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  1. 31 May, 2017 2 commits
    • Imre Deak's avatar
      drm/i915: Prevent the system suspend complete optimization · adfdf85d
      Imre Deak authored 
      Since

commit bac2a909
Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date:   Wed Jan 21 02:17:42 2015 +0100

    PCI / PM: Avoid resuming PCI devices during system suspend

PCI devices will default to allowing the system suspend complete
optimization where devices are not woken up during system suspend if
they were already runtime suspended. This however breaks the i915/HDA
drivers for two reasons:

- The i915 driver has system suspend specific steps that it needs to
  run, that bring the device to a different state than its runtime
  suspended state.

- The HDA driver's suspend handler requires power that it will request
  from the i915 driver's power domain handler. This in turn requires the
  i915 driver to runtime resume itself, but this won't be possible if the
  suspend complete optimization is in effect: in this case the i915
  runtime PM is disabled and trying to get an RPM reference returns
  -EACCESS.

Solve this by requiring the PCI/PM core to resume the device during
system suspend which in effect disables the suspend complete optimization.

Regardless of the above commit the optimization stayed disabled for DRM
devices until

commit d14d2a84
Author: Lukas Wunner <lukas@wunner.de>
Date:   Wed Jun 8 12:49:29 2016 +0200

    drm: Remove dev_pm_ops from drm_class

so this patch is in practice a fix for this commit. Another reason for
the bug staying hidden for so long is that the optimization for a device
is disabled if it's disabled for any of its children devices. i915 may
have a backlight device as its child which doesn't support runtime PM
and so doesn't allow the optimization either.  So if this backlight
device got registered the bug stayed hidden.

Credits to Marta, Tomi and David who enabled pstore logging,
that caught one instance of this issue across a suspend/
resume-to-ram and Ville who rememberd that the optimization was enabled
for some devices at one point.

The first WARN triggered by the problem:

[ 6250.746445] WARNING: CPU: 2 PID: 17384 at drivers/gpu/drm/i915/intel_runtime_pm.c:2846 intel_runtime_pm_get+0x6b/0xd0 [i915]
[ 6250.746448] pm_runtime_get_sync() failed: -13
[ 6250.746451] Modules linked in: snd_hda_intel i915 vgem snd_hda_codec_hdmi x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul
snd_hda_codec_realtek snd_hda_codec_generic ghash_clmulni_intel e1000e snd_hda_codec snd_hwdep snd_hda_core ptp mei_me pps_core snd_pcm lpc_ich mei prime_
numbers i2c_hid i2c_designware_platform i2c_designware_core [last unloaded: i915]
[ 6250.746512] CPU: 2 PID: 17384 Comm: kworker/u8:0 Tainted: G     U  W       4.11.0-rc5-CI-CI_DRM_334+ #1
[ 6250.746515] Hardware name:                  /NUC5i5RYB, BIOS RYBDWi35.86A.0362.2017.0118.0940 01/18/2017
[ 6250.746521] Workqueue: events_unbound async_run_entry_fn
[ 6250.746525] Call Trace:
[ 6250.746530]  dump_stack+0x67/0x92
[ 6250.746536]  __warn+0xc6/0xe0
[ 6250.746542]  ? pci_restore_standard_config+0x40/0x40
[ 6250.746546]  warn_slowpath_fmt+0x46/0x50
[ 6250.746553]  ? __pm_runtime_resume+0x56/0x80
[ 6250.746584]  intel_runtime_pm_get+0x6b/0xd0 [i915]
[ 6250.746610]  intel_display_power_get+0x1b/0x40 [i915]
[ 6250.746646]  i915_audio_component_get_power+0x15/0x20 [i915]
[ 6250.746654]  snd_hdac_display_power+0xc8/0x110 [snd_hda_core]
[ 6250.746661]  azx_runtime_resume+0x218/0x280 [snd_hda_intel]
[ 6250.746667]  pci_pm_runtime_resume+0x76/0xa0
[ 6250.746672]  __rpm_callback+0xb4/0x1f0
[ 6250.746677]  ? pci_restore_standard_config+0x40/0x40
[ 6250.746682]  rpm_callback+0x1f/0x80
[ 6250.746686]  ? pci_restore_standard_config+0x40/0x40
[ 6250.746690]  rpm_resume+0x4ba/0x740
[ 6250.746698]  __pm_runtime_resume+0x49/0x80
[ 6250.746703]  pci_pm_suspend+0x57/0x140
[ 6250.746709]  dpm_run_callback+0x6f/0x330
[ 6250.746713]  ? pci_pm_freeze+0xe0/0xe0
[ 6250.746718]  __device_suspend+0xf9/0x370
[ 6250.746724]  ? dpm_watchdog_set+0x60/0x60
[ 6250.746730]  async_suspend+0x1a/0x90
[ 6250.746735]  async_run_entry_fn+0x34/0x160
[ 6250.746741]  process_one_work+0x1f2/0x6d0
[ 6250.746749]  worker_thread+0x49/0x4a0
[ 6250.746755]  kthread+0x107/0x140
[ 6250.746759]  ? process_one_work+0x6d0/0x6d0
[ 6250.746763]  ? kthread_create_on_node+0x40/0x40
[ 6250.746768]  ret_from_fork+0x2e/0x40
[ 6250.746778] ---[ end trace 102a62fd2160f5e6 ]---

