Commit Graph

905 Commits

Author SHA1 Message Date
Steven Rostedt (VMware) 8a49f3e03c ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stub
No need to add ugly #ifdefs in the code. Having a standard stub file is much
prettier.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17 21:53:32 -04:00
Naveen N. Rao a0e6369e4b ftrace/instances: Clear function triggers when removing instances
If instance directories are deleted while there are registered function
triggers:

  # cd /sys/kernel/debug/tracing/instances
  # mkdir test
  # echo "schedule:enable_event:sched:sched_switch" > test/set_ftrace_filter
  # rmdir test
  Unable to handle kernel paging request for data at address 0x00000008
  Unable to handle kernel paging request for data at address 0x00000008
  Faulting instruction address: 0xc0000000021edde8
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2048
  NUMA
  pSeries
  Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc kvm iptable_filter fuse binfmt_misc pseries_rng rng_core vmx_crypto ib_iser rdma_cm iw_cm ib_cm ib_core libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c multipath virtio_net virtio_blk virtio_pci crc32c_vpmsum virtio_ring virtio
  CPU: 8 PID: 8694 Comm: rmdir Not tainted 4.11.0-nnr+ #113
  task: c0000000bab52800 task.stack: c0000000baba0000
  NIP: c0000000021edde8 LR: c0000000021f0590 CTR: c000000002119620
  REGS: c0000000baba3870 TRAP: 0300   Not tainted  (4.11.0-nnr+)
  MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE>
    CR: 22002422  XER: 20000000
  CFAR: 00007fffabb725a8 DAR: 0000000000000008 DSISR: 40000000 SOFTE: 0
  GPR00: c00000000220f750 c0000000baba3af0 c000000003157e00 0000000000000000
  GPR04: 0000000000000040 00000000000000eb 0000000000000040 0000000000000000
  GPR08: 0000000000000000 0000000000000113 0000000000000000 c00000000305db98
  GPR12: c000000002119620 c00000000fd42c00 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 c0000000bab52e90 0000000000000000
  GPR24: 0000000000000000 00000000000000eb 0000000000000040 c0000000baba3bb0
  GPR28: c00000009cb06eb0 c0000000bab52800 c00000009cb06eb0 c0000000baba3bb0
  NIP [c0000000021edde8] ring_buffer_lock_reserve+0x8/0x4e0
  LR [c0000000021f0590] trace_event_buffer_lock_reserve+0xe0/0x1a0
  Call Trace:
  [c0000000baba3af0] [c0000000021f96c8] trace_event_buffer_commit+0x1b8/0x280 (unreliable)
  [c0000000baba3b60] [c00000000220f750] trace_event_buffer_reserve+0x80/0xd0
  [c0000000baba3b90] [c0000000021196b8] trace_event_raw_event_sched_switch+0x98/0x180
  [c0000000baba3c10] [c0000000029d9980] __schedule+0x6e0/0xab0
  [c0000000baba3ce0] [c000000002122230] do_task_dead+0x70/0xc0
  [c0000000baba3d10] [c0000000020ea9c8] do_exit+0x828/0xd00
  [c0000000baba3dd0] [c0000000020eaf70] do_group_exit+0x60/0x100
  [c0000000baba3e10] [c0000000020eb034] SyS_exit_group+0x24/0x30
  [c0000000baba3e30] [c00000000200bcec] system_call+0x38/0x54
  Instruction dump:
  60000000 60420000 7d244b78 7f63db78 4bffaa09 393efff8 793e0020 39200000
  4bfffecc 60420000 3c4c00f7 3842a020 <81230008> 2f890000 409e02f0 a14d0008
  ---[ end trace b917b8985d0e650b ]---
  Unable to handle kernel paging request for data at address 0x00000008
  Faulting instruction address: 0xc0000000021edde8
  Unable to handle kernel paging request for data at address 0x00000008
  Faulting instruction address: 0xc0000000021edde8
  Faulting instruction address: 0xc0000000021edde8

To address this, let's clear all registered function probes before
deleting the ftrace instance.

Link: http://lkml.kernel.org/r/c5f1ca624043690bd94642bb6bffd3f2fc504035.1494956770.git.naveen.n.rao@linux.vnet.ibm.com

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17 21:52:22 -04:00
Steven Rostedt b9ef0326c0 tracing: Move postpone selftests to core from early_initcall
I hit the following lockdep splat when booting with ftrace selftests
enabled, as well as CONFIG_PREEMPT and LOCKDEP.

 Testing dynamic ftrace ops #1:
 (1 0 1 0 0)
 (1 1 2 0 0)
 (2 1 3 0 169)
 (2 2 4 0 50066)
 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 13 at kernel/rcu/srcutree.c:202 check_init_srcu_struct+0x60/0x70
 Modules linked in:
 CPU: 0 PID: 13 Comm: rcu_tasks_kthre Not tainted 4.12.0-rc1-test+ #587
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
 task: ffff880119628040 task.stack: ffffc900006a4000
 RIP: 0010:check_init_srcu_struct+0x60/0x70
 RSP: 0000:ffffc900006a7d98 EFLAGS: 00010246
 RAX: 0000000000000246 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: ffff880119628040 RSI: 00000000ffffffff RDI: ffffffff81e5fb40
 RBP: ffffc900006a7e20 R08: 00000023b403c000 R09: 0000000000000001
 R10: ffffc900006a7e40 R11: 0000000000000000 R12: ffffffff81e5fb40
 R13: 0000000000000286 R14: ffff880119628040 R15: ffffc900006a7e98
 FS:  0000000000000000(0000) GS:ffff88011ea00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffff88011edff000 CR3: 0000000001e0f000 CR4: 00000000001406f0
 Call Trace:
  ? __synchronize_srcu+0x6e/0x140
  ? lock_acquire+0xdc/0x1d0
  ? ktime_get_mono_fast_ns+0x5d/0xb0
  synchronize_srcu+0x6f/0x110
  ? synchronize_srcu+0x6f/0x110
  rcu_tasks_kthread+0x20a/0x540
  kthread+0x114/0x150
  ? __rcu_read_unlock+0x70/0x70
  ? kthread_create_on_node+0x40/0x40
  ret_from_fork+0x2e/0x40
 Code: f6 83 70 06 00 00 03 49 89 c5 74 0d be 01 00 00 00 48 89 df e8 42 fa ff ff 4c 89 ee 4c 89 e7 e8 b7 42 75 00 5b 41 5c 41 5d 5d c3 <0f> ff eb aa 66 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00
 ---[ end trace 5c3f4206ce50f6ac ]---

What happens is that the selftests include a creating of a dynamically
allocated ftrace_ops, which requires the use of synchronize_rcu_tasks()
which uses srcu, and triggers the above warning.

