Add a new kselftest to detect and report slowdowns in key boot events. The
test uses ftrace to track timings for specific boot events and compares
these timestamps against reference values provided in YAML format.
The test includes the following files:
- `bootconfig` file: configures ftrace and lists reference key boot
events.
- `config` fragment: enables boot time tracing and attaches the
bootconfig file to the kernel image.
- `kprobe_timestamps_to_yaml.py` script: parses the current trace file to
extract event names and timestamps and writes them to a YAML file. The
script is intended to be run once to generate initial reference values;
the generated file is not meant to be stored in the kernel sources but
should be provided as input to the test itself. YAML format was chosen
to allow easy integration with per-platform data used in other tests,
such as the discoverable devices probe test in
tools/testing/selftests/devices. Another option is to use JSON, as the
file is not intended for manual editing and JSON is already supported
by the Python standard library.
- `test_boot_time.py` script: parses the current trace file and compares
timestamps against the values in the YAML file provided as input.
Reports a failure if any timestamp differs from the reference value by
more than the specified delta.
- `trace_utils.py` file: utility functions to mount debugfs and parse the
trace file to extract relevant information.
The bootconfig file provided is an initial draft with some reference kprobe
events to showcase how the test works. I would appreciate feedback from
those interested in running this test on which boot events should be added.
Different key events might be relevant depending on the platform and its
boot time requirements. This file should serve as a common ground and be
populated with critical events and functions common to different platforms.
Feedback on the overall approach of this test and suggestions for
additional boot events to trace would be greatly appreciated.
Example output with a deliberately small delta of 0.01 to demonstrate failures:
TAP version 13
1..4
ok 1 populate_rootfs_begin
# 'run_init_process_begin' differs by 0.033990 seconds.
not ok 2 run_init_process_begin
# 'run_init_process_end' differs by 0.033796 seconds.
not ok 3 run_init_process_end
ok 4 unpack_to_rootfs_begin
# Totals: pass:2 fail:2 xfail:0 xpass:0 skip:0 error:0
This patch depends on "kselftest: Move ksft helper module to common
directory":
https://lore.kernel.org/all/20240705-dev-err-log-selftest-v2-2-163b9cd7b3c1…
which was picked through the usb tree and is queued for 6.11-rc1.
Best,
Laura
Laura Nao (1):
kselftests: Add test to detect boot event slowdowns
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/boot-time/Makefile | 17 ++++
tools/testing/selftests/boot-time/bootconfig | 8 ++
tools/testing/selftests/boot-time/config | 4 +
.../boot-time/kprobe_timestamps_to_yaml.py | 55 +++++++++++
.../selftests/boot-time/test_boot_time.py | 94 +++++++++++++++++++
.../selftests/boot-time/trace_utils.py | 63 +++++++++++++
7 files changed, 242 insertions(+)
create mode 100644 tools/testing/selftests/boot-time/Makefile
create mode 100644 tools/testing/selftests/boot-time/bootconfig
create mode 100644 tools/testing/selftests/boot-time/config
create mode 100755 tools/testing/selftests/boot-time/kprobe_timestamps_to_yaml.py
create mode 100755 tools/testing/selftests/boot-time/test_boot_time.py
create mode 100644 tools/testing/selftests/boot-time/trace_utils.py
--
2.30.2
Hi Kees and All,
There are several tests in kselftest subsystem which load modules to tests
the internals of the kernel. Most of these test modules are just loaded by
the kselftest, their status isn't read and reported to the user logs. Hence
they don't provide benefit of executing those tests.
I've found patches from Kees where he has been converting such kselftests
to kunit tests [1]. The probable motivation is to move tests output of
kselftest subsystem which only triggers tests without correctly reporting
the results. On the other hand, kunit is there to test the kernel's
internal functions which can't be done by userspace.
Kselftest: Test user facing APIs from userspace
Kunit: Test kernel's internal functions from kernelspace
This brings me to conclusion that kselftest which are loading modules to
test kernelspace should be converted to kunit tests. I've noted several
such kselftests.
This is just my understanding. Please mention if I'm correct above or more
reasons to support kselftest test modules transformation into kunit test.
[1] https://lore.kernel.org/all/20221018082824.never.845-kees@kernel.org/
--
BR,
Muhammad Usama Anjum
The kernel has recently added support for shadow stacks, currently
x86 only using their CET feature but both arm64 and RISC-V have
equivalent features (GCS and Zicfiss respectively), I am actively
working on GCS[1]. With shadow stacks the hardware maintains an
additional stack containing only the return addresses for branch
instructions which is not generally writeable by userspace and ensures
that any returns are to the recorded addresses. This provides some
protection against ROP attacks and making it easier to collect call
stacks. These shadow stacks are allocated in the address space of the
userspace process.
