Commit Graph

2791 Commits

Author SHA1 Message Date
Linus Torvalds c0f486fde3 More ACPI and power management updates for 3.19-rc1
- Fix a regression in leds-gpio introduced by a recent commit that
    inadvertently changed the name of one of the properties used by
    the driver (Fabio Estevam).
 
  - Fix a regression in the ACPI backlight driver introduced by a
    recent fix that missed one special case that had to be taken
    into account (Aaron Lu).
 
  - Drop the level of some new kernel messages from the ACPI core
    introduced by a recent commit to KERN_DEBUG which they should
    have used from the start and drop some other unuseful KERN_ERR
    messages printed by ACPI (Rafael J Wysocki).
 
  - Revert an incorrect commit modifying the cpupower tool
    (Prarit Bhargava).
 
  - Fix two regressions introduced by recent commits in the OPP
    library and clean up some existing minor issues in that code
    (Viresh Kumar).
 
  - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout
    the tree (or drop it where that can be done) in order to make
    it possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki,
    Ulf Hansson, Ludovic Desroches).  There will be one more
    "CONFIG_PM_RUNTIME removal" batch after this one, because some
    new uses of it have been introduced during the current merge
    window, but that should be sufficient to finally get rid of it.
 
  - Make the ACPI EC driver more robust against race conditions
    related to GPE handler installation failures (Lv Zheng).
 
  - Prevent the ACPI device PM core code from attempting to
    disable GPEs that it has not enabled which confuses ACPICA
    and makes it report errors unnecessarily (Rafael J Wysocki).
 
  - Add a "force" command line switch to the intel_pstate driver
    to make it possible to override the blacklisting of some
    systems in that driver if needed (Ethan Zhao).
 
  - Improve intel_pstate code documentation and add a MAINTAINERS
    entry for it (Kristen Carlson Accardi).
 
  - Make the ACPI fan driver create cooling device interfaces
    witn names that reflect the IDs of the ACPI device objects
    they are associated with, except for "generic" ACPI fans
    (PNP ID "PNP0C0B").  That's necessary for user space thermal
    management tools to be able to connect the fans with the
    parts of the system they are supposed to be cooling properly.
    From Srinivas Pandruvada.
 
 /
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Merge tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are regression fixes (leds-gpio, ACPI backlight driver,
  operating performance points library, ACPI device enumeration
  messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
  PM), some cleanups in the operating performance points (OPP)
  framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
  minor intel_pstate driver changes, a new MAINTAINERS entry for it and
  an ACPI fan driver change needed for better support of thermal
  management in user space.

  Specifics:

   - Fix a regression in leds-gpio introduced by a recent commit that
     inadvertently changed the name of one of the properties used by the
     driver (Fabio Estevam).

   - Fix a regression in the ACPI backlight driver introduced by a
     recent fix that missed one special case that had to be taken into
     account (Aaron Lu).

   - Drop the level of some new kernel messages from the ACPI core
     introduced by a recent commit to KERN_DEBUG which they should have
     used from the start and drop some other unuseful KERN_ERR messages
     printed by ACPI (Rafael J Wysocki).

   - Revert an incorrect commit modifying the cpupower tool (Prarit
     Bhargava).

   - Fix two regressions introduced by recent commits in the OPP library
     and clean up some existing minor issues in that code (Viresh
     Kumar).

   - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
     tree (or drop it where that can be done) in order to make it
     possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
     Hansson, Ludovic Desroches).

     There will be one more "CONFIG_PM_RUNTIME removal" batch after this
     one, because some new uses of it have been introduced during the
     current merge window, but that should be sufficient to finally get
     rid of it.

   - Make the ACPI EC driver more robust against race conditions related
     to GPE handler installation failures (Lv Zheng).

   - Prevent the ACPI device PM core code from attempting to disable
     GPEs that it has not enabled which confuses ACPICA and makes it
     report errors unnecessarily (Rafael J Wysocki).

   - Add a "force" command line switch to the intel_pstate driver to
     make it possible to override the blacklisting of some systems in
     that driver if needed (Ethan Zhao).

   - Improve intel_pstate code documentation and add a MAINTAINERS entry
     for it (Kristen Carlson Accardi).

   - Make the ACPI fan driver create cooling device interfaces witn
     names that reflect the IDs of the ACPI device objects they are
     associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").

     That's necessary for user space thermal management tools to be able
     to connect the fans with the parts of the system they are supposed
     to be cooling properly.  From Srinivas Pandruvada"

* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  MAINTAINERS: add entry for intel_pstate
  ACPI / video: update the skip case for acpi_video_device_in_dod()
  power / PM: Eliminate CONFIG_PM_RUNTIME
  NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / EC: Fix unexpected ec_remove_handlers() invocations
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
  tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
  PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
  mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
  PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
  ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / PM: Do not disable wakeup GPEs that have not been enabled
  ACPI / utils: Drop error messages from acpi_evaluate_reference()
  ...
2014-12-18 20:28:33 -08:00
Linus Torvalds a7c180aa7e As the merge window is still open, and this code was not as complex
as I thought it might be. I'm pushing this in now.
 
 This will allow Thomas to debug his irq work for 3.20.
 
