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linux-next/Documentation
Alban Crequy 696ced4fb1 tracing/kprobes: expose maxactive for kretprobe in kprobe_events
When a kretprobe is installed on a kernel function, there is a maximum
limit of how many calls in parallel it can catch (aka "maxactive"). A
kernel module could call register_kretprobe() and initialize maxactive
(see example in samples/kprobes/kretprobe_example.c).

But that is not exposed to userspace and it is currently not possible to
choose maxactive when writing to /sys/kernel/debug/tracing/kprobe_events

The default maxactive can be as low as 1 on single-core with a
non-preemptive kernel. This is too low and we need to increase it not
only for recursive functions, but for functions that sleep or resched.

This patch updates the format of the command that can be written to
kprobe_events so that maxactive can be optionally specified.

I need this for a bpf program attached to the kretprobe of
inet_csk_accept, which can sleep for a long time.

This patch includes a basic selftest:

> # ./ftracetest -v  test.d/kprobe/
> === Ftrace unit tests ===
> [1] Kprobe dynamic event - adding and removing	[PASS]
> [2] Kprobe dynamic event - busy event check	[PASS]
> [3] Kprobe dynamic event with arguments	[PASS]
> [4] Kprobes event arguments with types	[PASS]
> [5] Kprobe dynamic event with function tracer	[PASS]
> [6] Kretprobe dynamic event with arguments	[PASS]
> [7] Kretprobe dynamic event with maxactive	[PASS]
>
> # of passed:  7
> # of failed:  0
> # of unresolved:  0
> # of untested:  0
> # of unsupported:  0
> # of xfailed:  0
> # of undefined(test bug):  0

BugLink: https://github.com/iovisor/bcc/issues/1072
Link: http://lkml.kernel.org/r/1491215782-15490-1-git-send-email-alban@kinvolk.io

