feaf377107d98cf9
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Introduce struct lttng_kernel_tracepoint_class, enum probe_desc field

Introduce struct lttng_kernel_tracepoint_class to clearly split the
event instance from the class, thus allowing the event instance to refer
to the class through a single symbol. This removes the need to rely on
ARRAY_SIZE() to calculate the size of the event field array (part of the
class) from within the event instance. This refactoring opens the door
to have event class and instance not only in different providers, but
also in providers emitted within different compile units and shared
objects in the future.

While refactoring kprobes, uprobes and kretprobes code, there is a lot
of dynamically allocated memory which can be turned into static data
structures for tp_class, fields and types. This simplification ends up
fixing a few memory leaks as well.

Introduce a probe_desc field in the enumeration descriptor to keep the
same pattern for both tp_class and enumerations.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I221ad33383de48144d0d14b2b461ecb38dfb54ab

Set probe descriptor field in event descriptor

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I8afd12cae160fbd7637fb2f9528309f5245f77cf

Split syscall tracepoint generation in their own files

This commit tracepoint generation of the 4 different types of syscalls
(entry, exit, entry_compat, and exit_compat) each in their own .c file.

The compilation time of the lttng-modules projects is currently
dominated by the compilation of the src/lttng-syscalls.o object.
This is caused by the extensive use of macros to generate tracepoint for
all syscalls. This also uses a lot of memory making the compilation of
the project tedious on system with low memory.

This allows for parallelization of the compilation which offers 2
improvements: Reduction of compilation time and reduction of the memory
usage.

In term of compilation time, on my 4 cpus laptop, I measured a 15sec
(20%) speedup over 10 runs when using all 4 cpus (make -j4).

On a larger machine (16 cpus), I measured 30sec (60%) speedup when using
all 16 cpus.

In term of memory usage, I was able to compile the project on a virtual
machine with 500MB of memory without hitting memory exhaustion errors.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I025a4c36ef16b935be2a86f5b6649526752a7393

Include `linux/in{,6}.h` closer to where it's used

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I5e2acc1cd081da131ae289506592e74de553133a

Group all syscall enums in one compile unit

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic0189984d9bc70ae3f76af08bffd127500adad80

Include `linux/mman.h` for mmap flag enum

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Id891f59aef1bb26b1ed8dff676bbad0f6d9fb69e

Add `struct trace_syscall_table`

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I72181800793e84f001e83caeea8d7b7ae9e8d07c

Define `static_assert()` when not defined by kernel

This macro is useful for build-time assertions. It was added in kernel
v5.1. It uses the C11 _Static_assert macro that was implemented with gcc
4.6. There is support for the _Static_assert in all C modes, including
gnu89.

Since our minimal gcc version is 4.8, we can simply define it manually
if the kernel is older than v5.1.

Kernel commit adding this macro:
  commit 6bab69c65013bed5fce9f101a64a84d0385b3946
  Author: Rasmus Villemoes <linux@rasmusvillemoes.dk>
  Date:   Thu Mar 7 16:27:00 2019 -0800

      build_bug.h: add wrapper for _Static_assert

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I5aa250f60f9dca4f13b8bcc093a006034c28e526

Move event hash tables to private header

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Id4c690c275bace3dee92b5c3c25e09ac4eb3b384

Move forward declarations to private header

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ibd6fa4f9ec751be8cdb0082c729c3c5662c02d0b

Move lttng_syscall_filter forward declaration to private header

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ife15ca8d175e33e4282a1dd9fd3dc7e759163c8f

Split ID tracker into public/private structures

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic17da38eb96d734110b59656d0fedce1bacd570a

Move id tracker hash node to private header

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I0b0cdb345a24f72a17a84a48a5f28acca72441bb

Split struct lttng_session into public/private structures

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3c8e5c826268659d78f4c177e846cc93727af1c2

Move struct lttng_metadata_stream to private header

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ieae3b2c4c2ffe50360a33db1056734d04668af82

Move event notifier and counter structures to private header

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I119a948c39edbe42e22a12d59e8908029d6acad0

Rename struct lib_ring_buffer_ctx to struct lttng_kernel_ring_buffer_ctx

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I81c3ef6dd226f2a27a32b303a096f60927462615

Refactoring: struct lttng_kernel_channel_buffer_ops

Introduce public/private structures for ring buffer channel operations.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3614d550615a4617541a292fa761bebbdf6a275a

Rename lttng_probe_{,un}register to lttng_kernel_probe_{,un}register

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I62e1d4765d2dd8dcd4a40f3a12e40bbef93a2ead