 This adds two new features:
 
 1) Allow traceopoints to be enabled right after mm_init(). By passing
 in the trace_event= kernel command line parameter, tracepoints can be
 enabled at boot up. For debugging things like the initialization of
 interrupts, it is needed to have tracepoints enabled very early. People
 have asked about this before and this has been on my todo list. As it
 can be helpful for Thomas to debug his upcoming 3.20 IRQ work, I'm
 pushing this now. This way he can add tracepoints into the IRQ set up
 and have users enable them when things go wrong.
 
 2) Have the tracepoints printed via printk() (the console) when they
 are triggered. If the irq code locks up or reboots the box, having the
 tracepoint output go into the kernel ring buffer is useless for
 debugging. But being able to add the tp_printk kernel command line
 option along with the trace_event= option will have these tracepoints
 printed as they occur, and that can be really useful for debugging
 early lock up or reboot problems.
 
 This code is not that intrusive and it passed all my tests. Thomas tried
 them out too and it works for his needs.
 
  Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org
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Merge tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "As the merge window is still open, and this code was not as complex as
  I thought it might be.  I'm pushing this in now.

  This will allow Thomas to debug his irq work for 3.20.

  This adds two new features:

  1) Allow traceopoints to be enabled right after mm_init().

     By passing in the trace_event= kernel command line parameter,
     tracepoints can be enabled at boot up.  For debugging things like
     the initialization of interrupts, it is needed to have tracepoints
     enabled very early.  People have asked about this before and this
     has been on my todo list.  As it can be helpful for Thomas to debug
     his upcoming 3.20 IRQ work, I'm pushing this now.  This way he can
     add tracepoints into the IRQ set up and have users enable them when
     things go wrong.

  2) Have the tracepoints printed via printk() (the console) when they
     are triggered.

     If the irq code locks up or reboots the box, having the tracepoint
     output go into the kernel ring buffer is useless for debugging.
     But being able to add the tp_printk kernel command line option
     along with the trace_event= option will have these tracepoints
     printed as they occur, and that can be really useful for debugging
     early lock up or reboot problems.

  This code is not that intrusive and it passed all my tests.  Thomas
  tried them out too and it works for his needs.

   Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org"

* tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Add tp_printk cmdline to have tracepoints go to printk()
  tracing: Move enabling tracepoints to just after rcu_init()
2014-12-16 12:53:59 -08:00
Steven Rostedt (Red Hat) 0daa230296 tracing: Add tp_printk cmdline to have tracepoints go to printk()
Add the kernel command line tp_printk option that will have tracepoints
that are active sent to printk() as well as to the trace buffer.

Passing "tp_printk" will activate this. To turn it off, the sysctl
/proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note,
this only works if the cmdline option is used. Echoing 1 into the sysctl
file without the cmdline option will have no affect.

Note, this is a dangerous option. Having high frequency tracepoints send
their data to printk() can possibly cause a live lock. This is another
reason why this is only active if the command line option is used.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-15 10:17:38 -05:00
Steven Rostedt (Red Hat) 5f893b2639 tracing: Move enabling tracepoints to just after rcu_init()
Enabling tracepoints at boot up can be very useful. The tracepoint
can be initialized right after RCU has been. There's no need to
wait for the early_initcall() to be called. That's too late for some
things that can use tracepoints for debugging. Move the logic to
enable tracepoints out of the initcalls and into init/main.c to
right after rcu_init().

This also allows trace_printk() to be used early too.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos
Link: http://lkml.kernel.org/r/20141214164104.307127356@goodmis.org

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-15 10:16:50 -05:00
Linus Torvalds caf292ae5b Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
Pull block driver core update from Jens Axboe:
 "This is the pull request for the core block IO changes for 3.19.  Not
  a huge round this time, mostly lots of little good fixes:

   - Fix a bug in sysfs blktrace interface causing a NULL pointer
     dereference, when enabled/disabled through that API.  From Arianna
     Avanzini.

   - Various updates/fixes/improvements for blk-mq:

        - A set of updates from Bart, mostly fixing buts in the tag
          handling.

        - Cleanup/code consolidation from Christoph.

        - Extend queue_rq API to be able to handle batching issues of IO
          requests. NVMe will utilize this shortly. From me.

        - A few tag and request handling updates from me.

        - Cleanup of the preempt handling for running queues from Paolo.

        - Prevent running of unmapped hardware queues from Ming Lei.

        - Move the kdump memory limiting check to be in the correct
          location, from Shaohua.

        - Initialize all software queues at init time from Takashi. This
          prevents a kobject warning when CPUs are brought online that
          weren't online when a queue was registered.

   - Single writeback fix for I_DIRTY clearing from Tejun.  Queued with
     the core IO changes, since it's just a single fix.

   - Version X of the __bio_add_page() segment addition retry from
     Maurizio.  Hope the Xth time is the charm.

   - Documentation fixup for IO scheduler merging from Jan.

   - Introduce (and use) generic IO stat accounting helpers for non-rq
     drivers, from Gu Zheng.