It appears that synchronize_rcu_tasks() is not set up at early_initcall(),
but it is at core_initcall(). By moving the tests down to that location
works out properly.

Link: http://lkml.kernel.org/r/20170517111435.7388c033@gandalf.local.home

Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-17 21:39:38 -04:00
Matthias Kaehlcke 4dbbe2d8e9 tracing: Use cpumask_available() to check if cpumask variable may be used
This fixes the following clang warning:

kernel/trace/trace.c:3231:12: warning: address of array 'iter->started'
  will always evaluate to 'true' [-Wpointer-bool-conversion]
        if (iter->started)

Link: http://lkml.kernel.org/r/20170421234110.117075-1-mka@chromium.org

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-08 21:22:04 -04:00
Amey Telawane e09e28671c tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()
Strcpy is inherently not safe, and strlcpy() should be used instead.
__trace_find_cmdline() uses strcpy() because the comms saved must have a
terminating nul character, but it doesn't hurt to add the extra protection
of using strlcpy() instead of strcpy().

Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org

Signed-off-by: Amey Telawane <ameyt@codeaurora.org>
[AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10
https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
[ Updated change log and removed the "- 1" from len parameter ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-03 22:15:11 -04:00
Linus Torvalds 4c174688ee New features for this release:
o Pretty much a full rewrite of the processing of function plugins.
    i.e. echo do_IRQ:stacktrace > set_ftrace_filter
 
  o The rewrite was needed to add plugins to be unique to tracing instances.
    i.e. mkdir instance/foo; cd instances/foo; echo do_IRQ:stacktrace > set_ftrace_filter
    The old way was written very hacky. This removes a lot of those hacks.
 
  o New "function-fork" tracing option. When set, pids in the set_ftrace_pid
    will have their children added when the processes with their pids
    listed in the set_ftrace_pid file forks.
 
  o Exposure of "maxactive" for kretprobe in kprobe_events
 
  o Allow for builtin init functions to be traced by the function tracer
    (via the kernel command line). Module init function tracing will come
    in the next release.
 
  o Added more selftests, and have selftests also test in an instance.
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Merge tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New features for this release:

   - Pretty much a full rewrite of the processing of function plugins.
     i.e. echo do_IRQ:stacktrace > set_ftrace_filter

   - The rewrite was needed to add plugins to be unique to tracing
     instances. i.e. mkdir instance/foo; cd instances/foo; echo
     do_IRQ:stacktrace > set_ftrace_filter The old way was written very
     hacky. This removes a lot of those hacks.

   - New "function-fork" tracing option. When set, pids in the
     set_ftrace_pid will have their children added when the processes
     with their pids listed in the set_ftrace_pid file forks.

   - Exposure of "maxactive" for kretprobe in kprobe_events

   - Allow for builtin init functions to be traced by the function
     tracer (via the kernel command line). Module init function tracing
     will come in the next release.

   - Added more selftests, and have selftests also test in an instance"

* tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits)
  ring-buffer: Return reader page back into existing ring buffer
  selftests: ftrace: Allow some event trigger tests to run in an instance
  selftests: ftrace: Have some basic tests run in a tracing instance too
  selftests: ftrace: Have event tests also run in an tracing instance
  selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances
  selftests: ftrace: Allow some tests to be run in a tracing instance
  tracing/ftrace: Allow for instances to trigger their own stacktrace probes
  tracing/ftrace: Allow for the traceonoff probe be unique to instances
  tracing/ftrace: Enable snapshot function trigger to work with instances
  tracing/ftrace: Allow instances to have their own function probes
  tracing/ftrace: Add a better way to pass data via the probe functions
  ftrace: Dynamically create the probe ftrace_ops for the trace_array
  tracing: Pass the trace_array into ftrace_probe_ops functions
  tracing: Have the trace_array hold the list of registered func probes
  ftrace: If the hash for a probe fails to update then free what was initialized
  ftrace: Have the function probes call their own function
  ftrace: Have each function probe use its own ftrace_ops
  ftrace: Have unregister_ftrace_function_probe_func() return a value
  ftrace: Add helper function ftrace_hash_move_and_update_ops()
  ftrace: Remove data field from ftrace_func_probe structure
  ...
2017-05-03 18:41:21 -07:00
Linus Torvalds da7b66ffb2 Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull splice updates from Al Viro:
 "These actually missed the last cycle; the branch itself is from last
  December"

* 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make nr_pages calculation in default_file_splice_read() a bit less ugly
  splice/tee/vmsplice: validate flags
  splice_pipe_desc: kill ->flags
  remove spd_release_page()
2017-05-02 11:38:06 -07:00
Linus Torvalds 7c8c03bfc7 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "The main changes in this cycle were:

  Kernel side changes:

   - Kprobes and uprobes changes:
      - Make their trampolines read-only while they are used
      - Make UPROBES_EVENTS default-y which is the distro practice
      - Apply misc fixes and robustization to probe point insertion.

   - add support for AMD IOMMU events

   - extend hw events on Intel Goldmont CPUs

   - ... plus misc fixes and updates.