v2:
- Use the new pci_dev->needs_resume flag, to avoid any overhead during
  the ->pm_prepare hook. (Rafael)

v3:
- Update commit message to reference the actual regressing commit.
  (Lukas)

v4:
- Rebase on v4 of patch 1/2.

Fixes: d14d2a84 ("drm: Remove dev_pm_ops from drm_class")
References: https://bugs.freedesktop.org/show_bug.cgi?id=100378
References: https://bugs.freedesktop.org/show_bug.cgi?id=100770
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Marta Lofstedt <marta.lofstedt@intel.com>
Cc: David Weinehall <david.weinehall@linux.intel.com>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: linux-pci@vger.kernel.org
Cc: <stable@vger.kernel.org> # v4.10.x: 4d071c32 - PCI/PM: Add needs_resume flag
Cc: <stable@vger.kernel.org> # v4.10.x
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reported-and-tested-by: default avatarMarta Lofstedt <marta.lofstedt@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1493726649-32094-2-git-send-email-imre.deak@intel.com
      adfdf85d
    • Michel Thierry's avatar
      drm/i915/guc: Fix doorbell id selection · 7f1ea2ac
      Michel Thierry authored 
      We are passing parameters in the wrong order to find next zero bit, and
when it doesn't find anything it returns size (offset in the code), which
is always zero.

For reference the function is defined as:
find_next_bit( *addr, size, offset )

The incorrect parameter order was added by commit abddffdf
("drm/i915/guc: Sanitize GuC client initialization"). Luckily, currently
we only use a single guc client and a single doorbell, which happens to be
zero; therefore it isn't necessary to backport this fix (which would be for
v4.12).

Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Signed-off-by: default avatarMichel Thierry <michel.thierry@intel.com>
Reviewed-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170531000546.30762-1-michel.thierry@intel.com
      7f1ea2ac
  3. 30 May, 2017 22 commits
  5. 29 May, 2017 2 commits
  7. 28 May, 2017 2 commits
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal · d09bc680
      Linus Torvalds authored 
      Pull thermal SoC management fixes from Eduardo Valentin:

 - fixes to TI SoC driver, Broadcom, qoriq

 - small sparse warning fix on thermal core

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
  thermal: broadcom: ns-thermal: default on iProc SoCs
  ti-soc-thermal: Fix a typo in a comment line
  ti-soc-thermal: Delete error messages for failed memory allocations in ti_bandgap_build()
  ti-soc-thermal: Use devm_kcalloc() in ti_bandgap_build()
  thermal: core: make thermal_emergency_poweroff static
  thermal: qoriq: remove useless call for of_thermal_get_trip_points()
      d09bc680
    • Dave Airlie's avatar
      Merge tag 'drm-misc-next-2017-05-26' of git://anongit.freedesktop.org/git/drm-misc into drm-next · 1afc4544
      Dave Airlie authored 
      UAPI Changes:
- Add DRM_MODE_ROTATE_ and DRM_MODE_REFLECT_ defines to the UAPI (Robert)