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-04 10:32:03 -04:00
..
ABI RTC for 4.11 2017-02-27 19:59:21 -08:00
accounting tools: move accounting tool from Documentation 2016-09-23 13:07:15 -06:00
acpi scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
admin-guide Power management updates for v4.11-rc2 2017-03-09 16:30:37 -08:00
aoe
arm arm: sunxi: add support for V3s SoC 2017-01-20 21:31:34 +01:00
arm64 irqchip/gicv3-its: Add workaround for QDF2400 ITS erratum 0065 2017-03-07 14:34:27 +00:00
auxdisplay samples: move auxdisplay example code from Documentation 2016-09-23 11:52:32 -06:00
backlight
blackfin samples: move blackfin gptimers-example from Documentation 2016-10-10 07:12:02 -06:00
block A slightly quieter cycle for documentation this time around. 2017-02-22 18:51:29 -08:00
blockdev scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
bus-devices
cdrom cdrom: Make device operations read-only 2017-02-14 08:29:56 -07:00
cgroup-v1 Merge branch 'for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2017-02-27 21:41:08 -08:00
cma
connector
console
core-api Documentation: Update CPU hotplug and move it to core-api 2017-01-13 10:32:32 -07:00
cpu-freq A slightly quieter cycle for documentation this time around. 2017-02-22 18:51:29 -08:00
cpuidle
cris
crypto crypto: doc - fix typo 2017-02-15 13:23:49 +08:00
dev-tools scripts/spelling.txt: add "disble(d)" pattern and fix typo instances 2017-03-09 17:01:09 -08:00
device-mapper scripts/spelling.txt: add "explictely" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
devicetree Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-03-14 21:31:23 -07:00
dmaengine dmaengine: Documentation: Fix typo in pxa_dma.txt 2016-11-14 08:14:24 +05:30
doc-guide docs-rst: parse-headers.pl: cleanup the documentation 2016-11-30 17:08:09 -07:00
DocBook A few fixes for the docs tree, including one for a 4.11 build regression. 2017-03-04 11:32:18 -08:00
driver-api Less anger inducing pull request for 4.11 2017-02-23 18:58:18 -08:00
driver-model irqdesc: Add a resource managed version of irq_alloc_descs() 2017-02-10 14:39:20 +01:00
early-userspace
EDID
extcon extcon: int3496: Add Intel INT3496 ACPI device extcon driver 2017-01-09 10:04:11 +09:00
fault-injection
fb
features 2nd round of ARC udpates for 4.10rc1 2016-12-23 10:22:47 -08:00
filesystems statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00
firmware_class firmware: revamp firmware documentation 2017-01-11 09:42:59 +01:00
fmc
fpga fpga: Add scatterlist based programming 2017-02-10 15:20:44 +01:00
frv docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
gpio gpio: random documentation update 2017-01-31 15:43:05 +01:00
gpu Less anger inducing pull request for 4.11 2017-02-23 18:58:18 -08:00
hid Documentation: HID: Intel ISH HID document 2016-08-17 11:13:07 +02:00
hwmon A slightly quieter cycle for documentation this time around. 2017-02-22 18:51:29 -08:00
i2c i2c: i801: Add support for Intel Gemini Lake 2017-02-09 17:39:16 +01:00
ia64 selftests: move ia64 tests from Documentation/ia64 2016-09-20 09:58:12 -06:00
ide
iio iio: Documentation: Correct the path used to create triggers. 2016-10-01 00:49:58 -06:00
infiniband IB/hfi1: Document new sysfs entries for hfi1 driver 2016-10-02 08:42:19 -04:00
input Documentation: input: fix path to input code definitions 2017-02-12 15:19:00 -07:00
ioctl rpmsg updates for v4.11 2017-02-23 09:41:03 -08:00
isdn docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
kbuild Kconfig: Introduce the "imply" keyword 2016-11-16 09:26:33 +01:00
kdump Documentation: kdump: Add description of enable multi-cpus support 2016-09-20 18:02:54 -06:00
laptops platform/x86: thinkpad_acpi: Add support for X1 Yoga (2016) Tablet Mode 2016-12-13 09:29:06 -08:00
leds leds: class: Add new optional brightness_hw_changed attribute 2017-01-29 19:59:42 +01:00
livepatch A slightly quieter cycle for documentation this time around. 2017-02-22 18:51:29 -08:00
locking locking/ww_mutex/Documentation: Update the design document 2017-01-14 11:14:55 +01:00
m68k docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
md MD: add doc for raid5-cache 2017-02-13 09:17:54 -08:00
media A few fixes for the docs tree, including one for a 4.11 build regression. 2017-03-04 11:32:18 -08:00
memory-devices
metag
mic samples: move mic/mpssd example code from Documentation 2016-09-20 12:38:48 -06:00
mips
misc-devices samples: move misc-devices/mei example code from Documentation 2016-09-23 11:51:43 -06:00
mmc mmc: core: Extend sysfs with DSR register 2016-07-25 10:34:51 +02:00
mn10300
mtd spi-nor: Add support for Intel SPI serial flash controller 2017-01-03 17:33:36 +00:00
namespaces
netlabel
networking Make IP 'forwarding' doc more precise 2017-03-12 23:28:43 -07:00
nfc
nios2
nvdimm libnvdimm, btt: update the usage section in Documentation 2016-06-17 16:23:23 -07:00
nvmem
parisc
PCI A few fixes for the docs tree, including one for a 4.11 build regression. 2017-03-04 11:32:18 -08:00
pcmcia tools: move pcmcia crc32hash tool from Documentation 2016-09-23 13:07:27 -06:00
perf perf: add qcom l2 cache perf events driver 2017-02-08 19:32:24 +00:00
phy
platform
power More power management updates for v4.11-rc1 2017-03-02 17:33:52 -08:00
powerpc powerpc updates for 4.9 2016-10-07 20:19:31 -07:00
pps Doc: clarify source of jitter in USB1.1, and USB2.0 2017-01-04 14:40:52 -07:00
prctl selftests: move prctl tests from Documentation/prctl 2016-09-20 09:09:09 -06:00
process Doc: Correct typo, "Introdution" => "Introduction" 2016-12-01 10:44:08 -07:00
pti
ptp selftests: move ptp tests from Documentation/ptp 2016-09-20 09:54:38 -06:00
rapidio rapidio/documentation/mport_cdev: add missing parameter description 2016-09-01 17:52:02 -07:00
RCU Merge branches 'doc.2017.01.15b', 'dyntick.2017.01.23a', 'fixes.2017.01.23a', 'srcu.2017.01.25a' and 'torture.2017.01.15b' into HEAD 2017-01-25 12:56:05 -08:00
s390 Documentation: Update path to sysrq.txt 2017-03-03 15:48:38 -07:00