   - Kill off artificial limiting of max sectors in a request from
     Christoph"

* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
  bio: modify __bio_add_page() to accept pages that don't start a new segment
  blk-mq: Fix uninitialized kobject at CPU hotplugging
  blktrace: don't let the sysfs interface remove trace from running list
  blk-mq: Use all available hardware queues
  blk-mq: Micro-optimize bt_get()
  blk-mq: Fix a race between bt_clear_tag() and bt_get()
  blk-mq: Avoid that __bt_get_word() wraps multiple times
  blk-mq: Fix a use-after-free
  blk-mq: prevent unmapped hw queue from being scheduled
  blk-mq: re-check for available tags after running the hardware queue
  blk-mq: fix hang in bt_get()
  blk-mq: move the kdump check to blk_mq_alloc_tag_set
  blk-mq: cleanup tag free handling
  blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
  blk: introduce generic io stat accounting help function
  blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
  genhd: check for int overflow in disk_expand_part_tbl()
  blk-mq: add blk_mq_free_hctx_request()
  blk-mq: export blk_mq_free_request()
  blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
  ...
2014-12-13 14:14:23 -08:00
Rafael J. Wysocki 798bc6d8d5 tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so files that are
build conditionally if CONFIG_PM_RUNTIME is set may now be build
if CONFIG_PM is set.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in kernel/trace/Makefile
for this reason.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org.
2014-12-13 02:23:30 +01:00
Linus Torvalds a7cb7bb664 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree update from Jiri Kosina:
 "Usual stuff: documentation updates, printk() fixes, etc"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
  intel_ips: fix a type in error message
  cpufreq: cpufreq-dt: Move newline to end of error message
  ps3rom: fix error return code
  treewide: fix typo in printk and Kconfig
  ARM: dts: bcm63138: change "interupts" to "interrupts"
  Replace mentions of "list_struct" to "list_head"
  kernel: trace: fix printk message
  scsi: mpt2sas: fix ioctl in comment
  zbud, zswap: change module author email
  clocksource: Fix 'clcoksource' typo in comment
  arm: fix wording of "Crotex" in CONFIG_ARCH_EXYNOS3 help
  gpio: msm-v1: make boolean argument more obvious
  usb: Fix typo in usb-serial-simple.c
  PCI: Fix comment typo 'COMFIG_PM_OPS'
  powerpc: Fix comment typo 'CONIFG_8xx'
  powerpc: Fix comment typos 'CONFiG_ALTIVEC'
  clk: st: Spelling s/stucture/structure/
  isci: Spelling s/stucture/structure/
  usb: gadget: zero: Spelling s/infrastucture/infrastructure/
  treewide: Fix company name in module descriptions
  ...
2014-12-12 10:08:06 -08:00
Linus Torvalds 350e4f4985 This code is a fork from the trace-3.19 pull as it needed the trace_seq
clean ups from that branch.
 
 This code solves the issue of performing stack dumps from NMI context.
 The issue is that printk() is not safe from NMI context as if the NMI
 were to trigger when a printk() was being performed, the NMI could
 deadlock from the printk() internal locks. This has been seen in practice.
 
 With lots of review from Petr Mladek, this code went through several
 iterations, and we feel that it is now at a point of quality to be
 accepted into mainline.
 
 Here's what is contained in this patch set:
 
  o Creates a "seq_buf" generic buffer utility that allows a descriptor
    to be passed around where functions can write their own "printk()"
    formatted strings into it. The generic version was pulled out of
    the trace_seq() code that was made specifically for tracing.
 
  o The seq_buf code was change to model the seq_file code. I have
    a patch (not included for 3.19) that converts the seq_file.c code
    over to use seq_buf.c like the trace_seq.c code does. This was done
    to make sure that seq_buf.c is compatible with seq_file.c. I may
    try to get that patch in for 3.20.
 
  o The seq_buf.c file was moved to lib/ to remove it from being dependent
    on CONFIG_TRACING.
 
  o The printk() was updated to allow for a per_cpu "override" of
    the internal calls. That is, instead of writing to the console, a call
    to printk() may do something else. This made it easier to allow the
    NMI to change what printk() does in order to call dump_stack() without
    needing to update that code as well.
 
  o Finally, the dump_stack from all CPUs via NMI code was converted to
    use the seq_buf code. The caller to trigger the NMI code would wait
    till all the NMIs finished, and then it would print the seq_buf
    data to the console safely from a non NMI context.
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Merge tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull nmi-safe seq_buf printk update from Steven Rostedt:
 "This code is a fork from the trace-3.19 pull as it needed the
  trace_seq clean ups from that branch.

  This code solves the issue of performing stack dumps from NMI context.
  The issue is that printk() is not safe from NMI context as if the NMI
  were to trigger when a printk() was being performed, the NMI could
  deadlock from the printk() internal locks.  This has been seen in
  practice.

  With lots of review from Petr Mladek, this code went through several
  iterations, and we feel that it is now at a point of quality to be
  accepted into mainline.

  Here's what is contained in this patch set:

   - Creates a "seq_buf" generic buffer utility that allows a descriptor
     to be passed around where functions can write their own "printk()"
     formatted strings into it.  The generic version was pulled out of
     the trace_seq() code that was made specifically for tracing.

   - The seq_buf code was change to model the seq_file code.  I have a
     patch (not included for 3.19) that converts the seq_file.c code
     over to use seq_buf.c like the trace_seq.c code does.  This was
     done to make sure that seq_buf.c is compatible with seq_file.c.  I
     may try to get that patch in for 3.20.

   - The seq_buf.c file was moved to lib/ to remove it from being
     dependent on CONFIG_TRACING.

   - The printk() was updated to allow for a per_cpu "override" of the
     internal calls.  That is, instead of writing to the console, a call
     to printk() may do something else.  This made it easier to allow
     the NMI to change what printk() does in order to call dump_stack()
     without needing to update that code as well.