Cross-subsystem Changes:
- Standardize sync_file.txt documentation format (Mauro)

Core Changes:
- Turf drm_[cm]alloc functions for kvmalloc alternatives (Michal)
- Add optional mode_valid() hook to crtc/encoder/bridge (Jose)
- Improve documentation around mode validation/alteration (Daniel)
- Reduce sync_file construction time by deferring name creation (Chris)

Driver Changes:
- pl111: Wire up the clock divider and add debugfs (Eric)
- various: Fix include notation and remove -Iinclude/drm (Masahiro)
- stm: Add Benjamin Gaignard and Vincent Abriou as STM maintainers (Vincent)
- various: Miscellaneous trivial fixes to pl111/stm/vgem/vc4

Cc: Michal Hocko <mhocko@suse.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Robert Foss <robert.foss@collabora.com>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>

* tag 'drm-misc-next-2017-05-26' of git://anongit.freedesktop.org/git/drm-misc: (55 commits)
  dma-buf/sync-file: Defer creation of sync_file->name
  sync_file.txt: standardize document format
  gpu: drm: gma500: remove two more dead variable
  drm/doc: Clarify mode_fixup vs. atomic_check a bit more
  drm/doc: Document adjusted/request modes a bit better
  drm: Add crtc/encoder/bridge->mode_valid() callbacks
  MAINTAINERS: update drm/stm maintainers list
  drm/stm: ltdc: fix duplicated arguments
  drm/pl111: Fix return value check in pl111_amba_probe()
  drm/amd: include <linux/delay.h> instead of "linux/delay.h"
  drm: Add DRM_MODE_ROTATE_ and DRM_MODE_REFLECT_ to UAPI
  drm/vgem: Fix return value check in vgem_init()
  drm/blend: Fix comment typ-o
  drm/stm: remove unneeded -Iinclude/drm compiler flag
  drm/vc4: fix include notation and remove -Iinclude/drm flag
  drm/pl111: Add a debugfs node to dump our registers.
  drm/pl111: make structure mode_config_funcs static
  drm/pl111: make structure pl111_display_funcs static
  drm/pl111: Register the clock divider and use it.
  drm: drop drm_[cm]alloc* helpers
  ...
      1afc4544
  9. 27 May, 2017 12 commits
    • Linus Torvalds's avatar
      Merge tag 'tty-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · 249f1efd
      Linus Torvalds authored 
      Pull tty/serial fixes from Greg KH:
 "Here are some serial and tty fixes for 4.12-rc3. They are a bit bigger
  than normal, which is why I had them bake in linux-next for a few
  weeks and didn't send them to you for -rc2.

  They revert a few of the serdev patches from 4.12-rc1, and bring
  things back to how they were in 4.11, to try to make things a bit more
  stable there. Rob and Johan both agree that this is the way forward,
  so this isn't people squabbling over semantics. Other than that, just
  a few minor serial driver fixes that people have had problems with.

  All of these have been in linux-next for a few weeks with no reported
  issues"

* tag 'tty-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: altera_uart: call iounmap() at driver remove
  serial: imx: ensure UCR3 and UFCR are setup correctly
  MAINTAINERS/serial: Change maintainer of jsm driver
  serial: enable serdev support
  tty/serdev: add serdev registration interface
  serdev: Restore serdev_device_write_buf for atomic context
  serial: core: fix crash in uart_suspend_port
  tty: fix port buffer locking
  tty: ehv_bytechan: clean up init error handling
  serial: ifx6x60: fix use-after-free on module unload
  serial: altera_jtaguart: adding iounmap()
  serial: exar: Fix stuck MSIs
  serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'
  serdev: fix tty-port client deregistration
  Revert "tty_port: register tty ports with serdev bus"
  drivers/tty: 8250: only call fintek_8250_probe when doing port I/O
      249f1efd
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 6f68a6ae
      Linus Torvalds authored 
      Pull powerpc fixes from Michael Ellerman:
 "Fix running SPU programs on Cell, and a few other minor fixes.

