Hi,
Here is an RFC patch to support polling on event 'hist' file.
There has been interest in allowing user programs to monitor kernel
events in real time. Ftrace provides `trace_pipe` interface to wait
on events in the ring buffer, but it is needed to wait until filling
up a page with events in the ring buffer. We can also peek the
`trace` file periodically, but that is inefficient way to monitor
a randomely happening event.
This patch set allows user to `poll`(or `select`, `epoll`) on event
histogram interface. As you know each event has its own `hist` file
which shows histograms generated by trigger action. So user can set
a new hist trigger on any event you want to monitor, and poll on the
`hist` file until it is updated.
There are 2 poll events are supported, POLLIN and POLLPRI. POLLIN
means that there are any readable update on `hist` file and this
event will be flashed only when you call read(). So, this is
useful if you want to read the histogram periodically.
The other POLLPRI event is for monitoring trace event. Like the
POLLIN, this will be returned when the histogram is updated, but
you don't need to read() the file and use poll() again.
Note that this waits for histogram update (not event arrival), thus
you must set a histogram on the event at first.
Here is an example usage:
----
TRACEFS=/sys/kernel/tracing
EVENT=$TRACEFS/events/sched/sched_process_free
# setup histogram trigger and enable event
echo "hist:key=comm" >> $EVENT/trigger
echo 1 > $EVENT/enable
# Wait for update
poll $EVENT/hist
# Event arrived.
echo "process free event is comming"
tail $TRACEFS/trace
----
The 'poll' command is in the selftest patch.
You can take this series also from here;
https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/log/?h=t…
Thank you,
---
Masami Hiramatsu (Google) (3):
tracing/hist: Add poll(POLLIN) support on hist file
tracing/hist: Support POLLPRI event for poll on histogram
selftests/tracing: Add hist poll() support test
include/linux/trace_events.h | 5 +
kernel/trace/trace_events.c | 18 ++++
kernel/trace/trace_events_hist.c | 101 +++++++++++++++++++-
tools/testing/selftests/ftrace/Makefile | 3 +
tools/testing/selftests/ftrace/poll.c | 34 +++++++
.../ftrace/test.d/trigger/trigger-hist-poll.tc | 46 +++++++++
6 files changed, 204 insertions(+), 3 deletions(-)
create mode 100644 tools/testing/selftests/ftrace/poll.c
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-poll.tc
--
Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
This patch series adds unit tests for the clk fixed rate basic type and
the clk registration functions that use struct clk_parent_data. To get
there, we add support for loading device tree overlays onto the live DTB
along with probing platform drivers to bind to device nodes in the
overlays. With this series, we're able to exercise some of the code in
the common clk framework that uses devicetree lookups to find parents
and the fixed rate clk code that scans device tree directly and creates
clks. Please review.
I Cced everyone to all the patches so they get the full context. I'm
hoping I can take the whole pile through the clk tree as they all build
upon each other. Or the DT part can be merged through the DT tree to
reduce the dependencies.