Our API for shadow stacks does not currently offer userspace any
flexiblity for managing the allocation of shadow stacks for newly
created threads, instead the kernel allocates a new shadow stack with
the same size as the normal stack whenever a thread is created with the
feature enabled. The stacks allocated in this way are freed by the
kernel when the thread exits or shadow stacks are disabled for the
thread. This lack of flexibility and control isn't ideal, in the vast
majority of cases the shadow stack will be over allocated and the
implicit allocation and deallocation is not consistent with other
interfaces. As far as I can tell the interface is done in this manner
mainly because the shadow stack patches were in development since before
clone3() was implemented.
Since clone3() is readily extensible let's add support for specifying a
shadow stack when creating a new thread or process in a similar manner
to how the normal stack is specified, keeping the current implicit
allocation behaviour if one is not specified either with clone3() or
through the use of clone(). The user must provide a shadow stack
address and size, this must point to memory mapped for use as a shadow
stackby map_shadow_stack() with a shadow stack token at the top of the
stack.
Please note that the x86 portions of this code are build tested only, I
don't appear to have a system that can run CET avaible to me, I have
done testing with an integration into my pending work for GCS. There is
some possibility that the arm64 implementation may require the use of
clone3() and explicit userspace allocation of shadow stacks, this is
still under discussion.
Please further note that the token consumption done by clone3() is not
currently implemented in an atomic fashion, Rick indicated that he would
look into fixing this if people are OK with the implementation.
A new architecture feature Kconfig option for shadow stacks is added as
here, this was suggested as part of the review comments for the arm64
GCS series and since we need to detect if shadow stacks are supported it
seemed sensible to roll it in here.
[1] https://lore.kernel.org/r/20231009-arm64-gcs-v6-0-78e55deaa4dd@kernel.org/
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v7:
- Rebase onto v6.11-rc1.
- Typo fixes.
- Link to v6: https://lore.kernel.org/r/20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@ke…
Changes in v6:
- Rebase onto v6.10-rc3.
- Ensure we don't try to free the parent shadow stack in error paths of
x86 arch code.
- Spelling fixes in userspace API document.
- Additional cleanups and improvements to the clone3() tests to support
the shadow stack tests.
- Link to v5: https://lore.kernel.org/r/20240203-clone3-shadow-stack-v5-0-322c69598e4b@ke…
Changes in v5:
- Rebase onto v6.8-rc2.
- Rework ABI to have the user allocate the shadow stack memory with
map_shadow_stack() and a token.
- Force inlining of the x86 shadow stack enablement.
- Move shadow stack enablement out into a shared header for reuse by
other tests.
- Link to v4: https://lore.kernel.org/r/20231128-clone3-shadow-stack-v4-0-8b28ffe4f676@ke…
Changes in v4:
- Formatting changes.
- Use a define for minimum shadow stack size and move some basic
validation to fork.c.
- Link to v3: https://lore.kernel.org/r/20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@ke…
Changes in v3:
- Rebase onto v6.7-rc2.
- Remove stale shadow_stack in internal kargs.
- If a shadow stack is specified unconditionally use it regardless of
CLONE_ parameters.
- Force enable shadow stacks in the selftest.
- Update changelogs for RISC-V feature rename.
- Link to v2: https://lore.kernel.org/r/20231114-clone3-shadow-stack-v2-0-b613f8681155@ke…
Changes in v2:
- Rebase onto v6.7-rc1.
- Remove ability to provide preallocated shadow stack, just specify the
desired size.
- Link to v1: https://lore.kernel.org/r/20231023-clone3-shadow-stack-v1-0-d867d0b5d4d0@ke…
---
Mark Brown (9):
Documentation: userspace-api: Add shadow stack API documentation
selftests: Provide helper header for shadow stack testing
mm: Introduce ARCH_HAS_USER_SHADOW_STACK
fork: Add shadow stack support to clone3()
selftests/clone3: Remove redundant flushes of output streams
selftests/clone3: Factor more of main loop into test_clone3()
selftests/clone3: Explicitly handle child exits due to signals
selftests/clone3: Allow tests to flag if -E2BIG is a valid error code
selftests/clone3: Test shadow stack support
Documentation/userspace-api/index.rst | 1 +
Documentation/userspace-api/shadow_stack.rst | 41 ++++
arch/x86/Kconfig | 1 +
arch/x86/include/asm/shstk.h | 11 +-
arch/x86/kernel/process.c | 2 +-
arch/x86/kernel/shstk.c | 104 +++++++---
fs/proc/task_mmu.c | 2 +-
include/linux/mm.h | 2 +-
include/linux/sched/task.h | 13 ++
include/uapi/linux/sched.h | 13 +-
kernel/fork.c | 76 ++++++--
mm/Kconfig | 6 +
tools/testing/selftests/clone3/clone3.c | 224 ++++++++++++++++++----
tools/testing/selftests/clone3/clone3_selftests.h | 40 +++-
tools/testing/selftests/ksft_shstk.h | 63 ++++++
15 files changed, 511 insertions(+), 88 deletions(-)
---
base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
change-id: 20231019-clone3-shadow-stack-15d40d2bf536
Best regards,
--
Mark Brown <broonie(a)kernel.org>
From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org>
A regression happened where running the ownership test passes on the first
iteration but fails running it a second time. This was caught and fixed,
but a later change brought it back. The regression was missed because the
automated tests only run the tests once per boot.