  Tooling side changes:

   - support s390 jump instructions in perf annotate (Christian
     Borntraeger)

   - vendor hardware events updates (Andi Kleen)

   - add argument support for SDT events in powerpc (Ravi Bangoria)

   - beautify the statx syscall arguments in 'perf trace' (Arnaldo
     Carvalho de Melo)

   - handle inline functions in callchains (Jin Yao)

   - enable sorting by srcline as key (Milian Wolff)

   - add 'brstackinsn' field in 'perf script' to reuse the x86
     instruction decoder used in the Intel PT code to study hot paths to
     samples (Andi Kleen)

   - add PERF_RECORD_NAMESPACES so that the kernel can record
     information required to associate samples to namespaces, helping in
     container problem characterization. (Hari Bathini)

   - allow sorting by symbol_size in 'perf report' and 'perf top'
     (Charles Baylis)

   - in perf stat, make system wide (-a) the default option if no target
     was specified and one of following conditions is met:
      - no workload specified (current behaviour)
      - a workload is specified but all requested events are system wide
        ones, like uncore ones. (Jiri Olsa)

   - ... plus lots of other updates, enhancements, cleanups and fixes"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (235 commits)
  perf tools: Fix the code to strip command name
  tools arch x86: Sync cpufeatures.h
  tools arch: Sync arch/x86/lib/memcpy_64.S with the kernel
  tools: Update asm-generic/mman-common.h copy from the kernel
  perf tools: Use just forward declarations for struct thread where possible
  perf tools: Add the right header to obtain PERF_ALIGN()
  perf tools: Remove poll.h and wait.h from util.h
  perf tools: Remove string.h, unistd.h and sys/stat.h from util.h
  perf tools: Remove stale prototypes from builtin.h
  perf tools: Remove string.h from util.h
  perf tools: Remove sys/ioctl.h from util.h
  perf tools: Remove a few more needless includes from util.h
  perf tools: Include sys/param.h where needed
  perf callchain: Move callchain specific routines from util.[ch]
  perf tools: Add compress.h for the *_decompress_to_file() headers
  perf mem: Fix display of data source snoop indication
  perf debug: Move dump_stack() and sighandler_dump_stack() to debug.h
  perf kvm: Make function only used by 'perf kvm' static
  perf tools: Move timestamp routines from util.h to time-utils.h
  perf tools: Move units conversion/formatting routines to separate object
  ...
2017-05-01 20:23:17 -07:00
Steven Rostedt (VMware) 73a757e631 ring-buffer: Return reader page back into existing ring buffer
When reading the ring buffer for consuming, it is optimized for splice,
where a page is taken out of the ring buffer (zero copy) and sent to the
reading consumer. When the read is finished with the page, it calls
ring_buffer_free_read_page(), which simply frees the page. The next time the
reader needs to get a page from the ring buffer, it must call
ring_buffer_alloc_read_page() which allocates and initializes a reader page
for the ring buffer to be swapped into the ring buffer for a new filled page
for the reader.

The problem is that there's no reason to actually free the page when it is
passed back to the ring buffer. It can hold it off and reuse it for the next
iteration. This completely removes the interaction with the page_alloc
mechanism.

Using the trace-cmd utility to record all events (causing trace-cmd to
require reading lots of pages from the ring buffer, and calling
ring_buffer_alloc/free_read_page() several times), and also assigning a
stack trace trigger to the mm_page_alloc event, we can see how many times
the ring_buffer_alloc_read_page() needed to allocate a page for the ring
buffer.

Before this change:

  # trace-cmd record -e all -e mem_page_alloc -R stacktrace sleep 1
  # trace-cmd report |grep ring_buffer_alloc_read_page | wc -l
  9968

After this change:

  # trace-cmd record -e all -e mem_page_alloc -R stacktrace sleep 1
  # trace-cmd report |grep ring_buffer_alloc_read_page | wc -l
  4

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-01 10:26:40 -04:00
Steven Rostedt (VMware) 2290f2c589 tracing/ftrace: Allow for the traceonoff probe be unique to instances
Have the traceon/off function probe triggers affect only the instance they
are set in. This required making the trace_on/off accessible for other files
in the tracing directory.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:48 -04:00
Steven Rostedt (VMware) cab5037950 tracing/ftrace: Enable snapshot function trigger to work with instances
Modify the snapshot probe trigger to work with instances. This way the
snapshot function trigger will only affect the instance that it is added to
in the set_ftrace_filter file.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:48 -04:00
Steven Rostedt (VMware) 6e4443199e tracing/ftrace: Add a better way to pass data via the probe functions
With the redesign of the registration and execution of the function probes
(triggers), data can now be passed from the setup of the probe to the probe
callers that are specific to the trace_array it is on. Although, all probes
still only affect the toplevel trace array, this change will allow for
instances to have their own probes separated from other instances and the
top array.

That is, something like the stacktrace probe can be set to trace only in an
instance and not the toplevel trace array. This isn't implement yet, but
this change sets the ground work for the change.

When a probe callback is triggered (someone writes the probe format into
set_ftrace_filter), it calls register_ftrace_function_probe() passing in
init_data that will be used to initialize the probe. Then for every matching
function, register_ftrace_function_probe() will call the probe_ops->init()
function with the init data that was passed to it, as well as an address to
a place holder that is associated with the probe and the instance. The first
occurrence will have a NULL in the pointer. The init() function will then
initialize it. If other probes are added, or more functions are part of the
probe, the place holder will be passed to the init() function with the place
holder data that it was initialized to the last time.

Then this place_holder is passed to each of the other probe_ops functions,
where it can be used in the function callback. When the probe_ops free()
function is called, it can be called either with the rip of the function
that is being removed from the probe, or zero, indicating that there are no
more functions attached to the probe, and the place holder is about to be
freed. This gives the probe_ops a way to free the data it assigned to the
place holder if it was allocade during the first init call.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:46 -04:00
Steven Rostedt (VMware) 7b60f3d876 ftrace: Dynamically create the probe ftrace_ops for the trace_array
In order to eventually have each trace_array instance have its own unique
set of function probes (triggers), the trace array needs to hold the ops and
the filters for the probes.

This is the first step to accomplish this. Instead of having the private
data of the probe ops point to the trace_array, create a separate list that
the trace_array holds. There's only one private_data for a probe, we need
one per trace_array. The probe ftrace_ops will be dynamically created for
each instance, instead of being static.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:46 -04:00
Steven Rostedt (VMware) b5f081b563 tracing: Pass the trace_array into ftrace_probe_ops functions
Pass the trace_array associated to a ftrace_probe_ops into the probe_ops
func(), init() and free() functions. The trace_array is the descriptor that
describes a tracing instance. This will help create the infrastructure that
will allow having function probes unique to tracing instances.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:45 -04:00
Steven Rostedt (VMware) 04ec7bb642 tracing: Have the trace_array hold the list of registered func probes
Add a link list to the trace_array to hold func probes that are registered.
Currently, all function probes are the same for all instances as it was
before, that is, only the top level trace_array holds the function probes.
But this lays the ground work to have function probes be attached to
individual instances, and having the event trigger only affect events in the
given instance. But that work is still to be done.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:45 -04:00
Steven Rostedt (VMware) d3d532d798 ftrace: Have unregister_ftrace_function_probe_func() return a value
Currently unregister_ftrace_function_probe_func() is a void function. It
does not give any feedback if an error occurred or no item was found to
remove and nothing was done.