scheduler sched/Documentation/sched-rt-group: Fix incorrect example 2017-01-22 10:34:17 +01:00
scsi scripts/spelling.txt: add "varible" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
security KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload() 2017-03-02 10:09:00 +11:00
serial Documentation: rs485: Do not define manually the ioctl 2016-08-18 11:08:33 -06:00
sh
sound scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
sparc Documentation/sparc: Steps for sending break on sunhv console 2017-02-23 08:27:25 -08:00
sphinx docs: sphinx-extensions: make rstFlatTable work with docutils 0.13 2016-12-18 13:30:29 -07:00
sphinx-static This is the documentation update pull for the 4.9 merge window. 2016-10-04 13:54:07 -07:00
spi spi: spi-ep93xx: simplify GPIO chip selects 2017-02-16 20:10:26 +00:00
sysctl A few fixes for the docs tree, including one for a 4.11 build regression. 2017-03-04 11:32:18 -08:00
target
thermal Documentation: fix spelling mistakes of "Celcius" -- > "Celsius" 2017-01-04 14:36:17 -07:00
timers time: Remove CONFIG_TIMER_STATS 2017-02-10 11:15:08 +01:00
trace tracing/kprobes: expose maxactive for kretprobe in kprobe_events 2017-04-04 10:32:03 -04:00
translations doc/ko_KR/memory-barriers: Update control-dependencies section 2017-03-03 15:54:55 -07:00
usb A slightly quieter cycle for documentation this time around. 2017-02-22 18:51:29 -08:00
virtual KVM: Add documentation for KVM_CAP_NR_MEMSLOTS 2017-03-09 09:13:20 +00:00
vm userfaultfd: non-cooperative: rollback userfaultfd_exit 2017-03-09 17:01:09 -08:00
w1
watchdog watchdog: Introduce watchdog_stop_on_unregister helper 2017-02-24 14:00:23 -08:00
wimax
x86 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-28 11:46:00 -08:00
xtensa xtensa: cleanup MMU setup and kernel layout macros 2016-07-24 06:33:58 +03:00
.gitignore Add .pyc files to .gitignore 2016-06-30 13:07:33 -06:00
00-INDEX Documentation: move MD related doc into a separate dir 2017-02-13 09:17:53 -08:00
bcache.txt bcache: documentation formatting, edited for clarity, stripe alignment notes 2016-06-23 07:58:38 -06:00
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
cachetlb.txt
cgroup-v2.txt cgroup: Fix indenting in PID controller documentation 2017-03-06 14:46:27 -05:00
Changes docs: add back 'Documentation/Changes' file (as symlink) 2016-12-14 16:30:12 -08:00
circular-buffers.txt Documentation: circular-buffers: use READ_ONCE() 2016-11-16 16:17:45 -07:00
clk.txt Documentation: clk: update file names containing referenced structures 2016-08-14 12:12:36 -06:00
CodingStyle doc: re-add CodingStyle and SubmittingPatches 2016-10-24 08:12:35 -02:00
conf.py Documentation/sphinx: fix primary_domain configuration 2017-03-03 16:12:30 -07:00
cpu-load.txt
cputopology.txt topology/sysfs: provide drawer id and siblings attributes 2016-06-13 15:58:27 +02:00
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
digsig.txt
DMA-API-HOWTO.txt Documentation: DMA-API-HOWTO: Fix a typo 2016-09-20 17:58:46 -06:00
DMA-API.txt dma-mapping: add dma_{map,unmap}_resource 2016-09-26 22:16:41 +05:30
DMA-attributes.txt common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute 2017-01-19 15:56:19 +00:00
DMA-ISA-LPC.txt Documentation: DMA-ISA-LPC.txt 2017-02-12 15:20:07 -07:00
docutils.conf doc-rst: add docutils config file 2016-08-14 11:52:40 -06:00
dontdiff Documentation: dontdiff: Update with additional entries 2017-01-26 15:08:06 -07:00
efi-stub.txt
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt GCC plugin infrastructure 2016-06-07 22:57:10 +02:00
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst docs/zh_CN: Add coding-style into docs build system 2017-01-26 15:30:34 -07:00
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt Documentation: Fix a typo in IPMI.txt. 2017-01-05 15:01:54 -06:00
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-doc-nano-HOWTO.txt docs-rst: doc-guide: split the kernel-documentation.rst contents 2016-11-19 10:22:04 -07:00
kernel-per-CPU-kthreads.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
kobject.txt
kprobes.txt Documentation: kprobes: Document jprobes stack copying limitations 2016-08-15 10:19:11 -06:00
kref.txt
kselftest.txt scripts/spelling.txt: add "an user" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
ldm.txt
lockup-watchdogs.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
logo.gif
logo.txt
lzo.txt
mailbox.txt
Makefile samples: move blackfin gptimers-example from Documentation 2016-10-10 07:12:02 -06:00
Makefile.sphinx Add a target to check broken external links in the Documentation 2017-02-15 15:22:47 -07:00
memory-barriers.txt doc: Update control-dependencies section of memory-barriers.txt 2017-01-14 21:29:15 -08:00
memory-hotplug.txt scripts/spelling.txt: add "followings" pattern and fix typo instances 2017-02-27 18:43:47 -08:00
men-chameleon-bus.txt
nommu-mmap.txt
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pinctrl.txt pinctrl: core: Fix regression caused by delayed work for hogs 2017-01-13 16:25:17 +01:00
pnp.txt
preempt-locking.txt
printk-formats.txt
pwm.txt pwm: Update documentation 2016-05-17 14:48:04 +02:00
rbtree.txt
remoteproc.txt remoteproc: Split driver and consumer dereferencing 2016-10-02 22:50:21 -07:00
rfkill.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt
SAK.txt
sgi-ioc4.txt
siphash.txt siphash: implement HalfSipHash1-3 for hash tables 2017-01-09 13:58:57 -05:00
SM501.txt
smsc_ece1099.txt
static-keys.txt jump_label: Reduce the size of struct static_key 2017-02-15 09:02:26 -05:00
SubmittingPatches doc: re-add CodingStyle and SubmittingPatches 2016-10-24 08:12:35 -02:00
svga.txt
sync_file.txt dma-buf: Rename struct fence to dma_fence 2016-10-25 14:40:39 +02:00
this_cpu_ops.txt
unaligned-memory-access.txt Documentation/unaligned-memory-access.txt: fix incorrect comparison operator 2016-12-27 13:08:42 -07:00
unshare.txt
vfio-mediated-device.txt vfio-mdev: Make mdev_parent private 2016-12-30 08:13:41 -07:00
vfio.txt
video-output.txt
xillybus.txt
xz.txt
zorro.txt