Change the ownership test to iterate through the tests twice, as this will
catch the regression with a single run.
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
.../ftrace/test.d/00basic/test_ownership.tc | 34 +++++++++++--------
1 file changed, 20 insertions(+), 14 deletions(-)
diff --git a/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc b/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc
index c45094d1e1d2..71e43a92352a 100644
--- a/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc
+++ b/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc
@@ -83,32 +83,38 @@ run_tests() {
done
}
-mount -o remount,"$new_options" .
+# Run the tests twice as leftovers can cause issues
+for loop in 1 2 ; do
-run_tests
+ echo "Running iteration $loop"
-mount -o remount,"$mount_options" .
+ mount -o remount,"$new_options" .
-for d in "." "events" "events/sched" "events/sched/sched_switch" "events/sched/sched_switch/enable" $canary; do
- test "$d" $original_group
-done
+ run_tests
+
+ mount -o remount,"$mount_options" .
+
+ for d in "." "events" "events/sched" "events/sched/sched_switch" "events/sched/sched_switch/enable" $canary; do
+ test "$d" $original_group
+ done
# check instances as well
-chgrp $other_group instances
+ chgrp $other_group instances
-instance="$(mktemp -u test-XXXXXX)"
+ instance="$(mktemp -u test-XXXXXX)"
-mkdir instances/$instance
+ mkdir instances/$instance
-cd instances/$instance
+ cd instances/$instance
-run_tests
+ run_tests
-cd ../..
+ cd ../..
-rmdir instances/$instance
+ rmdir instances/$instance
-chgrp $original_group instances
+ chgrp $original_group instances
+done
exit 0
--
2.43.0
This revision only updates the tests from the previous revision[1], and
integrates an Acked-by[2] and a Reviewed-By[3] into the first commit
message.
Documentation/admin-guide/cgroup-v2.rst | 22 ++-
include/linux/cgroup-defs.h | 5 +
include/linux/cgroup.h | 3 +
include/linux/memcontrol.h | 5 +
include/linux/page_counter.h | 11 +-
kernel/cgroup/cgroup-internal.h | 2 +
kernel/cgroup/cgroup.c | 7 +
mm/memcontrol.c | 116 +++++++++++++--
mm/page_counter.c | 30 +++-
tools/testing/selftests/cgroup/cgroup_util.c | 22 +++
tools/testing/selftests/cgroup/cgroup_util.h | 2 +
tools/testing/selftests/cgroup/test_memcontrol.c | 264 ++++++++++++++++++++++++++++++++-
12 files changed, 454 insertions(+), 35 deletions(-)
[1]: https://lore.kernel.org/cgroups/20240729143743.34236-1-davidf@vimeo.com/T/
[2]: https://lore.kernel.org/cgroups/20240729143743.34236-1-davidf@vimeo.com/T/#…
[3]: https://lore.kernel.org/cgroups/20240729143743.34236-1-davidf@vimeo.com/T/#…
Thank you all for the support and reviews so far!
David Finkel
Senior Principal Software Engineer
Vimeo Inc.
Hello,
this series brings a new set of test converted to the test_progs framework.
Since the tests are quite small, I chose to group three tests conversion in
the same series, but feel free to let me know if I should keep one series
per test. The series focuses on cgroup testing and converts the following
tests:
- get_cgroup_id_user
- cgroup_storage
- test_skb_cgroup_id_user
Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore(a)bootlin.com>
---
Alexis Lothoré (eBPF Foundation) (4):
selftests/bpf: convert get_current_cgroup_id_user to test_progs
selftests/bpf: convert test_cgroup_storage to test_progs
selftests/bpf: add proper section name to bpf prog and rename it
selftests/bpf: convert test_skb_cgroup_id_user to test_progs
tools/testing/selftests/bpf/.gitignore | 3 -
tools/testing/selftests/bpf/Makefile | 8 +-
tools/testing/selftests/bpf/get_cgroup_id_user.c | 151 -----------------
.../selftests/bpf/prog_tests/cgroup_ancestor.c | 159 ++++++++++++++++++
.../bpf/prog_tests/cgroup_get_current_cgroup_id.c | 58 +++++++
.../selftests/bpf/prog_tests/cgroup_storage.c | 65 ++++++++
...test_skb_cgroup_id_kern.c => cgroup_ancestor.c} | 2 +-
tools/testing/selftests/bpf/progs/cgroup_storage.c | 24 +++
tools/testing/selftests/bpf/test_cgroup_storage.c | 174 --------------------
tools/testing/selftests/bpf/test_skb_cgroup_id.sh | 63 -------
.../selftests/bpf/test_skb_cgroup_id_user.c | 183 ---------------------
11 files changed, 309 insertions(+), 581 deletions(-)
---
base-commit: 0e2eaf4b33f65e904b69bae6b956f3f610dbba9a
change-id: 20240725-convert_cgroup_tests-d07c66053225
Best regards,
--
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com