Change it to return status and success if it removed something. Also update
the callers to return that feedback to the user.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:42 -04:00
Steven Rostedt (VMware) 1a48df0041 ftrace: Remove data field from ftrace_func_probe structure
No users of the function probes uses the data field anymore. Remove it, and
change the init function to take a void *data parameter instead of a
void **data, because the init will just get the data that the registering
function was received, and there's no state after it is called.

The other functions for ftrace_probe_ops still take the data parameter, but
it will currently only be passed NULL. It will stay as a parameter for
future data to be passed to these functions.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:41 -04:00
Steven Rostedt (VMware) 1a93f8bd19 tracing: Have the snapshot trigger use the mapping helper functions
As the data pointer for individual ips will soon be removed and no longer
passed to the callback function probe handlers, convert the snapshot
trigger counter over to the new ftrace_func_mapper helper functions.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:38 -04:00
Steven Rostedt (VMware) bca6c8d048 ftrace: Pass probe ops to probe function
In preparation to cleaning up the probe function registration code, the
"data" parameter will eventually be removed from the probe->func() call.
Instead it will receive its own "ops" function, in which it can set up its
own data that it needs to map.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-20 22:06:37 -04:00
Steven Rostedt (VMware) df62db5be2 tracing: Allocate the snapshot buffer before enabling probe
Currently the snapshot trigger enables the probe and then allocates the
snapshot. If the probe triggers before the allocation, it could cause the
snapshot to fail and turn tracing off. It's best to allocate the snapshot
buffer first, and then enable the trigger. If something goes wrong in the
enabling of the trigger, the snapshot buffer is still allocated, but it can
also be freed by the user by writting zero into the snapshot buffer file.

Also add a check of the return status of alloc_snapshot().

Cc: stable@vger.kernel.org
Fixes: 77fd5c15e3 ("tracing: Add snapshot trigger to function probes")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-19 14:19:08 -04:00
Namhyung Kim 1e10486ffe ftrace: Add 'function-fork' trace option
The function-fork option is same as event-fork that it tracks task
fork/exit and set the pid filter properly.  This can be useful if user
wants to trace selected tasks including their children only.

Link: http://lkml.kernel.org/r/20170417024430.21194-3-namhyung@kernel.org

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-17 17:13:00 -04:00
Namhyung Kim d879d0b8c1 ftrace: Fix function pid filter on instances
When function tracer has a pid filter, it adds a probe to sched_switch
to track if current task can be ignored.  The probe checks the
ftrace_ignore_pid from current tr to filter tasks.  But it misses to
delete the probe when removing an instance so that it can cause a crash
due to the invalid tr pointer (use-after-free).

This is easily reproducible with the following:

  # cd /sys/kernel/debug/tracing
  # mkdir instances/buggy
  # echo $$ > instances/buggy/set_ftrace_pid
  # rmdir instances/buggy

  ============================================================================
  BUG: KASAN: use-after-free in ftrace_filter_pid_sched_switch_probe+0x3d/0x90
  Read of size 8 by task kworker/0:1/17
  CPU: 0 PID: 17 Comm: kworker/0:1 Tainted: G    B           4.11.0-rc3  #198
  Call Trace:
   dump_stack+0x68/0x9f
   kasan_object_err+0x21/0x70
   kasan_report.part.1+0x22b/0x500
   ? ftrace_filter_pid_sched_switch_probe+0x3d/0x90
   kasan_report+0x25/0x30
   __asan_load8+0x5e/0x70
   ftrace_filter_pid_sched_switch_probe+0x3d/0x90
   ? fpid_start+0x130/0x130
   __schedule+0x571/0xce0
   ...

To fix it, use ftrace_clear_pids() to unregister the probe.  As
instance_rmdir() already updated ftrace codes, it can just free the
filter safely.

Link: http://lkml.kernel.org/r/20170417024430.21194-2-namhyung@kernel.org

Fixes: 0c8916c342 ("tracing: Add rmdir to remove multibuffer instances")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-17 16:44:23 -04:00
Steven Rostedt (VMware) af0009fc16 tracing: Move trace_handle_return() out of line
Currently trace_handle_return() looks like this:

 static inline enum print_line_t trace_handle_return(struct trace_seq *s)
 {
        return trace_seq_has_overflowed(s) ?
                TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
 }

Where trace_seq_overflowed(s) is:

 static inline bool trace_seq_has_overflowed(struct trace_seq *s)
 {
	return s->full || seq_buf_has_overflowed(&s->seq);
 }

And seq_buf_has_overflowed(&s->seq) is:

 static inline bool
 seq_buf_has_overflowed(struct seq_buf *s)
 {
	return s->len > s->size;
 }

Making trace_handle_return() into:

 return (s->full || (s->seq->len > s->seq->size)) ?
           TRACE_TYPE_PARTIAL_LINE :
           TRACE_TYPE_HANDLED;

One would think this is not an issue to keep as an inline. But because this
is used in the TRACE_EVENT() macro, it is extended for every tracepoint in
the system. Taking a look at a single tracepoint x86_irq_vector (was the
first one I randomly chosen). As trace_handle_return is used in the
TRACE_EVENT() macro of trace_raw_output_##call() we disassemble
trace_raw_output_x86_irq_vector and do a diff:

- is the original
+ is the out-of-line code

I removed identical lines that were different just due to different
addresses.