Changes from v4: https://lore.kernel.org/r/20240422232404.213174-1-sboyd@kernel.org
* Picked up reviewed-by tags
* Check for non-NULL device pointers before calling put_device()
* Fix CFI issues with kunit actions
* Introduce platform_device_prepare_wait_for_probe() helper to wait for
a platform device to probe
* Move platform code to lib/kunit and rename functions to have kunit
prefix
* Fix issue with platform wrappers messing up reference counting
because they used kunit actions
* New patch to populate overlay devices on root node for powerpc
* Make fixed-rate binding generic single clk consumer binding
Changes from v3: https://lore.kernel.org/r/20230327222159.3509818-1-sboyd@kernel.org
* No longer depend on Frank's series[1] because it was merged upstream[2]
* Use kunit_add_action_or_reset() to shorten code
* Skip tests properly when CONFIG_OF_OVERLAY isn't set
Changes from v2: https://lore.kernel.org/r/20230315183729.2376178-1-sboyd@kernel.org
* Overlays don't depend on __symbols__ node
* Depend on Frank's always create root node if CONFIG_OF series[1]
* Added kernel-doc to KUnit API doc
* Fixed some kernel-doc on functions
* More test cases for fixed rate clk
Changes from v1: https://lore.kernel.org/r/20230302013822.1808711-1-sboyd@kernel.org
* Don't depend on UML, use unittest data approach to attach nodes
* Introduce overlay loading API for KUnit
* Move platform_device KUnit code to drivers/base/test
* Use #define macros for constants shared between unit tests and
overlays
* Settle on "test" as a vendor prefix
* Make KUnit wrappers have "_kunit" postfix
[1] https://lore.kernel.org/r/20230317053415.2254616-1-frowand.list@gmail.com
[2] https://lore.kernel.org/r/20240308195737.GA1174908-robh@kernel.org
Stephen Boyd (11):
of/platform: Allow overlays to create platform devices from the root
node
of: Add test managed wrappers for of_overlay_apply()/of_node_put()
dt-bindings: vendor-prefixes: Add "test" vendor for KUnit and friends
dt-bindings: test: Add KUnit empty node binding
of: Add a KUnit test for overlays and test managed APIs
platform: Add test managed platform_device/driver APIs
dt-bindings: test: Add single clk consumer
clk: Add test managed clk provider/consumer APIs
clk: Add KUnit tests for clk fixed rate basic type
dt-bindings: clk: Add clk_parent_data test
clk: Add KUnit tests for clks registered with struct clk_parent_data
Documentation/dev-tools/kunit/api/clk.rst | 10 +
Documentation/dev-tools/kunit/api/index.rst | 21 +
Documentation/dev-tools/kunit/api/of.rst | 13 +
.../dev-tools/kunit/api/platformdevice.rst | 10 +
.../bindings/clock/test,clk-parent-data.yaml | 47 ++
.../devicetree/bindings/test/test,empty.yaml | 30 ++
.../test/test,single-clk-consumer.yaml | 34 ++
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
drivers/clk/.kunitconfig | 2 +
drivers/clk/Kconfig | 9 +
drivers/clk/Makefile | 9 +-
drivers/clk/clk-fixed-rate_test.c | 379 +++++++++++++++
drivers/clk/clk-fixed-rate_test.h | 8 +
drivers/clk/clk_kunit_helpers.c | 204 ++++++++
drivers/clk/clk_parent_data_test.h | 10 +
drivers/clk/clk_test.c | 451 +++++++++++++++++-
drivers/clk/kunit_clk_fixed_rate_test.dtso | 19 +
drivers/clk/kunit_clk_parent_data_test.dtso | 28 ++
drivers/of/.kunitconfig | 1 +
drivers/of/Kconfig | 10 +
drivers/of/Makefile | 2 +
drivers/of/kunit_overlay_test.dtso | 9 +
drivers/of/of_kunit_helpers.c | 74 +++
drivers/of/overlay_test.c | 116 +++++
drivers/of/platform.c | 9 +-
include/kunit/clk.h | 28 ++
include/kunit/of.h | 115 +++++
include/kunit/platform_device.h | 20 +
lib/kunit/Makefile | 4 +-
lib/kunit/platform-test.c | 223 +++++++++
lib/kunit/platform.c | 302 ++++++++++++
31 files changed, 2193 insertions(+), 6 deletions(-)
create mode 100644 Documentation/dev-tools/kunit/api/clk.rst
create mode 100644 Documentation/dev-tools/kunit/api/of.rst
create mode 100644 Documentation/dev-tools/kunit/api/platformdevice.rst
create mode 100644 Documentation/devicetree/bindings/clock/test,clk-parent-data.yaml
create mode 100644 Documentation/devicetree/bindings/test/test,empty.yaml
create mode 100644 Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml
create mode 100644 drivers/clk/clk-fixed-rate_test.c
create mode 100644 drivers/clk/clk-fixed-rate_test.h
create mode 100644 drivers/clk/clk_kunit_helpers.c
create mode 100644 drivers/clk/clk_parent_data_test.h
create mode 100644 drivers/clk/kunit_clk_fixed_rate_test.dtso
create mode 100644 drivers/clk/kunit_clk_parent_data_test.dtso
create mode 100644 drivers/of/kunit_overlay_test.dtso
create mode 100644 drivers/of/of_kunit_helpers.c
create mode 100644 drivers/of/overlay_test.c
create mode 100644 include/kunit/clk.h
create mode 100644 include/kunit/of.h
create mode 100644 include/kunit/platform_device.h
create mode 100644 lib/kunit/platform-test.c
create mode 100644 lib/kunit/platform.c
base-commit: 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0
--
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git
Hi,
Jason A. Donenfeld, I've added you because I ended up looking through
your latest "implement getrandom() in vDSO" series [1], which also
touches this Makefile, so just a heads up about upcoming (minor) merge
conflicts.