   - Finally, the dump_stack from all CPUs via NMI code was converted to
     use the seq_buf code.  The caller to trigger the NMI code would
     wait till all the NMIs finished, and then it would print the
     seq_buf data to the console safely from a non NMI context

  One added bonus is that this code also makes the NMI dump stack work
  on PREEMPT_RT kernels.  As printk() includes sleeping locks on
  PREEMPT_RT, printk() only writes to console if the console does not
  use any rt_mutex converted spin locks.  Which a lot do"

* tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  x86/nmi: Fix use of unallocated cpumask_var_t
  printk/percpu: Define printk_func when printk is not defined
  x86/nmi: Perform a safe NMI stack trace on all CPUs
  printk: Add per_cpu printk func to allow printk to be diverted
  seq_buf: Move the seq_buf code to lib/
  seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF
  tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
  tracing: Have seq_buf use full buffer
  seq_buf: Add seq_buf_can_fit() helper function
  tracing: Add paranoid size check in trace_printk_seq()
  tracing: Use trace_seq_used() and seq_buf_used() instead of len
  tracing: Clean up tracing_fill_pipe_page()
  seq_buf: Create seq_buf_used() to find out how much was written
  tracing: Add a seq_buf_clear() helper and clear len and readpos in init
  tracing: Convert seq_buf fields to be like seq_file fields
  tracing: Convert seq_buf_path() to be like seq_path()
  tracing: Create seq_buf layer in trace_seq
2014-12-10 20:35:41 -08:00
Linus Torvalds 1dd7dcb6ea There was a lot of clean ups and minor fixes. One of those clean ups was
to the trace_seq code. It also removed the return values to the
 trace_seq_*() functions and use trace_seq_has_overflowed() to see if
 the buffer filled up or not. This is similar to work being done to the
 seq_file code as well in another tree.
 
 Some of the other goodies include:
 
  o Added some "!" (NOT) logic to the tracing filter.
 
  o Fixed the frame pointer logic to the x86_64 mcount trampolines
 
  o Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems.
    That is, the ftrace trampoline can be dynamically allocated
    and be called directly by functions that only have a single hook
    to them.
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Merge tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "There was a lot of clean ups and minor fixes.  One of those clean ups
  was to the trace_seq code.  It also removed the return values to the
  trace_seq_*() functions and use trace_seq_has_overflowed() to see if
  the buffer filled up or not.  This is similar to work being done to
  the seq_file code as well in another tree.

  Some of the other goodies include:

   - Added some "!" (NOT) logic to the tracing filter.

   - Fixed the frame pointer logic to the x86_64 mcount trampolines

   - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems.
     That is, the ftrace trampoline can be dynamically allocated and be
     called directly by functions that only have a single hook to them"

* tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits)
  tracing: Truncated output is better than nothing
  tracing: Add additional marks to signal very large time deltas
  Documentation: describe trace_buf_size parameter more accurately
  tracing: Allow NOT to filter AND and OR clauses
  tracing: Add NOT to filtering logic
  ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter
  ftrace/x86: Get rid of ftrace_caller_setup
  ftrace/x86: Have save_mcount_regs macro also save stack frames if needed
  ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs
  ftrace/x86: Simplify save_mcount_regs on getting RIP
  ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter
  ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments
  ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file
  ftrace/x86: Have static tracing also use ftrace_caller_setup
  ftrace/x86: Have static function tracing always test for function graph
  kprobes: Add IPMODIFY flag to kprobe_ftrace_ops
  ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict
  kprobes/ftrace: Recover original IP if pre_handler doesn't change it
  tracing/trivial: Fix typos and make an int into a bool
  tracing: Deletion of an unnecessary check before iput()
  ...
2014-12-10 19:58:13 -08:00
Arianna Avanzini 7eca210375 blktrace: don't let the sysfs interface remove trace from running list
Currently, blktrace can be started/stopped via its ioctl-based interface
(used by the userspace blktrace tool) or via its ftrace interface. The
function blk_trace_remove_queue(), called each time an "enable" tunable
of the ftrace interface transitions to zero, removes the trace from the
running list, even if no function from the sysfs interface adds it to
such a list. This leads to a null pointer dereference.  This commit
changes the blk_trace_remove_queue() function so that it does not remove
the blk_trace from the running list.

v2:
    - Now the patch removes the invocation of list_del() instead of
      adding an useless if branch, as suggested by Namhyung Kim.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 14:59:09 -07:00
Al Viro ba00410b81 Merge branch 'iov_iter' into for-next 2014-12-08 20:39:29 -05:00
Dan Carpenter 3558a5ac50 tracing: Truncated output is better than nothing
The initial reason for this patch is that I noticed that:

	if (len > TRACE_BUF_SIZE)

is off by one.  In this code, if len == TRACE_BUF_SIZE, then it means we
have truncated the last character off the output string.  If we truncate
two or more characters then we exit without printing.

After some discussion, we decided that printing truncated data is better
than not printing at all so we should just use vscnprintf() and remove
the test entirely.  Also I have updated memcpy() to copy the NUL char
instead of setting the NUL in a separate step.