--- /tmp/irq-vec-orig	2017-03-16 09:12:48.569384851 -0400
+++ /tmp/irq-vec-ool	2017-03-16 09:13:39.378153385 -0400
@@ -6,27 +6,23 @@
        53                      push   %rbx
        48 89 fb                mov    %rdi,%rbx
        4c 8b a7 c0 20 00 00    mov    0x20c0(%rdi),%r12
        e8 f7 72 13 00          callq  ffffffff81155c80 <trace_raw_output_prep>
        83 f8 01                cmp    $0x1,%eax
        74 05                   je     ffffffff8101e993 <trace_raw_output_x86_irq_vector+0x23>
        5b                      pop    %rbx
        41 5c                   pop    %r12
        5d                      pop    %rbp
        c3                      retq
        41 8b 54 24 08          mov    0x8(%r12),%edx
-       48 8d bb 98 10 00 00    lea    0x1098(%rbx),%rdi
+       48 81 c3 98 10 00 00    add    $0x1098,%rbx
-       48 c7 c6 7b 8a a0 81    mov    $0xffffffff81a08a7b,%rsi
+       48 c7 c6 ab 8a a0 81    mov    $0xffffffff81a08aab,%rsi
-       e8 c5 85 13 00          callq  ffffffff81156f70 <trace_seq_printf>

 === here's the start of the main difference ===

+       48 89 df                mov    %rbx,%rdi
+       e8 62 7e 13 00          callq  ffffffff81156810 <trace_seq_printf>
-       8b 93 b8 20 00 00       mov    0x20b8(%rbx),%edx
-       31 c0                   xor    %eax,%eax
-       85 d2                   test   %edx,%edx
-       75 11                   jne    ffffffff8101e9c8 <trace_raw_output_x86_irq_vector+0x58>
-       48 8b 83 a8 20 00 00    mov    0x20a8(%rbx),%rax
-       48 39 83 a0 20 00 00    cmp    %rax,0x20a0(%rbx)
-       0f 93 c0                setae  %al
+       48 89 df                mov    %rbx,%rdi
+       e8 4a c5 12 00          callq  ffffffff8114af00 <trace_handle_return>
        5b                      pop    %rbx
-       0f b6 c0                movzbl %al,%eax

 === end ===

        41 5c                   pop    %r12
        5d                      pop    %rbp
        c3                      retq

If you notice, the original has 22 bytes of text more than the out of line
version. As this is for every TRACE_EVENT() defined in the system, this can
become quite large.

   text	   data	    bss	    dec	    hex	filename
8690305	5450490	1298432	15439227	 eb957b	vmlinux-orig
8681725	5450490	1298432	15430647	 eb73f7	vmlinux-handle

This change has a total of 8580 bytes in savings.

 $ objdump -dr /tmp/vmlinux-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l
324

That's 324 tracepoints. But this does not include modules (which contain
many more tracepoints). For an allyesconfig build:

 $ objdump -dr vmlinux-allyes-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l
1401

That's 1401 tracepoints giving us:

   text    data     bss     dec     hex filename
137920629       140221067       53264384        331406080       13c0db00 vmlinux-allyes-orig
137827709       140221067       53264384        331313160       13bf7008 vmlinux-allyes-handle

92920 bytes in savings!!!

Link: http://lkml.kernel.org/r/20170315021431.13107-2-andi@firstfloor.org

Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-03-24 20:51:50 -04:00
Steven Rostedt (VMware) dbeafd0d61 ftrace: Have function tracing start in early boot up
Register the function tracer right after the tracing buffers are initialized
in early boot up. This will allow function tracing to begin early if it is
enabled via the kernel command line.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-03-24 20:51:48 -04:00
Steven Rostedt (VMware) 9afecfbb95 tracing: Postpone tracer start-up tests till the system is more robust
As tracing can now be enabled very early in boot up, even before some
critical system services (like scheduling), do not run the tracer selftests
until after early_initcall() is performed. If a tracer is registered before
such time, it is saved off in a list and the test is run when the system is
able to handle more diverse functions.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-03-24 20:51:46 -04:00
Steven Rostedt (VMware) e725c731e3 tracing: Split tracing initialization into two for early initialization
Create an early_trace_init() function that will initialize the buffers and
allow for ealier use of trace_printk(). This will also allow for future work
to have function tracing start earlier at boot up.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-03-24 13:08:43 -04:00
Naveen N. Rao 35b6f55aa9 trace/kprobes: Allow return probes with offsets and absolute addresses
Since the kernel includes many non-global functions with same names, we
will need to use offsets from other symbols (typically _text/_stext) or
absolute addresses to place return probes on specific functions. Also,
the core register_kretprobe() API never forbid use of offsets or
absolute addresses with kretprobes.

Allow its use with the trace infrastructure. To distinguish kernels that
support this, update ftrace README to explicitly call this out.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/183e7ce2921a08c9c755ee9a5da3134febc6695b.1487770934.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-03-03 19:07:18 -03:00
Anton Blanchard 6b0b755142 perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS
We have uses of CONFIG_UPROBE_EVENT and CONFIG_KPROBE_EVENT as
well as CONFIG_UPROBE_EVENTS and CONFIG_KPROBE_EVENTS.

Consistently use the plurals.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: davem@davemloft.net
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20170216060050.20866-1-anton@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-01 10:26:39 +01:00
Linus Torvalds 79b17ea740 This release has no new tracing features, just clean ups, minor fixes
and small optimizations.
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Merge tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This release has no new tracing features, just clean ups, minor fixes
  and small optimizations"

* tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (25 commits)
  tracing: Remove outdated ring buffer comment
  tracing/probes: Fix a warning message to show correct maximum length
  tracing: Fix return value check in trace_benchmark_reg()
  tracing: Use modern function declaration
  jump_label: Reduce the size of struct static_key
  tracing/probe: Show subsystem name in messages
  tracing/hwlat: Update old comment about migration
  timers: Make flags output in the timer_start tracepoint useful
  tracing: Have traceprobe_probes_write() not access userspace unnecessarily
  tracing: Have COMM event filter key be treated as a string
  ftrace: Have set_graph_function handle multiple functions in one write
  ftrace: Do not hold references of ftrace_graph_{notrace_}hash out of graph_lock
  tracing: Reset parser->buffer to allow multiple "puts"
  ftrace: Have set_graph_functions handle write with RDWR
  ftrace: Reset fgd->hash in ftrace_graph_write()
  ftrace: Replace (void *)1 with a meaningful macro name FTRACE_GRAPH_EMPTY
  ftrace: Create a slight optimization on searching the ftrace_hash
  tracing: Add ftrace_hash_key() helper function
  ftrace: Convert graph filter to use hash tables
  ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip
  ...
2017-02-27 13:26:17 -08:00
Joel Fernandes 67d04bb2bc tracing: Remove outdated ring buffer comment
The comment about ring buffer's organization is outdated and the code sits
elsewhere, remove the comment.
Link: http://lkml.kernel.org/r/20170217041058.23904-1-joelaf@google.com