Changes since v2:
1. Added two patches, both of which apply solely to the Makefile.
These provide a smaller, cleaner, and more accurate Makefile.
2. Added Reviewed-by and Tested-by tags for the original patch, which
fixes all of the clang errors and warnings for this selftest.
3. Removed an obsolete blurb from the commit description of the original
patch, now that Valentin Obst LLVM build fix has been merged.
[1] https://lore.kernel.org/20240614190646.2081057-1-Jason@zx2c4.com
John Hubbard (3):
selftests/vDSO: fix clang build errors and warnings
selftests/mm: remove partially duplicated "all:" target in Makefile
selftests/vDSO: remove duplicate compiler invocations from Makefile
tools/testing/selftests/vDSO/Makefile | 29 ++++++++-----------
tools/testing/selftests/vDSO/parse_vdso.c | 16 ++++++----
.../selftests/vDSO/vdso_standalone_test_x86.c | 18 ++++++++++--
3 files changed, 39 insertions(+), 24 deletions(-)
base-commit: 2ccbdf43d5e758f8493a95252073cf9078a5fea5
--
2.45.2
The open() function returns -1 on error. openat() and open() initialize
'from' and 'to', and only 'from' validated with 'if' statement. If the
initialization of variable 'to' fails, we should better check the value
of 'to' and close 'from' to avoid possible file leak. Improve the checking
of 'from' additionally.
Fixes: 32ae976ed3b5 ("selftests/capabilities: Add tests for capability evolution")
Signed-off-by: Ma Ke <make24(a)iscas.ac.cn>
---
Changes in v3:
- Thank you for your interest in our vulnerability detection method. We
extract vulnerability characteristics from a known vulnerability and match
the same characteristics in the project code. As our work is still in
progress, we are not able to disclose it at this time. Appreciate your
understanding, we could better focus on the potential vulnerability itself.
Reference link: https://lore.kernel.org/all/20240510003424.2016914-1-samasth.norway.ananda@…
Changes in v2:
- modified the patch according to suggestions;
- found by customized static analysis tool.
---
tools/testing/selftests/capabilities/test_execve.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/capabilities/test_execve.c b/tools/testing/selftests/capabilities/test_execve.c
index 47bad7ddc5bc..6406ab6aa1f5 100644
--- a/tools/testing/selftests/capabilities/test_execve.c
+++ b/tools/testing/selftests/capabilities/test_execve.c
@@ -145,10 +145,14 @@ static void chdir_to_tmpfs(void)
static void copy_fromat_to(int fromfd, const char *fromname, const char *toname)
{
int from = openat(fromfd, fromname, O_RDONLY);
- if (from == -1)
+ if (from < 0)
ksft_exit_fail_msg("open copy source - %s\n", strerror(errno));
int to = open(toname, O_CREAT | O_WRONLY | O_EXCL, 0700);
+ if (to < 0) {
+ close(from);
+ ksft_exit_fail_msg("open copy destination - %s\n", strerror(errno));
+ }
while (true) {
char buf[4096];
--
2.25.1
** Background **
Currently, OVS supports several packet sampling mechanisms (sFlow,
per-bridge IPFIX, per-flow IPFIX). These end up being translated into a
userspace action that needs to be handled by ovs-vswitchd's handler
threads only to be forwarded to some third party application that
will somehow process the sample and provide observability on the
datapath.