Link: http://lkml.kernel.org/r/20141127155752.GA21914@mwanda

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 17:10:14 -05:00
Byungchul Park 8e1e1df29d tracing: Add additional marks to signal very large time deltas
Currently, function graph tracer prints "!" or "+" just before
function execution time to signal a function overhead, depending
on the time. And some tracers tracing latency also print "!" or
"+" just after time to signal overhead, depending on the interval
between events. Even it is usually enough to do that, we sometimes
need to signal for bigger execution time than 100 micro seconds.

For example, I used function graph tracer to detect if there is
any case that exit_mm() takes too much time. I did following steps
in /sys/kernel/debug/tracing. It was easier to detect very large
excution time with patched kernel than with original kernel.

$ echo exit_mm > set_graph_function
$ echo function_graph > current_tracer
$ echo > trace
$ cat trace_pipe > $LOGFILE
 ... (do something and terminate logging)
$ grep "\\$" $LOGFILE
 3) $ 22082032 us |                      } /* kernel_map_pages */
 3) $ 22082040 us |                    } /* free_pages_prepare */
 3) $ 22082113 us |                  } /* free_hot_cold_page */
 3) $ 22083455 us |                } /* free_hot_cold_page_list */
 3) $ 22083895 us |              } /* release_pages */
 3) $ 22177873 us |            } /* free_pages_and_swap_cache */
 3) $ 22178929 us |          } /* unmap_single_vma */
 3) $ 22198885 us |        } /* unmap_vmas */
 3) $ 22206949 us |      } /* exit_mmap */
 3) $ 22207659 us |    } /* mmput */
 3) $ 22207793 us |  } /* exit_mm */

And then, it was easy to find out that a schedule-out occured by
sub_preempt_count() within kernel_map_pages().

To detect very large function exection time caused by either problematic
function implementation or scheduling issues, this patch can be useful.

Link: http://lkml.kernel.org/r/1416789259-24038-1-git-send-email-byungchul.park@lge.com

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 17:10:13 -05:00
Steven Rostedt (Red Hat) eabb8980a9 tracing: Allow NOT to filter AND and OR clauses
Add support to allow not "!" for and (&&) and (||). That is:

 !(field1 == X && field2 == Y)

Where the value of the full clause will be notted.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 10:00:27 -05:00
Steven Rostedt (Red Hat) e12c09cf30 tracing: Add NOT to filtering logic
Ted noticed that he could not filter on an event for a bit being cleared.
That's because the filtering logic only tests event fields with a limited
number of comparisons which, for bit logic, only include "&", which can
test if a bit is set, but there's no good way to see if a bit is clear.

This adds a way to do: !(field & 2048)

Which returns true if the bit is not set, and false otherwise.

Note, currently !(field1 == 10 && field2 == 15) is not supported.
That is, the 'not' only works for direct comparisons, not for the
AND and OR logic.

Link: http://lkml.kernel.org/r/20141202021912.GA29096@thunk.org
Link: http://lkml.kernel.org/r/20141202120430.71979060@gandalf.local.home

Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Suggested-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 10:00:13 -05:00
Masami Hiramatsu f8b8be8a31 ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict
Introduce FTRACE_OPS_FL_IPMODIFY to avoid conflict among
ftrace users who may modify regs->ip to change the execution
path. If two or more users modify the regs->ip on the same
function entry, one of them will be broken. So they must add
IPMODIFY flag and make sure that ftrace_set_filter_ip() succeeds.

Note that ftrace doesn't allow ftrace_ops which has IPMODIFY
flag to have notrace hash, and the ftrace_ops must have a
filter hash (so that the ftrace_ops can hook only specific
entries), because it strongly depends on the address and
must be allowed for only few selected functions.

Link: http://lkml.kernel.org/r/20141121102516.11844.27829.stgit@localhost.localdomain

Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ fixed up some of the comments ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-21 14:42:10 -05:00
Steven Rostedt (Red Hat) 0af26492d5 tracing/trivial: Fix typos and make an int into a bool
Fix up a few typos in comments and convert an int into a bool in
update_traceon_count().

Link: http://lkml.kernel.org/r/546DD445.5080108@hitachi.com

Suggested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-20 10:05:36 -05:00
Jiri Kosina a02001086b Merge Linus' tree to be be to apply submitted patches to newer code than
current trivial.git base
2014-11-20 14:42:02 +01:00
Frans Klaver eff264efee kernel: trace: fix printk message
s,produciton,production

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-11-20 14:29:19 +01:00
Steven Rostedt (Red Hat) 8d58e99af5 seq_buf: Move the seq_buf code to lib/
The seq_buf functions are rather useful outside of tracing. Instead
of having it be dependent on CONFIG_TRACING, move the code into lib/
and allow other users to have access to it even when tracing is not
configured.

The seq_buf utility is similar to the seq_file utility, but instead of
writing sending data back up to userland, it writes it into a buffer
defined at seq_buf_init(). This allows us to send a descriptor around
that writes printf() formatted strings into it that can be retrieved
later.

It is currently used by the tracing facility for such things like trace
events to convert its binary saved data in the ring buffer into an
ASCII human readable context to be displayed in /sys/kernel/debug/trace.

It can also be used for doing NMI prints safely from NMI context into
the seq_buf and retrieved later and dumped to printk() safely. Doing
printk() from an NMI context is dangerous because an NMI can preempt
a current printk() and deadlock on it.