Cc: Ingo Molnar <mingo@redhat.com>

Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-02-17 09:56:51 -05:00
Steven Rostedt (VMware) 0e684b6578 tracing: Reset parser->buffer to allow multiple "puts"
trace_parser_put() simply frees the allocated parser buffer. But it does not
reset the pointer that was freed. This means that if trace_parser_put() is
called on the same parser more than once, it will corrupt the allocation
system. Setting parser->buffer to NULL after free allows it to be called
more than once without any ill effect.

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-02-03 10:59:31 -05:00
Eric W. Biederman 93faccbbfa fs: Better permission checking for submounts
To support unprivileged users mounting filesystems two permission
checks have to be performed: a test to see if the user allowed to
create a mount in the mount namespace, and a test to see if
the user is allowed to access the specified filesystem.

The automount case is special in that mounting the original filesystem
grants permission to mount the sub-filesystems, to any user who
happens to stumble across the their mountpoint and satisfies the
ordinary filesystem permission checks.

Attempting to handle the automount case by using override_creds
almost works.  It preserves the idea that permission to mount
the original filesystem is permission to mount the sub-filesystem.
Unfortunately using override_creds messes up the filesystems
ordinary permission checks.

Solve this by being explicit that a mount is a submount by introducing
vfs_submount, and using it where appropriate.

vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
sget and friends know that a mount is a submount so they can take appropriate
action.

sget and sget_userns are modified to not perform any permission checks
on submounts.

follow_automount is modified to stop using override_creds as that
has proven problemantic.

do_mount is modified to always remove the new MS_SUBMOUNT flag so
that we know userspace will never by able to specify it.

autofs4 is modified to stop using current_real_cred that was put in
there to handle the previous version of submount permission checking.

cifs is modified to pass the mountpoint all of the way down to vfs_submount.

debugfs is modified to pass the mountpoint all of the way down to
trace_automount by adding a new parameter.  To make this change easier
a new typedef debugfs_automount_t is introduced to capture the type of
the debugfs automount function.

Cc: stable@vger.kernel.org
Fixes: 069d5ac9ae ("autofs:  Fix automounts by using current_real_cred()->uid")
Fixes: aeaa4a79ff ("fs: Call d_automount with the filesystems creds")
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-02-02 04:36:12 +13:00
Al Viro f81dc7d7d5 splice_pipe_desc: kill ->flags
no users left

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-26 23:53:38 -05:00
Thomas Gleixner a5a1d1c291 clocksource: Use a plain u64 instead of cycle_t
There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
2016-12-25 11:04:12 +01:00
Linus Torvalds 179a7ba680 This release has a few updates:
o STM can hook into the function tracer
  o Function filtering now supports more advance glob matching
  o Ftrace selftests updates and added tests
  o Softirq tag in traces now show only softirqs
  o ARM nop added to non traced locations at compile time
  o New trace_marker_raw file that allows for binary input
  o Optimizations to the ring buffer
  o Removal of kmap in trace_marker
  o Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
  o Other various fixes and clean ups
 
 Note, there are two patches marked for stable. These were discovered
 near the end of the 4.9 rc release cycle. By the time I had them tested
 it was just a matter of days before 4.9 would be released, and I
 figured I would just submit them in the merge window. They are old
 bugs and not critical. Nothing non-root could abuse.
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Merge tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This release has a few updates:

   - STM can hook into the function tracer
   - Function filtering now supports more advance glob matching
   - Ftrace selftests updates and added tests
   - Softirq tag in traces now show only softirqs
   - ARM nop added to non traced locations at compile time
   - New trace_marker_raw file that allows for binary input
   - Optimizations to the ring buffer
   - Removal of kmap in trace_marker
   - Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
   - Other various fixes and clean ups"

* tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (42 commits)
  selftests: ftrace: Shift down default message verbosity
  kprobes/trace: Fix kprobe selftest for newer gcc
  tracing/kprobes: Add a helper method to return number of probe hits
  tracing/rb: Init the CPU mask on allocation
  tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
  tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too
  fgraph: Handle a case where a tracer ignores set_graph_notrace
  tracing: Replace kmap with copy_from_user() in trace_marker writing
  ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it
  tracing: Allow benchmark to be enabled at early_initcall()
  tracing: Have system enable return error if one of the events fail
  tracing: Do not start benchmark on boot up
  tracing: Have the reg function allow to fail
  ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline
  ring-buffer: Froce rb_update_write_stamp() to be inlined
  ring-buffer: Force inline of hotpath helper functions
  tracing: Make __buffer_unlock_commit() always_inline
  tracing: Make tracepoint_printk a static_key
  ring-buffer: Always inline rb_event_data()
  ring-buffer: Make rb_reserve_next_event() always inlined
  ...
2016-12-15 13:49:34 -08:00
Linus Torvalds 9465d9cc31 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "The time/timekeeping/timer folks deliver with this update:

   - Fix a reintroduced signed/unsigned issue and cleanup the whole
     signed/unsigned mess in the timekeeping core so this wont happen
     accidentaly again.