  Thanks to Alistair Popple, Jeremy Kerr, Michael Neuling, Nicholas
  Piggin"

* tag 'powerpc-4.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Add PPC_FEATURE userspace bits for SCV and DARN instructions
  powerpc/spufs: Fix hash faults for kernel regions
  powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N
  powerpc/powernv/npu-dma.c: Fix opal_npu_destroy_context() call
  selftests/powerpc: Fix TM resched DSCR test with some compilers
      6f68a6ae
    • Linus Torvalds's avatar
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 38e6bf23
      Linus Torvalds authored 
      Pull x86 fixes from Thomas Gleixner:
 "A series of fixes for X86:

   - The final fix for the end-of-stack issue in the unwinder
   - Handle non PAT systems gracefully
   - Prevent access to uninitiliazed memory
   - Move early delay calaibration after basic init
   - Fix Kconfig help text
   - Fix a cross compile issue
   - Unbreak older make versions"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/timers: Move simple_udelay_calibration past init_hypervisor_platform
  x86/alternatives: Prevent uninitialized stack byte read in apply_alternatives()
  x86/PAT: Fix Xorg regression on CPUs that don't support PAT
  x86/watchdog: Fix Kconfig help text file path reference to lockup watchdog documentation
  x86/build: Permit building with old make versions
  x86/unwind: Add end-of-stack check for ftrace handlers
  Revert "x86/entry: Fix the end of the stack for newly forked tasks"
  x86/boot: Use CROSS_COMPILE prefix for readelf
      38e6bf23
    • Linus Torvalds's avatar
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 39b8ab31
      Linus Torvalds authored 
      Pull timer fixlet from Thomas Gleixner:
 "Silence dmesg spam by making the posix cpu timer printks depend on
  print_fatal_signals"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-timers: Make signal printks conditional
      39b8ab31
    • Linus Torvalds's avatar
      Merge branch 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · de0b9d75
      Linus Torvalds authored 
      Pull RAS fixes from Thomas Gleixner:
 "Two fixlets for RAS:

   - Export memory_error() so the NFIT module can utilize it

   - Handle memory errors in NFIT correctly"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  acpi, nfit: Fix the memory error check in nfit_handle_mce()
  x86/MCE: Export memory_error()
      de0b9d75
    • Linus Torvalds's avatar
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · fac3fcae
      Linus Torvalds authored 
      Pull perf tooling fixes from Thomas Gleixner:

 - Synchronization of tools and kernel headers

 - A series of fixes for perf report addressing various failures:
    * Handle invalid maps proper
    * Plug a memory leak
    * Handle frames and callchain order correctly

 - Fixes for handling inlines and children mode

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/include: Sync kernel ABI headers with tooling headers
  perf tools: Put caller above callee in --children mode
  perf report: Do not drop last inlined frame
  perf report: Always honor callchain order for inlined nodes
  perf script: Add --inline option for debugging
  perf report: Fix off-by-one for non-activation frames
  perf report: Fix memory leak in addr2line when called by addr2inlines
  perf report: Don't crash on invalid maps in `-g srcline` mode
      fac3fcae
    • Linus Torvalds's avatar
      Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 805f2869
      Linus Torvalds authored 
      Pull locking fix from Thomas Gleixner:
 "A fix for a state leak which was introduced in the recent rework of
  futex/rtmutex interaction"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()
      805f2869
    • Linus Torvalds's avatar
      Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · d024baa5
      Linus Torvalds authored 
      Pull kthread fix from Thomas Gleixner:
 "A single fix which prevents a use after free when kthread fork fails"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kthread: Fix use-after-free if kthread fork fails
      d024baa5
    • Linus Torvalds's avatar
      Merge tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 77d64656
      Linus Torvalds authored 
      Pull ftrace fixes from Steven Rostedt:
 "There's been a few memory issues found with ftrace.

  One was simply a memory leak where not all was being freed that should
  have been in releasing a file pointer on set_graph_function.

  Then Thomas found that the ftrace trampolines were marked for
  read/write as well as execute. To shrink the possible attack surface,
  he added calls to set them to ro. Which also uncovered some other
  issues with freeing module allocated memory that had its permissions
  changed.