A particularly interesting use-case is controller-driven
per-flow IPFIX sampling where the OpenFlow controller can add metadata
to samples (via two 32bit integers) and this metadata is then available
to the sample-collecting system for correlation.
** Problem **
The fact that sampled traffic share netlink sockets and handler thread
time with upcalls, apart from being a performance bottleneck in the
sample extraction itself, can severely compromise the datapath,
yielding this solution unfit for highly loaded production systems.
Users are left with little options other than guessing what sampling
rate will be OK for their traffic pattern and system load and dealing
with the lost accuracy.
Looking at available infrastructure, an obvious candidated would be
to use psample. However, it's current state does not help with the
use-case at stake because sampled packets do not contain user-defined
metadata.
** Proposal **
This series is an attempt to fix this situation by extending the
existing psample infrastructure to carry a variable length
user-defined cookie.
The main existing user of psample is tc's act_sample. It is also
extended to forward the action's cookie to psample.
Finally, a new OVS action (OVS_SAMPLE_ATTR_PSAMPLE) is created.
It accepts a group and an optional cookie and uses psample to
multicast the packet and the metadata.
--
v6 -> v7:
- Rebased
- Fixed typo in comment.
v5 -> v6:
- Renamed emit_sample -> psample
- Addressed unused variable and conditionally compilation of function.
v4 -> v5:
- Rebased.
- Removed lefover enum value and wrapped some long lines in selftests.
v3 -> v4:
- Rebased.
- Addressed Jakub's comment on private and unused nla attributes.
v2 -> v3:
- Addressed comments from Simon, Aaron and Ilya.
- Dropped probability propagation in nested sample actions.
- Dropped patch v2's 7/9 in favor of a userspace implementation and
consume skb if emit_sample is the last action, same as we do with
userspace.
- Split ovs-dpctl.py features in independent patches.
v1 -> v2:
- Create a new action ("emit_sample") rather than reuse existing
"sample" one.
- Add probability semantics to psample's sampling rate.
- Store sampling probability in skb's cb area and use it in emit_sample.
- Test combining "emit_sample" with "trunc"
- Drop group_id filtering and tracepoint in psample.
rfc_v2 -> v1:
- Accommodate Ilya's comments.
- Split OVS's attribute in two attributes and simplify internal
handling of psample arguments.
- Extend psample and tc with a user-defined cookie.
- Add a tracepoint to psample to facilitate troubleshooting.
rfc_v1 -> rfc_v2:
- Use psample instead of a new OVS-only multicast group.
- Extend psample and tc with a user-defined cookie.
Adrian Moreno (10):
net: psample: add user cookie
net: sched: act_sample: add action cookie to sample
net: psample: skip packet copy if no listeners
net: psample: allow using rate as probability
net: openvswitch: add psample action
net: openvswitch: store sampling probability in cb.
selftests: openvswitch: add psample action
selftests: openvswitch: add userspace parsing
selftests: openvswitch: parse trunc action
selftests: openvswitch: add psample test
Documentation/netlink/specs/ovs_flow.yaml | 17 ++
include/net/psample.h | 5 +-
include/uapi/linux/openvswitch.h | 31 +-
include/uapi/linux/psample.h | 11 +-
net/openvswitch/Kconfig | 1 +
net/openvswitch/actions.c | 65 ++++-
net/openvswitch/datapath.h | 3 +
net/openvswitch/flow_netlink.c | 32 ++-
net/openvswitch/vport.c | 1 +
net/psample/psample.c | 16 +-
net/sched/act_sample.c | 12 +
.../selftests/net/openvswitch/openvswitch.sh | 115 +++++++-
.../selftests/net/openvswitch/ovs-dpctl.py | 272 +++++++++++++++++-
13 files changed, 565 insertions(+), 16 deletions(-)
--
2.45.2
Adrian Moreno (10):
net: psample: add user cookie
net: sched: act_sample: add action cookie to sample
net: psample: skip packet copy if no listeners
net: psample: allow using rate as probability
net: openvswitch: add psample action
net: openvswitch: store sampling probability in cb.