   - Add a new trace clock based on boot time

   - Prevent injection of random sleep times when PM tracing abuses the
     RTC for storage

   - Make posix timers configurable for real tiny systems

   - Add tracepoints for the alarm timer subsystem so timer based
     suspend wakeups can be instrumented

   - The usual pile of fixes and updates to core and drivers"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  timekeeping: Use mul_u64_u32_shr() instead of open coding it
  timekeeping: Get rid of pointless typecasts
  timekeeping: Make the conversion call chain consistently unsigned
  timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
  alarmtimer: Add tracepoints for alarm timers
  trace: Update documentation for mono, mono_raw and boot clock
  trace: Add an option for boot clock as trace clock
  timekeeping: Add a fast and NMI safe boot clock
  timekeeping/clocksource_cyc2ns: Document intended range limitation
  timekeeping: Ignore the bogus sleep time if pm_trace is enabled
  selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"
  clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap
  clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()
  arm64: dts: rockchip: Arch counter doesn't tick in system suspend
  clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
  posix-timers: Make them configurable
  posix_cpu_timers: Move the add_device_randomness() call to a proper place
  timer: Move sys_alarm from timer.c to itimer.c
  ptp_clock: Allow for it to be optional
  Kconfig: Regenerate *.c_shipped files after previous changes
  ...
2016-12-12 19:56:15 -08:00
Pavankumar Kondeti c59f29cb14 tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
The 's' flag is supposed to indicate that a softirq is running. This
can be detected by testing the preempt_count with SOFTIRQ_OFFSET.

The current code tests the preempt_count with SOFTIRQ_MASK, which
would be true even when softirqs are disabled but not serving a
softirq.

Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@codeaurora.org

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-12 13:51:02 -05:00
Steven Rostedt (Red Hat) 656c7f0d2d tracing: Replace kmap with copy_from_user() in trace_marker writing
Instead of using get_user_pages_fast() and kmap_atomic() when writing
to the trace_marker file, just allocate enough space on the ring buffer
directly, and write into it via copy_from_user().

Writing into the trace_marker file use to allocate a temporary buffer
to perform the copy_from_user(), as we didn't want to write into the
ring buffer if the copy failed. But as a trace_marker write is suppose
to be extremely fast, and allocating memory causes other tracepoints to
trigger, Peter Zijlstra suggested using get_user_pages_fast() and
kmap_atomic() to keep the user space pages in memory and reading it
directly. But Henrik Austad had issues with this because it required taking
the mm->mmap_sem and causing long delays with the write.

Instead, just allocate the space in the ring buffer and use
copy_from_user() directly. If it faults, return -EFAULT and write
"<faulted>" into the ring buffer.

Link: http://lkml.kernel.org/r/20161208124018.72dd0f86@gandalf.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Henrik Austad <henrik@austad.us>
Cc: Peter Zijlstra <peterz@infradead.org>
Updates: d696b58ca2 "tracing: Do not allocate buffer for trace_marker"
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09 09:18:14 -05:00
Sebastian Andrzej Siewior b32614c034 tracing/rb: Convert to hotplug state machine
Install the callbacks via the state machine. The notifier in struct
ring_buffer is replaced by the multi instance interface.  Upon
__ring_buffer_alloc() invocation, cpuhp_state_add_instance() will invoke
the trace_rb_cpu_prepare() on each CPU.

This callback may now fail. This means __ring_buffer_alloc() will fail and
cleanup (like previously) and during a CPU up event this failure will not
allow the CPU to come up.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161126231350.10321-7-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-02 00:52:34 +01:00
Joel Fernandes 80ec355210 trace: Add an option for boot clock as trace clock
Unlike monotonic clock, boot clock as a trace clock will account for
time spent in suspend useful for tracing suspend/resume. This uses
earlier introduced infrastructure for using the fast boot clock.

Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1480372524-15181-7-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-29 18:02:59 +01:00
Steven Rostedt (Red Hat) 52ffabe384 tracing: Make __buffer_unlock_commit() always_inline
The function __buffer_unlock_commit() is called in a few places outside of
trace.c. But for the most part, it should really be inlined, as it is in the
hot path of the trace_events. For the callers outside of trace.c, create a
new function trace_buffer_unlock_commit_nostack(), as the reason it was used
was to avoid the stack tracing that trace_buffer_unlock_commit() could do.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org

Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-23 20:30:51 -05:00
Steven Rostedt (Red Hat) 4239174570 tracing: Make tracepoint_printk a static_key
Currently, when tracepoint_printk is set (enabled by the "tp_printk" kernel
command line), it causes trace events to print via printk(). This is a very
dangerous operation, but is useful for debugging.

The issue is, it's seldom used, but it is always checked even if it's not
enabled by the kernel command line. Instead of having this feature called by
a branch against a variable, turn that variable into a static key, and this
will remove the test and jump.

To simplify things, the functions output_printk() and
trace_event_buffer_commit() were moved from trace_events.c to trace.c.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-23 15:52:45 -05:00
Steven Rostedt (Red Hat) 3e9a8aadca tracing: Create a always_inlined __trace_buffer_lock_reserve()
As Andi Kleen pointed out in the Link below, the trace events has quite a
bit of code execution. A lot of that happens to be calling functions, where
some of them should simply be inlined. One of these functions happens to be
trace_buffer_lock_reserve() which is also a global, but it is used
throughout the file it is defined in. Create a __trace_buffer_lock_reserve()
that is always inlined that the file can benefit from.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org

Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-23 11:29:58 -05:00
Chunyan Zhang 478409dd68 tracing: Add hook to function tracing for other subsystems to use
Currently Function traces can be only exported to the ring buffer. This
adds a trace_export concept which can process traces and export
them to a registered destination as an addition to the current
one that outputs to Ftrace - i.e. ring buffer.

In this way, if we want function traces to be sent to other destinations
rather than only to the ring buffer, we just need to register a new
trace_export and implement its own .write() function for writing traces to
storage.

With this patch, only function tracing (trace type is TRACE_FN)
is supported.

Link: http://lkml.kernel.org/r/1479715043-6534-2-git-send-email-zhang.chunyan@linaro.org

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-22 17:40:00 -05:00
Steven Rostedt fa32e8557b tracing: Add new trace_marker_raw
A new file is created:

 /sys/kernel/debug/tracing/trace_marker_raw

This allows for appications to create data structures and write the binary
data directly into it, and then read the trace data out from trace_pipe_raw
into the same type of data structure. This saves on converting numbers into
ASCII that would be required by trace_marker.