Link: http://lkml.kernel.org/p/20140619213952.058255809@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:20 -05:00
Steven Rostedt (Red Hat) 2448913ed2 seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF
The function bstr_printf() from lib/vsprnintf.c is only available if
CONFIG_BINARY_PRINTF is defined. This is due to the only user currently
being the tracing infrastructure, which needs to select this config
when tracing is configured. Until there is another user of the binary
printf formats, this will continue to be the case.

Since seq_buf.c is now lives in lib/ and is compiled even without
tracing, it must encompass its use of bstr_printf() which is used
by seq_buf_printf(). This too is only used by the tracing infrastructure
and is still encapsulated by the CONFIG_BINARY_PRINTF.

Link: http://lkml.kernel.org/r/20141104160222.969013383@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:19 -05:00
Steven Rostedt (Red Hat) 01cb06a4c2 tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
Add two helper functions; seq_buf_get_buf() and seq_buf_commit() that
are used by seq_buf_path(). This makes the code similar to the
seq_file: seq_path() function, and will help to be able to consolidate
the functions between seq_file and trace_seq.

Link: http://lkml.kernel.org/r/20141104160222.644881406@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.977571447@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:18 -05:00
Steven Rostedt (Red Hat) 8cd709ae76 tracing: Have seq_buf use full buffer
Currently seq_buf is full when all but one byte of the buffer is
filled. Change it so that the seq_buf is full when all of the
buffer is filled.

Some of the functions would fill the buffer completely and report
everything was fine. This was inconsistent with the max of size - 1.
Changing this to be max of size makes all functions consistent.

Link: http://lkml.kernel.org/r/20141104160222.502133196@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.811957882@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:17 -05:00
Steven Rostedt (Red Hat) 9b77215382 seq_buf: Add seq_buf_can_fit() helper function
Add a seq_buf_can_fit() helper function that removes the possible mistakes
of comparing the seq_buf length plus added data compared to the size of
the buffer.

Link: http://lkml.kernel.org/r/20141118164025.GL23958@pathway.suse.cz

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:17 -05:00
Steven Rostedt (Red Hat) 820b75f63d tracing: Add paranoid size check in trace_printk_seq()
To be really paranoid about writing out of bound data in
trace_printk_seq(), add another check of len compared to size.

Link: http://lkml.kernel.org/r/20141119144004.GB2332@dhcp128.suse.cz

Suggested-by: Petr Mladek <pmladek@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:16 -05:00
Steven Rostedt (Red Hat) 5ac4837841 tracing: Use trace_seq_used() and seq_buf_used() instead of len
As the seq_buf->len will soon be +1 size when there's an overflow, we
must use trace_seq_used() or seq_buf_used() methods to get the real
length. This will prevent buffer overflow issues if just the len
of the seq_buf descriptor is used to copy memory.

Link: http://lkml.kernel.org/r/20141114121911.09ba3d38@gandalf.local.home

Reported-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:15 -05:00
Steven Rostedt (Red Hat) 74f06bb723 tracing: Clean up tracing_fill_pipe_page()
The function tracing_fill_pipe_page() logic is a little confusing with the
use of count saving the seq.len and reusing it.

Instead of subtracting a number that is calculated from the saved
value of the seq.len from seq.len, just save the seq.len at the start
and if we need to reset it, just assign it again.

When the seq_buf overflow is len == size + 1, the current logic will
break. Changing it to use a saved length for resetting back to the
original value is more robust and will work when we change the way
seq_buf sets the overflow.

Link: http://lkml.kernel.org/r/20141118161546.GJ23958@pathway.suse.cz

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:14 -05:00
Steven Rostedt (Red Hat) eeab98154d seq_buf: Create seq_buf_used() to find out how much was written
Add a helper function seq_buf_used() that replaces the SEQ_BUF_USED()
private macro to let callers have a method to know how much of the
seq_buf was written to.

Link: http://lkml.kernel.org/r/20141114011412.170377300@goodmis.org
Link: http://lkml.kernel.org/r/20141114011413.321654244@goodmis.org

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:13 -05:00
Steven Rostedt (Red Hat) dd23180aac tracing: Convert seq_buf_path() to be like seq_path()
Rewrite seq_buf_path() like it is done in seq_path() and allow
it to accept any escape character instead of just "\n".

Making seq_buf_path() like seq_path() will help prevent problems
when converting seq_file to use the seq_buf logic.

Link: http://lkml.kernel.org/r/20141104160222.048795666@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.338523371@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:10 -05:00
Steven Rostedt (Red Hat) 3a161d99c4 tracing: Create seq_buf layer in trace_seq
Create a seq_buf layer that trace_seq sits on. The seq_buf will not
be limited to page size. This will allow other usages of seq_buf
instead of a hard set PAGE_SIZE one that trace_seq has.

Link: http://lkml.kernel.org/r/20141104160221.864997179@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.170377300@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:09 -05:00
Markus Elfring 16a8ef2751 tracing: Deletion of an unnecessary check before iput()
The iput() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/5468F875.7080907@users.sourceforge.net

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 16:28:45 -05:00
Steven Rostedt (Red Hat) 8e2e095cbe tracing: Fix return value of ftrace_raw_output_prep()
If the trace_seq of ftrace_raw_output_prep() is full this function
returns TRACE_TYPE_PARTIAL_LINE, otherwise it returns zero.

The problem is that TRACE_TYPE_PARTIAL_LINE happens to be zero!