  Kprobes had a similar issue which is fixed and a selftest was added to
  trigger that issue again"

* tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  x86/ftrace: Make sure that ftrace trampolines are not RWX
  x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range()
  selftests/ftrace: Add a testcase for many kprobe events
  kprobes/x86: Fix to set RWX bits correctly before releasing trampoline
  ftrace: Fix memory leak in ftrace_graph_release()
      77d64656
    • Thomas Gleixner's avatar
      x86/ftrace: Make sure that ftrace trampolines are not RWX · 6ee98ffe
      Thomas Gleixner authored 
      ftrace use module_alloc() to allocate trampoline pages. The mapping of
module_alloc() is RWX, which makes sense as the memory is written to right
after allocation. But nothing makes these pages RO after writing to them.

Add proper set_memory_rw/ro() calls to protect the trampolines after
modification.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705251056410.1862@nanosSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      6ee98ffe
    • Steven Rostedt (VMware)'s avatar
      x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range() · a53276e2
      Steven Rostedt (VMware) authored 
      With function tracing starting in early bootup and having its trampoline
pages being read only, a bug triggered with the following:

kernel BUG at arch/x86/mm/pageattr.c:189!
invalid opcode: 0000 [#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc2-test+ #3
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
task: ffffffffb4222500 task.stack: ffffffffb4200000
RIP: 0010:change_page_attr_set_clr+0x269/0x302
RSP: 0000:ffffffffb4203c88 EFLAGS: 00010046
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 00000001b6000000
RDX: ffffffffb4203d40 RSI: 0000000000000000 RDI: ffffffffb4240d60
RBP: ffffffffb4203d18 R08: 00000001b6000000 R09: 0000000000000001
R10: ffffffffb4203aa8 R11: 0000000000000003 R12: ffffffffc029b000
R13: ffffffffb4203d40 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff9a639ea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff9a636b384000 CR3: 00000001ea21d000 CR4: 00000000000406b0
Call Trace:
 change_page_attr_clear+0x1f/0x21
 set_memory_ro+0x1e/0x20
 arch_ftrace_update_trampoline+0x207/0x21c
 ? ftrace_caller+0x64/0x64
 ? 0xffffffffc029b000
 ftrace_startup+0xf4/0x198
 register_ftrace_function+0x26/0x3c
 function_trace_init+0x5e/0x73
 tracer_init+0x1e/0x23
 tracing_set_tracer+0x127/0x15a
 register_tracer+0x19b/0x1bc
 init_function_trace+0x90/0x92
 early_trace_init+0x236/0x2b3
 start_kernel+0x200/0x3f5
 x86_64_start_reservations+0x29/0x2b
 x86_64_start_kernel+0x17c/0x18f
 secondary_startup_64+0x9f/0x9f
 ? secondary_startup_64+0x9f/0x9f

Interrupts should not be enabled at this early in the boot process. It is
also fine to leave interrupts enabled during this time as there's only one
CPU running, and on_each_cpu() means to only run on the current CPU.

If early_boot_irqs_disabled is set, it is safe to run cpu_flush_range() with
interrupts disabled. Don't trigger a BUG_ON() in that case.

Link: http://lkml.kernel.org/r/20170526093717.0be3b849@gandalf.local.homeSuggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      a53276e2
    • Masami Hiramatsu's avatar
      selftests/ftrace: Add a testcase for many kprobe events · bdd7e3d6
      Masami Hiramatsu authored 
      Add a testcase to test kprobes via ftrace interface
with many concurrent kprobe events.

This tries to add many kprobe events (up to 256) on
kernel functions. To avoid making ftrace-based
kprobes (kprobes on fentry), it skips first N bytes
(on x86 N=5, on ppc or arm N=4) of function entry.
After that, it enables all those events, disable it,
and remove it.

Since the unoptimization buffer reclaiming will
be delayed, after removing events, it will wait
enough time.

Link: http://lkml.kernel.org/r/149577388470.11702.11832460851769204511.stgit@devboxSigned-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Suggested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      bdd7e3d6
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