Suggested-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-15 15:13:59 -05:00
Masami Hiramatsu 60f1d5e3ba ftrace: Support full glob matching
Use glob_match() to support flexible glob wildcards (*,?)
and character classes ([) for ftrace.
Since the full glob matching is slower than the current
partial matching routines(*pat, pat*, *pat*), this leaves
those routines and just add MATCH_GLOB for complex glob
expression.

e.g.
----
[root@localhost tracing]# echo 'sched*group' > set_ftrace_filter
[root@localhost tracing]# cat set_ftrace_filter
sched_free_group
sched_change_group
sched_create_group
sched_online_group
sched_destroy_group
sched_offline_group
[root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter
[root@localhost tracing]# head set_ftrace_filter
sys_arch_prctl
sys_rt_sigreturn
sys_ioperm
SyS_iopl
sys_modify_ldt
SyS_mmap
SyS_set_thread_area
SyS_get_thread_area
SyS_set_tid_address
sys_fork
----

Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devbox

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-14 16:42:58 -05:00
Linus Torvalds 95107b30be This release cycle is rather small. Just a few fixes to tracing.
The big change is the addition of the hwlat tracer. It not only detects
 SMIs, but also other latency that's caused by the hardware. I have detected
 some latency from large boxes having bus contention.
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Merge tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This release cycle is rather small.  Just a few fixes to tracing.

  The big change is the addition of the hwlat tracer. It not only
  detects SMIs, but also other latency that's caused by the hardware. I
  have detected some latency from large boxes having bus contention"

* tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Call traceoff trigger after event is recorded
  ftrace/scripts: Add helper script to bisect function tracing problem functions
  tracing: Have max_latency be defined for HWLAT_TRACER as well
  tracing: Add NMI tracing in hwlat detector
  tracing: Have hwlat trace migrate across tracing_cpumask CPUs
  tracing: Add documentation for hwlat_detector tracer
  tracing: Added hardware latency tracer
  ftrace: Access ret_stack->subtime only in the function profiler
  function_graph: Handle TRACE_BPUTS in print_graph_comment
  tracing/uprobe: Drop isdigit() check in create_trace_uprobe
2016-10-06 11:48:41 -07:00
Linus Torvalds 12b7bcb43e Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "The main kernel side changes were:

   - uprobes enhancements (Masami Hiramatsu)

   - Uncore group events enhancements (David Carrillo-Cisneros)

   - x86 Intel: Add support for Skylake server uncore PMUs (Kan Liang)

   - x86 Intel: LBR cleanups and enhancements, for better branch
     annotation tracking (Peter Zijlstra)

   - x86 Intel: Add support for PTWRITE and power event tracing
     (Alexander Shishkin)

   - ... various fixes, cleanups and smaller enhancements.

  Lots of tooling changes - a couple of highlights:

   - Support event group view with hierarchy mode in 'perf top' and
     'perf report' (Namhyung Kim)

     e.g.:

     $ perf record -e '{cycles,instructions}' make
     $ perf report --hierarchy --stdio
     ...
     #   Overhead  Command / Shared Object / Symbol
     # ......................  ..................................
     ...
     25.74%  27.18%sh
     19.96%  24.14%libc-2.24.so
      9.55%  14.64%[.] __strcmp_sse2
      1.54%   0.00%[.] __tfind
      1.07%   1.13%[.] _int_malloc
      0.95%   0.00%[.] __strchr_sse2
      0.89%   1.39%[.] __tsearch
      0.76%   0.00%[.] strlen

   - Add branch stack / basic block info to 'perf annotate --stdio',
     where for each branch, we add an asm comment after the instruction
     with information on how often it was taken and predicted. See
     example with color output at:

       http://vger.kernel.org/~acme/perf/annotate_basic_blocks.png

     (Peter Zijlstra)

   - Add support for using symbols in address filters with Intel PT and
     ARM CoreSight (hardware assisted tracing facilities) (Adrian
     Hunter, Mathieu Poirier)

   - Add support for interacting with Coresight PMU ETMs/PTMs, that are
     IP blocks to perform hardware assisted tracing on a ARM CPU core
     (Mathieu Poirier)

   - Support generating cross arch probes, i.e. if you specify a vmlinux
     file for different arch than the one in the host machine,

        $ perf probe --definition function_name args

     will generate the probe definition string needed to append to the
     target machine /sys/kernel/debug/tracing/kprobes_events file, using
     scripting (Masami Hiramatsu).

   - Allow configuring the default 'perf report -s' sort order in
     ~/.perfconfig, for instance, "sym,dso" may be more fitting for
     kernel developers. (Arnaldo Carvalho de Melo)

   - ... plus lots of other changes, refactorings, features and fixes"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (149 commits)
  perf tests: Add dwarf unwind test for powerpc
  perf probe: Match linkage name with mangled name
  perf probe: Fix to cut off incompatible chars from group name
  perf probe: Skip if the function address is 0
  perf probe: Ignore the error of finding inline instance
  perf intel-pt: Fix decoding when there are address filters
  perf intel-pt: Enable decoder to handle TIP.PGD with missing IP
  perf intel-pt: Read address filter from AUXTRACE_INFO event
  perf intel-pt: Record address filter in AUXTRACE_INFO event
  perf intel-pt: Add a helper function for processing AUXTRACE_INFO
  perf intel-pt: Fix missing error codes processing auxtrace_info
  perf intel-pt: Add support for recording the max non-turbo ratio
  perf intel-pt: Fix snapshot overlap detection decoder errors
  perf probe: Increase debug level of SDT debug messages
  perf record: Add support for using symbols in address filters
  perf symbols: Add dso__last_symbol()
  perf record: Fix error paths
  perf record: Rename label 'out_symbol_exit'
  perf script: Fix vanished idle symbols
  perf evsel: Add support for address filters
  ...
2016-10-03 12:47:28 -07:00
Linus Torvalds 4c04b4b534 Al Viro has been looking at the tracefs code, and has pointed out
some issues. This contains one fix by me and one by Al. I'm sure that
 he'll come up with more but for now I tested these patches and they
 don't appear to have any negative impact on tracing.
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Merge tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracefs fixes from Steven Rostedt:
 "Al Viro has been looking at the tracefs code, and has pointed out some
  issues.  This contains one fix by me and one by Al.  I'm sure that
  he'll come up with more but for now I tested these patches and they
  don't appear to have any negative impact on tracing"

* tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  fix memory leaks in tracing_buffers_splice_read()
  tracing: Move mutex to protect against resetting of seq data
2016-09-25 18:40:13 -07:00
Al Viro 1ae2293dd6 fix memory leaks in tracing_buffers_splice_read()
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-25 13:30:13 -04:00