The thing is, the caller of ftrace_raw_output_prep() expects a
success to be zero. Change that to expect it to be
TRACE_TYPE_HANDLED.

Link: http://lkml.kernel.org/r/20141114112522.GA2988@dhcp128.suse.cz

Reminded-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:48 -05:00
Steven Rostedt (Red Hat) dba39448ab tracing: Remove return values of most trace_seq_*() functions
The trace_seq_printf() and friends are used to store strings into a buffer
that can be passed around from function to function. If the trace_seq buffer
fills up, it will not print any more. The return values were somewhat
inconsistant and using trace_seq_has_overflowed() was a better way to know
if the write to the trace_seq buffer succeeded or not.

Now that all users have removed reading the return value of the printf()
type functions, they can safely return void and keep future users of them
from reading the inconsistent values as well.

Link: http://lkml.kernel.org/r/20141114011411.992510720@goodmis.org

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:47 -05:00
Steven Rostedt (Red Hat) 183742f08c tracing: Do not use return values of trace_seq_printf() in syscall tracing
The functions trace_seq_printf() and friends will not be returning values
soon and will be void functions. To know if they succeeded or not, the
functions trace_seq_has_overflowed() and trace_handle_return() should be
used instead.

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:46 -05:00
Steven Rostedt (Red Hat) 8579a107a6 tracing/uprobes: Do not use return values of trace_seq_printf()
The functions trace_seq_printf() and friends will soon no longer have
return values. Using trace_seq_has_overflowed() and trace_handle_return()
should be used instead.

Link: http://lkml.kernel.org/r/20141114011411.693008134@goodmis.org
Link: http://lkml.kernel.org/r/20141115050602.333705855@goodmis.org

Reviewed-by: Masami Hiramatsu <masami.hiramatu.pt@hitachi.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:45 -05:00
Steven Rostedt (Red Hat) d2b0191a38 tracing/probes: Do not use return value of trace_seq_printf()
The functions trace_seq_printf() and friends will soon not have a return
value and will only be a void function. Use trace_seq_has_overflowed()
instead to know if the trace_seq operations succeeded or not.

Link: http://lkml.kernel.org/r/20141114011411.530216306@goodmis.org

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:44 -05:00
Steven Rostedt (Red Hat) a72e10afab tracing: Do not check return values of trace_seq_p*() for mmio tracer
The return values for trace_seq_printf() and friends are going to be
removed and they will become void functions. The mmio tracer checked
their return and even did so incorrectly.

Some of the funtions which returned the values were never checked
themselves. Removing all the checks simplifies the code.

Use trace_seq_has_overflowed() and trace_handle_return() where
necessary instead.

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:44 -05:00
Steven Rostedt (Red Hat) 85224da0b8 kprobes/tracing: Use trace_seq_has_overflowed() for overflow checks
Instead of checking the return value of trace_seq_printf() and friends
for overflowing of the buffer, use the trace_seq_has_overflowed() helper
function.

This cleans up the code quite a bit and also takes us a step closer to
changing the return values of trace_seq_printf() and friends to void.

Link: http://lkml.kernel.org/r/20141114011411.181812785@goodmis.org

Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:43 -05:00
Steven Rostedt (Red Hat) 9d9add34ec tracing: Have function_graph use trace_seq_has_overflowed()
Instead of doing individual checks all over the place that makes the code
very messy. Just check trace_seq_has_overflowed() at the end or in
strategic places.

This makes the code much cleaner and also helps with getting closer
to removing the return values of trace_seq_printf() and friends.

Link: http://lkml.kernel.org/r/20141114011410.987913836@goodmis.org

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:42 -05:00
Steven Rostedt (Red Hat) 7d40f67165 tracing: Have branch tracer use trace_handle_return() helper function
The branch tracer should not be checking the trace_seq_printf() return value
as that will soon be void. There's a new trace_handle_return() helper function
that will return TRACE_TYPE_PARTIAL_LINE if the trace_seq overflowed
and TRACE_TYPE_HANDLED otherwise.

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:41 -05:00
Steven Rostedt (Red Hat) c0cd93aa16 ring-buffer: Remove check of trace_seq_{puts,printf}() return values
Remove checking the return value of all trace_seq_puts(). It was wrong
anyway as only the last return value mattered. But as the trace_seq_puts()
is going to be a void function in the future, we should not be checking
the return value of it anyway.

Just return !trace_seq_has_overflowed() instead.

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:40 -05:00
Steven Rostedt (Red Hat) f4a1d08ce6 blktrace/tracing: Use trace_seq_has_overflowed() helper function
Checking the return code of every trace_seq_printf() operation and having
to return early if it overflowed makes the code messy.

Using the new trace_seq_has_overflowed() and trace_handle_return() functions
allows us to clean up the code.

In the future, trace_seq_printf() and friends will be turning into void
functions and not returning a value. The trace_seq_has_overflowed() is to
be used instead. This cleanup allows that change to take place.

Cc: Jens Axboe <axboe@fb.com>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:39 -05:00
Steven Rostedt (Red Hat) 19a7fe2062 tracing: Add trace_seq_has_overflowed() and trace_handle_return()
Adding a trace_seq_has_overflowed() which returns true if the trace_seq
had too much written into it allows us to simplify the code.

Instead of checking the return value of every call to trace_seq_printf()
and friends, they can all be called normally, and at the end we can
return !trace_seq_has_overflowed() instead.

Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq
overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function
was created called trace_handle_return() which takes a trace_seq and
returns these enums. Using this helper function also simplifies the
code.

This change also makes it possible to remove the return values of
trace_seq_printf() and friends. They should instead just be
void functions.

Link: http://lkml.kernel.org/r/20141114011410.365183157@goodmis.org

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:39 -05:00
Steven Rostedt (Red Hat) e400a40cff tracing: Fix trace_seq_bitmask() to start at current position
In trace_seq_bitmask() it calls bitmap_scnprintf() not from the current
position of the trace_seq buffer (s->buffer + s->len), but instead from
the beginning of the buffer (s->buffer).

Luckily, the only user of this "ipi_raise tracepoint" uses it as the
first parameter, and as such, the start of the temp buffer in
include/trace/ftrace.h (see __get_bitmask()).

Reported-by: Petr Mladek <pmladek@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:38 -05:00
Steven Rostedt (Red Hat) aec0be2d6e ftrace/x86/extable: Add is_ftrace_trampoline() function
Stack traces that happen from function tracing check if the address
on the stack is a __kernel_text_address(). That is, is the address
kernel code. This calls core_kernel_text() which returns true
if the address is part of the builtin kernel code. It also calls
is_module_text_address() which returns true if the address belongs
to module code.

But what is missing is ftrace dynamically allocated trampolines.
These trampolines are allocated for individual ftrace_ops that
call the ftrace_ops callback functions directly. But if they do a
stack trace, the code checking the stack wont detect them as they
are neither core kernel code nor module address space.

Adding another field to ftrace_ops that also stores the size of
the trampoline assigned to it we can create a new function called
is_ftrace_trampoline() that returns true if the address is a
dynamically allocate ftrace trampoline. Note, it ignores trampolines
that are not dynamically allocated as they will return true with
the core_kernel_text() function.

Link: http://lkml.kernel.org/r/20141119034829.497125839@goodmis.org

Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:26 -05:00
Steven Rostedt (Red Hat) a9ce7c36aa tracing: Fix race of function probes counting
The function probe counting for traceon and traceoff suffered a race
condition where if the probe was executing on two or more CPUs at the
same time, it could decrement the counter by more than one when
disabling (or enabling) the tracer only once.

The way the traceon and traceoff probes are suppose to work is that
they disable (or enable) tracing once per count. If a user were to
echo 'schedule:traceoff:3' into set_ftrace_filter, then when the
schedule function was called, it would disable tracing. But the count
should only be decremented once (to 2). Then if the user enabled tracing
again (via tracing_on file), the next call to schedule would disable
tracing again and the count would be decremented to 1.

But if multiple CPUS called schedule at the same time, it is possible
that the count would be decremented more than once because of the
simple "count--" used.

By reading the count into a local variable and using memory barriers
we can guarantee that the count would only be decremented once per
disable (or enable).

The stack trace probe had a similar race, but here the stack trace will
decrement for each time it is called. But this had the read-modify-
write race, where it could stack trace more than the number of times
that was specified. This case we use a cmpxchg to stack trace only the
number of times specified.

The dump probes can still use the old "update_count()" function as
they only run once, and that is controlled by the dump logic
itself.

Link: http://lkml.kernel.org/r/20141118134643.4b550ee4@gandalf.local.home

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-18 23:06:35 -05:00
Byungchul Park 4526d0676a function_graph: Fix micro seconds notations
Usually, "msecs" notation means milli-seconds, and "usecs" notation
means micro-seconds. Since the unit used in the code is micro-seconds,
the notation should be replaced from msecs to usecs.

Link: http://lkml.kernel.org/r/1415171926-9782-2-git-send-email-byungchul.park@lge.com

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-14 07:56:03 -05:00
Daniel Bristot de Oliveira 678f845ed0 ftrace-graph: show latency-format on print_graph_irq()
On the function_graph tracer, the print_graph_irq() function prints a
trace line with the flag ==========> on an irq handler entry, and the
flag <========== on an irq handler return.

But when the latency-format is enable, it is not printing the
latency-format flags, causing the following error in the trace output:

 0)   ==========> |
 0)  d...              |  smp_apic_timer_interrupt() {

This patch fixes this issue by printing the latency-format flags when
it is enable.

Link: http://lkml.kernel.org/r/7c2e226dac20c940b6242178fab7f0e3c9b5ce58.1415233316.git.bristot@redhat.com

Reviewed-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-14 07:56:02 -05:00
Rasmus Villemoes 1177e43641 trace: Replace single-character seq_puts with seq_putc
Printing a single character to a seqfile might as well be done with
seq_putc instead of seq_puts; this avoids a strlen() call and a memory
access. It also shaves another few bytes off the generated code.

Link: http://lkml.kernel.org/r/1415479332-25944-4-git-send-email-linux@rasmusvillemoes.dk

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-14 07:55:55 -05:00
Rasmus Villemoes d79ac28fde tracing: Merge consecutive seq_puts calls
Consecutive seq_puts calls with literal strings can be merged to a
single call. This reduces the size of the generated code, and can also
lead to slight .rodata reduction (because of fewer nul and padding
bytes). It should also shave a off a few clock cycles.

Link: http://lkml.kernel.org/r/1415479332-25944-3-git-send-email-linux@rasmusvillemoes.dk

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-13 21:33:34 -05:00