selftests: openvswitch: add psample action
selftests: openvswitch: add userspace parsing
selftests: openvswitch: parse trunc action
selftests: openvswitch: add psample test
Documentation/netlink/specs/ovs_flow.yaml | 17 ++
include/net/psample.h | 5 +-
include/uapi/linux/openvswitch.h | 31 +-
include/uapi/linux/psample.h | 11 +-
net/openvswitch/Kconfig | 1 +
net/openvswitch/actions.c | 65 ++++-
net/openvswitch/datapath.h | 3 +
net/openvswitch/flow_netlink.c | 32 ++-
net/openvswitch/vport.c | 1 +
net/psample/psample.c | 16 +-
net/sched/act_sample.c | 12 +
.../selftests/net/openvswitch/openvswitch.sh | 115 +++++++-
.../selftests/net/openvswitch/ovs-dpctl.py | 272 +++++++++++++++++-
13 files changed, 565 insertions(+), 16 deletions(-)
--
2.45.2
From: Quan Zhou <zhouquan(a)iscas.ac.cn>
Due to the path that modifies a0 in syscall_enter_from_user_mode before the
actual execution of syscall_handler [1], the kernel currently saves a0 to
orig_a0 at the entry point of do_trap_ecall_u as an original copy of a0.
Once the syscall is interrupted and later resumed, the restarted syscall
will use orig_a0 to continue execution.
The above rules generally apply except for ptrace(PTRACE_SETREGSET,),
where the kernel will ignore the tracer's setting of tracee/a0 and
will restart with the tracee/orig_a0. For the current kernel implementation
of ptrace, projects like CRIU/Proot will encounter issues where the a0
setting becomes ineffective when performing ptrace(PTRACE_SETREGSET,).
Here is a suggested solution, expose orig_a0 to userspace so that ptrace
can choose whether to set orig_a0 based on the actual scenario. In fact,
x86/orig_eax and loongArch/orig_a0 have adopted similar solutions.
[1] link:
https://lore.kernel.org/lkml/20230403-crisping-animosity-04ed8a45c625@spud/…
---
Changes from RFC->v1:
- Rebased on Linux 6.10-rc5.
- Updated the patch description.
- Adjust MAX_REG_OFFSET to match the new bottom of pt_regs (Charlie).
- Simplify selftest to verify if a0 can be set (Charlie).
- Fix .gitignore error (Charlie).
---
RFC link:
https://lore.kernel.org/all/cover.1718693532.git.zhouquan@iscas.ac.cn/
Quan Zhou (2):
riscv: Expose orig_a0 in the user_regs_struct structure
riscv: selftests: Add a ptrace test to verify syscall parameter
modification
arch/riscv/include/asm/ptrace.h | 7 +-
arch/riscv/include/uapi/asm/ptrace.h | 2 +
tools/testing/selftests/riscv/Makefile | 2 +-
tools/testing/selftests/riscv/abi/.gitignore | 1 +
tools/testing/selftests/riscv/abi/Makefile | 12 ++
tools/testing/selftests/riscv/abi/ptrace.c | 124 +++++++++++++++++++
6 files changed, 144 insertions(+), 4 deletions(-)
create mode 100644 tools/testing/selftests/riscv/abi/.gitignore
create mode 100644 tools/testing/selftests/riscv/abi/Makefile
create mode 100644 tools/testing/selftests/riscv/abi/ptrace.c
base-commit: f2661062f16b2de5d7b6a5c42a9a5c96326b8454
--
2.34.1